Day 4 4 fractures mapping

Two post fracture temperature logs minimum!. First 1-3 hours aΗer treatment!. Post Fracture Gamma-ray logs.. Temperature and Radioac4ve logs!. Tilt meters: Earth surface displacement due

Fracture Mapping

!  Temperature Log

!  Radioac4ve tracers (in fluid or in proppant)

!  Surface Tiltmeter survey

!  Microseismic monitoring

!  Hydraulic Impedance Tes4ng (HIT)

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Source Cipolla and Wright 2000

Run 1

Run 2

Pre-frac profile

Perfs

!  Pre-Frac temperature log essen4al

!  Two post fracture temperature logs minimum

!  First 1-3 hours aΗer treatment

!  Second 4-6 hours aΗer treatment

!  Best results by logging down, undisturbed

!  Ver4cal wells only

!  Post Fracture Gamma-ray logs

!  Different isotopes in different proppant stages

!  Measure count rate vs depth

!  Permits not easy

!  Temperature and Radioac4ve logs

!  Shallow inves4ga4on

!  Deviated wellbore errors

!  Last proppant in may end up at the 4p

!  Placed in shallow boreholes in circle around wellbore

!  Sensi4vity: 3 10-8 inch over 1000 Η

!  Geometry, Orienta4on and dip detectable up to 1200 m deep

!  Time dependent frac length growth up to 600 m

!  Between 1200 and 3400m only fracture orienta4on

50-150 accuracy

!  Solar/Lunar tides will affect read-outs, so will kangaroos

!  Extrac4ng signals from back ground noise is key

Tilt meters:

Earth surface displacement due to fracture genera4on

Frac Mapping - Microseismic Imaging

Detec4ng and triangula4on of micro-’earthquakes’ triggered by

growing fracture

!  Passive borehole seismic uses the acous4c signals emi⊥ed during and aΗer hydraulic fracturing

!  Active borehole seismic, the fracture is irradiated by an

artificial seismic source

Frac Mapping - Microseismic Imaging

Fracture Growth Direction Frac fluid injection

σmin

Micro-Seismic Activities

Acoustics Sensors

!  Star shaped Array of geophones offset 20 km

!  Covers about 18 km2

!  1154 channels with 12 Geophones

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Top view Side view (north)

Microseismic monitoring Results

Grid Size 100 x 100 m

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Source: Weatherford

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