Tài liệu Dictionary of Petroleum Exploration, Drilling and production ppt

2 abnormal low pressure ® absorber abnormal high pressure pressure reservoir, the Auids have been prevented from being expelled by the surrounding rocks, and the rock or lithostatic pre

Pennwell Books

PENNWELL PUBLISHING COMPANY

Dictionary of Petroleum Exploration, ' Drilling, & Production

~ Foreword

The Dictionary of Petroletan Exploration, Drilling and Production conains words, phrases unc abbreviations used in all aspects of upstream peuoleum Topics that are covered include accounting, legal, tand, econom geology, geophysics, geochemistry, drilling, fogging, completion, reservoir engineering and production This book was compiled by reading more than 100 textbooks, perusing the training manuals of several major oi! compinies and interviewing such experts as Parke A Dickey, Lewis Mosburg Jr John Harris, Wayne Swearington

and many others Most of the illustrations were done by Herb and Sharon Scott, My san, Ranely ftyne, keybourded

the manuscript

Although J feel the Dictioney is very comprehensive, I'm sure there will be many more itcnis to be added

in future editions 1 solicit any aceitions for the dictionary to be sent to the following addr

Norman J dyne, Phd Continuing Educwion

The University of Tulsa

Tulsa, OK 74104 (218) 631-3088

A 1) activity 2) apparent 3) aumospheric 4) air 5)

air apparent 6) Stiles mobility ratio 7) area 8)

amplitude 9) atomic weight 9) ampere 10) Avogadro's

a 1) area 2) areal 3) tortuosity 4) apparent 5) acoustic

6) atmospheric 7) formation factor coelficient 8) year

Aalenian A global age of geological time that

occurred about 180-175 m y ago It és part of the

Middle jurassic epoch

AAMPL acoustic amplinde log

AAODC American Association of Oilwell Drilling

Contractors

AAPG American Association of Petroleum Geologists

AAPL American Association of Peoleum Lancmen

ab above

A.B able-bodied (seamun)

abaft 1) ¡n a direction toward the stern or back of

an offshore drilling rig or ship 2) behind

aban abandoned

abandon 1) to permanently cease production of oil

and gas from a well followed by plugging the well

2) to not attempt to complete a-well that has been

drilled Casing can sometimes be pulled and salvaged

from an abandoned well, und a cement plug must

be put in it to prevent groundwater pollution

Abandoning a well is in contrast to temporarily

in a well that can later be put back on production

abandoned oil crude oil Uyat has leaked from at

pipeline or tank, and the Operator has made no cifort

to recover it :

abandoned pressure the maximum average gus

reservoir pressure that will produce insufficient g:

to make the gas wells in that reservoir economic

Abdandoned pressure depends primarily on the

pipeline purchase contract pressure, which is ofien

beeen 700 and 1,000 psi, and the economic viability

of compression 2,

abandoned well 1) a well that has been drilled as

a dry hole 2) a well that no longer serves a purpose

shutting *

A @ abnormal high pressure 1

An abandoned oil or gas well is no longer an economic

producer of oi! or An ubundoned water, injection, service, or observation well no longer serves thất

purpose All abandoned wells are required by the

government regulatory agency to be properly plugged

abandonment plug a cement bridge used to seal

a dry hole or depleted well

abbreviated abstract a set of summaries of all recorded instruments concerning the tilde to a tracer

of tand An abbreviated abstract is in contrast wa

verbatim abstract with complete copies of all the

recorded instruments (bob-tail abstract)

ABC method a technique used in refraction seismic

to determine the effect of the irregular weathered zone or low-velocily fayer near the surface ‘wo seismic shots are made at A and C and are recorded ava, B, and C

abd 1) abandoned 2) abuncant

abd-gw abandoned gas well

abd loc abandoned location

abd-ogw abandoned oil znd gas well

abd-ow abandoned oil well

AB electrodes the electrodes on the sonde used

in electric resistivity logs A-BHC amplitude logging abiogenic gas methane yas that was formed from

an inorganic source such as a volcano

abiogenic theory a theory that some methane on

earth was formed inorganicully and is primeval gas

(abiotic theory) abiotic theory see abiogenic theory ABND or abnd abandoned

abnormal event an event on seismic that is nota direct rellection, An abnormal event can be a multiple,

refruction, surface wave, or diffraction,

abnormal high pressure subsurface Nuidl pressure

that is higher chan would be expected for that depth with normal hydrosiatic pressure alone ‘The normal hydrostatic pressure increase depends on the density

of the ground water The pressure increase is 45 psi/

100 ft for water with a salinity of $5.4 ppt and 46.5 psi/100 ft for water sulinity of 100 ppt Abnormal high pressure usually occurs in reservoirs that are sealed

by surrounding rocks such as shales or by faults that

do not allow fluids 10 escape the reservoir, During burial, the sedimentary rocks compact by expelling fluids from the pore spaces: In an abnormatly high-

2 abnormal low pressure ® absorber

abnormal high pressure

pressure reservoir, the Auids have been prevented

from being expelled by the surrounding rocks, and

the rock or lithostatic pressure, which increases about

300 psi/100 ft depth, is transferred to the fluid pressure

Abnormal high-pressure reservoirs have pressures

between hydrostatic and fithastatic pressures

Reservoirs with abnormal high pressures have

relatively low seismic velocities and low densities and

are in contrast to abnormal high pressure reservoirs

(super-normal pressure)

abnormal low pressure subsurface fluid pressure

that is lower than would be expected from normal

hydrostatic (Muid) pressure at that depth Abnormal

low pressure is often caused by crosion removing

some of the overlying sedimentary rock, decreasing

the depth of the reservoir bul not relieving the fluid

pressure in the isolated reservior Abnormal low

pressure reservoirs are in contrast 10 abnormal high

pressure reservoirs (sbnormal pressure)

abnormal pore pressure pore pressure that is

greater or lower than normal hydrostatic pressure

for that depth

aboard on a ship or offshore drilling rig

AB-P abnormal pressure

ABPR abandoned producer

abrasion mechanical wearing away or grinding by

friction

abrasion drilling a well-cutting method in which

abrasive particles such as sand are jetted from nozzles

abrasive jet cleaning awell-stimulation technique

that uses a jetting lool with nozzles on 2 tubing suring

Water, sometimes carrying sand or acid, is jetted out

the nozzles of a jetting tool at pressures up to 1,000

psi to clean perforations and remove gypsum

abrasive resistance the ability of a diamond bit to

resist scratching by the rocks it drills

abrogate to fail to fulfill a contract

abrsi jet abrasive jet

abs absent

ABSC abandoned sul commerciat

absolute dogleg a dogleg angle reported for a well’

that allows for the horizontal component of the deviation along with the vertical component If a well

changes in deviation from 2° east to 2° west in 100

feet, lhe absolute dogicg would be 4/100 ft

absolute filter a filter designed to separate all particles above a specific size An absolute filter is

absolute humidity the amount of water in air

measured in weight-per-unit-volume such as milligrams of water per cubic meter of air (mgm?) absolute open flow potential the theoretical rate

at which a well (sand face) would flow at the wall

of the wel! with zero pounds pressure in the well

Absolute open flow potential depends upon the fluid

pressure in the reservoir, reservoir permeability,

thickness of the pay and other factors It can be calculated in a gas well from a four-point test AOFP absolute permeability a measure of the ease (permeability) in which a single fluid can flow through

the pores of a rock when only that one fluid is present

in the pores of the rock Absolute permeability is independent of the Auid viscosity Usually, however,

two fluids are present in the pores of a reservoir rock and effective permeability is applicable

absolute porosity the ratio'of the volume of all

spaces between particles (pores), both interconnected and isolated, to the total volume of the rock Absolute porosity is expressed as a percentage and is in contrast

to effective porosity (total porosity) absolute pressure tolal pressure including both atmospheric pressure and gauge pressure Absolute pressure is often measured in pounds per square inch absolute (psia) Absolute pressure is in contrast to gauge pressure,

absolute refractive index the inverse ratio of the specd of light through a substance to the speed of light through a vacuuni The absolute cefractive index

is usually obtained from the refractive index measured

in air

absolute temperature a temperature based ona temperature scale in which 0° equals the temperature (—273.18°C) at which molecular motion ceases and there is no heat On the Kelvin absohite temperature

Kelvin can be converted to degrees centigrade by subtracting 273°

absolute viscosity the ratio of the viscosity of a fluid

viscosity is expressed in units of stokes or centistokes

(kinematic viscosity) absolute volume volume per unit mass

absolute zero the temperature at which there is a complete absence of heat and there is no molecular movement Absolute zero is —273.15°C and

—459.688°F, which is usually rounded off to —460°F

absorb see absorption

absorbent the material used to remove liquids from

a gasby absarption Absorption oil is used to remove

absorber equipment, typically a tower, that is designed to use absorption to remove liquids from

a gas stream In an absorption plant, an absorber is

used to remove liquid hydrocarbons from natural pas

absorption oil enters the top As the natural gas rises

and bubbles through the descending oil in bubble

ways, the liquid hydrocarbons are absorbed from the

gas The liquid hydrocarbons ure then removed from

the oil by distillation A glycol absorber or TEG unit

removes water from natural gas in the field The natural

gas is injected into the bottom of the absorber and

bubbles up through descending triethylene glycol

The dry gas exits the top of the absorber, and the

wet glycol is reconcentrated in a reboiler Natural

gas sweetening by iron sponge and the alkanulamine

process are also done in an absorber Absorbers are `

designed as either packed or tray-type towers

(absorption or absorber tower) asbr

absorber capacity a maximum amount of natural

gas that can be processed by a sorpuon Lower al

a specilic absorption rate, temperature, and pressure

absorber tower see absorber

absorption 1) the removal of a liquid by the cupillury,

osmatic, chemical, or solvent reaction in a subsuiiece

The extraction is made by a physical and/or chemical

change in a sorbent material, and the molecules or

ions of one substance penetrate into the interior of

a liquid or solid Absorption is in contrast lo adsorpiion

which is a surface phenomon 2) the decrease in the

energy of a seismic wave as it passes through rocks

and is converted into heat energy 3) the radiation

loss us energy passes through a material abs

absorption gasoline the retrograde gas, natural

gasoline, or condensate removed from natural gas

by absorption oil in an absorption tower

absorption oil oil used in an absorber to separace

liquid hydrocarbons from natural gas ‘The oil absorbs

the liquid hydrocarbons out of the gas as it bubbles

up through the oil The liquid hydrocarbons are then

removed from the oil by distillation

absorption plant a facility used to remove liquid

hydrocarbons from natural gus in the field The gas,

usually casinghead gas, bubbles through oil

(absorption oil) which absorbs the liquid

hydrocarbons This is done in an absorber at

temperatures berween 80 to 120°F An absorption plant

can remove between 40% and 75% of the propane

and up to 100% recovery of I, and heavier

hydrocarbons The liquid hydrocarbons are then

removed from the oi! by distillation

absorption-refrigeration cycle a type of

refrigeration system used in a natural-gas su'ipping

plant in which a refrigerant, usually ammonia, is

’ absorbed by water

absorption tower see absorber

absorptivity the capacity of a substance to absorb

incident radiant energy

absrn absorption

abst abstract

abstract or abstract of tide a set of a) copies

(verbatim abstract) or b) summaries (abbreviated or

bab-tail abstract) of all the recorded instruments

concerning the tide to a tract of land It is used in

the tide examination for a parced of land and is made

by a tandman or abstract company An abstract can

be base, complemental, or supplemental abst

abstract-based title opinion a tide opinion that is made from a complete abstract in contrast to a stind-

up tide opinion that is made from a ren sheet

abstract company or plant a commercial firm that has compiled and maintains land ownership records

“Phe abstract company contiins tract books and card systems recording individuals and the transactions in

that county Other information on file includes

probates, court suits, civorees, marriages, and

bankruptcies Some companies charge a Mat rate or

hourly rate to fet fandmen use their facilities Ouhers

do not let landmen use their facility but prepare a

run sheet or other data for a fee An absiract plant is

nol a tide Company that insures property tiles Tide

conipaniés are usually not involved in oil and gas

abstracting service a commercial firm that makes

sununarieés of the interests or legal ownerships of tind andVor mineral rights

ACBL acoustic cement bond log

ACC annual capital charge

accelerated cost recovery system a method used

to calcukue depreciation of equipment for federal ux based on the rates and lives as delined in federal

tax kaw The equipment is amortized over a short period, ACKS

accelerated delay rental an increase in the amount

of delay rental payment during the last years of the primary term of a lease

in carly years with declining amounts in later years

‘Two types include a) declining balance and b) sum-

ofthe-years Accelerated depreciaiion allows for a

faster tax write-off and is in contrast to the straight-

line depreciation method |

acceleration of gravity 980.616 cnysec/sec or

32.172 fUsec/sec at 45° latitude and sea level accelerator a chemical thất is used to increase reaction rate A cement accelerator is used to speed

up the rate of reaction between cement and.water

‘This resulis in a more capid development of strength and a reduction in setting and thickening time Some

cement accelerators are calcium chloride, sodium

silicate; sodium chloride in low concentrations, scawiicr, gypsum, dnd ammonium cliorite,

access road a road constructed from a public road

to a drillsiie The route is first surveyed and flagged

in coordination with the drilling foreman An earth moving contractor is used to construct the road accident the completion of a task that seemed impossible

4 accommodation block @ acid additives

accommodation block the living module or

quarters deck house on aq offshore rig AR

accommadation block can Contain office space,

storage, catering, and recreational facilities

accommodation platform a ship or

semisubmersible (Motel) or fixed platform that is used

to house offshore workers The accommodation

platform is often adjacent and connected to a

production platform

accordian display a type of 3-D seismic display

consisting of narrow, horizontal slices, one above the

other

accordion fold a fold in sedimentary rocks in which

the fold limbs are straight with uniform thickness but

there is a angular hinge line with thickening (chevror

or zigzag fold)

accredited investor an individual defined under

Regnlation 1 of the Federal Securities Act, who has

institutional status, an insider position, or a minimum

level of income or net worth ACI

accrued royalty rovalty payments due on oil and

gas that has already been produced

accrued treasury asset the sum ofall the discounted

canh flows until discounted payout ATA

accumulation chamber equipment used in gas lift

when the volume of formation (luids produced makes

continuous gas lift impractical The fluids are alowed

to build up in the chamber until intermittent

application of compressed gas forces the accumulated

fluids up the production tube As the fMuids flow up

the tubing, the formation is protected from the

pressure by closing of the standing valve Two types

are insert and wwo packer The insert type uses an

expanding tubing section and a dip tube, whereas

the wo-packer type uses the tubing and the tubing-

casing annulus

accumulator 1) a high-pressure cylinder that is used

to store liquid or gas under pressure for a hydraulic

or air-activated system An accumulator is used to

activaie blowout preventers and tensioner systems on

drilling rigs An blowout preventer accumulator is

located on a landing at least 100-150 ft from the

wellhead It usually contains of hydraulic fluid stored

under pressure from compressed nitrogen The

nitrogen is separated from the hydraulic Nuid by a

floating separator or rubber diaphragm A small-

volume, high-pressure pump compresses the nitrogen

by forcing it into steel bottles The accumulator

provides power when the hydraulic pumps are not

working or is used to supplement the pump pressure

accumulators (off rotary drilling rig chart)

The blowout preventer accumulators are located on the wellhead on a subsea well 2) a tank used to temporarily store the continuous-process liquid used

in a gas plant

accumulator drill a test run once or more each week ona drilling rig The accumulator pumps are shut off, and the initial accumulator pressure is recorded All the preventers are thrown at the same

time and their closing is timed and recorded The

final accumulator pressure is recorded The results are reported on the Friday morning drilling report

All the preventers should have closed within 20

minutes, and the final pressure should have been above 1,150 psi

accuracy the actual divided by the measured value

Accuracy can be expressed as a percent of full scale

or percent of reading on an instrument,

acd acidize

ACDW acid water ACEAG acetic acid A-Cem acoustic cement

acetic acid an organic acid (C,H,Q2) that is used

to acidize wells Acetic acid is less corrosive than many ˆ acids ACEAC

acetylene series an unsaturated, open-chain hydrocarbon with one triple bond Acetylene series

molecules are highly reactive but are not naturally common The general formula for the acetylene series

is C,H,,—2 An example is acetylene C,H) (alkyne)

