Shell/Esso plans Galleon, Brent expansions

Shell U.K. Exploration & Production is continuing with development work in U.K. North Sea producing fields, disclosing plans for a new platform in Galleon field and for more wells in Brent.

The operator, a joint venture of Shell U.K. Ltd. and Esso Exploration & Production U.K. Ltd., will spend £135 million ($220 million) to install a new platform to deplete a remote corner of Block 48/15a Galleon field.

On Block 211/29, Brent field Shell/Esso has disclosed results of its first coiled tubing well-which it claimed as a world record-drilled from Brent Delta platform and outlined plans for further use of the technology.

Galleon

The Galleon expansion project will involve installation of a new wellhead platform, Galleon PG, and drilling of 11 development wells. The new development wells will be multilaterals with horizontal sections.

Galleon PG will be installed in the northwest corner of the field at yearend 1997. It is expected to recover at least 770 bcf of gas that cannot be reached from the existing Galleon PN wellhead platform.

Gas from Galleon PN is exported via a 14-in. pipeline to Sole Pit gas compression in nearby Clipper field. From there, it is sent to shore at Shell/Esso's Bacton terminal in Norfolk.

Gas from the new platform will also go to Sole Pit via a new dedicated pipeline for compression and export. First gas is slated for October 1998, when three wells are to be brought into production.

The new platform, like Galleon PN, will not be normally manned. Galleon PG will be controlled remotely from Clipper field.

Shell/Esso said the new platform's 800-metric ton jacket and 650-metric tons topsides will be built at the Methil yard of Kvaerner Offshore Ltd., near Fife, Scotland.

Brent well

The D-38 well drilled from Brent Delta was sidetracked in 1995, brought on stream near the end of October 1996, and is producing 6,000 b/d of oil of a total 55,000 b/d output from the platform.

Total Brent production from four platforms is currently 190,000 b/d. Brent D platform is expected to be shut in next year for refurbishment under a £1.3 billion ($2.1 billion) redevelopment scheme (OGJ, Dec. 2, p. 30).

Shell/Esso said Brent D-38 well is the deepest offshore coiled tubing well in the world, having reached a total measured depth of 11,238 ft.

The kick-off point for the coiled tubing section was at 9,750 ft. The operator said the 1,488 ft coiled tubing section also stands as the longest offshore coiled tubing run to date.

Shell/Esso said the well was sidetracked to reach a pocket of oil, with reserves estimated at 500,000 bbl, that had previously been regarded as uneconomic to develop.

Use of coiled tubing meant Shell/Esso did not have to remove existing pipe sections from the borehole, and so the cost of the well was about half that of a conventional redrill.

Coiled tubing prospects

Walter van de Vijver, Brent field general manager for Shell/Esso, said, "Coiled tubing wells have been tried before to a limited extent in the North Sea, but this is far and away the most successful application.

"Brent at present has estimated remaining recoverable reserves of more than 400 million bbl of oil. We estimate that by drilling a number of coiled tubing wells the next few years we can tap into another 10-20 million bbl.

"The success of the D-38 well builds upon a previous trial in our North Cormorant field earlier this year. Shell/Esso will also be looking at applications in other North Sea fields."