U.K. sanctions major HP/HT developments

U.K.

Department of Trade and Industry has approved plans by Elf Exploration U.K. plc and Shell U.K. Exploration & Production to develop two large high-pressure/high-temperature (HP/HT) North Sea fields.

Elf is to develop Elgin and Franklin finds on Blocks 22/30c and 29/5b, respectively, while the Shell U.K. Ltd./Esso Exploration & Production U.K. Ltd. joint venture is to develop nearby Block 22/30b Shearwater find.

Both developments are due to begin production in 2000, with gas being sent to shore through a new jointly owned pipeline known as the Shearwater & Elgin Area Line (SEAL).

The developments are the second to be sanctioned of a group of central North Sea discoveries. Texaco Ltd. will bring North Sea's first HP/HT field, Erskine, into production this year (OGJ, Mar. 17, 1997, p. 36).

Elgin/Franklin

Elgin has estimated reserves of 889 bcf of gas and 244 million bbl of condensate, while Franklin reserves are estimated at 821 bcf of gas and 123 million bbl of condensate.

Elf plans a £1.5 billion ($2.4 billion) development of the two fields, to begin production in April 2000 and reach average output of 470 MMcfd of gas and 150,000 b/d of liquids by fourth quarter that year.

Elgin and Franklin reservoirs are at a depth of 5,400 m, with reservoir pressures of 1,050 bar and a temperature of 190° C. Water depth is about 95 m.

Development will involve installation of a TPG 500 design production jack up production, utilities, and quarters (PUQ) platform in Elgin, bridge-linked to a wellhead platform.

An unmanned wellhead platform will be installed in Franklin, linked by two 12-in. flowlines to Elgin's main platform 6.5 km northwest.

Gas will be exported via the SEAL pipeline to Shell's Bacton terminal in Norfolk, while liquids will be exported through a 24-in. pipeline link to the Forties oil pipeline system operated by BP Exploration

Operating Co. Ltd.

Elf let contract last month to a London-based group of Technip U.K. Ltd., McDermott Marine Construction Ltd., and Brown & Root McDermott Fabricators Ltd. (Barmac), to build the PUQ platform at Barmac's Nigg yard in Scotland.

Jackets for the two wellhead platforms are under construction at the Lewis Offshore Ltd. yard at Stornoway, in the Orkney Islands.

Galaxy 1 heavy duty jack up rig spudded the first Elgin development well on Mar. 24, through a template placed on the seabed there last November.

Shearwater

Shell/Esso plans to develop Shearwater under a £714 million ($1.15 billion) program, with first production slated for mid-2000.

Shearwater discovery has estimated reserves of 844 bcf of gas and 159 million bbl of liquids.

Development will involve two bridge-linked, four-legged steel platforms, one a PUQ platform and one a wellhead platform, standing in 90 m of water.

Production capacity will be 410 MMcfd of gas and 90,000 b/d of liquids. Gas will be exported via the SEAL pipeline, while liquids will join the Forties network via a 24-in. spur line to the same Y-piece link point as Elgin/ Franklin liquids.

Construction is being carried out by a combine of AMEC plc, London, and Heerema VOF, Leiden, Netherlands. They will build the platforms at AMEC's Wallsend yard in the U.K., and Heerema's Hartlepool, U.K., and Vlissingen, Netherlands, yards.

SEAL pipeline

The 463 km, 34-in SEAL pipeline will be the longest on the U.K. continental shelf and will take gas from the two PUQ platforms to Bacton terminal. Capacity will be 922 MMcfd of gas.

SEAL will cost £400 million ($640 million) to build and will deliver gas to the U.K. gas grid at Bacton and to the Interconnector pipeline-currently under construction-to Belgium.

Construction is expected to begin in 1998. Elf will be operator of the pipeline during construction, and Shell/Esso will take over operatorship once commercial gas flow begins.

Elgin/Franklin interest holders are operator Elf 46.173%, Agip (U.K.) Ltd. 13.867%, BG Exploration & Production Ltd. 12.35%, Shell/Esso 8.75%, Hardy Exploration & Production Ltd. 8%, Ruhrgas U.K. Exploration & Production Ltd. 5.2%, Texaco 3.9%, and ARCO British Ltd. 1.76%.

Shearwater partners are Shell/Esso 56%, ARCO 27.5%, and Mobil North Sea Ltd. 16.5%.

Copyright 1997 Oil & Gas Journal. All Rights Reserved.