H—C=C—H

acetylene welding a method of burning acetyiene

gas and oxygen at high temperatures to join steel

ACE autocorrelation function ACE or acf actual cubic feet

ACFM or acfm actual cubic feet per minute

ACFR ot acfr acid fracture treatment AC-FT or ac-ft acre feet

three times longer than its width acic

acid acidize

acid a chemical compound that can react with a base

to form a salt Acid contains hydrogen which dissociates in solution to form hydrogen ions Acids occur from 0 to 7 on the pH scale Hydrochloric and

sulfuric acids are examples The most common acids used in acidizing a well are 15% lydrochloric or HCI (regular acid), a combination af hydrochloric and ˆ

hydrofluoric or HCVHF (mud acid), hydrofluoric or

acid additives chemicals and materials that are

added to acid to change the properties of the acid

during acidizing Some eypes of acid additives are

surfactants, sequestering agents, antisludge agents,

corrosion inhibiters, alcohol, gelling agents, Muiel loss

materials, clay stabilizers, scale inhibitors, acid

dispersions, mutual solvent surfactants, and formadon

cleaners

acid bottle the first well surveying tool The 4-02

soda-lime-glass boule was filled half-full with

hydrofluoric acid and encased in a long cylinder called

a bomb or a clinometer case of brass or steel

acid-bottle inclinometer a device that is used 10

determine the angle (inclination) of a well during

an acid-dip survey A gluss conutiner of hydrofluoric

acid is lowered into the well The hydrofluoric acid

etches the level surface of the acid on the glass From

this, the inclination of the well is read

acid bottle inclinometer

with protractor

acid brittleness a form of corrosion on steel in

which free hydrogen ions form on a wet metal surface

as the result of corrosion Some of the hydrogen ions

enter the steel, reduce the steel’s cductliry, and cause

brite fractures (hydrogen embrittlement or bydrogen

Stress Cracking}

acid-dip survey a method that uses an acid boule

inclinometer to determine the inclination of a well

Hydrofluoric acid etches the level of the acid on a

glass container in the- well

acid dispersion a solvent-in-acid that is used 10

remove oil and parattin from a formation during matrix

acidizing The dispersion is a mineral or organic acid

and an aromatic solvent Both the solvent and acid

contact the formation at the same time Acid dispersion

is also used to remove scale

acidfrac or acid fracturing a well-stimukiion

technique used to both dissolve and fracture carbonate

reservoirs An inert, gelled water pad is first injected

into the well to fracture the forination An acid-in-oil

emulsion is then injected with or without proppants

lu etch the fracture face A slug of regular acid can

then be injected Ar

acidg acidizing

acid gas 1) a gas that forms an acid with water and

is corrosive Two common acid gases are hydrogen

sulfide (H,S) and carbon dioxide (CO) 2) natural

gas hat contains noahydrocarbon gases that, when

alved in water, will form an acid They-include

hydrogen sulfide, mercaptains and carbon dioxide

(sour gas) acid inhibitor an additive used in an acid job to retard the acid reaction rate to prevent damage wo well equipment Acid inhibitors are cither organic, such us nitrogen or sulfur bearing compounds, or inorganic such as copper or arsenic

acid intensifier an additive used in an acid job to accelerate or intensify the acid reaction An intensified

acid is a mixture of inhibited hydrochloric and

hydrofluoric acids The fluoride intensifies ube acid reaction rate

acidity 1) the quality of being acidic, usually

measured on the pH scale, where below 7 is acidic

in contrast to basic 2) a measure of the silica content

ofa rock Granites are acidic, whereas basalts are basic

acidize, acidizing or acid job a method used to

increase production in a well hat is producing from

a carbonate formation by using acid to dissolve the

reservoir rock The most common acids used are 15% FIC] (regular acid), HCVHF (mud acid), HP, acetic, and formic An acid inhibitor or reaction-rate retarder

can be used to delay the reaction time of a strong acid to protect equipment in the well and allow the acid to peneuiue the formation ‘the acid is usuaily

pumped down the well and held under pressure for

a period of time ‘Fhe spent acid is then pumped back out during cleanout and the well is swabbed Acid volumes cummonly range from £000 t© 100,000 pals

of 10-20% acid Matrix or interstitial acidizing is used

to etch a formation, usually a carbonate to increase

permeability in a well Matrix acidizing is done with pressures fess than formation fracture pressure, anc the acid flows through the natural permeability routes

in the formation A wellbore cleanup weaunent us acid 10 remove cement residue, drifling mud, scale and perforation debris from a well There is linle or

no circulation of acid during a wellbore cleanup An

acidfrac is a hydraulic fracture job ihat uses an acidic frac fluid with Or withaut propellents Acid additives

can be combined with the acid 10 reduce friction,

control clay, stabilize clays and break emulsions ‘Typ

of acid jobs include a) uncontrolied teaument, b)} controlled (reatment, and ¢) stage acidizing Acidizing was first avempied in 1895 by Herman Krasch using HCI but did not become effective until 1932 when inhibitors were developed (acid stimulation or

treatment) acd, acid or acidy

acid number the milligrams of potassium hydroxide that are neutralized by 1 g of crude oil Acid number

is a measure of crude oil reactivity with a caustic

solution used in enhanced oil recovery

acid pickling the use of a hydraulic or sulfuric acid

jxuh for steel tubulars before galvanizing

acid-reaction-rate cetarder a surfactant additive that is used in acidizing ‘the rewarder coats the rock surfaces and forms a physical barrier to reduce the rate of acid reaction with the rock

acid resistance the resistance of cement to sohening und corrosive effects of acids

acid soak or spot a weil treatment in which acid,

usually regular acid composed of 15% hydrochloric acid and water, is pumped down the tubing and allowed to stand in ihe completion zone Acid soak

6 acid stimulation © acreage-based royalty

is used to remove scale, coatings, and sludges and

to clean the perforation tunnels It is foltowed by

backflow or return of the spent acid Acid soak is

similar t) a treatment called acid wash

acid stinnulation see acidize, acidizing or acid job

acid test the application of acid to a rock to test

for limestone or the minerals calcite or aragonite

Carbon dioxide bubbles form when the acid reacts

with the calcium carbonate

acid treatment sce aciclize, acidizing, or acid job

acid wash a weil treatment in which acid, usually

regular acid composed of 19% hydrochloric acid and

water, is pumped down the tubing and past the

completion zone several times Acid wash is used to

remove scale, coatings, and sludges and to clean the

perforation tunnels A backflow or cleanout is used

to return the spent acid A similar treatment is an

acid soak or spot

ACM acid-cut mud

Acme junior or senior gas gravity balance an

instrument used to determine the specific gravity of

natural gas in the field The balance operates on the

principle that densities of two gases at base pressure

are in an inverse ratio to the pressures that give both

gases equal buoyant forces The Acme senior gas

gravity balance is used to test large volumes of gas,

whereas the Acme junior gas gravity balance is used

to test small volumes of casinghead gas

acoustic hasement the opaque area on a seismic

profile that is usually located below the well-layered

sedimentary rock Acoustid basement is usually

igneous or metamorphic rock

acoustic enclosure an enclosing structure around

machinery that is designed to reduce the noise level

acoustic impedance scismic velocity times density

Acoustic impedance is sometimes called hardness

acoustic location navigation using underwater

sound transmission In the active system, the searching

vessel gives off the sound impulse which is received

on an acoustic transponder on seafloor objects to be

located The acoustic transponder then gives off its

own answering signal In the passive system, pingers

at specific locations on the seafloor give off sound

impulses which are received on the searching vessel

The passive system is used in dynamic positioning

acoustic log™ a sonic log

acoustic log a group of wireline well logs, each of

which records some property of acoustic wave travel

either through the rocks adjacent to the wellbore or

through the casing and cement A sonic log measures

the velocity ofa compressional wave through the rock

Anamplitude log measures the amplitude of the waves

massing through the rocks The character log,

microseismogram log, signature log, and others record

some aspect of the acoustic wave train The cement-

bond log indicates the quality af the cement bond

behind the pipe casing ‘The fracture log is used to

locate fractures in the rocks adjacent to the wellbore

the borehole televiewer images the wellbore ACSI

acoustic plenum a souncd-proof room

acoustic position reference a location system used

by drill ships to keep the drillship above the drill

site An acoustic position reference consists of acoustic

transmitters on the seafloor and hydrophones

mounted on the hull of the drill ship A shipboard

computer is used lo accurately locate the drillship in- reference to the transmitters Acoustic position reference is called a dynamic positioning or ask system

- acoustic reentry the use of acoustic signals to

relocale a wellhead on the seabed

acoustic signature the oscilloscope pattern made

by a sonic cement-bond log with different cement bondings between the casing and the weil bore acoustic survey an acoustic velocity or sonic log

measurement

acoustic transponder a device that is put on the seafloor and is both a receiver and transmitter of sonic energy The acoustic transponder will transmit only

after it receives a specific signal The signal allows

the searching vessel to accurately locate the direction

and distance to the acoustic transponder it is used

to reposition a semisubmersible or driliship for reentering a subsea well

acoustic travel time the time that it tikes sound

to travel from one point to another

acoustic-velocity log 1) a wireline well log that

records sound velocity through rock layers in a well

The velocity is recorded in units of micraseconds

per foot Cw sec/ft) and are called interval transit time, for At The sonde has a transmitier and two receivers;, -

one 3 ft from the transmitter and the other 5 ft The compensated sonic log has two sound transmitters

on the sonde Their values are averaged to reduce

errors due to sonde tilt or borehole size changes

The velocities are used to determine the lithologies

and compute the porosity of the rocks, Shale strongly

affects the porosity of a formation determined by an

acoustic-velocity log, and shaly formations must be corrected for this effect Gas will decrease the sound

velocity and increase the apparent velocity Porosity measured by the acoustic-velocity log does not record

vugular and fracture pores (sortic or velocity fog) AVL

or ALC 2) see sonic log

acoustic wave a sound or seismic wave

Acoustilog® a sonic log

AC PAR D acoustic parameter-depth

AC PAR L acoustic parameter-logging

AC PAR 16 acoustic parameter-16-mm scope

acquired lands United States federal lands that were obtained by purchase, condemnation, gift, or

exchange Acquired fands are in contrast to public domain lands

acquisition costs the costs of obtaining leases or

property

acre land area in the English system containing 43,560 for 4,840 yd? There are 640 ac in a section or square

mile and 23,040 ac in a township ac

acreage land held under lease acrz

acreage attribution a term used in setting

production allowable by a government regulatory

agency Acreage attribution is the acreage drained by

a well in excess of the normal drilling and spacing

acreage-based royalty royalty paid on a per-acre

basis An acreage-based royalty is used for a shut-in

acreage-contribuiion agreement or letter a

support agreement between two companies One

company gives leases or interests in leases in the area

of a well drilled down to a certain depth by the other company in exchange for information on that well

A variation is the cash contribution

acreage exchange a cross assignment of interests

in leases between parties in order to pool the rights

of the parties in those leases (acreage swap)

acreage factor the acreage that is allocated io a well

in order to determine allowable production by a

government regulatory agency

pays money to put that acreage under a longer term

purchaser to select the leases to be ussigned

acreage swap see acrecige exchange acreage tolerance the amount‘of acreage, usually

expressed as a percentage, in which a specified urea

can exceed for a specific purpose such as pooling

acre-foot a unit of volume that is an acre in area and one foot deep One acre-foot holds 7,758 bbl of oil and is the equivalent of 43,560 f* «eft, AC-FT or acre-ft

acre foot acre-ft acre foot

acre yield the average production of oil and gis from one acre of reservoir area

acrg acreage

acritarch a microfossil of uncertain biological

affinity They are unicellar and are related to algae

Acritarchs range from Precambrian to present

ACRS accelerated cost recovery system

ACS American Chemical Society

AC-SCR system alternating current-silicon-

controlled rectifier system

AC SIGN acoustic signature ACSE acoustic log

ACT automatic custody transfer

Act actinolite

activated charcoal carbon that has a high absorptive

and adsorptive capacity

;activation the changing of a stable element into un

unstable isotope by bombardment with neutrons

activation energy the energy necessary for reaciing substances to make a chemical transformation activation logging ‘wireline well logging using

acreage-contribution agreement or letier @ actual calendar day allowabic 7

acritach

neurons to irradiate formation in a well to create

radioisotopes The radioisotope energy emissions and decay times are used to identify the elements present

in the formiations

active clay a clay that reacts with drilling and completion Iluids Active clay is in contrast to passive clay

active length the distance from the bit to the point

of tangency located on the drill collars in a pendulum

bouombole assembly active margin a plae edge that is characterized by

a subduction zone such #s a deep ocean wench and/

or coastal mountain range The other margins in place tectonics are passive and transform,

active pit one of the steel mud-pil tanks that holds drilling mud next to a rotary drilling rig Mt is located

on the end where the mud pumps or supercharging centrifugal pumps suck the mud out of the tanks to

start the mud circulating The active pit is used to

mix, condition, treat, and store the mud (suction pit

or suction tek, mud suction tank or sump pit)

active system the total volume of drilling mud in the well and mud tanks that is circulated while drilling

a well active well 1) a well in production or service in contrast to an abandoned or shut-in well 2) ihe producing or injecting well in an interference test

in contrast to the observation well act-of-God clause a provision in an oil and gas tease

that states that the lessee will not have violated the terms of the lease if prevenred from fulfilling the lease

by conditions beyond the lessee’s control (force

mneajeure clawse)

ACT system automatic custody tunsfer system actual calendar day allowable an allowable (ihe amount of gas and/or, oil production that is allowed

8 actual gas volume! ® adsorption

by a government regulatory agency) calculated on a per-day basis (calendar day allowable)

actual gas volume the space occupied by a given amount of gas under line temperature and pressure

Actual gas volume is measured in actual cubic feet

actuation test a mechanical test of the working of

closing elements on a blowout preventer

actuator a mechanism used to remotely or automatically open and close valves and stops ACW acid-cut water

acyclic without rings acyclic hydrocarbon a hydrocarbon molecule that

occurs as in open chain Acyclic hydrocarbons include the normal and branched alkane groups, the

unsaturated alkene group with double bonds, and

the unsaturated alkyne group with triple bonds These

are in contrast to alicyclic and polycyclic hydrocarbons

AD authorized depth

A/D assistant driller adamantine drill a drill with steel shot set in the cutting edge that is used for hard formations The stcel shot revolves under the rim of a rotating table

(hot drill)

adapter or adaptor a fitting dat has two different

nominal sizes, thread sizes and designs, and/or

pressure ralings and is used to connect equipment

of different nominal sizes and/or pressure ratings

fcrossover) adaptor spool a short, sicel cylinder with flanged

ends that connects blowout preventers of different

sizes, thread sizes and designs, or pressure ratings

to the casinghead of a well ADD or add additive ADDC Association of Desk and Derrick Clubs of North America

addition gypsunvanhydrite and water Uiat is added

to cement clinker during manufacture addition section a mud tank comparuncnt located between the removal and suction sections that is agitated for mixing substances into the drilling mud

additive a chemical or material that is added in small

amounts to a large volume of another substance to

change its characteristics Some examples of cement additives include calcium chloride as an accelerator,

gypsum as a retarder, and barium sulfate as weighing material Mud additives are primarily mud thinners

and thickeners, Some other types include friction reducers, clay stabilizers, and surface-tension reducers ADD or add

adiabatic change a change in gas volume, pressure,

or temperature without any net loss or gain of heat

adjacent-bed effect the effect of the rock layers above and below on the well-log response of a rock

layer The adjacent-bed effect is amplified with thin

beds and deep investigation logs A focused log is

engineered to minimize this effect (sboulder-bed effect)

ADJCK adjustable choke

adjustable choke a manual or automatic, conical ncedle in a seat valve that can be changed to alter

the amount of fluid or gas flow through it An adjustable choke is in contrast to a fixed choke AD/CK adjusted posted price a contract price between a

buyer and seller of oil that has been adjusted for the CAPT, sulfur content and/or any other properties

of the oil as well as the selling and marketing costs

of the oil adjustment-of-unit interest a reallocation of

interests in a unit agreement as more complete

allocation could have been made before a property

covered by the unit was fully developed Subsequent development could have altered the original estimate

of reserves allocated to each unit The unit agreement allows a certain time for the participants to reallocate the interests in the unit as more facts become known

ADOM adomite admix 19 mix one substance into another

admixture effect an intermolecular effect that causes

two volumes of different pases that are added together

to result ina volume that is not the sum of the wo’

separate volumes A gallon of ethane and a gallon of propane will mix to form less than 2 gal However,

1 Ib of ethane mixed with J tb of propane will result

in 2 Shs

ADR asset depriciation range ADS atmospheric diving system adsorbent a solid, such as activated charcoal or silica

gel, that uses adsorption to remove liquids from gas adsorber tower a tower in which gas flows down through tables covered with a chemical called an adsorbent that removes a liquid from the gas The

reaction is a batch process and the adsorbent can

usually be regenerated by heating Dehydration of natural gas using activated alumina (bauxite) or silica

gel occurs in an adsorption tower The process can

be used for a higher dew-point depression than absorption It can remove the water down to less than 1⁄4 Ibs/MMscf with a dew point of -40°F

adsorption the attraction of the molecules of a liquid -

or gas to the surface of a solid Adsorption is used

to remove fluids from either the aunosphere or

mixtures of gases and liquids Adsorption does not cause either physical or chemical changes in the

sorbent material which is called the adsorbent

Activated alumina and silica gel are used to adsorb

water from natural gas Activated charcoal or silica gel are used to adsorb liquid hydrocarbons qt of Tự

natural gas Zeolites are often used to adsorl acid

gases such as hydrogen sulfide and carbon dioxide

`

from fiatural gas ‘The liquids are then removed by

steam treatment of the adsorbent Adsorption is in contrast to abs6fption in which the molecules or ions

penetrate the interior of the substance adspr adsorption column 4 glass column in a gas

chromatograph that is packed with charcoal, silica pel,

zeolites, or polymers that adsorb gas The adsorption column is used to separate oxygen, nitrogen, and methane and is in contrast to a partition or gas/iquid

column (gas/solid cotunm) adsorption gasoline the natural gasoline

(retrograde gas) unat is removed from wet gas by acuvated charcoal or silica gel in an adsorption plant

adsorpuon plant field equipment that is designed

to remove water and liquid hydrocarbons from natural

gas by using an adsorbent

ad valorem charge a lease rental payment that is

based on the appraised value of the unproduced minerals in the ground As drilling discovers new

reserves, the value of the unproduced minerals and

amount of rental will change

ad valorem tax the state or county tax that is assessed

on the value of property advance payment an interest-free loan made by an

interstate pipeline to a gas exploration company to drilt gas wells in return for a) the dedication of the discoveries to the pipeline or b) a full reimbursement for the dry holes - advanced payment agreement a method used to finance the development of oil and gas property The

money is advanced for drilling and developing the property in exchange for the right to receive some

of the oil and gas production from that property

advanced recovery methods waterfloodiny and enhanced-oil-recovery methods

advance royalty 1) shut-in royulty in certtin lease forms Shut-in royalty is 2 payment made to the lessor

in order tò maiiitain a lease when a weil is not producing 2) a minimum royalty or payment that must be made to the lessor An advance royalty is often taken out of future production

adverse mobility ratio the-mobility ratio is computed by dividing the viscosity of crude oil by the viscosity of an injection fluid An adverse mobility

ratio occurs in waterfloods and enhanced-oil-recovery

projects when the viscosity of the oil is much higher than the fluid injected into the reservoir to move it

