Specialized Offshore Acid Stimulation Using Advanced Technology

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Specialized Offshore Acid Stimulation Using
Advanced Technology

• Presented by
• Leonard Kalfayan Steve Metcalf
• BJ Services Company

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What is BJ Sandstone AcidTM?

• Retarded HF Acid system unique to BJ.
• BJ SSA systems can be HCl-HF organic-HF
• Retarder component organophosphonic acid complex

Proprietary chemistry U.S. Patent No. 5,529,125
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BJ Sandstone AcidTM Features

• Moderates formation dissolution
• Provides delayed in situ release of HF acid
• Increases dissolution of silica and non-clay
  silicates
• Low corrosivity low total acid strength systems
• Highly water-wetting

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BJ Sandstone AcidTM Features

• Reduces reprecipitation reactions
• calcite scale, aluminum salts, silica
• System flexibility
• wide HF concentration range (lt1 to gt6)
• variety (HCl, acetic, formic, citric acid systems)

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Effect of Various HF Systems on Compressive
Strength (CS measurement of 3 sections of
acidized cores)
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BJ Sandstone AcidTM
Offshore Acidizing Producer Well Case Example
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Gulf of Mexico Gravel Pack Completion

• Type Oil
• Temperature 204 ?F (96 ?C)
• Permeability 170 mD
• Mineralogy --
• Damage Paraffin deposition, fines migration
  plugging
• Objective damage removal sustained rate

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Gulf of Mexico Procedure
Through CT - Reciprocating Stage 1
Stage 2 1. Pickle coil tubing 15 HCl
2. Paraffin removal Paravan D 750 gal
-- 3. Pre-acid foam stage N2 foam (8
NH4Cl) 500 gal -- 4. HCl preflush 10
HCl 450 gal 1050 gal 5a. Main acid
(HF) 9 HCl-1 HF 675 gal 1575 gal 5b.
Main acid (HF) BJ SSA (1.5 HF) 900 gal
2100 gal 6. Overflush 7.5 HCl 900 gal
2100 gal 7. Diverter stage N2 foam (8
NH4Cl) 420 gal -- 8. Repeat steps 4-6
9. Flush 8 NH4Cl 500 gal 10.
Displacement N2
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Gulf of Mexico Treatment Results

• Rate before 39 bopd
• Rate After 130 bopd
• Objective accomplished
• Rate sustained long-term

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BJ Sandstone AcidTM
Offshore Acidizing Injection Well Case Example
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Offshore Nigeria Dual Completion Injection Well

• Type Brine Injector
• Completion Vertical (6054 to 6114)
• (6273 to 6318)
• Temperature 150 ?F (66 ?C)
• Permeability Short string lt 0.5 D
• Long string gt 1 D
• Mineralogy High quartz (gt90)
• Damage Silica fines plugging

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Offshore Nigeria Procedure in Dual Completion
Injector

• Through CT - Reciprocating
• 1. Pre-treatment Xylene/mutual
  solvent 20 gpf
• 2. Displacement 8 NH4Cl 20 gpf
• 3. HCl preflush stage 10 HCl 25 gpf
• 4. Sandstone AcidTM stage 1.5 HF (SS)
  3 HF (LS) 4050 gpf
• 5. Overflush 10 HCl 25 gpf
• 6. Diverter Foam
• 7. Repeat steps 3, 4, 5 two (LS) or three
  (SS) times
• 8. Displacement 8
  NH4Cl 75 gpf

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Offshore NigeriaTreatment Results

• Injection Rate (BWPD)
• Before After
• Short String 1000 6000
• Long String 1500 9000
• Stimulation For Water Management

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Specialized Offshore Acid Stimulation Using
Advanced Technology

• Questions???