N. SEA DEVELOPMENT ACTIVITY SURGES

Aug. 10, 1992
Operators in the North Sea have reported a burst of upstream activity. Off the U.K.: Amoco (U.K.) Exploration Co. installed three jackets in its North Everest and Lomond fields. It also completed laying the Central Area Transmission System (CATS pipeline, which will carry the fields' gas to shore.

Operators in the North Sea have reported a burst of upstream activity.

Off the U.K.:

  • Amoco (U.K.) Exploration Co. installed three jackets in its North Everest and Lomond fields. It also completed laying the Central Area Transmission System (CATS pipeline, which will carry the fields' gas to shore.

  • BP Exploration Operating Co. Ltd. installed the jacket for its Unity riser platform 5 1/2 km from its Forties Charlie platform. The 7,000 metric ton Unity jacket was installed by the DBI02 barge owned by Heeremac vof, Leiden, Netherlands. Installation of the new platform's 2,800 metric ton topside module is imminent.

  • Conoco (U.K.) Ltd. tested a successful appraisal well in Britannia field in Block 15/30, about 130 miles northeast of Aberdeen. Conceptual engineering for field development is under way.

    In the Norwegian North Sea, Saga Petroleum AS placed Snorre oil and gas field on production 6 weeks ahead of schedule and 1.5 billion kroner ($260 million) under budget at a cost of 16.6 billion kroner ($2.86 billion).

    Downstream off the U.K., Phillips Petroleum Co. (U.K.) Ltd. awarded Allseas Marine Contractors SA, Essen, Belgium, a pipelay and trenching contract for its Ann field development project in Block 49/6a.

AMOCO JACKETS

Amoco's North Everest and Lomond fields, about 140 miles east of Aberdeen, are due on stream in April 1993. They are being developed as part of a 1 billion ($1.93 billion) project incorporating the CATS line, in which spare capacity is being marketed for potential developments in the Central Graben area of the North Sea.

The fields' jackets were fabricated by Highland Fabricators Ltd. at Nigg Bay, Scotland, for the North Everest and Lomond production platforms and the CATS riser platform. They are conventional steel jackets weighing 5,000 tons, 5,200 tons, and 2,700 tons respectively.

The jackets were installed in separate lifts in April, June, and July using the M7000 crane barge operated by Saipem U.K. Ltd., London. All three stand in 295 ft of water.

Topsides for North Everest and Lomond, each weighing 9,500 tons, are under construction in Scotland at the RGC Offshore plc yard at Methil and the UIE Scotland Ltd. yard in Clyde-bank, respectively. They will be installed in October and November by Heeremac using the DBI02 barge.

The 2,880 ton CATS riser platform was built by Highland Fabricators. The riser deck and flare boom were installed last week, using M7000. The riser platform will be linked by bridge to the North Everest platform.

North Everest field, in Blocks 22/9, 22/10a, and 22/14a, has recoverable reserves of 900 bcf of sale gas, 35 million bbl of condensate, and 25 million bbl of NGL. Some liquids will be carried in the CATS line to Teesside, England, while the heavier fraction will go by spur line to Forties and on to Cruden Bay.

Development partners are Amoco 21.14%, British Gas 57.79%, Amerada Hess Ltd. 18.67%, Phillips Petroleum Co. (U.K.) Ltd. 1.01%, Fina Exploration Ltd. 0.87%, and Agip (U.K.) Ltd. 0.52%.

Lomond, in Block 23/21, is estimated to hold 600 bcf of sale gas, 20 million bbl of condensate. and 15 million bbl of NGL. Gas and NGL will go through CATS to Teesside, while heavier liquids will travel by spur line via Forties to Cruden Bay.

Field partners are Amoco with 22.22%, British Gas Exploration & Production Ltd. 61.11%, and Amerada Hess 16.67%.

CATS pipeline is a 255 mile, 36 in. transmission system from the Central North Sea to Teesside. Although it will initially carry 300 MMcfd from North Everest and Lomond fields beginning in April 1993, its capacity will be 1.4 bcfd.

North Everest and Lomond gas will fuel a combined cycle heat and power station under construction by Teesside Power Ltd. at Wilton, England.

CATS interests are Amoco (U.K.) Petroleum Co. with 29.53%, British Gas 39.37%, BG North Sea Holdings Ltd 11.81%, Amerada Hess 17.72%, Phillips 0.66%, Fina 0.57%, and Agip 0.34%.

BP PLATFORM

BP's Unity riser platform will form part of a 650 million ($1.25 billion) Forties pipeline system (FPS) expansion. Onshore, the expansion will include new pump stations, processing facilities at Kinneil, and storage and export facilities at Dalmeny and Hound Point.

The expansion will enable the FPS to handle 1 million b/d of oil. It currently takes 400,000 b/d of liquids from 11 fields: BP's Forties, Buchan and Miller; Marathons North, South, and Central Brae; British Sun Oil Co. Ltd.'s Balmoral and Glamis; Amoco's Montrose and Arbroath; and Heimdal field off Norway, operated by Elf Aquitaine Norge AS, plus NGL from the St. Fergus, Scotland, terminal.

The Unity platform will initially handle fluids from BP's Bruce fields, Amerada Hess's Scott field, and Enterprise Oil plc's Nelson field. Commissioning and testing will take place this month and next month, with final tie-in to Forties in March 1993.

CONOCO APPRAISAL

Conoco's 15/30-10 appraisal well flowed an average 22 MMcfd of gas during a 4 day test through a restricted choke from lower Cretaceous Kopervik pay. Total condensate production amounted to 1,860 bbl.

A further 4 hr gauge was 26.7 MMcfd and 2,280 b/d of condensate, also through a restricted choke.

Conoco drilled the well to 13,490 ft with the Neddrill 6 semisubmersible.

The company holds a 66.67% interest in the block. Chevron U.K. Ltd. holds the remaining interest.

Conoco said Britannia is one of Britain's largest gas/condensate discoveries with a reservoir that is known to span five U.K. North Sea blocks.

Last January the 12 coventurers in the five blocks signed a joint planning agreement that provides, for the first time in the U.K. North Sea, for two companies - Conoco and Chevron - to share the duties of field operator.

SNORRE PRODUCTION

Saga's first phase Snorre field development uses a steel tension leg platform in 1,000 ft of water in the south part of the field and a subsea tie-back 6 km to the north.

The second phase will involve either moving the TLP north and tying in a new subsea unit or leaving it where it is and tying in two new subsea systems.

The TLP can process 190,000 b/d of oil before passing it on to Statfiord Platform A for further processing and loading into tankers.

Lying in Blocks 34/4a and 34/7a, the field is estimated to hold 745 million bbl of oil, 250 bcf of sale gas, and 20 million bbl of NGL.

ANN PIPELINE

Phillips' project includes laying a 26 mile, 12 in. gas pipeline in 15-30 m of water from Ann field to a riser platform under construction for the Lincolnshire Offshore Gas Gathering System (Loggs) complex.

The line will be coated with fusion-bonded epoxy.

Allseas also will trench the entire length of the pipeline, perform tie-ins at the Ann riser platform and Loggs complex and cross three other pipelines and three cables. The company's Lorelay dynamically positioned pipelay vessel will perform the pipelay work during first half 1993.

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