The pressure drop per unit distance is lower in any injecied fluid finger than in the oif bank causing the

pressure at the énd of the injected fluid finger to

become higher than that in the surrounding oil This causes the injected fluid fingers to push ahead,

extending the injected fluid fingers and causing a

breakthrough An effective waterflood or enhanced- oil-recovery project uses a low mobility ratio

adverse possession ownersliip of land that is

claimed by hostile, notorious, and open possession

against the tite holder of record

AEC anion exchange capacity

A electrode the current-emiting eletrode in a well- log resistivity sonde

acolian transported and deposited by wind such as

the sand in sand dunes in a desert environment

(eolian) acolianite a clastic sedimentary rock composed of

consolidated wind-biown sediments An aeolianite is typically a dune sund that is niuturally cemented

feolianite)

aerated flow a type of fluid flow that is characterized

by liquid containing a large number of gas bubbles aerated fluid fluid that contains entrained yas bubbles Aerated drilling Nuids include air, naturat

gas, mist, foam, and aersted mud

aerated mud a drilling Nuid formed by injecting air

or gas into the mud benveen the mud tinks and the

standpipe Aérated mud is used to reduce the hydrostatic pressure in a well and to drill low-pressure

formations ft combines the advantages of air and mud drilling

density aerial magnetic survey is Nown with flight lines spaced one-third to one-half the distance from the surface to basement The survey is used to estimuie

depth to basement and to’ locate struceur S

aerial photograph a photograph, usually in black

and white, of the earth's surface made by a camera

in an airplane The photographs can be taken in stereo

a slighuy different angles with an overiap) and

examined under a stereoscope in order to see relief Aerial photographs are used for making topographic and geological maps

acrify 1) to inject dir inte 2) to change into a pas aerobic the presence of free air or oxygen When applied to water, it is water thal contains enough oxygen lo support aerobic bacteria and contains greater than 0.2 mVI oxygen Aerobic is in contrast

to anaerobic oxic aerobic bacteria bacteria that require Iree oxygen

in ais or water (0 live Aerobic bacteria are responsible

for most organic decay The bacteria cun produce

slime that accumulates on metal surfaces of wells and Causes corrosion

acromagnetic magnetic readings made with an

airborne magnetometer Two types of magnetometers

can be used The fluxgate magnetometer is the oldest The commonest is the proton precession magnetometer An alkuli-vapor magnetometer been developed The magnetic units are measured

affiant the party that makes an affidavit

affidavit 2 sworn declaration of facts in writing aflidavit of noncompliance a declaration by the

10 affidavit of production © air-balanced beam pumping or pump unit

owner of land (lessor) that is filed after a lease has

been forfeited This occurs after the Jessee fails to

comply with provisions of the lease and has failed

to execute and record a release of record for the

lease

affidavit of production a form or declaration Usat

the operator of a new well files for record with a

government agency to testify that production in paying

quantities has commenced An affidavit of production

is required in certain states to extend the lease or

interest in the well (certificate of production}

affiliated company a company that owns a

controlling or influential share of another company

affiliated producer a company engaged in the

production of natural gas which is affiliated with a

AFIT after federal income tax

AFP average flowing pressure

A-frame 1) the A-shaped, highest portion bfa

standard derrick on a drilling rig that is used to support

the crown black 2} the stationary, A-shaped structure

that supports and anchors in upright position the mast

of a jackknife rig on a drilling rig 3) an A-shaped

lifting device

aft alter

aft toward the back or stere of a ship or offshore

drilling rig Aft is in contrast to forward

after-acquired rights clause a provision found in

an agreement such as a joint venture or farmout that

allows parties in an agreement to share in certain

future acquisition of interests by other parties in the

agreement

after-acquired title an interest that was acquired

by the grantor or lessor after the execution of a lease

or conveyance

after-acquired title clause a provision in an oil

and gas lease that extends the coverage of the leas

to any interest in the property acquired after the lease

afterburn the combustion of any unburned

hydrocarbons in the exhaust gas manifold ofan engine

after cooler the heat exchangers that cool natural

gas after the gas has been heated by compression in

a compressor slation

after flow the flow of fluid from the reservoir into

awell after the well has been shut in (afferproduction}

afternoon tour a drilling rig shift that goes from

4.00 p.m to midnight

afterproduction 1) ihe flow of fluids from the

reservoir into a well after the well has been shut in

fafter flow) 2) the fluids that Now from a reservoir

into a well after the well has been shut in

AGA American Gas Association

against pressure A valve that is closed on a Nowing

fluid stream

AGC automatic gain control

age 1) a time subdivision of an epach 2) to allow

the cement in a well to cure or harden

agent an old term for a pipeline employee who

permits the flow of oil from producer's storage tanks

into a pipeline and in return gives the producer a

voucher for the quantity of oil see gauger

ager: a water-Alled pressure chamber that is used to apply external pressure to gas lift valves

AGFR acid-gel frac Age ot ager aggregate

aggradational built up by deposition of sediments

ageregate 1) bvo or more particles that are strongly hound together and cannot be broken by normal

mixing or shaking 2) inert mineral material having a

particle size generally greater than 10 mesh Agg or

AGI American Geological Institute

aging 1) the natural or artificial curing of cement

2) the stabilization on an emulsion interface agitator apparatus uscd to stir a fluid A mud-pit

agitator is used to stir the drilling mud in the mud

tanks Two common types are electric-driven rotting blades and centrifugal pump jets called mud, surface,”

or submarine guns One or more agitators of 10-20

hy are used per tank Agitators are desigried to move

liquids and keep the solids suspended stt-rer

ABSV anchor-handling supply vessel ART anchor-handling tug

AHYV anchor-handling vessel

AI artificial intelligence

a, decline rate at đ; in a decline curve analysis

ATChE American Institute of Chemical Engineers

AICPA American Institute of Certified Public

air activated operated by the force and movement

of a gas under pressure Air activated is in contrast

to hydraulic (prenmatic) air-balanced beam pumping or pump unit atype

of oil well pump that uses a piston and rod in a cylinder with compressed air to balance the weight

of the sucker-rod string An air-bakanced beam pumping unit is in contrast to the type of pump that uses a counterweight to balance the sucker rods It

is more compact and lighter that the crank

counterbalanced and beam balanced types Because

air balanced beam pumping unit

of this, the unit is often found in remote and difficult

locations or offshore:

airborne magnetometer a device carried by an airplane that is used to measure variations in the earth's magnetic field Most measure total-field intensity,

although vector and verticul component are sometimes

measured The most common types are the flux-gate,

magnetometers ‘The magnetometer can be used 1

estimate depth to basement and locate subsurface geological structures

ais chamber a small surge chaiber that is filled

with air that is connected to a reciprocating pump’s discharge line see pulsation dampener

air clutch a device that is used to engage and

disengage a power transmission, High-pressure air

acts on a diaphragm chamber to move a pressure plaie to compress a release spring that holds the air clutch in the disengaged position Air clutches are common on a drilling rig

air-cooled exchanger equipment that uses air blowing across external fins to cool a liquid air cut air in a liquid system

air cutting the accidental inclusion of air in a drilling

or well fluid air drill an air or pneumatic drifling rig that pumps air down the ceruer of the pipe to remove cuutings

from the bottom of the well

air drilling rowary drilling that uses compressed air instead of a circulating mud system The air is supplied

by a skid-mounted air compressor and diesel engine

that delivers 300-500 fi? of air per minute at 300—

600 psi Three to five compressors are used The air

is pumped down the mud line The top of the bell

nipple is fined with an air drilling head to prevent the air from flowing out the top of the bell nipple

Conventional roller cone bits are used The air and

well cuttings come up to to the surface through the

annulus of the well and blow out through a blooey line into a blooey pit The circulation is controlled

by a standpipe valve on the rig floor More weight is put on the bit and less rpms are used compared to drilling with mud Air drilling is two to five times faster and jess expensive than mud drilling but cannot effectively contro! abnormually high pressures or build

a filter cake to stabilize the well It is ineffective when

“too much water enters the well The water, air, and

air driting rig (truck mounted) dust can form mud rings that stick to the bottom

hole assenably Air drilling, however, alleviates the

problems of formation damage and fost circulation,

but there is a danger of an air-methane explosion

to control the unloading of the compressor at a

predetermined high-pressure seuing and to restrict

the air flow at a predetermined low-pressure setting

air gun 1) a common type of marine seismic source

‘The air gun or array of air guns is towed behind a

boat at a depth of about 20-30 ft and releases a very

high-pressure bubble of air (2,000-3,000 psi) into the Mier Air guns are made in different sizes and are measured in cubic centimeters (cc) of chamber volune The air gun gives a seismic pulse ranging from 0 t 250 Hz The frequency spectrum of the

air gun depends on the volume and pressure of uir

in the chamber Different air guns in an array ofien have different chamber sizes to produce a signal with

a broad frequency spectrum Air guns can also be used to work in swamps, tanks, or pits of water on land A secondary emission of a bubble pulse is a problem with the air gun signal 2) a hand tool that

is powered by compressed air

pulley near the top of the derrick

air injection 1) un enhanced oil recovery technique that uses injection wells ta pump air into a subsurface, depleted oil reservoir Disadvantages of air injection are that air injection can corrode metal equipment

in the well and form an explosive mixture ‘The air can also oxidize oil in the reservoir which results in the formation of compounds that can reduce the flow

of oil Air, however, is cheaper to inject than any other gas such as natural gas or inert gases 2) a method

to inject diesel fuel into the combustion chamber of

a diesel engine by using a compressed air chamber

air-injection porosity the porosity of a rock sample measured with a porosimeter, Air is injected into a vacuum chamber with a sample of known volume

Boyle's law, using pressure changes and volume, is

12 airreceiver ® alkalinity

utilized to calculate porosity Air-injection porasity is

the most accurate field method for calculating porosity

air receiver a compressed air storage bottle

air shooting 4 scismic method using explosive

charges in sacks located 18 in above ground on stakes

Several charges in a pattern are shot in a nearby

simultaneous sequence by explose cord connecting

the shots

air-tube chitch a device that engages a driven

member when a tube is inflated and disengages when

the tube is deflated

air tugger a semiportable, pneumatic winch

aie weight the weight of a drillstring completely

suspended in air

AJET abrasive jet

AI andaliesite

A fab analytical laboratory

albertite a jet-black asphaltic bitumen that occurs

in veins It a conchoicdal fracture and a specitic

gravity of about 1.1, Albertite is a focal term ancl is

found in Albert County, New Brunswick, Canada, anc

in Scotland, Australia, and Indiana,

Albian a global age of geological time that occurred

from about 108-100 m y ago It is part of the Lower

Cretaceous epoch

ALC acoustic velacity log

ALC-GR acoustilog, caliper, gamma ray log

ALC-GRN acoustilog gamma ray, neutron log

ALC-N acoustilog, neutron fog

alcohol slug process a type of enhanced oil

recovery that uses miscible fload by the injection of

a small amount of organic solvent such as isopropyl

alcohol into a depleted oil reservoir

Alexandrian a North American age of geological

lime that occurred from ahout 425-422 m, y ago Tt

is part of the Silurian period

ALG or alg along

Alg or alg alge

algae fossil and modern planis that range from

unicellular to colonial and have existed from

Precambrian to the present They are aquatic both

floating and attached Calcareous or calcilied algae

have contributed enormous amounts of limestone

19 the geological record Discoasters and

coccolithophores, types of floating algae, are good

guide fossils Algae contain lipids that are thought to

he the precursors of crude oil Afg or alg :

algal mat a surface of algac that grows in a tropical,

intertidal area Algal tilaments hold the undertying

micrite Gimestonc mud) in place Storms wash micrite

onto the algal mat and a new algal mat is formed on top In this manner, great thicknesses of algal mats can be built up The limestone deposited can be both

asource rock and reservoir rock for petroleum

algorithm a sequence of instructions used to solve

a problem A computer program can be an algorithm,

aliasing the creation of a false image caused by

insufficient sampling when digitizing The ambiguity

in frequency resolution from seismic signal sampling

is caused by aliasing Alias or antialias Alters can be used to remove the frequencies that cause aliasing

alicyclic a group of saturated, closed-ring hydrocarbons with the formula CI, An example

is cyclobutane C,Hg (cycloparaffin series, eycloalkanes, or nathene series)

alidade a surveyor's instrument that consists of a

telescope with a ruler along its base An alidade is used on a plane table to measure angles between a hase line anc points that are surveyed

alignment angle of stabilizer the angle between

hole and the center line of the well

aliphatic organic compounds that are not aromatic

and nonpolar Aliphatic compounds include alkanes,

alkenes and alkynes The term » originally described fatty

alk alkalinity alkali a base or hydroxide that has very alkaline or

alkaline having the propertics of an alkali

alkaline flooding an enhanced oil-recovery process

in which alkaline chemicals such as sodium hydroxide are injected into the reservoir ‘The alkaline chemicals

react with oil in the reservoir to form surfactants

The surfactants and oi! flow better through the

reservoir because of reduced interfacial tension,

spontaneous emulsification, and changes in wettability

A stag of polymer-thickenced water is then injected

into the reservoir to produce a more uniform sweep

of the surfactants and oil This is followed by injection

producing wells (caustic flooding) tp alkalinity the number of equivalents of acid-that a

substance will react with to form a salt Alkalinity is

the sum of carbonate, bicarbonates, hydrocarbonates,

is determined by acid titration ae alkalinity control the adjustment of drilling mud

pH by the addition of sodium hydroxide or lime

alkane a hydrocarbon molecule formed by a saturated (no double or uiple bonds bewveen carbons)

that form straight chains, b) branched alkanes which

have limbs, and c) cyclic alkanes that form a circle

Alkanes include the nornial alkanes of methane,

ethane, propane, butane, ane pentane and the higher

alkanes staring with hexane, heptane, octane, and larger molecules Alkane boiling points increase

chemical activities but are important fuels Long-chain

normal alkane molecules (C)>,) are solids and are known as waxes Crude oils generally contain 5-80%

alkanes, and almost all of the hydrocarbons in raturat

gus are alkanes

alkanolamine a family of orgunic compounds tdi

include monoethinolamine (MEA), diethanolamine

carbon dioxide from natural gas The process u

an alkanolamine solution of monoethanolamine, diethanolamine, or triethanolamine to absorb the acid Gases in a Continuous process in an absorber The sour gas goes into the, bottom of the tower through

an inlet scrubber where the liquids are removed It bubbles up through bubble traps of solution that are descending in the tower The sweet gas exits the tower through a scrubber that removes any solution A reboiler uses heat treatment to strip the acid gases

from the absorbent solution

alkene a hydrocarbon with carbon-carbon double bonds and the formula Clay The structure of the

molecule can be normal, branched, or cyclic Onty

minor amounts of alkene accur in sediments and petroleum An example is propylene QC, (0/2/01) alkylation a refinery process that combines light

hydrocarbons to form high octane gasoline

alkyne an unsaturated, opéen-chain hydrocarbon with one triple bond Alkynes are highly reactive but are fol naturally common The general formula for an alkyne is C,Hiy—», and an example is acetylene CI

all-inclusive clause a provision in an oil and gas

lease that protects the lessee from errors in the description of the land under the lease by including

all the land owned by the lessor in that area (carch-

all, cover all or Mother Hubbard clause) Allo ailochem

allocation sev allowable allochem a relatively coarse carbonate particle in a carbonate rock that was Wansported and deposited

as u whole particle Affo

allochemical rock a rock composed of allochems

Allocheniical rock is in contrast to orthochemical and autochthonous rocks

allodapic limestone a limesione deposited by turbidity currents

allogenic something tha formed somewhere else

than where it is located now An example would be

sedimentary grains that were wansported and deposited fatlochthonous)

allogenic grain a sedimentary particle that was

transported und deposited (detrital grain)

agreemen On a lease, an aWonge is a separately: fisted provision, (rider or exbibit)

allophane an amorphous clay mineral thất is

composed of AlOsSiO., 4,0 Allophane occurs in a

variely of colors as incrustations and scams in rocks

allotted Land indian land that is designated tor ¢ specific individual's use but the title is held by the United Sunes

allow allowable allowable the maximum amount of gas andor oil that a well, lease, or Held is permiued lo produce per given Gime by a government regulttory agency

