Published: 10/31/2016
Published: 10/31/2016
A multilayer limestone reservoir located in the Sabriyah field of Kuwait is highly heterogeneous with natural fractures and multiple perforation intervals. To attain economical productivity for a vertical well in this reservoir, Kuwait Oil Company required an acid fracturing treatment designed to achieve good fracture conductivity, an extended fracture length, and effective diversion of some of the acid stimulation from the upper section of the formation to the lower section.
Schlumberger recommended using OpenPath Sequence service to divert the acid stimulation to the target zones. The service accomplishes diversion through the use of a composite pill made of a proprietary blend of degradable fibers and multimodal particles that provides consistent, effective isolation plugs. Covering multiple reservoir layers in the same stage, the treatment also provides high leakoff control.
The treatment alternated between three acid stimulation stages and two diversion stages of OpenPath Sequence system composite pills to cover all perforation intervals and accomplish diversion from the upper reservoir to the lower reservoir.
Diversion within the perforated intervals after placement of the OpenPath Sequence system composite pills was indicated by diversion pressures of 500 to 1,600 psi [3.45 to 11.03 MPa] and instantaneous shut-in pressure changes. Effective diversion was also confirmed by injection log data based on stationary spinner and temperature measurements.
Injection logging performed after the prejob injection and after each diversion stage indicated coverage of all perforation intervals. The injection flow profile for the upper reservoir intervals improved 70% after the first diversion stage and more than 150% after the second diversion stage. Injection logging also confirmed fracture initiation and propagation in the lower reservoir after the second OpenPath Sequence service diversion stage.
Production in terms of barrels per day improved by 243% after the treatment was complete. In addition, the productivity index increased more than 300%.
"OpenPath Sequence service reduced both the cost and time needed to effectively fracture a very challenging well and opened the door for treating similar wells in the near future."
- Mohammad Al-Othman, Engineering Unit Head, Kuwait Oil Company
Challenge: Stimulate multiple perforation intervals in the upper and lower sections of a carbonate formation without mechanical isolation during a continuous stimulation treatment.
Solution: Use OpenPath Sequence diversion stimulation service to direct stimulation fluid to target zones.
Results:
