More North Sea oil fields due on stream

Operators are advancing oil production plans in the U.K. and Norwegian sectors of the North Sea.

Off Britain, BP Exploration Operating Co. Ltd. has completed installation of a conventional steel platform in Andrew field. It's part of a 370 million ($555 million) field development program due to start production in late June.

Off Norway, Esso Norge AS has let contract to Aker AS, Oslo, for a conceptual development study for its Elli, South Elli, and Tau oil discoveries. The three finds hold reserves estimated at 200 million bbl of oil. An Esso official said the company believes it will be possible to produce the three fields from one installation.

Andrew field

BP earlier installed a 7,500 metric ton platform jacket in Andrew field on Block 16/27a, where water depth is 116 m. This was topped off by installation of a 10,400 metric ton integrated deck.

The lifts were undertaken by Saipem U.K. Ltd., Aberdeen, using the S7000 semisubmersible crane vessel.

Andrew's reserves are estimated at 112 million bbl of oil, 9 million bbl of condensate, and 135 bcf of gas. Plateau production is expected to be 55,000 b/d of oil and 40 MMcfd of gas.

Oil will move to shore through a 16 km, 10 in. pipeline to BP's Forties export network. Gas will move through a 44 km, 8 in. pipeline into the Central Area Transmission System operated by Amoco Exploration (U.K.) Ltd.

Andrew platform also will deplete nearby Cyrus field on Block 16/28. Earlier, BP produced Cyrus from April 1990 to March 1992 using the OPV Seillean production ship.

BP has since upgraded Cyrus reserves to 25 million bbl of oil.

Two new horizontal production wells will be tied back to Andrew platform by a 10 km flow line.

Cyrus field is due on stream once more later this year, with production expected to peak at about 12,000 b/d of oil.

Esso Norge options

Esso Norge is studying three main development options for Elli, South Elli, and Tau fields: a production storage and offloading vessel with subsea wellheads, a production storage and offloading ship linked to a wellhead platform, and a wellhead platform in the field tied back to a new platform in Heimdal field, where Elf Petroleum Norge AS is operator.

Oil production from the additional fields is to begin in late 1998 or early 1999.

The names Elli and Tau are Esso's in-house designations. The company has applied for a formal name now that development is being studied.

Esso has proposed Jotun as the name for the entire development project, with Elli referred to as Jotun, Tau as East Jotun, and South Elli as South Jotun.

Esso earlier disclosed a plan to develop its Balder discovery, which lies 25 km south of Jotun. Balder will be developed using 15 subsea wellheads tied back to a production, storage, and offloading vessel (OGJ, Feb. 19, p. 58).