An allowable is olien given in barrels of oil/day (BOPD)

fora certain oumber of days each month The allowable can be based on depth (depth yardstick)

and spacing, ‘The right ofa state to regulate production

is called proradoning and is done on the basis of

market demand Not all states impose allowables

(permitted production) allow

allowable allocation formula the instructions issued by a government regulatory agency to divide the umount of petroleum that the agency allows 10

be produced from each well or leasehold pér unit

of time (allowable) among all operators in the ficld The formula can be based on acreage, number of wells, and acre-leet of pay ,

allowable depletion ihe money that a specific producing party can deduct from it able income during a year, Allowable depletion is the greater of cither cost or percentage depletion

allowable dry holes a nicasure of the economic viability of drilling an exploratory well, Allowable dry

holes are the net present value of the successful well

(production revenues minus costs discounted for

Unie) divided by the cost of the exploratory well if

it was a dry hole ‘This gives an indication of how

many explorutory dry hotes can be drilled to justily the return

14 allowable period © amorphous

allowable or amount of production permitted by a

government regulatory agency for a well because of

a location exception in the drilling of the well

allowable period the time period during which an

allowable or permitted amount of production can be

produced

allowable rope load the nominai breaking strength

of a rope divided by a design factor

allowable stress the maximum stress thal a structure

is designed 10 withstand for safe operations

alloy a metallic substance formed by a solid solution

of wo or more clements, one of which has metallic

properties

all-thread nipple a short pipe with threads all along

its length

alluvial sediments deposited by a stream or river

alluvial fan a fan-shaped deposit of sediments

formed by an intermittent river flowing onto a plain

such as a desert The upper fan deposits tend to be

mud-flow deposited, whereas the Jower fan deposits

are stream deposited Potential reservoir rocks can

be deposited in an alluvial fan environment

aloe rape a rope made from aloe plant fiber used

in cable-tool drilling

along-teack scanner a scanner used in remote

sensing with a linear array of detectors that is oriented

normal to the flight path

ALP articulated loading platform

o& 1) angle 2} spontaneous potential (SP) reduction

factor 3) alternative coefficient 4) dip 5) absorption

coefficient 6) azimuth 7) alpha particle 8) angle of

well inclination from vertical

alpha pseudostate spontaneous potential divided by

static spontancous potential

alpha or @ map an isopachous map of clean sand

thickness in a formatior The distribution of the clean

sands is calculated from the spontaneous potential

measurement of the reservoir and is based on the

observation that shale in the formation will decrease

the spontaneous potential response The ’static

spontaneous potential (SSP) valve for a clean sand is

calculated and an arbitrary cutoff of alpha such as

50% Cotsg) Or 75% Catz.) is selected based on regional

production histories The thickness of the reservoir

with a spontaneous potential response greater than

the alpha cutoff is measured and plotted

Alpha I artificial lift equipment that balances the rod

string driving the rod pump in the producing well

with a banging countenveight of cast iron weights

in an adjacent, shallow well The Alpha J system

consists of a winch, cable, and rotary cam mechanism

The cable connects the rod string with the

counterweight and the polished rod is replaced with

a polished tube The Alpha 1 system gives long (30-

40 fO, slow pumping strokes that decrease peak load

on the rods and yields a higher uid output than

other pumping units Getrch and cable or winch-npe

prmping wit)

alpha particle an atomic particle that is positively

charged and consists of pvo pratons and two neutrons

and has a mass of 4 on the atomic weight scale The

alpha particle travels at a speed of about one-tenth

that of light An alpha particle can be emitted from

an atomic nucleus during radioactive decay of uranium ` 238.œ

alpha ring a guarded electrode alt 1) altered 2) alternate

alternating current an clectric current that regularly reverses its flow of direction Alternating

current is described by its frequency, the number of

cycles per second, or hertz A direct current flows

in one direction AC

alternator an electric generator or dynamo that produces an alternating current

altg alternating

° 8m descending wave particle motion amplitude

A-mast an A-shaped assembly, usually of steel, used for lifting amb amber

ambient temperature the surrounding

Amerada pressure gauge a mechanical, self- contained instrument that is used to measure

bottomhole pressures The gauge contains 2 pressure

sensitive, helical Bourdon tube that rotates a stylus ona circular chart A clock drives the chart and depth

is correlated with time

Ame Mud filtrate activity

AMI area of mutual interest amine an organic compound that is made by

substituting one or more hydrogen atoms in ammonia with an organic radical Amines are used to remove hydrogen sulfide and carhon dioxide from natural gas

amine/gas absorber tower a vertical bubble-tray

tower used in sour gas sweetening with the alkanolamine process The bubble trays contain monethanolamine, diethanolamine, or tricthanolamine (TEA) The sour gas inlet is on the

bottom and the sweet gas outlet on the top of the tower The process is called alkanolamine sweetening

amine unit a type of natural gas treatment installation that uses organic bases (amines) to absorb

HS, carbonly sulfide (COS) and CO, from the natural gas The units are often portable see alkanolamine

seecetentig Amm ammonite ammeter an instrument that measures electrical

current

ammonia water or ammonium hydroxide a

chemical (NFLZOH) that is used to neutralize hydrogen sulfide during drillstem and wireline tests

ammonite an extinct type of cephalopod belonging

to the order Ammonoidea that existed from the Devonian to Cretaceous period They were similar

lo squids and lived in coiled chambered shells in

the ocean Ammonites are guide fossils.to the Mesozoic

when the sutures on their shells became very ornate Aninit

amor amorphous

amorphous a substance such as a rock that lacks

crystal structure amor

ammonite

amortize the deduction of an expense over i fixed

period of years from the income amp ampere

Amp amphbolite

ampere the System International CS unit for electric Current An ampere is the amount of current produced

by an electromotive force of one volt acting through

a resistance of one ohm A current of one ampere

has 6.28 x 10"cleetvans tlowing by a point each

second One ampere equals one coulomb per second (Cs) A or amp

amphibole a common, dark-colored (black to Hight green) mineral found in igneous, metamorphic, aod immature sedimentary rocks Amphiboles are at group

of calcium, magnesium, iron, and aluminum silicates that form long, prismatic, six-sided erystils

Hornblende is the most conimon amphibole

amphipathic slug injection a type of enhanced oil recovery A volume or slug of alcohol ar other tluidl

that is miscible (mixes) with both water and cil is

pumped down injection wells Water is then injected into the reservoir to deive the chemicals and oi toward producing wells

amphiphatic a balance in the interfacial tension of oil and water in an oil-base drilling mud

amphoteric surfactant 2n organic molecule with

a water-soluble group that can be either + or — charged or uncharged An amphoteric surfactant is

in contrast to an anionic, cationic, or nonionic

surfactant

amplifier an instrument thal increases the amplitude

of a signal such as voltage, current, or power amplitude height measured vertically from base to lop a

unusually high o¢ low cunplitude such as a bright or

amplitude log a wireline well log uit records the amplitude of the wave train that has passed through the rocks adjacent to the wellbore or cusing Coment- bond acoustic logs and fracture logs are exumptes

amplitude ratio the amplitude of an anomalous

seismic wave divided by the normal or background scismic-wave amplitude Ay

amplitude shadow i decrease in the wnptitude of

reflections below a hydrocarbon deposit on a seismic profile

amplitude time an acoustic wave train display mode

in which the amplitude of the acoustic wave train is

amortize ® anchor contractor 15

ploued against time Amplitude time is in contrast to imensity-modulited time or variable density amplitude versus offset a scismic exploration technique in whieh long ofsers (souree-to-receiver distances) from 1.2 to 1.5 times the target depth are shot The rcilecions front a subsurface reflector will

have different amplitudes with varying allsuts as a

function of Hilhologies AVO

AMPS S-wave amplitude

AMT, Amt or amt amount

AMITYV active mud tank volume A-MUD gerued mud

An anorthite

an unnulus

anaerobic the absence of free oxygen in contrast

to acrobic The environment does not have enough oxygen LO support aerobic bacteria

anacrobic bacte: bacteria thar do not need free

oxygen to live, Anaerobic bacteria obtain their oxygen

from the reduction of oxygen-containing compounds This is in contrast to.aerebic bacteria, Under certain

conditions in a well, anaerubic bacteria can cause

scate formation in water systems and the formation

oF hydrogen sublide from sulfates Pyrite in sediments

is indicative Of anaerobic bacteria

anal analysis

analog computer a computer that stores

information ina manner hat varies uniformly benween specific limits A slide rule is an example Modern computers are digitil

analog recording a recording of a sible by recording another variable that has a direct relaionship Early seismic was analog recurded by burning a tace Gn paper The greater the seismic energy or amplitude of the reflection of a s evem, the darker the bucn on the seismic recording Today seisinic is usually digitally recorded

analog-to-digital converter the elecuonic equipment used in scismic exploration to convert the seisini¢e signal wo a binary code number with 16 bits anastomosing stream a stream formed of numerous, interovining channels separated by sand and gravel bars The cop grained sand and gravel deposits can become potential reservoir rocks

also used to hold a boat or semisubmersible in

position 2) The wubing tht extends below the working barrel of an insert pump 3) An extension below a Urillstem test tool thal supports the weight applied

to the toot to set the packer The anchor normally seis on the bouom of the well or on a cement plug Swaddle packers use steel prongs called dogs instead

of an anchor

anchor buoy a floating device that is used to position

or to mark the position of an anchor on a driltship

or semisubmersible, spread mooring padenn anchor contractor a service company Ubat builds and buries anchors used to attach the guy wires used

16 anchor pattern @ angular unconformity

ana guyed rig The same anchors are also used for

the compietion rig and any workover rigs used on

the same well

anchor pattern the pntern of microscopic

irregularities on a metal surface that has heen treated

with sand blasting, chemical ciching, or some other

technique to improve its adhesiveness for surface

coatings

anchor piling a pile that is cemented into a shallow

borehole on the seafloor and is usedto moor a drilt-

ship or semisubmersihle

anchor pipe the section of perforated pipe below

a packer in a drillstem test Formation fluids flow

into and up the anchor pipe (fail pipe)

anchor spread the pattern of anchor fines and

anchors on a scmisubmersible or drillship There are

usually 8 or 10 anchors deployed symmetrically by

anchor-handling boats

anchor string a short length (string) of casing that

is run inte the seabed to anchor the wellhead

equipment on the scabed (foraidation pile or outer

conductor)

anchor washpipe spear a fishing tool chat is

attiched to a washover pipe The washover pipe uscs

a jet of drilling mud to clean around a tubular fish

atthe botiom of hole ‘the spear is then released to

stab inte the fish to retrieve it

ancient document iin instrument of writing that w

recorded in a county or parish courthouse 30 or more

years before it was offered in evidence An ancient

document can include a map, survey, or plot

An Cpt Ser™

and andesine

analog computer service

andesite a dark-colored volcanic rock that is

aphanitic (very small crystals) and has pkigiochise

feldspar mineral grains, but no quartz Andesite has

a matrix density of 2.70 gii/cc Andesite volcanoes

ANG angular

ang angie

angiosperm pollen the dust-sized reproductive

particles given aff by a flowering plant Angiospercm

pollen are offen carried great distances by the wind

and are common in sedimenis Flowering plants have

existed from the Cretaceous period to the present,

and their pollen are used to determine the age ane

depositional environment of sedimentary rocks

ANGL angic

angle azimuth indicator an acoustic or electric

instrument that is used to determine the angle on

the flex joint helow a semisubmersibte drilling rig

or dvillship (riser angle Ardicator)

angle-build assembly see fideriean csscotbly

angle-build motor ahigh-speed, low-larquc or fow-

speed, high-zorque positive displacement motor with

one or more bends built into the motor transmission

or bearing arca that is used to deflect a well with an

almost constant hole curvature rale between 6° and

20? pcr 100 ft

angle-build rate the change of inclination in a

deviation well measured in %/100 ft (radius of

cureature)

angle-build section the portion of a deviated well

in which the deviation angle is increased

angle buildup see cirgle of buildup

angle control section the grooved portion of the

drawworks drum on a drilling cig that guides the wire rope ta a new wrap on the drum fcrossover) angle dropoff the change in °/100 ft or 10 m of the inclination of a well section as the inclination is

decreasing toward vertical Angle dropoff is in contrast

to angle of buildup (aagle of dropoff) angle of attack the angle between the direction of

the well inclination and the direction of the dip

inclination angle of attack of bit the angle between the center

tine of a deviated well at the location of the bit and

the center line of the bit The angle is positive when

the bit points above the well and negative when it

points below the well

angle of buildup the change in 100 ft or 10 m

of the inclination of a well section as the inclination

is increasing from vertical Angle of buildup is in contrast to angle dropoff (angle brildup)

angle of deviation the angle Sctween a crooked

or deviated hole and vertical (deflection, drift, drift aude, bole deviation or inclination)

angle dropping assembly see pendutian assembly

angle of dropoff see angle dropoff

angle of incidence, reflection, or refraction the

angic berween a wavefront and an interface

angle of twist the azimuth change through which

the drillstem must be turned to counter the downhole

motor Lorque

angle of wrap the length in degrees that a brake hand wraps around a brake flange

angle sub a small length of bent drillpipe that is

used to kick off a deviated well An angle sub is run between the mud or turbine motor and the lowest drill collar One of the connecting threads is machined „ with an angle to the axis of the sub This gives the sub a ¥°-2%° bend A ¥2° angle sub will give an angle change of 2°-3°/100 ft and a 2° bent sub will give 6°-87100 ft The angle sub can have a muleshoe orientating sleeve and key to determine the actual orientation of the bottomhole assembly in the well

A bent sub can also be used as part of a fishing string

to give the right approach angle to the fish for the

fishing tool (bent, crooked or offset sub) angle valve a valve with a 90° turn in the base

angstrom a unit of measure in the metric system

equal to 19-8 em A angular a propery of a sedimentary particle such

as sand having sharp angles Angulic particles indicate that the particle has not been transported very far, since erosion rounds particles ANG

2m

angularity test a test that determines how much a well deviates from vertical (slope test)

angular unconformity a buried erosional surface

with the rock layers below the unconformity tiked

at an angle Angular unconformities can form

stratigraphic petroleum traps

anhydrite 1) a common salt evaporite mineral or

rock composed of CuSO,, Anhydrite is gypsum without

water in the crystal and readily akters to gypsum

Anhydrite occurs as white-to slightly colored beds

density of 2.977 ymvcc, a matrix velocity of 20,000 fy

sec, and un interval transit time of 54 psec/ft ANHY,

Anby, anby, anh, or anbyd 2) a substance formed

by the removal of water from another substance Kor

example, CaO is the anhydrite of Ca(OH), anhydrous without water

ani anisotropic aniline point the lowest temperature, usually expressed in °F, at which equal amounts of the chemical aniline and an oi will completely mix ‘rhe aniline point isan indication of the character of the oi! and the oil's deterioraiing effect on materials nude

of natural or synthetic rubber The lower the

lemperature, the more severe the effect The aniline

point gives an evaluation of the oil's use in an oil-

“based drilling mud ‘The lighter or more paraflinic the oil, the lower the aniline point

anion a negatively charged ion Exumpltes of anions are CIT and SO,7 ~ An anion is in contrast to a cation

anion surfactant an organic molecule with a negatively charged, witer-soluble group An anionic

surfactant is in contrast 10 a cationic, nonionic, or

amphoteric surfacunt

Anisian a global age of geological ime that occurred from about 245-240 m y ago IC is part of the Middle

Tr ic epoch

anisotropic uneven in composition and/or texture

in contrast to isotopic cai +

anisotropy a substance that is anisotropic and is not uniform in any direction

ankle buster a drilling rig with peddle clutches

annealing (to heat or temper a substance and then cool slowly Annealing forms a very thin and hard surface to steel that resists corrosion Sucker rods

are annealed

anh ® annular packoff 17

annelid a worm-like invertebrate with i segmented

body and belonging to the phylum Annelida Annelids

existed from the Preeambrian Era (2) to the

present but are care as fossils becuuse they lack of hard parts Indirect evidence (urace fossils) such as

burrows and tracks ure More common

anniversary date the eltective dale of a lease The

anniversary date isthe date on which payment must

be made to the lessor for delay rental or shut-in in

order to maintain a lease.”

annual acreage rental see delay rental annual capital charge a method for ecomonic eviluction of a discounted cash flow Annuat capital

charge is the net cash tow sufficient for an adequate

rate Of renenn and the recovery of full capital costs

annual production decline rate one minus (the production rate at the end of any year divided by the production rate at the beginning of the yeur) The annual deeline rate is expressed as a decimal

or percentage ¢f

annubar a device that is used to measure fluid velocity An annubur averages pitot tube measurements al four impuct pressure points

annular blowout preventer

annular blowout preventer or annular

preventer a closing device at the top of the well

above the ram preventers on a blowout preventer stick that will close the well with either a kelly, pipe,

or wireling in the well, or with an open wellbore The annular preventer uses a reinforced oval-shaped elastomer or hard-rubber packing element uvat is squeezed with a piston activated by hyd

trom accumubitors to close the well The closing pressure on the rubbe aU can be eased to allow drillpipe to be removed in a proc called stripping The anoukw preventer has « lower pressure rating than the pipe rams and a higher risk of filuce under high pressure (Spherical blowout, sleeve blowout, or

bay preventer)

tubule or hanger and the head or spool through

which the tubular pa or the hanger is suspended

18 annular space © antifoam, antifoamer, or antifoaming agent

2) the decrease of the diameter of the original drilled

wellbore by well cuttings and/or the drilled

formations This include a) cave-in, bh) landslide,

c) creeping, swelling, or heaving formations d) seuling

of solids, ¢) salt precipitation, and 1) mud rings

annular SDTCC se 07001111

annular stream pattern a sircanm drainage paitern

that is characterized by several concentric, ring-shaped

streams An annular stream pattern is formed by the

erosion of a dome to expose alternating layers of

soft and resistant formations

annular velocity the rate ai which a Muid such as

drilling mud is rising or falling in the annulus of a

well Annular velocity is ahout 100 fi/min and depends

on the pump rate and volume of the annulus AV

annulus J) the space between a) the drillpipe and

the wellbore b) the tubing and casing, or-c) the casing

and the wellbore faruadar space) anor ANUL 2) a

ring of interstitial water caused by mud filtrate invasion

of a hydrocarbon-hearing formation

annulus pressure-responsive safety valve 2 valve

that is sensitive to the pressure in the annulus ina

well and will automatically open to relieve excess

pressure in the annuhis The anoulus pressure-

responsive safety valve can be adjusted to any pressure

threshold at the surface AUR safety naire

anmunciater an audio-visual alarm or indicuor

anode an electrode at which oxidation occurs It is

the positive terminal of an clectralytic cell or the

negative terminal of a battery An anode corrodes

Anode is in contrast to a cathode

anodic protection a method that retirds

electrochemical corrosion on large, marinc, and

buried structures such as offshore platforms and

pipelines A low-vollage direct current of 25-40 volts

aad several hundred amperes is generted between

anodes that usually permanent stecl diaaium, or

magnetite fittings and the structure Anodic protection

is similar in principle to cathodic protection but docs

not cely on sacrificial anodes (aupressed crrrent

anomaly of higher or lower geavity values on a gravity

s ora structure such as a dome on a seismic profile 7

anoxic a chemically reducing environment anoxic basin awater-filledl basin in which the bottom walers are oxygen deficient Because of the lack of oxygen in the water, organic-rich sediments can be

deposited on the bottom of the basin

ANSE American National Standards Institute Anthr anthracite

anthracite the highest rank coal Anthracite has the

greatest heat and least volatile content and is formed

by intense heat and pressure, (hard coal) Anthr

anathrozoan an aquatic invertchrate that belongs to

inchide corals, both solitary and colonial,

and have existed from the Ordovician period to the present Anthrozoans are important reef builders and

guide fossils

anticlinal nose a plunging anticline without closure

(nose or structural nose) anticlinal theory an early and correct theory that petroleum accumulates in the high area of reservoir rocks in anticlines The anticlinal theory was First popularized by 1.C White in 1882

anticline anticline a large, long arch of rocks that have heen

bent upward, An anticline has cocks becoming older

in age toward the core The top of the anticline is

called the crest, and the center is called the axial

surface Anticlines in reservoir rocks were one of the first types of petroleum traps recognized Anticlines

can be either buckling folds formed by tangential compression forces parallel to the bedding with stratal

shortening, or they can he bending folds formed by diflerential movement perpendicular to the bedding

