Oxy claims record slimhole rotary steerable well in Oman

June 11, 2002
Occidental of Oman Inc. and Schlumberger Oilfield Services claim to have achieved a world first for the successful geosteering of a 4,712 ft, 6 1/8-in. slimhole lateral well in Oman's Safah field.

By OGJ editors

HOUSTON, June 11 -- Occidental of Oman Inc. and Schlumberger Oilfield Services claim to have achieved a world first for the successful geosteering of a 4,712 ft, 6 1/8-in. slimhole lateral well in Oman's Safah field. The field test follows a successful run last month of Schlumberger's slimhole rotary steerable drilling system for Shell UK Exploration & Production in the UK North Sea's Brent Delta field (OGJ, May 13, 2002, p.8).

This latest project underscores the capabilities of using such a steerable system in Oman, said Hal Owens, drilling manager, Occidental of Oman. Ownes added that the use of the company's current systems would require drilling in the slide mode about 30% of the time, thus decreasing by two thirds the firm's penetration rates. In addition, by remaining in rotary mode, added lateral length can be reached, Owens said. The Occidental Petroleium Corp. unit plans to use the system to drill two additional wells, with the second well getting under way in the next few weeks, he said.

Although the new lateral well received a "significant gas influx" from a neighboring injector well, all of the well's horizons registered as planned and log responses proved accurate, Schlumberger said. "To respond to the gas influx, mud weight had to be increased and drilling rates had to be controlled at times," the company said, adding that the use of conventional mud motors would have slowed the well's progress and may have impeded reaching TD.