Sakhalin-1 Project drills well exceeding 7 miles in length.

Exxon Mobil Corp. has announced that its subsidiary, Exxon Neftegas Limited, has completed drilling of the Z-11 well, the longest measured depth extended-reach drilling (ERD) well in the world. Located on Sakhalin Island offshore eastern Russia, the record-setting Z-11 achieved a total measured depth of 37,016 feet, or more than 7 miles.

The multiphase Sakhalin-1 Project includes the Chayvo field, which is located 5 miles to 7 miles offshore. The Z-11 was drilled to the Chayvo reservoir from the Yastreb rig, the world's largest land-based drilling rig. Overall, the Chayvo field reached its peak production rate of 250,000 barrels per day in February 2007 after an on-schedule startup in October 2005. The Z-11 is the 17th ERD producing well to be completed as part of the Sakhalin-1 Project. It was drilled in 61 days, more than 15 days ahead of schedule.

Since the first Sakhalin-1 well was drilled in 2003, the time required to drill these wells has been reduced by more than 50 percent. When compared to industry benchmarks, Sakhalin-1 wells are the world's fastest drilled ERD wells.

The project team applied ExxonMobil proprietary technologies, including Integrated Hole Quality (IHQ) technology and the Fast Drill Process, to deliver the Z-11 well.

"The physics based modeling and experimental validations of our IHQ technology allowed us to successfully design and drill the Z-11," says Steve Cassiani, president of ExxonMobil Upstream Research Co. "With this technology, we were able to take into account a broad range of interdependent design variables including rock strengths, stresses and wellbore hydraulics to successfully drill this well."

Used in conjunction with IHQ technology was an optimization process called Fast Drill, which is an energy-based analysis tool and work process designed to allow rig site and drilling engineering personnel to maximize performance in every foot of hole drilled.

Exxon Neftegas Limited is operator for the project, which includes the Japanese company Sakhalin Oil and Gas Development Co. Ltd.; affiliates of Rosneft, the Russian state-owned oil company, RN-Astra, Sakhalinmorneftegas-Shelf; and the Indian state-owned oil company ONGC Videsh Ltd.