A plunging anticline has an axis that dips in one direction, whereas, a doubly plunging anticline dips

in opposite directions Anticlines-are in contrast to synclines : anticlinorium a series of anticlines and sydclines

of regional extent

antifoam, antifoamer, or antifoaming agent an `

additive that prevents foaming, Antifoam is often.a

antiform a fold diate is concave upward Antiform is

in contrast to synform and a neurtal fold

antifriction bearings the bearings that rolate in a circle around the journal on a eg of a roller-cone bit to allow the cone to turn The bearing arrangement

can be either a) roller-buall-roller or b) rotler-balk

antisludge agent an additive that is used during acidizing a reservoir containing heavy asphaltic oil,

An antisludge agent is a surface-active chemic:l thái prevents the formation of a thick sludge that could réduce formation permeability

antithetic fauits

antithetic fault relatively minor fault nal is parallel

to a major fault but has displacement opposite that

of the major fault Antithetic faulés are in contrast 10 synthetic faults and are a type of secondary faults

anti-top-lease provision a special provision in an agreement such as a farmout that prevents the parties from top leasing the land included under the

agreement

ANUL annulus

ANYA allowable aot yet available

AOCS American Oil Chemisis Society

AOF absolute open flow AOFP absolute open flow potential AOGA Alaska Oil und Gus Association AOS automitic oi skinner

AOSC Association of Oilwell Servicing Contractors

ap appears

apatite fission track analysis a method tha

uses the length of ionization uwacks from U3

disimegeations in the mineral apatite that is inversely

Proportional to the temperature of the mineral to analyze the thermal history of the rock AF FA A-PEL aluminum pellets

aph aphinitic

aphanitic an igneous rock texture with mineral

grins tou small to be seen by the naked eye Apbariitic

texture includes microcrystalline and cryplocrystalline textures and is in contrast lo phaneritic apb

API American Petroleum tnstitute A.P.L the expected

API cement class an oil well cement classiticuion

by the American Petroleum Institute lt includes Classes a, B,C, D, EF, G, HL, 1, and J and is based

on depths, corrosive environments, strength and

pressures, und temperatures for which the cement

is recommended ị

API gamma ray unit 1 idard unit of gamma ray measurement that is calibrated in the American Pevoleam Institute’s test pits atthe University of Houston The average Mid-Continent shale hus about

100 API gamoia ray units.”

API gravity a scale reflecting the density of a fluid

such as cruce oi], water, or natural gas It is computed

by dividing the specific gravity of the fluid at 60°F

into 141.5 and subiracting 131.5 Fresh water has 10°

5

API Crude oils generally range front 6° (very heavy)

lo 60° (very light), Average oils range Irom 35° w 25° APL Light oils range front 35° 10 45° and heavy

oils are less than 25° APL °APL is the preferred term

CAPE or gravity) API log grid the standard format used for recording

on the lett and two tracks on the right Each tack is

2% in wide, ancl the depth column is 44 in wide

‘The wacks can have either a linear or togarithmic

API well number i 12-digil number that is assigned

to each well drilled in the United States Digits 1 and

2 are codes far the state, Digits 3 through 5 are for the coun, parish, or offshore, Digits 6 through 10

identify the individual well, and Digits 11 and 22 record

a property of the well such as sidetracking

to the bedding plane in comwrast to true bed thickness

apparent dip the angle that a plane such as a bedding pling or fault plane makes with horizontal, provided

that it is not measured perpendicular to the strike

or horizonuil direction of drat pkane ‘the perpendicular measurement is called true dip The apparent dip will vary fram almost zero when measured at a low angle to the strike of the pline, tow maximum value tat approaches the wue dip at

an angle near perpendicular to the sưike,

20 apparent liquid density © Archie's equation or formula

apparent liquid density the mass of gas divided

by the volume of gas dissolved in a liquid at 14.7

psi anc GO°F

apparent matrix transit time a parameter

tised an a MID plot Apparent matrix transit ume

a byl

is equal ta ah lime-average relationship and

Prat

LÊ TÊN :

At— _ fñield-observed rektionship in which Af is

sonic log interval transil time, &,, is apparent total

porosity, Af,is pore fluid transit time and c is a constant

apparent resistivity the recorded resistivity on a

resistivity well log Apparent resistivity differs From

true resistivity hecause of borchole effects adjacent

beds, the invacledt zone, and the drilling mud

apparent velocity the apparent wavelength times

the frequency ¥,

apparent viscosity 1) the viscosity of a fluid flowing

through a porous rock that it shares with another

fluid (effective viscosity) 2) the viscosity of a Muid

measured in an instrument ata stated rate of shear

iris measured in centipoises (cp) froma direct reading

viscometer at 600 rpm and is a function of the fuid’s

plastic viscosity and yield point

apparent wavelength the distance between similar

points on a wave measured acan angle to the wavelront

The true wavelength will be smaller than the apparent

wavelength anc is measured at 90° to the wavefront

appd approved

apple a small object such as a nutor bolt that falls

to the drill Noor of a rig

apple butter belt dressing

apportionment the division of royalties bet Ww een

imlerest owners of the lane

“apportionment account an account that

accumulates expenses fora period with the account

being credited for activities on some predetermined

basis

apportionment rule it rule in some states that

royalties from a ease on property that was subdivided

afier the lease was granted arc to be divided

proportionately between the property owners’

appraisal curve a graph used to predict the ultimate

recovery of wells producing from the same reservoir

bul with different initial productions The ultimate

cumulative percent oif production per well is plotted

versus the first year’s production per well to yicld

an average, maximum, and minimum cumulative

production percentage curve An ultimate production

per well is ploued versus daily production of oil per

well during the first year to give an average, niaiximum,

and mininwum ulữmile production curve

appraisal well a well drilled after a discovery well

to gain more information an the producing, reservoir

such as the elevation of the oilawater contact Appraisal

wells are often cored An appraisal well is a step-out

or delinetion well

approx of apprx approximately

APR annulus pressure responsive

APT additional profits tax Aptian a global age of geological time that occurred about (15-308 m y.ago It is part of the Lower

Crétaceous epoch

Aquagel!™ a type of bentonite used to condition drilling mud and to hibricate,the bit

Aquapulse™ a sleeve exploder that is used as a

marine seismic source A propane and oxygen mixture

is exploded by a spark plug in a thick rubber bag

that is called a sleeveMultipte arrays are often used

aquasorption process a water washing process in

a contact tower that is used to sweeten natural gas

aquifer a porous and permeable rock that contains

waler

Aquitanian a global age of geological time that

occurred about 25-23 m y age It is part of the Lower Miocene epoch

aquitard a rock that is impermeable and does not allow fluids to pass Examples are shale and salt layers

An aquitard is in contrast to an aquifer

AR acid residue

Ar argon , relative amplinade

Arag ot arag aragonite

aragonite a common mineral that has the chemical

formula CaCO, the same as thé mineral calcite Their

and denser and has a different crystal structure and

is less stable than calcite Aragonite is white, yellowish,

or gray and is cammon in coral and mollusk shells

and oolites Arag or arag

arc cutter a downhole assembly used to deviate a

well arch () long uplift An arch is an anticlinal fold of regional scale 2) see scented arch

Archean rocks formed during Archeozoic time Archeo Archeozoic

‘Archeozoic a subdivision of the Precambrian era

of geological time It occurred about 4500-2500

Archie’s equation or formula an cmpirical

formula used in well-log analysis to evaluate the bydrocarbon content of a reservoir it states that:

EX Ry\™

(Se R, )

Sy is water saturation Fis the formation resistivity

factor F can be calculated from the formula F = 1.0/b™, where ® is porosity of the reservoir rdck,

and az is the cementation factor for the reservoir rock which varies [rom 1.0 to 3.0, but is commonly 16 to 2.2 R,, is the resistivity of the formation waters that

is usually obtained from water samples in nearby wells

or is calculated from the spontaneous potential log.

A, isthe wue formation resistivity 4 is measured [rom

the resistivity log The saturation exponent 27 ranges:

from 1.8 to 2.5;-but is commonly 2.0 Hydrocarbon

saturation is calculted by solving for S„ and subtructing 1 ‘The formutit is accurate only with clean

sandstones and carbonates; shaly formations pive erroneous results, The equation is named after George

E Archie who first presented the equation in 1041 and published it in 1942

Archimidean screw a type of artificial Lill in which

a# spiral activated by a rotating sucker-rod string driven

arc-plasma torch an underwater cutting and

welding torch that feeds gas through a nozzle ina

copper anode An arc of ionized gas occuis bepveen

areweld a method used w join mens by an electrical current discharge in un are between a welding rod, which is an electrode, and the metal The heat generated by the are melis both the welding rod and

the metal to form the bond

area of mutual interest «specific area unat his heen

defined by two or more parties where each pariy, a

their option, Gin proportionally share in the costs and ownership of acreage acquisitions with the other parties The area of mutual interest is ofien detined

in a Contract such as a farmout, joint Operaling ,

agreement, or seismic Option An area of mutuat

interest is sometimes confused with a wor ing interest

area in which the parties share in the development

of the net lease acreage AMS

is effectively swept by injected tluicls during enhanced

areawide pricing a regional wellhead price ceiling for inerstate gas producers, Areawide pricing was used by the Federal Power Commission in the 1960s

AREN or aren arenaceous arenaceous sandy AREN or aren

arene see aromatic

Arenigian a global age of geological time dia occurred about 490-485 m y ago It is part of the Lower Ordovician epoch

arenite sand-sized sediments with a diameter beeween 40 and 2 mm Arenites are in contrast 10

rudites and pelites, (sec)

areometer a tube-shuped instrument that is mace

of glass with a weighted lower end and a é printed

on its upper end IL is designed 10 float in u liquid

‘The height to which the areometer floats depends

on the density of the liquid, which is read off the scale One API oil gravity areometer is usedl to Measure crude oils 10°—45° API gravity and another 45°-90°

A mudwater hydrometer is used to determine drilling

mud density (aydrometer)

ARG or arg argillaceous

Archimidean screw ® aromadc 21

argillaceous shily ARG or ary

argillite or argillyte 1) a hard, compacted shile

or mudstone that hus fewer liminaions than shale,

No fissility that is found in shale and no skuy cleavage 3) ay rock that has been naturally cemented by calcite (petite) aryl

arkose a pink-to-bull cotored sandstone derived from

the erosion of a granite An arkose contains a large percentage of quariz grtins but also has more dian 25% feldspar minerals and some minor chy minerals and cement The grains are angular to subangular

and sorting is poor to modermely well sorted An

(gramie wash) ARK, Ark or ark

arkosic a term used 10 describe sandstones, ar€nnitcs,

graywackes, conglomerates and limestones with relatively large amounts of the mineral feldspar ARKIC

arm 1) to prepare s perforating gun ror ring 2) the lever or bow spring on a wireline sonde that is used 10 ether centralize or press the tool to the opposite side of the borehole The arm is opened

by cleeiic motor and helel against the wall by spring tension `

a torque in an electric motor

arm’s-length transaction a transaction benween unalilited companies

ARO atthe rate of

aromatic a type of hydrocarbon molecule found in

crude oils that is formed by an unsaturated, closed ting The principle aromatic hydrocarbons are the

BTX group (benzene, toluene, and xylene), cumene,

styrene, and ethylbenzene Crude oils rich in this type

of molecule have a sweet, fruity smell The original definition of aromatic implied fragrant compounds.

22 arpent ® ASGMT or asgmt

Simple aromatic compounds in crude oil cause

Iuorescence of the oil The general formula is

CaHay—«- An example is benzene (C.H,) (arene or

bevzene) aroni

arpent a French unit of length used in southern

Louisiana that varies with location but is generally

191.833 ft

array 1) the pattern of a group of geophones or

100 ft across that are altached to a single recording

channel The array is used to attenuate horizontal

waves Most arrays are in line but some arc areal 3)

a group of shotpoints that are fired at the same time

4) the configuration of clccirodes on a.wireline sonde

used in well logging

arrestor see surge chamber

Arrhenius equation an:equation that relates

chemical reaction rates tobe temperature The

equation is & = Ae "kT in which k is the rate constant,

A ts the Arrhenius constant, & is the activation energy

of the reaction, & is the universal gas constant anc 7

is the temperature in Kelvin the equation implies

that the reaction rate doubles for every 10° C (18?

arrival time the time difference between the shot

and the arrival or appearance of a wave train or event

onaseismic display Arrival time can be with or without

corrections

arrow plot a wpe of dipmeier display

artesian ground water under lydrostatic pressure

artesian well a well in which the fluid flows to the

for the aquifer is higher in elevation than the wellhead

arthropod an advanced type of invertebrate with a

segmented body and external hard parts that belongs

to the phylum Arthropoda They include insects,

crustaceans, and trilobites Arthropods have existed

from the Cambrian period to the present

articulate brachiopod a type of marine invertebrate

with ewo shells (bivalved) that are dissimilar The

articulate type of brachiopods have hingement with

teeth and sockets for movement of the shells and

have existed from the Lower Cambrian epoch to the

present They are guide fossils for the Paleozoic era

articulated pipe drillpipe in 1-f sections that form

interlocking segments with up to 2° flexibility benween

universal joint to a concrete and ‘stecl base on the

seafloor Buoyancy tanks keep the structure floating vertically An articluated platform is used primarily for Maring gas and to moor and load tankers

artificial intelligence a computer process that

simulates human thinking Instead of working through programmed steps to solve a problem, it uses creative solutions, The process utilizes a knowledge base and can learn from mistakes Petroleum exploration with - its many factors that affect decisions, such as drilling

ay exploratory well, is a possible application of

artificial intelligence Af

artificial island a shallow-water dritling platform

made with gravel or boulders artificial lift a mechanical method that is used to

assist in Hifling crude oil in a well to the surface The

most common methods are a) sucker-rod pump, b)

hydraulic pump, c) gas lift, and d) electric submersible pump Ninety-four percent of oil wells in the United States use artificial lift

Artinskian a global age of gcological tinie that occurred about 275-270 m y ago It is part of the Lower Permian epoch

arrival time the time that it takes a particular wave phase of seismic energy to travel from the shot to a reflector and back to the detector that records it during seismic exploration Arrival time can be with or without static and dynamic corrections

AS after shot

A, amplitude of shear wave

ASA American Standards Association ASAP as soon as possible

asbestos a gencric name for a group of naturally occurring, fibrous silicate minerals Asbetos is used

as vdrilling mud additive to improve carrying capacity

asbestos felt pipe coating material made of asbestos saturated with asphalt

asbr absorber ASCE American Society of Civil Engincers

ASGAS associated gas ASGMT or asgmt assignment

ARTESIAN WELL

anesian well

artificial lift

ash the noncombustible residue left afler burning a substance such as a hydrocarbon

| Ashyillian a global age of geologicul time that

occurred from about 450-425 m y ago It is puct of the Upper Ordovician epoch

ask system a method used to keep a drillship on

station The early ask systems used the angle on a

taut wire secured by a clump weight The system is

sul used but not in deep water where a hydro-acoustic

position system is used Transponders or beacons are

* positioned on the seabed The signals are picked up

by bydrophones (usually four) on the

semisubmersible or driliship and sent to a computer for processing if the ship drifts off the drillsite because

of waves, Currents, or wind, a computer aboard the

drillship detects it from the seabed sound lransmissions and uses the ship's Uhrusters to put the

drillship back on station The thrusters have controlled

pitch propellers to adjust the position of the drill- ship, Another system uses prepositioned radio transmitters On fixed structures such as production platforms that transmit signals to the antenna on a

vessel This is used to determine range and bearing

(dynamic positioning, positioning system or

Stationing) ASME American Society of Mechanical Engineers ASNT American Society for Non-Destructive Testing

ASOFR acid sand/oil frac

ASOIL associated oil ASP 1) acoustic scope picture 2) apparent

spontaneous potential

ASPH asphattic oil Asph or asph 1) asphalt 2) asphaltic asphalt a dark brown to black; solid or very viscous liquid that is composed almost entirely of

hydrocarbons Asphalt has very high molecular weights and melts above 20°C (70°F), which distinguishes it from heavy oil lt has a specific gravity between 1.0

and 1.1 Asphalt is composed of bitumen and is soluble

in carbon disulfide and insoluble in normal heptane

it is found in most crude oils Pure asphalt is formed naturally by a variety of processes that affect crude oil and by refinery processes that remove the lighter

fractions from crude oil Natural asphalt deposits are formed by degradation of crude oi! by evaporation, water washing, and/or evaporation Asphalt is used

in oil-base drilling Auids, Jost circulation material,

emulsifiers, fluid-loss agents, and wall-plastering

agents Asphalt in the United States is the same as

bitumen in England Solid asphalt is known as

asphait-base crude oil a crude oil that contains liule

or no paraffin but has an asphalt residue upon distillation When burned it leaves a tar-like residue Asphali-base crude oil is dominated by the napthenic

hydrocarbon compounds The oil is black in color and tends:to have low SAP] and a low pour point Asphalt-base crude oil represents about 15% of the world’s oil supply Most of the world’s oil is mixed-

based or is paraffin-base (nephthene-base cructe oil)

asphalt enamel pipe coating made of ground mica, clay, soapstone, or tale with asphatt that is applied hol to pipes before they are buried to prevent corrosion

asphaltene a general term that includes any solid, dark brown to bkick bitumen that occurs either

dissolved or dispersed in crude oil or by itself in

sediments Asphaltines are soluble in carbon disulfide but not in normal heptane or paraffin naptha They have high molecular’ weights (500-1,500) and are composed primarily of carbon and hydrogen with lesser amounts of nitrogen, sulfur, and oxygen The basic structure of asphaltenes is aromatic rings with 3-10 or more rings per molecule, Asphaltenes can

be precipitated by bubbling gas through an oil

24 asphaltic @ Atokan reservoir and can form atar mat at the oflAwater contact

Resins are similar to asphaltenes

asphaltic containing significant amounts of asphait

asphaltic bitamen a low-cmperature reservoir

bitumen that formed by the degradation of liquid hydrocarbons by evaporation, water washing, and/or

microbial activity into asphalt and pitch Asphaltic bitumen is soluble in organic solvents

asphaltic sands a sandstone that is cemented together with a natural soft asphalt

asphaltine a bitumen that melis above 110°C

Asphalline is black to dark brown in color and is soluble in CS, and chloroform but only partially soluble in CCly The fraction that is soluble in Cs,

but not in CCh, is called carbenes Asphaltine goes

by such local names as manjak, glance pitch, and

gilsonite

asphaltite a naturally occurring, hard, solid, black bitumen Asphaltite is soluable in carbon disulfide but not ia paraffin naptha and fuses above 230°F Types

of natural asphaltites include gilsonite, grahamite, and

glance pitch Asphaltite is an asphaltene

asphalt plant a facility that buys basic sediment and water and recovers crude oil from it (reevcling unit) ASSE American Society of Safety Engineers

