9 directional drilling

Petroleum Engineering 405 Drilling Engineering 1 Well Drilling Engineering Directional Drilling Dr DO QUANG KHANH 2 Directional Drilling  When is it used?  Type I Wells  Type II Wells  Type III We[.]

1

Well Drilling Engineering

Directional Drilling

Dr DO QUANG KHANH

 Type III Wells

 Directional Well Planning & Design

 Survey Calculation Methods

Build and Hold

Build-Hold Build

3 Read ADE Ch.8 (Reference)

5

Max Horiz Depart

?

7

10

11

EOC

18 r

π

=

14

Fig 8.11

4 2

1 3

1 x and r r x

r < + <

16

4 2

1 3

1 x and r r x

r < + >

17

N18E

N55W S20W

S23E

Azimuth Angle

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Example 1: Design of Directional Well

Design a directional well with the following

restrictions:

• Total horizontal departure = 4,500 ft

• True vertical depth (TVD) = 12,500 ft

• Depth to kickoff point (KOP) = 2,500 ft

• Rate of build of hole angle = 1.5 deg/100 ft

• Type I well (build and hold)

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Example 1: Design of Directional Well

(i) What is the maximum hole angle

required

(ii) What is the total measured depth (MD)?

(MD = well depth measured

along the wellbore,

not the vertical depth )

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(i) Maximum

Inclination Angle

ft 820 ,

3 5

1

000 ,

10

500 ,

2 500

, 12

, 4

x4 =

=

500 ,

4 )

820 ,

3 ( 2

500 ,

4 ) 820 ,

3 ( 2 000

, 10 500

, 4 000

,

10 tan

2

2 2

1 -



3

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max = θ

+

−

− +

1

4 2

1

2 1 4

2 4 1

4 1

max

x )

r r

( 2

x ) r r

( 2 )

D D

( x

D

D tan

2

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(ii) Measured Depth of Well

ft 395

) 26.3 cos

3,820(1

-) cos 1

( r

395 500

, 4

, 9 L

105 ,

4 sin

∴

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(ii) Measured Depth of Well

Hold rad

, 13

265 ,

9 180

26.3 3,820

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* The actual well path hardly ever coincides with

the planned trajectory

* Important: Hit target within specified radius

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