Norske Shell will recommend to partners that Troll gas field in the Norwegian North Sea be developed using multiphase flow pipelines and onshore processing instead of a large integrated drilling and production platform.
A study of the two systems showed costs are very similar. But greater safety of onshore processing swung Shell in favor of multiphase flow pipelines with onshore gas processing.
Shell will make a full technical presentation of the onshore processing project to its partners Jan. 16. The biggest single partner in the project, Norway's Den norske stats oljeselskap AS, which will operate the field during the production phase, favors the onshore solution.
A final decision on the project, due on stream in 1996, is expected in March.
Meantime, a report by London broker James Capel & Co. predicts exploration and appraisal drilling in the North Sea could hit a record level this year.
Based on forecasts from operating companies, Capel says about 330 wells could be drilled in 1990, with about 70% of them in the U.K. sector. Last year about 230 wells were drilled in the sector.
TROLL PROJECT DETAILS
The project Shell will present to partners calls for a concrete based drilling platform, with basic processing, set in 993 ft of water on the eastern flank of Troll field.
Two 35 mile, 36 in. multiphase flow pipelines will move raw gas to a terminal at Kolsnes, northwest of Bergen. Shell has engineered a processing plant that can be expanded on a modular basis as Troll production builds to a peak of 2.65 bcfd by 2002.
The four legged drilling platform will carry a 15,000 metric ton topsides from which a total of 40 wells will be drilled. Facilities will remove some water from the gas.
The weight of the drilling platform topsides compares with 42,000 metric tons for a drilling/production platform.
Pipelines serving Troll will have a life of at least 50 years. Shell reckons that water removal and glycol injection will keep corrosion problems manageable with the use of stainless steel pipelines.
After onshore processing, gas will move through 36-40 in. pipelines linking Kolsnes with Sleipner and Heimdal fields off Norway.
Shell has an 8.288% interest in Troll. Its partners are Statoil 74.576%, Norsk Hydro Produksjon AS 7.688%, Saga Petroleum AS 4.08%, Norkse Conoco AS 2.015%, Elf Aquitaine Norge AS 2.353%, and Total Marine Norsk AS 1%.
DRILLING UPTURN
Capel cites a number of factors responsible for the upturn in North Sea drilling this year. New acreage is available from last year's awards off the U.K., Norway, Netherlands, and Denmark, relinquishments under the ninth U.K. round are looming, and oil prices have stabilized.
Activity off the U.K. will reach a record high. The number of wells drilled will range from 232 to 254 with BP Exploration as the most active operator.
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