Assclian a global age of geological ume that occurred from about 290-285 m ¥ ago It is part of the Lower Permian epoch assem asscmblage

assemblage a group of fossils that occurs and defines

a specilic fevel in the racks @ssenz

assembly equipment composed of numerous individual pieces that is used for a particular purpose assessment additional capital that is requested from

an investor after the initial investment Assessment can be cither mandatory jor optional If it is optional

or voluntary and the investor declines, there is a

penalty for noncompliance

assgd_ assigned

assign to transfer An a the assignor to the as

signment is assigned from

ANC

assigned when earned an agreement in a farmout

in which the farmee is not assigned an interest until

after the earning conditions such as drilling a well are satisfied Assigned when earned is in contrast to

J present assignment

a Signce.t person or campuny who receives an

gnment or transfer of interes! such as an oil and

gas lease

assignment the conveyance that transfers an interest

in a property or a contract from an assignor lo the assignee asgnu

assignment clause a provision in an oil and gas lease that requires the lessor to give notice to the lessee of any changes in ownership (change of ownership clause)

assignor the party who grants or transfers an assignment or an interest such as an oi! and gas lease assistant driller a drilling contractor employee who assists the driller on that tour on an offshore drilling

sistant driller often relieves the driller on

the drawworks brake and maintains the mud pumps -

and circulation equipment AAD

assn or assoc assaciation

associated gas natural gas that is in contact with

crude oil in the subsurface reservoir It occupies a

separale portion of the reservoir and is wet gas

Associated gas is in contrast to nonassociated and

dissolved gas If production of associated gas will not substantially affect the recovery of crude oil, a government regulatory agency can ccchassify it as nonassociated gas ASGAS

associated gas well allowabfe the amount of

natural gas that a government regulatory agency allows

a well or leasehold to produce per unit of time from wells draining a free gas cap It is ofien related in volume to an oil allowable

associated reservoir allowable a special reduced

gis allowable, the amount of gas production permitted

per time by-a government regulatory agency, on an

associated gas well that also produces oil The gas

allowable is based on the equivalent volume of oil

equipment such as pipe on a drill floor ass work heavy work done by hand astern toward or behind the back (stern) of a ship

or offshore drilling rig asthenosphere the portion of the earth located just

below the lithosphere starting at a depth of about

60 mi The asthenosphere is less rigid than the lithosphere and seismic waves are strongly attenuated

not vertical and will migrate horizontally with depth

An asymmetric fold is in contrast to a symmetric fold

of air at sea level which is 14.6959 psi, 101:325 kPa, 1.01325 bar, 33.90 ft of fresh water, or 760 mm of

mercury An atmosphere is equal to LỢI x 10°n/m?

ain

atmospheric pressure the pressure exerted hy the

weight af the column of air in the atmosphere

Atmospheric pressure is 14.6959 psi at sea level and

decreases with altitude (barometric pressure)

atmospheric-pressure oil stabilized oil existing under surface conditions of temperature and pressure

(60°F and 1 atm) Stabilized oil exists after the oil has been processed through separators to remove

solution gas and water (lease crude or stock-fank or

stocktamk oil) Atokan a North American epoch of geological time

atoll

atoll a relatively large (1 ta 80 mi in diameter)

circular or elliptical reef with a central lagoon ‘The

atall is surrounded by deep water and does not have

a central island

1 PROTON 2 PROTONS

1 ELECTRON 2 NEUTRONS HYDROGEN 2 ELECTRONS:

alom

atom the smallest particle that has all the properties

of an element The nucleus of the atom is composed

of protons and neutrons while electrons orbit in shells about the nucteus All mauer is composed of atoms

atomic number the number of electrons or proians

in the atom of an element ‘The atomic number of carbon is 6

atomic weight ihe rekitive weight of the average

#lom of a element based on the carbon 12 isotope being exactly 12 A

atomize to spray a liquid through a small hole causing it to séparate into numerous very snialt droplets

attapulgite a group of clay minerals with a chain- lattice and a chemical formula-of (Mg,Al).5i,0 9

(Ol): 2H, 0 The clay minerals are light weight, tough,

and fibrous Atapulgite is a colloidal clay chat is used

to increase the viscosity of drilling und completion

fluids and develops a gel when mixed with salt water,

Attapulgite has high viscosity in both fresh and water (palygorskite)

altapulgite cement a slurry formed by adding dry cement to water with prehydrated ataipulgite It is used usa lost circulation material

attenuation the reduction in amplitude or energy

of a wave such as a seismic wave attenuator a device used to reduce the amplitude

of a wave or signal An auenuator is usually calibrated in decibels

attic 1) a platform that goes around the crown of the derrick on a drilling rig The railing that goes

around the attic is called the pigpen, and both the

attic and pigpen are called the duck’s nest The atic

conuins the water table that holds the crown block

The auic is accessed by the derrick ladder (crown

Plaiform or crows nest) 2) the derrick board on a

roluuy rig attic man ¡1 derrickman on a rotury drilling rig

attic oil oil that occurs in the very top of the reservoir Auic oil is not drained by wells vat drain the reservoir

irom lower elevations Because there may not be a

well located on the very highest point of the reservoir,

some attic oi! is often lef in every reservoir that is drained

attitude 1) the horizontal orientation of a line or plane 2) the angular orientation of a cumera or the photograph used in aerial photography

atto the metric prefix for 107" ø

- attributable acreage the acreuge what is assigned

to a well Jor the purpose of determining an allowable

where there is an acreage factor in the allowable

formula

attribute a particular characteristic of data Seismic atuributes include amplitude, frequency, velocity, and polarity

attribute map 4 contoured map bused on a seismic utribute The uttcibute, in numerical form, is ploned shor point and contoured

au augite audit a documented investigation

auger a drill with Jong helical grooves that wind up the drillpipe to carry thế cutings to the top of the

hole when the auger is routed An auger drill is often

used lor shot holes No air or niudl is circulated when

drilling

auger man a rotary driller auger stem four bars of iron that are fined to the auger stem of a cable-taal rig w form a heavy steel shaft that prevents deviation of the well The bit jars are serewed into them, (sarker bar giride)

austenitic a vonmagnetic state of iron or an iron

alloy Austenitic is in contrast to ferritic

austenitic stainless steel A nonmagnetic alloy with over 16% chromium and over 7% nickel Qvhich can

be partially replaced by manganese) and iron Ít is

used to make nonmagnetic drill collars Austeniti stainless steel is in contrast to ferritic stainless sueel which is magnetic

to be termed metamorphic eeahy

audhigenic clay minerals! ckiy minerals that have

precipitated out of subsurfite waters (neoformed clays) or formed from the alteration of a precursor

26 authority or authorization for expenditure °

material (transformed clays), such as feldspar grain

in a subsurface rock Authigenic clays decrease the

primary porosity in sedimentary rocks They create

microporasity which results in a high irreducible water ?

conient for the rock and a high water saturation

Authigenic clays have high conductivity and reduce

the resistivity of sedimentary rocks such as shaly sands

This can result in a high water saturation estimate

from weil logs Authigenic clays are responsible for

formation damage as they can be dislodged from

mineral grains and/or clispersed by drilling mud filtrate

or other fluids injected into the formation adjacent

to the wellbore They clog and bridge.pore throats

to decrease the permeability of the rock

AFE

{Authority For Expenditure)

Ory Hole Dritting Intangibles

authority for expenditure

authority or authorization for expenditure a

form that is filled out before drilling a well The

authorization for expenditure fists all the estimated

costs of drilling the well with owo results: a dry hole

and a producer i is used to analyze the economic

feasibility of drilling the well and to keep costs under

control when drilling the well An authorization for

expenditure is also made before any major purchase

AFE

authorized total depth or authorized depth the

total depth of a well that is approved by the operator

ona drilling contract AD

auta automatic

autochthonous something that is found in the same

place where it was formed, It has nat been transported

(i sittt)

autocorrelation a crosscorrelation in which a signal

is correlated with itself The autocorrelation function

measures the statistical dependence of a wave form

automatic slips

at a Jater time with the wave form at an earlier time

Autocorrelation is used in seimsic signal processing

and can be used to determine the kind of deconvolution necessary

auto-lock safety joint a pipe joint used on a fishing

string that disconnects on tension ora quarter reverse

turn when the string is caught automated shutdown asysicm ona producing weil

that is designed tc react to the sensors such as high- and low-pressure valves and storm chokes that detect abnormal downhole conditions and will automatically -shut in the well An automated shutdown can be manually reopened

automatic catheads cathcads with the catline spools

mounted on roller bearings around the cat shaft with

a friction clutch Automatic catheads are controlled manually, hydraulically, or pneumatically

automatic choke an orifice operated by power that

is used to contral the pressure on a flowing fluid

automatic custody transfer a system designed to

move oil from lease storage to a pipeline Automatic custody transfer has a field sampling and measuring

system for‘crude oil that works without manual input

The equipment includes a pump, back pressure valve, BS&W monitor and oil meter ACT

automatic driller or automatic drilling control

unit a hydraulic or pneumatic device that is

connected to the drawworks brake handle on a drilling

rig and maintains a predetermined weight on the bit without input from the driller (drilling control)

automatic elimination clause a provision ina unit

agreement that automatically eliminates certain lands from the unit area after a specific date unless certain developmental operations are not done (elimination

clause)

automatic feed control see automatic driller automatic fillup shoe a device with a pressure-

activated valve that is used on the first joint of casing

to regulate the amount of drilling mud flowing into

the casing as it.is run

amplification or attenuation of input signal strength

coming into an amplifier It is automatic on seismic

amplifiers if the gain of each channel is independent

of the other channels AGC automatic gas detector a sampling and analytical

device that measures gas-cut drilling mud in the mud

pits

automatic gauge see automatic tank garge

automatic pump accumulator unit see accumulator

automatic pump controller see percentage timer

automatic rabbit washers used on the sucker rods

of 8 pumping well to clean out paralin automatic ram lock a mechanical lock that keeps

the subsea blowout preventers closed if the hydraulic

pressure is lost or released automatic shutdown a system: with sensors that can

stop a process ifabnormal conditions are detected

automatic slips a wedge-shaped device that is part

of a modern rotary table and is powered by air or

hydraulic Auid from a pedal at the driller’s position

on a drilling rig The automatic slips, are used to

suspend the drillstring in the well (ower slips)

automatic tank gage or gauge un instrument on

a tank ubat uses a float on a tine to show the height

of a liquid in the wank

automatic weight-on-bit control a device that uses the rig-weight indicalor on the dead line to

aumomatically maintain the consiant required weight

on the bit during drilling

automatic well testing the automatic gauging and sampling of a well AWS *

‘aux auxiliary

auxiliaries secondary equipment on a drilling rig

that is not directly involved in drilling the well

Generators for rig lighting are un exampte of auxiliaries

‘ auxiliary brake a hydrodynamic or clectrodynamic brake used to lower heavy loads at slow rates on at drilling rig Auxiliary brakes are used lo prevent wear

on the main brakes

AV annular velocity

AVC al) automatic volume control 2) automatic vent chamber

avdp avoirdupois AVG, Av, av or avg average

AVL acoustic velocity log

AVO umplitude versus offset

Avogadro's number 6.0247 10"/mole avoirdupois a system of weights in which 1 Ib equals

16 oz Two thousand tbs equals a short ton and 2,240

Ibs equals a long ton Seven thousand grains equals

! lb One pound avdp equals 1,215 Ibs t, cedp

AVP actual value profit

Av Sp Gr iverage specific gravity

avulsion

avulsion an abrupt change in the course of a river

as it abandons one portion of a channel to erode another channel

AW acid water

a, Sali water activity

AWG American Wire Gauge AWS Anicrican Welding Society AWT sutomatic well-testing awig awailing

ax axinile

axial compression inward directed forces paratlel

to the long axis of an object Compressive forces are directed along a tength of pipe when the pipe

encounters wt deviation or sticky spot in the well as

it is being lowered into the well

axial compressor a type of gas compressor that

compresses gus flowing from an inlet to the discharge

along a long shalt with numerous short propellors

or blades that are rapidly revolving

or axes along maximum bénding of layers of rocks

in a fold The surluce is essentially the center of the

fold and symmetrically divides the fold The axial surfice is curved on un asymmetrical fold and is Sight On a symmetrical fole It is more correctly

ribed asa surface rather than a pline

axial tension oulward-lirecied forces parallel to the tong axis of an object Vensional forces are directed long a dength of pipe when the drill string is caught

in a keyseat when tripping out

axial trace the line formed by the intersection of

an axial surface on a fold with a topographic surface axial trend ‘the azimuth or direction of a hinge line

on a fold axis aline wong the maximum bending of rock kiyers

of the fold and is essentially the center of uhe fold

AZIMU azimuth

azimuth 1) the horizontal angle (0°-360°) measured clockwise from true nocth in surveying 2) the horizontal ungle measured clockwise between the fice

of a devinion tool in a well and magnetic north 3) the horizonuul angle measured clockwise from magnetic north in well logging « AZIMU or b

azimuth bar a reference point used to establish

compass Orientaion on a permanent bench mark

28D ® hack-off wheel

B 1) formation volume factor 2) turbulence 3)

magnetic induction 4) bottom of 5) angle between

interface and bed 6) barrel 7) boundstone 8) cation

mobility

b VD) reciprocal of formation volume factor 2) bubble

point 3) bulk 4) bank 5) burned 6) bubble 7) billion

8) har (pressure) 9) radius of investigation

B/ 1) base 2) bottom of

BA barrels of acid

babbit 1) a material that is similar to lead Babbit is

melted ina babbit ladi¢ and poured into a rope socket

The babbit solidifies and holds the sand tine in the

rope socket which is used to attach tools 2) a pot

with along handle that is used to melt babbit (abdit

fadle) see Rabbit metat

babbit ladle a pot with a long handle that is used

to melt babbit (habbit)

Babbit metal a sofi, white metal alloy usually made

of tin, copper, and antimony that is used in Iriction

bearings Babhit metal is named after Isaac Babbit who

discovered it (habhit}

baby driller an inexperienced driller

back the side of the drilling rig facing away from

the V-door

back-arc basin a basin located betveen an island

are ancl a continent Back-arc basins characteristicatly

contain volcanic sediments and are in contrast to fore-

arc, trench, intra-arc, and retro-arc basins

back band the brake band on a bull wheel drum

of a cabletool rig

back brake the brake used on the sand-reel hoist

of a cable-ool drilling rig

backfill 1 replace soil dug from a ditch

backflow fluid Now opposite the normal flow

direclion Backflow is used in a well to remove or

return treament fluid from a well and to clean

perforations

background the noise that is not part of the signal,

such as a seismic reflection event

background gas natural gas in the returning,

circulating drilling aud Background gas is the

that is detected by mud logging when drilling through

a homogeneous lithology Background gas is in

contrast ta zero gas and a gas show,

back-in farmout or back-in farm out a type of

farmout agreement in which the grantor who has a

retained nonoperating interest in the earning weil

can convert it ata later date into a specified undivided working interest

back-in interest « carried share in a well that converts to a regular working: interest at a specific time, such.as payout The interest of a-farmor in a

farmoul agreement or assignor (ibe party that turns

over their interest) of a lease reverts to a specific

share of the working interest for the farmor or assignor

afier the farmee or assignee (the party that receives the interest in the lease) has recovered specified costs,

such as drilling and completion costs from production

thack-im right) back-in option an agreement between two parties

with working interests in a well If one party elects

to not participate in the drilling of the well, the other party can drill the well and recover a predetermined

amount of revenue from the production The first “ party can then back in and share proportionally the

working interest in the well The carried party bears

no cosis until back in `

back-in provision a farmout agreement provision

in which the farmor has the option of exchanging a

retained override for a partion of the working interest

back-in right see hack-in interest back-in unit a self-propelled workover rig that is mounted on wheels The cab and mast are mounted

on opposite encls so that it is backed up to the well

A hack-in unit is in contrast to a drive-in unit

backlash the turning of the rotary table on a drilling

rig after the power has been shut off Backlash is due to the torque on the drillstring

backlimb the shortest lim! on an asymmetrical fold

in sedimentary rocks The other limb is called the

forelimis:

back load to reload supplics from an offshore rig

or plavform to a supply boat back off 1) to unscrew a pipe coupling 2) to unscrew stuck pipe in a well This is done by locating the

