ACTIVITY MIXED OUTSIDE MAIN N. SEA SECTORS

Activity levels are mixed in sectors outside the North Sea's major producing regions.

Danish sector production prospects are improving in step with horizontal drilling technology.

Dutch activity centers on laying of the Nogat pipeline system and developing gas fields that will feed it.

And Ireland is considering ways of boosting exploratory interest.

DENMARK'S PRODUCTION

In Denmark, offshore production has risen to a new peak of about 135,000 b/d and is set to increase as new pipeline capacity becomes available.

State-owned Danish Oil & Natural Gas (DONG) is installing compression at the landfall of the oil pipeline from Dansk Undergrunds Consortium's offshore complex that will boost capacity to 160,000 b/d from 130,000 b/d. The work should be finished by the end of this year.

And to maintain the production momentum, DUC-A.P. Moller, Royal Dutch/Shell Group, and Texaco Inc.-has proposed two development plans that make use of horizontal drilling.

In Dan field, where a program of seven horizontal wells is in progress, DUC is seeking approval for a wellhead platform and flare tower as part of a program to drill 25 new wells, 18 of them horizontal. It includes conversion of 14 conventional producing wells to water injectors.

Maersk Oil & Gas AS, on behalf of DUC, has submitted a plan for integrated development of Harald, Valdemar, and Svend (formerly Nord-Arne) fields. Development, which will cost 3 billion kroner ($434 million), has been brought forward from the end of the century to provide early production experience ahead of a larger development later in the decade.

The new program in Dan field, one of the most mature producers in the whole North Sea, will cost 4 billion kroner ($579 million) and will boost output to 50,000 b/d from 30,000 b/d.

The Dan program calls for four horizontal water injectors that will have a direct water drive effect on four horizontal producers drilled alongside the injectors, which will have hydraulically induced, sandpacked fractures.

Harald, Svend, and Valdemar fields are all in the northern part of the Danish offshore. Svend and Valdemar will come on stream in 1993. Harald will start up a year later.

Production from all three fields will be carried through a 52 mile, 16 in. multiphase flow pipeline to Tyra East facilities. The ability to move as much as 25,000 b/d of oil and condensate plus 390 MMcfd of gas through a single pipeline and make use of existing facilities is one of the main factors behind the decision to bring forward development.

Two horizontal wells have been drilled in Valdemar field. DUC plans to install a Star-style unmanned platform like those installed in Kraka and Dagmar fields last year.

A third horizontal well will be drilled into the thin and tight Barremian zone, the first time that production will have been achieved from this difficult reservoir.

In Svend field, DUC is considering an unmanned satellite platform developed by Maersk Oil & Gas from experience gained with the Star platform. A concrete gravity based unit might be used for two horizontal wells that will be required.

Harald will require three wells and use a platform similar to that chosen for Svend.

At the Tyra end of the pipeline, a Star platform will be installed and connected to Tyra East with a bridge module for reception of the multiphase flow prior to treatment at the field's central processing facilities. these will be expanded to increase processing capacity for oil and condensate to 60,000 b/d from 30,000 b/d.

DUC will proceed with the long term objective of building a production complex in the northern Danish North Sea, using production experience from the three unmanned platforms.

DUTCH ACTION

In the Dutch sector, Nederlandse Aardolie Mij (NAM) and Elf Petroland started work this summer on the Nogat system's first phase, a 93 mile, 36 in. line from the landfall at Den Helder to the L2-FA/FB-1 development. The final 66 mile, 24 in. section to the F/3 development will be completed in 1992.

The government has approved another project along the route of the Nogat system. NAM will develop the L/2 and L/5 fields.

The Shell/Esso company will spend about $65 million on a minimum facilities, unmanned drilling and processing platform in L/2, which is expected to produce 50-55 MMcfd starting in 1992.

Similar facilities will be installed in L/5a at similar cost. Production, also starting next year, will average 40-45 MMcfd.

