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Monday 23 Sept. 2013  

Sakhalin-1 Drilling Program Marks 10th Anniversary with World Records

- New world record for extended reach drilling set by Z-42 well with measured depth 12,700 meters (41,667 feet) and horizontal reach 11,739 meters (38,514 feet)
- 8 of the 10 world’s longest wells belong to the Sakhalin-1 Consortium
- Russia’s most complex offshore multilateral well completed this year

Yuzhno-Sakhalinsk, Russia – Exxon Neftegas Limited, on behalf of the Sakhalin-1 Consortium, today announced new drilling achievements of the Sakhalin-1 drilling program, now in its 10th year.

In August 2003, drilling of the first extended reach well began from the onshore well site at Chayvo in North East Sakhalin.

Extended reach well drilling continued and in 2013, the Exxon Neftegas drilling team completed two wells, which set two consecutive world records for measured depth. With these accomplishments, currently 8 of the 10 world’s longest wells belong to the Sakhalin-1 Consortium. The technology used for the wells enables drilling from an onshore-based well site to the oil and gas reservoirs located offshore. A well is usually started vertically and then steered gradually to a horizontal path to tap a subsoil formation containing hydrocarbons.

In April, the Z-43 well broke the previous world record set at Sakhalin-1, reaching 12,450 meters (40,847 feet) of measured depth.

The record was then beaten in June by the Z-42 well, with a measured depth of 12,700 meters (41,667 feet) and a horizontal reach of 11,739 meters (38,514 feet). This well was completed in only 73 days, and maintained a high degree of precision by placing the bottom-hole location within 4 meters of the planned target.

In March this year, Exxon Neftegas also completed Russia’s most complex offshore multilateral well, marking the beginning of the Sakhalin-1 multilateral well drilling program. Multilateral technology enables increased production from a single well by drilling multiple sidetracks from the main borehole to the reservoir’s oil and gas producing areas.

The multilateral well was drilled from an existing production well and faced a combination of unique challenges such as maintaining integrity of the original wellbore, cutting a lateral window in existing metal casing approximately 4 kilometers downhole, and installation of a specially designed multilateral junction and production packer.

“We are proud that Sakhalin-1 proved its leadership by developing offshore energy resources in severe climatic and geological conditions,” said Exxon Neftegas President James Taylor. “The most valued outcome is that these achievements were conducted to the highest standards of safety and protection for the environment.”

Since 2003, a total of 51 extended reach wells have been drilled at Sakhalin-1 to develop both the Chayvo and Odoptu fields, setting records for measured depth five times.

Sakhalin-1 extended reach wells are also among the fastest-drilled wells thanks to the use of ExxonMobil’s proprietary Fast Drill Process, which allows bottleneck identification in the drilling process and solution development to enable optimal drilling and completion.

Successful implementation of these state-of-the-art technologies reduces costs associated with additional offshore facilities, pipelines and other production infrastructure. They also protect the environment by minimizing areas involved in drilling and production operations.

Notes to editors:

The Sakhalin-1 Project is being implemented by an international consortium which includes the Japanese consortium SODECO (30 percent); affiliates of the Russian state company Rosneft – RN-Astra (8.5 percent) and Sakhalinmorneftegas-Shelf (11.5 percent); the Indian state oil company, ONGC Videsh Ltd., (20 percent); and Exxon Neftegas Limited (30 percent), an affiliate of Exxon Mobil Corporation and the Sakhalin-1 project operator.

Sakhalin-1 includes three oil and gas fields - Chayvo, Odoptu, and Arkutun Dagi - located off the northeast coast of Sakhalin Island in the Russian Far East. More detailed information on the Sakhalin-1 Project can be found on