Third West Don production well under study

Nov. 19, 2009
A third production well is under study for West Don field in the UK North Sea, 150 km northeast of the Shetland Islands.

By OGJ editors
HOUSTON, Nov. 19
-- A third production well is under study for West Don field in the UK North Sea, 150 km northeast of the Shetland Islands.

Stratic Energy Corp., London, said an independent reserves review it commissioned by Ryder Scott lowered ultimately recoverable reserves in the field by 9% from previous expectations but raised net remaining reserves as of Dec. 31, 2009, to 1.72 million bbl proved, up 33%, and 2.84 million bbl proved and probable, up 16%.

The new estimates for ultimately recoverable volumes are 2.03 million bbl proved and 3.17 million bbl proved and probable.

West Don, in 170 m of water, started production Apr. 28 from two wells flowing into the Northern Producer floating production vessel. Petrofac Energy Developments, operator of West Don and nearby Don Southwest, owns the vessel.

Peak production originally was estimated at 25,000 b/d, but Stratic said the rate will be lower because of reduced water injection rates and “continuing equipment issues.” But future decline rates will be lower, it said, with production beyond 2010 “substantially higher than originally planned.”

The production facility now offloads oil into a tanker but will be linked by pipeline to facilities at Thistle field, 12 km south, for delivery into the Brent pipeline system.

Stratic said the pipeline connection will reduce weather downtime and allow consistent production. It said in a statement that it considers a third producer needed in the southern part of the field.

“We have observed the beginning of pressure support in the West Don reservoir from water injection,” said Stratic Chief Operating Officer Mark Bilsland. “The field operator is taking the necessary steps to increase the injection pump pressure levels and to resolve the issues on gas lift equipment.”

Other West Don partners are Valiant Petroleum and Nippon Oil Exploration & Production (UK).