Schlumberger

Performance Report: Combination of CLEANPERF WB System Proves Effective in South America

Challenge: An operator in South America wanted to improve their perforation procedure. Loss of completion fluid to the formation during perforation and completion operations resulted in less than optimal production performance.

Solution: A fit-for-purpose CLEANPERF WB system was designed to provide an effective seal at the face of the formation along the perforation tunnel. To ensure efficient bridging of the CLEANPERF WB system, an optimized particle size distribution for formation pores, along with filter-cake building polymers, was used. In addition, it was designed to inhibit any formation clays that could swell or disperse in the presence of the invaded filtrate. In this case 1.5% by weight potassium chloride was sufficient as very little clay had been observed in formation analyses. This also adjusted the density of CLEANPERF WB fluid to 8.7 lb/gal (1.04 SG). Completion fluid was a KC1 brine of 8.4 lb/gal (1.01 SG) which provided 320 psi of overbalance. A dispersing agent is also incorporated into the CLEANPERF WB fluid to ensure the fluid flowed back readily during production.

Result: The CLEANPERF WB pill was spotted across the interval prior to perforating. After perforating with the PURE technique, there were no fluid losses to the formation. Production started immediately. Cleanup time was limited to a few minutes as there was no water lost to the formation during completion operations. Offset wells routinely required several days to remove lost fluid and emulsion generated by lost fluid and formation fluids.

Well Information
Location Ecuador
Interval completed 14 ft (4 m) perforated 5 shots /ft
Completion type 7-in. casing

Operationally, the CLEANPERF WB fluid was spotted across the interval to be perforated by displacing the clear completion brine with a viscous spacer preceding the CLEANPERF WB fluid. The interval was than perforated using a PURE system designed to provide 400 psi dynamic underbalance. This underbalance was followed by 320-psi overbalance. During and immediately after the perforating operation zero losses of CLEANPERF WB and completion fluid were seen to the formation. The well remained static for the next hours while extracting the perforating guns and finishing the completion operations. After inserting the upper completion electric submersible pump, the well was brought on production.


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“The CLEANPERF WB systems were used to effectively bridge and seal the perforated interval along the face of the perforation tunnel.”
José Guzmán
WP Regional Technical Service Manager
SAN