NORWAY Amoco Norway pursuing oil in Valhall's extremities

April 1, 1995
Amoco Norway's plans to tap untouched parts of the Valhall Field by means of a new wellhead platform are now moving ahead with a late 1996 start-up as the aim. After suffering some delay last year, the wellhead platform (WP) project has been streamlined along Norsok principles.

Fast schedule EPIC contract set up to provide 1996 startup

Amoco Norway's plans to tap untouched parts of the Valhall Field by means of a new wellhead platform are now moving ahead with a late 1996 start-up as the aim.

After suffering some delay last year, the wellhead platform (WP) project has been streamlined along Norsok principles.

Costs are currently estimated at Nkr1.5-2 billion, but Amoco sees scope for savings through collaboration with contractors. With partner approval scheduled for the end of March, it hopes to place an engineering, procurement, construction, and installation (EPIC) contract for the platform in early June, so that fabrication can begin in the fall, and installation take place about a year later- a much faster schedule than usual on the Norwegian shelf.

This is partly made possible by performing in parallel some activities which would previously have been carried out in sequence. "This approach saves time," says Terry Hughes, Amoco's resource development manager. "On the other hand, it puts some stress into the system, as everything does not necessarily fit together like a nice jigsaw. But it's a healthy stress."

As conceptual work proceeds, so does preparation of the plan for operation and development (PDO). Discussions are already under way with the Norwegian Petroleum Directorate (NPD).

"The NPD is getting documentation at the same time as the partners," says Hughes. "In other words, the PDO submission is taking place over a period of time. The NPD believes it can approve the PDO by May."

Contractors have been asked to indicate their interest in the project, and in February the operator was drawing up a shortlist of 3-5.

"When we met to discuss the project with a number of contractors back in November, we gave them functional specs for what we wanted from the platform - the number of slots, its location, the kind of drilling techniques we had in mind - and they gave us recommendations based on off-the-shelf concepts requiring some modifications," says Hughes.

In another new step, the company has allowed the 11 qualifiers to choose their own partners - in the past it would have indicated the groupings it wanted to see.

The shortlisted contractors may find themselves invited to participate in a design competition based on functional specs, giving them scope to develop their ideas conceptually. In the UK Amoco was pleased with the results of the design competition it used to select the contractor for its Trent/Tyne development.

The unmanned platform, which will be sited at the field centre and bridge-linked to the processing platform, accounts for some 30-40% of the overall project cost, but Amoco hopes to make savings through adopting a partnering type of contract strategy. "We're looking at ways of building a joint risk/reward structure into the contract," says Hughes.

A concrete base for the platform has not been ruled out, but with time to first oil of the essence, a steel jacket is the base case choice.

More than half the project cost is accounted for by the drilling program, which calls for 15 long-reach and horizontal wells. Many of these will extend for 5-6 km or more, with horizontal sections of up to 1 km in the reservoir zone. About half will be directed into the southern part of the field, where the productive zone thins to a mere 20 meters.

A 900-day contract has been awarded to Maersk Drilling's jackup Maersk Guardian, which is due to start pre-drilling up to seven wells through a template when it comes off its current contract in August or September. The rig will drill the remaining wells through the platform once it is installed.

Well workovers, however, will be performed with a small lightweight drilling package which will be brought to the platform as required.

The platform design will enable Amoco to take up a number of future options such as a water injection capability and production prospects - both Amoco's and third parties' - in the area. However, it will not be possible to implement all the options.

"Low-cost off-the-shelf concepts save you money," says Hughes. "but what you lose is some flexibility."

The Valhall expansion project will add an estimated 66 million bbl of oil and 120 bcf of gas to the field's recoverable reserves. Its importance to Amoco is enhanced by the fact that it is the company's only operated field in Norway. Its partners are Amerada Hess and Enterprise (28.09% each, the same as Amoco) and Elf (15.72%).

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