Irkutsk Oil Company (INK-Service) needed to improve penetration rates while drilling the horizontal interval of the 6-in production section in the Yaraktinskoe Field. Consisting of sandstone interbedded with claystone, the formation has high unconfined compressive strength (UCS), ranging from 68.95 to 172.37 MPa [10,000 to 25,000 psi]. Typical measured depth in and out ranges from 3,000 to 4,000 m [9,843 to 13,123 ft] and inclination ranges from 88° to 90°. Hydraulic horsepower per square inch averages just 0.7 to 1.0 hhp/in2—leading to bit balling, shorter bit life, and poor ROP. In previous drilling campaigns, abrasive wear of the PDC cutters was concentrated in the shoulder area. This led to low penetration rates, dogleg severity issues, and an additional round trip for a bit and BHA change.
SLB used the IDEAS™ integrated dynamic design and analysis platform to simulate alternative bit designs and identify optimal drilling technologies. After an extensive study of offset well data, Schlumberger recommended the AxeBlade ridged diamond element bit for improved durability and cutting efficiency. In addition, Schlumberger proposed using new-generation, 13-mm Axe elements—a first for the Yaraktinskoe Field and one of the first implementations worldwide.
Using the AxeBlade bit with 13-mm Axe elements, INK-Service successfully drilled 734 m [2,408 ft] from shoe to TD in just one run—eliminating multiple trips and saving 40 hours of rig time. INK-Service achieved an average ROP of 17.7 m/h [58.07 ft/h], nearly doubling the average field ROP of 9.2 m/h [30.2 ft/h]. Additionally, the bit was pulled out of hole in repairable shape with only minor wear in the shoulder area, enabling INK-Service to prolong the life of the tool and mitigate drilling costs.