{ree point A left-handed torque is then placed on

the assembly, and a string shot is used to break and

“remove the free section The stuck pipe then can be

pulled with a fishing operation using a washover tool

In a blind back-olf, the joints are all tightened with

right-handed torque under tension or overpull: Slow

left-handed torque applied by the pipe tongs with

the swivel disconnected is then applied with overpull

After one turn, the overpull is increased and the assembly should unscrew near the free point If the

stuck pipe cannot be fished, the well is plugged back and sidetracked 3) to raise the drill bit a short distance

off the bouom of the hole 4) to slack off on a line S3 to let drilling tine out of the drawworks back-off joint a scction of pipe that has conventional right-hand threads on one end and Jeft- hand threads

on the other

back-off shot see string sbot

back-off wheel a manual wrench in the shape of a

hype back-off wrench)

backpressure 1) pressure against the face of the reservoir rock (sand face) in the wellbore

Backpressure is the pressure in a wellbore against

which the fluid is dowing out of the reservoir and

into the well i is usually controlled [rom the surface with the use of chokes and valves and other techniques

;to reduce the pressure differential bewween the réservoir and the wellbore This reduces the raté.of

* How from the reservoir to the wellbore It also reduces

the gas flow and the gas/oil ratio and will result in higher uluimate oil recovery Backpressure is ofien

Me

at the surface and added to the weight of a column

of Nuid in the well 2) the pressure maintained on a

system through which a fluid flows 3) the resistance

of exhaust gas to flow through un engine's exhaust

pipe 4) the pressure at the outlet of a pressure relief

system that is due to pressure in the discharge system

BP or BP , backpressure equation An empirical relationship between rate and flowing pressure in a normal single-

the flow rate in standard volumes per day, C is ¿ coefficient, P, is the static reservoir pressure, P,y

the stabilized flowing bouombole pressure, and 7 is

the reciprocal of the mathematic slope which is equal

to 0.5 for turbulent Now and 1.0 for laminar flow

backpressure regulator a vaive that is operated by

a diaphragm to mainutin a constant upstream pressure

while allowing fluid uw

10,000

1000 Az?xio 3

—— SIABILIZED

ĐELIVERY

100

9 10 100 FLOW RATE MMSCFD

where Ap = P2 — P, Zand QO = the flow rate in

MMSCE/d P, = static bouomhote pressure in pounds per square inch absolute (psia) and Puy = lowing bottamhole pressure in psia A plot yields 2 straight tine which is the weill’s stabilized deliverability The test can be used to calculate a) the maximum flow rate, b) the effects of diflerent size procluction strings

on the flow rate, c} the effect of surface backpressure

~on flow and d) the flow rate at different static pressure

sured in pounds per square inch absolute (psia)

pressure valves are diaphragm, spring and weighted

lever The most common type uses spring tension and pressure against a plunger to maintain the pressure 2) a check valve thất is used in the drillstring

to allow drilting fluids to be pumped down the well but to prevent fluids from Nowing up the inside of the drillswing (drilistring flodt or drilistring float value)

backside pumping a method in which a prime

mover pumps Ovo wells atthe same time with the

upsuoke of one well being balanced by the downsuoke of the other weil

backsurge tool a downhole tool that is used to clean perforations ‘The backsurge ol consists of a reating packer and an aunospheric aif chamber with evo valves

above and below the chamber It is lowered into the well with aumospheric pressure in the chamber The lower shock valve is opened to create the backsurge

in the well

back surging a process used in wells to clear out material Clogging perforations in the casing A

backsurging tool is used to create a sudden reduction

in pressure in the well to aumospheric pressure This causes a sudden flow of fluids through the perforations

into the well w clean out the perforations

backswamp 1 swampy or nxirshy area on the

Noodplains on a river located adjacent to the river levees The backswamp is covered with slow-moving

or stagnant water during floods and is the site of fine-grained organic deposition Occasional crevasse splays can deposit course sediments in this

environment (overbank)

backtank see mud box

back twist a turn by a wrench on the drilling line

of a cable-tool rig in a direction opposite the line lay or winding, It unwinds the line that tends to bwist

in che direction of the lay

back up or backup 1) tw hold a section of pipe as

another section of pipe is either screwed on or off

it 2) to hold a bolt as a nut is screwed on or off it

backup corner the location on a drilt Noor that is given to a new hand (bolt-weevil conier)

backup curve 4 curve in a track on a well tog chat

measures the same piirameter t5 unother curve in

the same track called the primary curve The backup

curve has smaller scale and does not print until the primary curve poes off scale

backup line the wireline that suspends the tongs

on a drilling cig

backup man a roughneck on a drilling rig who us

backup tongs t hold the pipe as another length of pipe is being screwed into or out of it

backup post the Samson post on the floor of a

drilling cig to which the snub ling of the backup tongs

is auached backup or back-up tongs a large wrench-like device used on the floor of a drilling rig to hold whe drilipipe as it is being made up or broken out of the drillstring ‘The backup tongs are hele stationary

a rope or chain around a cat head

backup wrench a wrench or gripping device that

holds a pipe or bolt from turning as something is

screwed into Or oul Of it

30 backwash ® bailout bittlee

backwash to reverse the flow of a fluid through a filter to clean the filter

bacteria unicellular microscopic organisms that have

no chlorophyll and multiply by simple division Bacteria can be classified into aerobic bacteria which

use oxygen from the air or water and anaerobic

bacteria which breakdown chemical compounds to obtain oxygen They occur in three forms: spheri

(cocci), rod-shaped (haccilli), and spiral (spirilla)

Bacteria have existed from the Precambrian era to

the present bacterial degradation removal of lighter, shorter molecules from crade oil by bacterial action leaving

remove the isoparaflins from crude oil first, depressing

the pour point of the oil Most heavy oil is bacterially

depraded oil

bactericide a chemical or agent that will kill beth pathogenic and nonpathogenic bacteria but may not kill bacterial spores Bactericides uscd in drifting nicl

are lime, starch, sodium hydroxide, and

paraformaldehyde (hiocide)

bacteriostat a chemical or agent that prevents bactcrial growth

BACW harrels of acict water,

had-faith trespasser an operator who drills and produces petroleum from land on which he does not have legal tile

bad oil 1) oil that has too high a basic sediment and water (BS&W’) content to be accepted by a pipeline 2) an emulsion or mixture of oil and water (crt aif) BAF barrels per acre-foot

baffle plates that are used in a separator to redirect

the fluid Row direction, decrease the uid velocity,

and aid in separating the gas oil, and water baffle collar a small length of steel pipe with a constricted orifice on the inside A baffle collar is

used to connect two joints of casing during a cement job The wiper plug seats on the baffle collar when

it is pumped down the pipe The battle collar orifice does not have a valve, in contrast to float, differential,

or atomic fil-up collars

baffle plate a board across a fluid stream Usat is uscd

to slow the velocity, change the flow direction, and

to promote the mixing Or separation of fluids

bafflestone a limestone rock composed of suilk-

shaped organisms such as bryozoans or coralline als

that acted as baffles for water flow when the rock

was deposited

bag preventer a closing device at the top of the above the ram preventers ona blowout preventer slack that will close the well with either akelly, pipe, wireline in the well, or with an open wellbore The hag preventer uses a reinforced ¢ shaped clastomer

or hard-rubber packing clement that is squeezed with

a pision activated by hvdraulic pressure from accumuktors to clasethe well The closing pressure

on the rubber seal cin be eased to allow drillpipe

to be removed in a process called stripping The bag preventer has a lower pressure rating than the pipe rams and a higher risk of failure under high pres:

faunidar, sleeve or spherical blowout preventer) BAIL hailing

bail 1) to lower the fluid level in a well 2) to use a

hailer or sand pump to remove fluids and well cuttings

from the botom of a well 3) a hanger-like device

that is made of an inverted U-shaped, solid cylindrical

distance between the traveling block and.the elevators that are used to grip and lift or lower tubular goods

in the well (fimks) 4) the eye on a downhole tool through which the wireline loops

bail down to lower the level of a liquid in a well

by using a bailer bailer 1) a tool that is run on a hailing or sand line

that is used to remove fluids and sediments from a

well the bailer is a long tube with holes near the top and a sealed body The flapper-valve bailer has

a hinged metal plate on the bottom that.allows

sediments to pass up inte the hailer hut closes when Ihe bailer is raised A dart-bottam bailer has a check valve on the bottam, The Huids enter the bailer through the ports near the top or through the check valve A

dump bailer can deposit the fluids at a specific location

in the well and is used to dump cement on a bridge plug The sand pump has 4 check valve on the bottom with a piston just above it that is atlached to a rod

that runs up the bailer When the piston is pulled

up Irom the bottom of the well, it acts as a plunger,

sucking sand and Nuid into the bailer A hydrostatic

bailer is lowered to the bottom of a well with

atmespheric pressure ina chamber On the bottom,

a port is opened and Gil material is swept into the tool and trapped (hailing bucket) bir 2) see baler

bailer crown-block a pulley on the crown block that is used to raise and lower the bailer

bailer dart the protrusion on the bottom of a bailer that activates the valve when the bailer is lowered to the bottom of the well

bailing 1) the process of using a bailer that is lowered

on a bailing or sand Tine to remove well cuttings and fluids from the bowen of the well Bailing is done after drilling every few Tcet on a cable tool rig

BAI 2) see baling

bailing drum 1) the reel on a cable-tool rig around which the bailing linc is wound 2) see baling dram

bailing line the cable that is used to lower a hailer

to the bottom of a cable-tool-rig well during bailing

‘The line is wound around a bailing drum, goes up

lo sheave at the top of the derrick, and down into

the well where it is connected lo the bailer (sad

bailing tub a tank that is used to recover the

produced fluids brought up a well by a bailer hail out to clean out

bailout zone a4 potential producing formation in a well being drilled that is higher than the target to *

which the well is being drilled If the target is

unproductive, the well can be tompleted in the bailout

zone which does not have the potential pfoduction

of the target £ bailout bottle a container of emergency-breathing gas that is carried ly a diver in case the umbilical hese hreaks

bajada see debris apron

Bajocian a global age of geological tithe that

occurred from about 175-176 m y ago Kis pan of

the Middle Jurassic epoch

balanced a condition during production from a gis

well in which the cumukuive gas take af each party

is equal to the amount that each party is entided to under an operating agreement Bakanced is in contrast

balanced drilling drilling with the hydrostatic head

generated by the drilling mud in the well equal te

the formation pressure Balanced drilling is in conuast

to overbalanced and underbakenced drilling

balanced-column cementing « method used to

deliver a batch of cement into a well by lowering a drillstring filled with cement slurry into the well filled with drilling mud A valve is then opened on the drillstring anid the cement slurry, being heavier Uian

the drilling mud, flows out of the drillstring and into

the well

balanced cross section a cross section that reverses

the geological history The balanced cross section umes an Original, linite volume of flat sedinientary

rock beds before deformation The present bed

volumes are measured and the assumption is made that no volumes have been gained or fost from the cross section The beds are then diagrammatically restored to their original thickness and orientation

to test the structural history of the area A balanced

cross section is one that can be restored to represent

an undeformed condition, assuming no materials have been moved in or out of the urea represented by the cross section and the, cross section displays admissible structures `

balanced-plug method a method for plugging buck

a well with cement using only deillpipe A preflush followed by a cement slurry and spacer fluid is pumped down the drillstring When the height of the cement column inside the drilipipe and whe annulus reach the same level, the drillpipe is slowly pulled out of the well to leave a balanced plug The top of the plug can be adjusied to a certiin height by reverse circulation

in the production gets their proportionate share

Balancing can be done by transferring either cash

bald-headed anticline or structure an anticline

which is barren of production on the crest of the

anticline due to the removal of reservoir rocks by erosion Production comes [rom the flanks of the structure (scalped structure)

bald-headed derrick a derrick on a drilling cig without a pkuform or attic at the top

baler a long cylinder made of light steel iron thất

is up to 50 ft long and over 1 fin diameter with a

valve on the lower end Balers were used to raise oi! w the surface in some early oil wells Jointed balers were used in crooked wells (bailer)

baling an old method used tw caise oil to the surface

that was avuched to a derrick and driven by a bel

from a motor It was used 10 raise and lower a baler

on a rope mide of fine ste¢lwire into a well to bring

the oil to the surface (baiting drum) ball the dink that connects the hook and swivel on

a drilling rig The ball supports the weight of the” hook and driliswing below it while allowing them

be steel, but is often scawater on an ollshore rig Computers can be used to adjust the seawater ballast

ia tanks on an offshore rig to compensate for sea conditions and to sink or raise a semisubmersible

to acertain level above sea level The seawater ballast can also be used to sink thé rig into position on the

seafloor and to raise it back to the surface On a gravity

structure, it keeps the offshore pladvorm in position

ballasted condition the condition on an offshore drilling rig when ballast is in position

ballast tank a container for water ballast located in

the pontoon or caisson of a semisubmersible drilling

rig Water ballast is used for stability and to raise and lower the semisubmersibte in the water

(buoyancy chamber) ball bearing a hardcned-steel ball that is used to convert sliding friction inty rolling friction, Bull bearings often rotate in a ball race

ball cock a hollow, flowing ball that is connected

to and opens and closes a valve A bali cock is used

to control the Muid level ia a container

balled or balled-up bit a drilling bit wnat has

collected a mass of sticky well cutings on its face, causing the bit to lose drilling effectiveness, BU bit

32 balling the bit © barefoot completion

balling the bit the coating of the bit face with soi

scdimems Balling the bịt often occurs when using a

hard-formation bit with short teeth on a soft formation

Tt can also occur when drilling through soft, sticky

formations called gumbo during inadequate drilting-

uid circulation or when using excessive bit weight

The bit hecomes hard to rotate (it balling or hall

rap)

ballistic prover an instrument uscd to tes! and

calibrate liquid flowmeters, 4 ballistic prover is similar

toa mechanical displacement prover but uses asmatler

volume of liquid and compares flow rates rather than

fluid volume The flow from the main line is diverted

through the prover that contains a sphere or piston

displacer Line pressure forces the displacer through

the prover

ball joint a connection between ovo pieces of

equipment that can rotate due toa ball and socket

joint (flex josnt) ,

ballooning the ouwvard bulging of tubulars ina well

due to internal pressure Reverse ballooning occurs

when the tubular is bent inward rather than ouavard

in normal ballooning |

ball pump a type of gas lift system in which synthetic

rubber balls are injected into the lower enc of the

production tubing string to separate the liquid and

gas phases

ball race the track in which ball bearings turn

ball sealers hard, rubber-covered bails of nylon,

aluminum, or plastic that are used to close perforations

in a well The ball sealer is at least Y% in larger in

diameter than the perforation

ball up see balling the bit

ball valve a valve that opens with a quarter turn by

rotaling a ball with a bole in i that is located ina

spherical container The ball is usually made of chrame

steel but can be made of stainiess steel for a corrosive

nylon and can he stainless steel for high temperatures

and corrosive environments, A ball vatve is used to

regulate and shut off the flow of fluids in a pipe

fatobe vatve)

band a specific range of frequencies or wavelengths

An example of a band is visible light

band brake a mechanical device that is used to slow

or stop a wheel or axle with cither an external

contracting band or an internal, expanding band lined

with heat- and friction-resistant material Friction of

the band against a drum causes the breaking

band clutch a mechanical coupling device that

allows a rotating part to gradually connect and

disconnect with a driven part by using either an

internal contracting banc or an internal expanding

band lined with heat- and friction-resisiant material

band pass the range of frequencies that can pass

through an instrument or system with little ar no

mtcnuation

band-reject filter a filler that attenuates a specific

range of frequencies

band strapping the use of metal bands to attach

plastic or metal sheets to cylindrical structures

hand wheel a large, vertical, wooden wheel, 9-11

ft in diameter, on a cable-tool rig It is used to transmit

band wheel (off cable tool drilling rig chart}

power from the engine to the walking beam The band wheel is attached to the engine by a belt and

to the walking beam by the pitman which is attached

to the band-wheel crank

bandwidth the specific range of frequencies within

which an instrument is designed to operate bank 1) long ridge or mound of sediments formed

by currents or waves 2) a concentration of fluid such

as if (oil bank) that moves cohesively through a

reservoir BAR barrels of acid residuc bar 1) harite 2) barrel

by waves or currents and oriented roughly parallel

to the shoreline 2) a unit of pressure that is

10°N/m?, 10°dyne/cm? or about 1 atm-(14.5 psi) The System International (ST) unit of pressure is the pascal,

equal 10 107% bar 3) to move or turn something by using a bar for a lever

barchan barchan dune a type of sand dune deposited by the wind in a desert cnvironment A barchan has a crescent shape with the horns antl slip face both facing downwind

barefoot charter a type of contract between an

operator and an offshore drilling contractor The party agrees to maintain and operate the offshore: rig with

their own personnel without any help frori the drilling contractor a

barefoot completion a type of well completion in

which the well is drilled to the top of the producing

formation and casing ís cemented, Tie producing

formation is then drilled A barefoot completion is

used primarily wif hard producing formations such

as sandstones, limestone:

unconsolidated producing sands, there is a sand

control problem, and an openhole gravel pack is often used (opernbole conipletion)

bar finger sand

bar finger sand a long, narrow sand body deposited

, as a distributary mouth bar on a prograding, constructive delta A bar finger sand is generally

oriented perpendicular to the shoreline

barge a shallow-draft vessel with a flat deck that is

usually towed Barge types include drilling, workover,

derrick, lay, bury, ramp, tow, jackup, flotation, and

crane barges

barge captain the person in charge of a floating

* drilling unit, such as a semisubmersible and its crew

barge engineer the person in charge of the equipment on a floating drilling unit such as semisubmersible

a barge job a dritling or workover rig mounted on « barge

bargemaster the legal master of u floating drilling rig The bargemaster is in charge of the marine deparument on the rig and is responsible for the crew,

the stability and ballasting of the vessel, and

supervision of the loading und backloading On a British rig, the bargemaster can be the Offshore installation Manager

barite a mineral composed of BaSO, that occurs as white, grayish, greenish, and reddish ores and crystalline masses Barite is chemically inert, nonabrasive, and is used as a weighting material in cement slurries and drilling mud lt has a specilic

gravity of 44.6 (baryte or beavy spar) bar barite plug a slurry that is composed of barite, a

phosphate thinner, and water, A barite plug is used

to control an underground blowout in which a well

is kicking and losing circulation al the same time

barium sulfate a type of scale composed of BaSO,

(barite) that forms in tubular production equipment

and is hard to remove ft is also the mineral barite

barker a device on the exhaust pipe of an engine

that makes noise so thal the pumper can tell from a distance if the engine is running

barn a unit of area used for capture cross section

equal to 10774 cm?

Barnaby a downhole scintillometer that measures

nidioactivity and records it on the surface barnburner a super well

baroid barite and Aquagel that is used to condition drilling mud for coring operations

ind dolomites In relatively

barometric pressure the pressure exerted by the

weight of the column of air in the aumosphere Barometric pressure is 14.6959 psi, 1.01325 bar, 33.90

lt of fresh water, or 760 mm of mercury at sea level and deercases with altitude (a@nospberic pressure)

barred basin a basin with a sill a the entrance that

restricis water flow into the basin The sill can be formed bya reef or tectonic block Only shallow waters

can How over the silf The waters in a barred basin are offen restricted and stratified

barrel 1) a common measure of crude oil containing

42 U.S gal, 34.97 Imperial gal, 15,915.615 fl or 0.15899

m* A metric ton contains about 7.33 bbl, depending

on the °API of the oil A barrel of averape crude oil weighs 0.14 tonnes (metric tons), whereas a barrel

of average light oi] weighs 0.13 tonnes, and average

heavy oil weighs 0.15 tonnes! One barrel of oil contains

ubout 5.60 million BTUs of heat and weighs about

306 Ibs The BTU content of one barrel of oil is the

equivalent of about 6,040 fof natural gas Bb/, bbl,

bar, brt or B 2) the body of a wire rope drum 3) a

measure of cement slurry volume that is equal to 42

gal 4) the cylindrical part of u downhole sucker-rod pump in which the piston moves up and down

barrel compressor a centrifugal compressor in a

barrel-shaped housiig barrel equivalent a unit used in the laboratory to test drilling fluids One gram of material mixed with

350 mi of Iluid is equivalent to 1 lb of material mixed with I bhi of fluid

barrel royalty a payment equal 10 a specific percentage plus a revenue equivalent up lo a specific number of barrels of oil

barrel wrench a hand wrench that is used to screw

or unscrew pump vilve seus in the working barrel

of a downhole pump (sect wrench)

Barremian a global age of geological Gime Lat occurred about 125-115 m y ago It is purt of the Lower Cretaceous epoch,

barrier beach oc island a long, narrow, partially subaerial, shoreline sand body not dauached co the land on either end and separated from the maintand

by a lagoon barrier effect the use of an acid-in-oil emulsion to returd the reaction time of an acid used in acidizing

‘the oil forms a film on the rock surface vo limit acid contact The oif must be ut least 20% of the emulsion barrier reef a relatively large, long, narrow reef that

is oriented parallel to the shoreline The barrier reef

is separated from the shoreline by a wide and dee}

Bartonian a global age of geological time that occurred about 45—41 m y ago It is part of the Middle Eocene epoch

34 barytc ® basin

barytc see barite

Bas or bas basalt

basal conglomerate a coarse-grained soit zone

located on an unconformity Weathered rocks in the

basal conglomerate are derived primarily from erosian

of the underlying rock

basalt a common volcanic or lava rock, Basall is very

fine-grained (aphanitic), dense, and dark to medium-

gray in color Basalt contains ferromagnesium

minerals, plagioclase, and-feldspars but no quartz

and has a matrix density of 2.82 gm/ce Gas bubbtes

are often trapped in the basalt Bas, bas or BASLT-

basal tar mat a reservoir bitumen composed of heavy

oil and asphakic tar layer at the oifAvater interface

of a reservoir The basal ar mat is caused by water

washing and bacterial degradation of the ot! or by

tle-asphalting

base basement

base a chemical that reacts with an acid to form a

salt Bases occur from above 7 to 14 on the pli scale

Lxamptes of bases inchide lime and caustic soda

base abstract a complete title opinion that covers

from sovereignty to a specific Lime

base allowable the amount of petroleum production

permitted by a governmental regulatory agency

without a penalty factor

BASEC British Approval Service for Ulectric Cables

BASEFFA British Approval Service for Electrical

Equipment in Flammable Aunospheres

base eighth the % royaltt that goes to the fessor

(mineral rights owner) for leasing the land

base exchange the replacement of one type of cation

such as sodium on the surface of a chy mineral with

another cation such as calcium see om excharge

base Jine 1) asurveved line of accurately determined

length and position It extends out fram a control

point to anather point Angles benveen the ends of

the base line and ether points are then measured to

accurately locate the points 2) an accurately surveyed

east-vesl line used in United States and Canada land

divisions The base line isthe fine from which township

boundaries are initiated The principal meridian is

the north-south line

baseline an arbitrary line that marks the inner

boundary of a country’s continental shelf Bascline

is often the low-water mark

base load the lowest load level during a daily or

annual cycle

base load liquefaction plant an installation that

uses compression and supercold {— 260°F) to

continuously make liquilied natural gas, primarily for

overseas transport The plant makes extensive use of

heat exchangers and compressors

base map a nip thar shows the accurate location

of data points such as wells or seismic shot points

along with georraphic or survey relerences A base

map is often made of transparent material such as

film and is a map fromwhich other maps are prepared

hasement or basement rocks undifferentiated

rocks such as igneous and/or metamorphic rocks that

are unproductive and are located below the sediment

cover of earth's surface The basement can be the

surface below which there is no current explore ation

base, bsiit, BM, Bin, or BSMT

base metal a common, chemically active metal such

as ead or copper A base metal occurs at the lower end of the electrochemical series

base-mounted reciprocating compressor a

compressor that uses pistons to compress air and is

mounted on a base rather than a tink base of weathering the boundary during seismic exploration between the surface low-velocity layer or weathering and the underlying higher velocity layer base pressure the pressure al which gas volumes are catculated or a standard volume of gas exists Base

pressure is usually at or near atmospheric pressure (14.7 psi) and is defined by law or contract

base price the crude oil price used for the computation of windfall profits tax Base price is

adjusted for oil grade, quality, and location Tier 2 oil hack a national average of $15.20 per bbl Tier 3 oil had a national average of $16.55 per bbl The price for Tier 1 oil was based on the price at which upper tier of from properties that first- began production after 1972 would have been sold for in May 1979 Iv averaged $12.8) /bbl The adjusted base price was adjusted quarterly for inflation

base royalty the payments made by a lessor (mineral

rights owner) on production revenue from a lease

A base royalty is free of the cost of production

base sediment and water sce basic sediment and

MCE

base square the cdlistance between the neutral axis

of adjacent derrick legs on a drilling rig Base square

is measured along the derrick floor from inside the derrick legs ata distance of one-fourth the leg angle width

Bashkirian a global age of geological time that ted about 330 m y agn It is part of the Middle

basic sediment solid impurities contained in oil

produced from an oil well Basic sediments are usually

removed by settling to the bottom of the le aise tank before the oil is sold

basic sediment and water solid impurities and salt

water that are mixed with crude oil Most of the salt”

water is removed in a separator, and the sediments

are removed by setting to the bettom of the lease

tank after the crude oil is produced from a well The

piunper or gauger measures the remaining basic sediment and water content of the oil before it is

taken from the jease tanks It is measured by volume ona centrifuged sample of the oil The maximum acceptable amounts vary from less than 5% to a small fraction of 1%, but are usually less than 1% in most

areas (base sediment and tater or botton settlings

hasic size the nominal standard basic sludge basic sediment basin a general term for any large area of tectonic origin with a thick accumulation of sedimentary rocks

A basin is a geological-structure with-a unique

sequence of rocks that are dissimilar to those out

in Because of the thick sedimentary rocks ` which range up to $0,000 It thick, these areas tend

by seismic or sequence stratigraphy

basket 1) a junk basket or basket sub fishing tool

and is used to dift or lower personnel and supplies between a supply boat and an offshore platform 3) a cementing basket 4) the shale shaker receptical that holds the deck with screcas mounted on it

currents in the circulating drilling mud cause the fragments to fall into the bowl: Basket subs are alw:

run with mills and whenever metal or cement is

drilled As many as three basket subs can be run on

a string A basket sub is in contrast to a junk baskel that uses reverse circulation und catches the fish on the inside Of the Wook (bout basket or sub or jtrtk:

sub)

BASLT basalt bastard a piece of equipment drat is not standard

A bastard has un irregular shape or s

BAT before acid weaunent bat bauery

batch 1) a specific quantity of material Unat is mace

or used in one operation during a process 2) measure

of the amount of crude oil in a pipeline

batch cementing « cement job on a well in which the cemént is injected in several barches or quantities rather than continuously

batch mixer a mechanical blender that is used to mix cement A quantity of dry cement and water is mixed in a tank with blades and the rotation of the tank ‘Two types include pneumatic and ribbon blenders The batch mixer is in contrast to a jet mixer

batch process a chemical procedure in which the subsiance 10 be treated is put through the process

in specific quantities aller which the reactant is

discarded or regenerated Iron sponge sweelcning,

of natural gas is a batch process A batch process is

in conte lo @ continuous proc

batch treatment the injection of chemical corrasion

inhibitors at regular intervals into a production system

bathayal the ocean environment located beeen

100-500 fh winer depth

batholith a large, irregular, subsuclece intrusion of igneous rocks such as granite or granodiorite

Bathonian a global age of geological time that

occurred about 170-165 m y ago It is part of the

Middle Jurassic epoch

bathymetric map a map that shows the depths of the seafloor, usually with contours

batter the outward slope on the legs of an offshore

plaform jacket The slope gives the base of the jacket

a greater area than the deck and makes the platform more stable

battery 1).any installation of identical pieces of equipment such as a tink or separator battery 2} a device composed of cells unat is used to produce and store elecurical energy by chemical action bat or bry baud a measure of the ability of a channel 10 ansmit information A baud is equal to 1 bivsec

Baumé gravity or scale « European scale of fluid density in which Baume gravity is equal to C140" = the specilic gravity or density of a fluid at 60°F)

— 130 ft was read off a Baumé hydrometer, a gluss column with graduations from 10 to 1,000, in crude oil al GO°F, or was corrected lo Uhat temperature Phe

scale was named after Antione Baumé, a French

chemist Baume gravity is also used to describe the density of acid solutions Baumé gravity has now been

superceded by “APL Bé

BAW barrels of acid water bay the space berween girts on the legs of a derrick The bays ona drilling rig derrick have a vertical height

of 7 tt (perrtel) BAYW bay winter

BB bridged back Bb! or bb barre!

Bbls/acre-foot barrels per acre-foot

bbi/d barrels per day bbIAMMscf barrels per million suindard cubic

Be bearden unit of consistency

rels of condensite 2) botom choke

BCD barrels per calendar day

BCE, Bef, or bef billion cubic feet

BCED, BCF/D, or Bef/d billion cubic feet per day BCK bottom choke

bem 1) become 2) becoming BCMCF harrels of conder feet

BCPMM buarrels of condensate per million cubic feet

36 BCS ® beam pumping unit

BCS borehole compensated sonic

BD 1) barrels of distilliue 2) heeded 3) building

derrick `

Bd or bd 1) bed 2) bedding

B.D baercls daily

BM or b/d barrels per day

BDA breakdown acid

BDC bottom dead center

BDE below derrick Moor

Rdg bedding Ị ‘

BDIAM hit diameter ,

BDO barrels of diesel oil

BDP breakdown pressure

BDPD barrels of distillate per day

BDPH barrels of distiflate per hour

BDPPP barrels per day per pound of pressure drop

Bidry bailed dry

Bdst boundstong

BNT blowdown test

Bé Baumé

beach price the price of ofishore crude ait on land

after it has been ircated offshore

bead the molten metal formed by welding

beaker sampler a metal or glass bottle that is

lowered into a tank to take an oil sample

beam 1) the maximum width of a ship s hull or

offshore drilling rig (breadih} 2) A walking beam on

a sucker-rod pumper or cable-+tool rig 3) a focused

pulse of energy

beam-balanced pumping unit

beam-balanced pumper, pumpjack, or pumping

unit a pumping unit that uses the walking beam to

bakince the weight of the sucker-rod string Heavy

iron plates (counterweights or beam counterbalance)

are located on the opposite side of the walking beam

from the sucker rods The location of the weights

on the beam is adjustable The beam balanced pumper

is used primarily on shallow wells and is in contrast

toa crank: or air-balanced pumper

beam counterbalance the weights on a walking

beam ona beam pumping unit Their positions are

adiustable on the opposite side of the walking beam

from the sucker rods The counterbalance is used to

offset the weight of the sucker-rod string,

fcounterwweights) :

beam head the end of the walking beam on a

pumping well where the sucker rods are attached heam pumper beam pumping unit

beam pumping unit artificial lift equipment that

uses a walking beam to raise ancl tower a sucker-

rod string in the well to activate a reciprocating piston-

the beam pumping unit the are a) structural members,

b) bearings, c) counterbalance, d) gear or speed *

reducer, and e) prime mover The walking beam pivots

up and down on a center bearing supported by the

Samson post to provide a reciprocating action with

beam well ® bellows-type gas or orifice meter 37

a stroke from 12 to over 240 in for the downhole pump The walking beam is connected to the gear reducer and prifie ‘mover with the two pitmen and

an equalizer The prime mover is either an electric

or internal combustion motor ‘he sucker-rod suring

and polished rod are auached to the horschead end

of the walking beam with a bridal and carrier bur

Three common types of beam pumping units include crank counterbalanced, beam balanced, and ais

balance A Class [ lever pumping system has the speed reducer rear mounted and the fulcrum at midbeam

A Class Hi lever pumping system has the speed reducer

front mounted and the fulcrum at the rear of the beam The air balance and Lufkin Mark Hare this type A beam-balanced pumping unit uses adjustable

weights on the walking bean to balance the load and

is used for shallow wells The pumping unit weights

between 2,000-6,000 Ibs Beam pumping units are

classified by the Americun Petroleum Institute by pear

reducer torque capacity, unit structural capacity, and

maximum stroke length (walking or rocking beam

-bean a constriction in a line (usually 4-1 in

diameter) used to resirict and conurol the rate of How during a test or during production Beans can be fixed

or adjustable Adjustuble beans use a needle, sleeve,

or cone-shaped stem with a seat to change the size

of the orifice A positive or fixed bean has a specific diameter Some types of beans include bouomhole, surface, and storm chokes Production of oil or

is often reported in barrels or cubic feet on a certain

sized bean (choke, flow-plig, or flow nipple) BN

bean a well back, down to or up to regulate the

flow from a well with a choke

bear cat a well with a high flow rate bear gun a tool used to fracture a reservoir in a well The bear gun lires a 1% in diameter projectile downward through the tool barrel where it is de(lecied horizontally to fracture thé formation

bearing 1) the horizontal direction of a point

measured clockwise from another point If it is

measured from wue or magnetic north, it is called

the azimuth 2) a surface of point that is used for

support 3) a part on which another part travels or

turns, such as a ball bearing or roller Types of bearings

include outboard, saddle, and sticrup ‘The bearings that wavel about the journal on the leg of the roller-

cone bit, allowing the cone to rotate, are either

antifriction or friction hearings They are also classified

as sealed and nonsealed

bearing cap the fitting around a bearing that holds

it in place

bearing raceway the surface of the bearing ring Ut

is in contact with the balls or rollers bearing ring the-routing or stationary ring that

contains the balls or collers that wavel or wirn on

the bearing surface in the ring

becquerel a derived unit in Systenis International

(SỐ for activity of radionuclides By

- BED bedding bed layer of rocks A bed has relatively well-delineet

“top and boom boundaries and is enher rekuively

uniform in Huhology, uniformly graded, or is composed of similar, smaller units A bed is a

stratigraphic subdivision of a member of a formation

(stvationt or layer) 2) The mounting skid or frame und supports on a shale shaker

bedding oc bedding plane the surface that

separuies wo sedimentary rock fayers A bedding

plane is caused by an interruption during

sedimeéntation or ¢rosion after sedimentation Bedding

planes occur on the top add bottom of beds, BED

bed form a deviation from a flat surface caused by adluid How over loose sediments Bed forms include ripples and dunes ` ; TS

bed load the coarser sediments that are transported

by rolling or bouncing along a sedimenuwwater

interface such as a stream bed by a current of water (icon load)

bedrock the relatively soticl rock that underlies soil

or unconsolidaicd sediments bedsheet cross section a very kirge cross section

or vertical slice of the subsurface behind the pipe crude oil or natural gas that is located in a reservoir(s) unat has been cased in a well ‘The well produces or has produced from another

reservoir

belching intermiuent Now on a well (brarping)

B electrode the current-return electrode in a resistivity sonde

belemnoids atype of extinct cephalopod that existed

from the Mississippian to Eocene epoch Belemniods had an internal skeleton that resembled a cigar and

we puide fossils, Befur belling tool a type of undecreamer that is used to

enlarge the wellbore at the level of the producing

zone A belling toot bas expandable cuuing arms that are used to cut a bell-shaped cavity just below the production string of tubing or casing on the bouem

of the well

bell nipple a device with an expanded or belted lop Uhat is used to At the above-ground casinghead

finings to the casing ‘The bell nipple is threaded an

used above the blowout preventer or marine riser

on a well to guide drill tools down into the well It has a mud ceturn line to direct circukuion drilling mud coming up the well to the shale shakers and a

seal

bellows-type gas or orifice meter a common type

of gas production meter that uses pvo bellows to measure the pressure dillerentiul across an orifice The brass bellows expand and contract with the pressure and drive « differential pen A static pen is driven by a Bourdon tube, and the chart is driven

by «clock.