WATCHING THE WORLD SLEIPNER OVER FINAL HURDLE

With David Knott from London If field development is comparable to a hurdles race, Norway's Block 15/9 East Sleipner gas project is a long distance event. It has a 50 ft high brick wall replacing one of the regular obstacles. The brick wall represents the sinking of the Sleipner A platform concrete base structure (OGJ, Oct. 28, 1991, p. 19). The finishing line marked for start of gas production Oct. 1, 1993, was set under the Troll gas sales agreement of 1986.

Aug. 30, 1993

3 min read

If field development is comparable to a hurdles race, Norway's Block 15/9 East Sleipner gas project is a long distance event.

It has a 50 ft high brick wall replacing one of the regular obstacles.

The brick wall represents the sinking of the Sleipner A platform concrete base structure (OGJ, Oct. 28, 1991, p. 19). The finishing line marked for start of gas production Oct. 1, 1993, was set under the Troll gas sales agreement of 1986.

Construction of the original base started in August 1988, allowing a comfortable jog to gas production. Field operator Den norske stats oljeselskap AS saw the base structure sinking as a challenge to its credibility as a gas supplier.

Statoil set the scene for a sprint finish to East Sleipner development by insisting it could rebuild the base structure and still make the deadline. Right on schedule, Norwegian Contractors AS, Oslo, installed the completed platform June 16.

FIRST GAS

The last hurdle was cleared Aug. 24, when Statoil placed two subsea wells on stream. A well in nearby Loke field will go on production in a few weeks, and a well will be drilled from the platform in September.

First gas through Sleipner A came from other fields Aug. 18 via a link to the Block 16/11 Statpipe trunk line riser platform. Now East Sleipner gas will be fine tune processing to meet customer specifications.

If Statoil stumbles while dashing for the finish line, the Statpipe link can be used again to provide gas from several fields to make up the 375 MMcfd maximum from East Sleipner agreed under the Troll contract.

With the East Sleipner race completed, Statoil will turn to West Sleipner field, estimated to hold 4.8 tcf of gas, 200 million bbl of oil, and 100 million bbl of NGL. First gas from West Sleipner is scheduled for April 1997.

WEST SLEIPNER

Two unmanned steel platforms will develop West Sleipner, controlled from Sleipner A. Sleipner T platform, which will process West Sleipner gas, is to be installed alongside Sleipner A platform (OGJ, May 10, p. 34).

Sleipner T will be bridge linked to Sleipner A to allow easy access for process equipment maintenance. Contracts to build gas processing and carbon dioxide reinjection modules for Sleipner T will be awarded late this fall,

Sleipner B will be a steel wellhead platform installed 7 miles from the other two structures. Tender assisted drilling will be carried out by Smedvig AS, Stavanger, using the West Epsilon jack up rig.

To reduce risk, Statoil will build Sleipner B under the first "partnering" development contract in the Norwegian North Sea. Norwegian Rig Consultants AS, Kristiansand, will be the engineering contractor, while a construction contractor partner will be chosen later this year.