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Case Study: Stimulation Pumping Pressure Reduced by 3,500 psi on OGDCL Sour Well in Fractured Limestone

Clean perforation tunnels provided by PURE perforating system using dynamic underbalance and PowerJet Omega deep penetrating shaped charges

Challenge: Provide deep, clean perforation tunnels to optimize stimulation operations in a northern Pakistan exploration well.

Solution: Increase penetration and minimize perforation damage with PowerJet Omega deep penetrating shaped charges and PURE perforating system for clean perforations.

Result: Reduced surface pumping pressure required for acid stimulation to 3,500 psi from an estimated 7,000 psi, lowering costs and improving safety.

Optimum stimulation operation requires effective perforations

Oil & Gas Development Company Limited (OGDCL) planned to stimulate Dakhni #10A, an exploration well drilled through the fractured limestone Chorgali/Sakesar formations in northern Pakistan. A gross interval of 198.5 m was to be perforated through 5-in liner and oil-base mud. Good penetration and clean perforation tunnels were required to optimize the stimulation operation. H2S concentration was 42,000 parts per million.

PowerJet Omega charges and PURE system provide deep, clean penetration

HSD high-shot-density guns, PowerJet Omega deep penetrating perforating shaped charges, and the PURE perforating system was used across the high-fracture–density intervals. The PURE system optimizes the well dynamic underbalance—the transient underbalance just after creation of the perforation cavity—that governs perforation cleanup. The system, therefore, does not rely on a large static pressure differential between the formation and the wellbore to remove perforation debris, creating clean and stable perforation tunnels with minimum perforation damage. PowerJet Omega charges penetrate deep into the formation, increasing the number of fractures they are likely to intersect.

Surface pumping pressure requirement decreases by 50%

During the subsequent stimulation, the required acid pumping rate of 4 bbl/min was achieved with a surface pumping pressure of just 3,500 psi, instead of the expected 7,000 psi, confirming the effectiveness of the perforations. Such a dramatic drop in the required pressure resulted in significant savings in energy costs and greater operational safety.


Download: Stimulation Pumping Pressure Reduced by 3,500 psi on OGD CL Sour Well in Fractured Limestone (0.15 MB PDF)

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PURE perforating system cleans the perforations, removing the permeability-impairing crushed zone.
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