NAM is also developing the L/12 and L/15 gas prospects as a joint project to be linked into the line.

At the northern end of the line, NAM is developing the 425 bcf of gas and 30 million bbl of condensate in F/3 field with the first concrete drilling and production platform in Dutch waters.

The base of the concrete unit will have 190,000 bbl of liquid storage to service a tanker loading operation through a buoy 1.2 miles away. The concrete unit will be bridge-linked to a steel accommodation platform.

Elf Petroland has received government approval to develop the 350 bcf F/1 5a gas field at a cost of $145 million. The project, part of the second phase of the Nogat pipeline project, is expected to come on stream toward the end of 1992 and reach a peak of 70 MMcfd the following year.

Petroland's development project in the K quadrant, based on a central processing platform on K/6c to serve a number of small accumulations, has been enhanced by discovery of more gas in the K/6-8 wildcat.

Holland's flagging oil production received a small boost from a horizontal drilling program in Helder field by Unocal Netherlands BV. Output climbed to 10,900 b/d from 4,200 b/d after five horizontal wells were drilled and 9 of 10 existing producers were converted to horizontals.

Unocal said the $19.5 million drilling program has added 7 million bbl to reserves-now estimated at 31.1 million bbl.

Amoco Netherlands Petroleum Co. is planning a gas development alongside its Rijn oil field complex on Block P/15.

A central gas processing platform will be bridge-linked to existing oil facilities. It will receive gas from six remotely operated satellite producing facilities, two of which will be subsea well completions.

The $400 million project is scheduled to produce first gas in 1993. Plateau production will be about 250 MMcfd delivered to the Hook of Holland through a 26.3 mile pipeline. Liquids from the new developments will be fed into the Rijn facilities and the existing oil line to shore.

Amoco said the facility is designed to handle peak flow of 500 MMcfd.

The Wintershall-operated Noordwinning group is considering development of a small gas discovery in P/14a through the new Amoco gas facilities.

Placid International Oil Ltd. started production from two small accumulations in Blocks L/11a and L/14, which have total reserves of about 90 bcf. A subsea wellhead on L/14 was tied back to a small wellhead platform on L/11 linked into the Noordgastransport system.

IRISH EFFORT

Irish efforts to promote exploration will come through detailed petroleum taxation legislation in the government's 1992 finance bill.

Also on the list of incentives is the first frontier licensing round covering the Slyne and Erris Troughs in the deep Atlantic west and northwest of the republic.

While immediate prospects for exploration activity are poor, renewed interest is being shown in oil development projects,offshore.

Atlantic Resources is running a feasibility study on small Helvick field in the Celtic Sea off southern Ireland, while Aran Energy is conducting a similar exercise in Connemara field in much deeper water off the west coast.

Marathon Ireland has brought on stream the first commercial field since Kinsale gas field, which it operates, was commissioned in 1978.

Ballycotton field was developed with a single subsea well tied back to Kinsale facilities. It came on stream in July and has added about 50 MMcfd to the 225 MMcfd being produced from Kinsale.

Industry sources say the key to reviving exploration lies in the long delayed clarification of the tax regime. Various administrations in Dublin have started the process of defining offshore taxation systems, but none has reached the legislative stage.

Tax uncertainty and spotty results have discouraged exploration.

Irish Energy Minister Robert Molloy recently said the new legislation will be based on taxing offshore oil production at the standard rate of corporation tax, currently 40%.

Ring fencing of offshore fields will be relaxed to allow expenditure on onshore minerals and mining activities to be offset against offshore petroleum profits.

Irish industry sources say the government will also allow free depreciation of development and exploration expenses, giving the Irish regime the lowest marginal tax rate in Europe.

The frontier round has been announced, but applications will not close until mid-1993. It will offer 128 blocks covering 28,000 sq km. New terms are likely.

Only four wells have been drilled in this area, the most recent by Ste. Nationale Elf Aquitaine in 1982. They were all dry.

Copyright 1991 Oil & Gas Journal. All Rights Reserved.