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WATER SHUTOFF & ZONE TRANSFER IN CAMBAY #15 WELL

ADJEI STEPHEN

MTECH PETROLEUM ENG

INDIAN SCHOOL OF MINES

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CAMBAY #15 WELL Well was drilled by Cardwell- IX rig. After cumulative oil production

of 11853.03 MT on self, water shut off by cement squeeze was carried out in April 2006. After cumulative production of 40000MT again water shut off by polymer gel followed by cement squeeze was carried out and well was put on SRP mode in January 2012. After cumulative production of 42220 MT, well is not operating due to 100% water cut.

Drilled Depth; 1502m F/collar 1448 m well type vertical Casing; Conductor- 9 5/’’, 600m, N-80 & J-55, 40 ppf. Cement rise

up to surface Production- 5 ½ ‘’ shoe at 1470m N-80, 17ppf cement rise

up to 960m F/collar - 1448m Wellbore clear; 1425m Interval open; 1400 – 1404.5m Tubing shoe; 1000.6m Last recorded reservoir pressure; 58.9 KSC at 1185m Last killed fluid; brine of sp. Gr 1.02

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High Press Gas

Gas

Oil

Water

Oil

5 ½ ‘’Production Casing

9 5/8’’Conductor Casing

1400 – 1404.5m

tubing

Tubing shoe at 1000.6m

c/rise to 960m

950m

WELLBORE CLEAR AT 1425M

c/rise to surface

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PROBLEM STATEMENT & SOLUTION THERE IS 100% WATER

CUT FROM THE CAMBAY #15 WELL

TO CURB THIS, A SQUEEZE CEMENT JOB WILL BE CARRIED OUT IN THE OPEN INTERVAL AND & ZONE TRANSFERRED TO UPPER SANDS

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CAUSES OF EXCESS WATER PRODUCTION

CONING OR CUSPING

CHANNELING VISCOUR FINGERING WATER

ENCROACHMENT

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WHY THE NEED TO CONTROL WATER PRODUCTION

Corrosion of production facilities

Huge costs incurred in treating produced water for disposal

Reduction in production rate

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NEED FOR WORKOVER

workover refers to any remedial operation done on a well to restore, maintain or enhance the recovery from the well

Completing for Production from a New Reservoir

Equipment failure (pump failure)

Wellbore problems ( sanding, formation damage, paraffin accumulation, water and gas coning)

Mechanical problems (casing leaks, tubing leaks, cement failure)

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SQUEEZE CEMENTING

This refers to the process of injecting cement slurry into a zone for purposes such as To abandon a zone To shutoff water or gas coning To repair casing leaks Seal off lost circulation zones

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PROCEEDIA FOR SQUEEZE JOB ON CAMBAY #15

1. Well volume was displaced with water and subdued/KILLED with brine of specific gravity 1.02

2. Christmas tree was then nippled down and BOP nippled up

3. Tubing was lowered from initial depth of 1000.6m to wellbore clear (1425m) to confirm the wellbore clear and reverse circulation of brine was carried out

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4. Tubing shoe (Tubing) was then adjusted up by 2m to 1423m 5. Injectivity test was conducted (liter per minute)injectivity test is conducted against the squeeze interval to determine if and at what rate below the fracture gradient, fluid can be placed against the formation.

Other reasons;• To ensure that the perforations are open and ready to

accept fluids.• To obtain an estimate of proper cement slurry injection

rate• To estimate the pressure at which the squeeze job will

be performed• To estimate amount of slurry to be used

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PUMPING SLURRY

5. Cement slurry was then squeezed into the existing interval and cement top kept at 1380m6. Tubing was pulled out AND waiting on cement was done for 24hours

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7. TCR bit was then run on 2 3/8’’ drill pipe to tag cement top ,plug was then tested at 100 KSC, then drilled to 1390m and TCR bit pulled out

8. A scrapper was lowered to scrape the casing up to 1390m and well circulated with brine.Casing collar log was recorded for depth control

9. Cement plug was again drilled to 1395m and scrapping done again. TCR bit pulled out

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HERMETICAL TESTING & RE-PERFORATION 11. Well was

hermetically tested to check for leaks, brine weight increased from 1.02 sp GR to 1.03 sp GR

12. New interval was perforated at 1392-1391m, 1390-1388m,1386-1385m & 1381-1379m at 18 SPM (shots per meter)

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13. Tubing was returned with BB shoe up to 1364m. Injectivity test was carried out. Test was less than 250 LPM at 700 psi so a well stimulation job with mud acid was carried out. 14.BOP was nippled down and X-mas tree nippled up. Kill fluid was displaced with water Finally well was activated by air compressor

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Thank You!