Jeremy Beckman
London
Twin development gains approval
Amerada Hess has won formal consent from the UK government to develop the Dauntless oilfield in block 21/1. This and the Durward Field, seven km to the southeast, will be produced jointly through an FPSO (currently a tanker undergoing conversion at a yard in Belfast). Dauntless was only discovered in December 1994, so Amerada can claim this as its fastest standalone development to date.
Subsequent appraisal wells on Dauntless were thought to have been disappointing. However, a recent development well on Durward appears to have performed better than expected. The two fields, which will be tapped via six producer and five injector wells, will realize plateau output of over 50,000 b/d shortly after start-up.
Amerada's first UKCS floater, the semisub AH001, has just produced its 150 millionth barrel from the Hamish, Ivanhoe, and Rob Roy Fields in block 15/21a. Originally just 90 MM bbl were considered recoverable, but improved reservoir performance will likely now maintain production into the next century.
A host of new floating production developments are expected to be announced shortly for the UK sector. The available fleet will be swelled next summer when Mitsui delivers the new Tentech 700 design vessel it is currently constructing to SLP, Teesside for topsides fit-out. Smedvig has just acquired a 50% stake in this vessel from Rasmussen.
Well engineering aids production
BP has continued its rejuvenation of the Forties infrastructure by recompleting one of the wells to produce the Eocene Brimmond accumulation. Reserves are thought to be between 1-3MM bbl. Production rates may be stepped up in time through recompleting further abandoned Forties wells as producers.
At another BP institution, Wytch Farm on/offshore southern England, a 10 km extended reach step-out is planned next year to access the offshore section of the Sherwood reservoir. This would exceed by 2 km the current longest ERD well on the field, M5, which also suffered high mud loss through seepage into rock.
The current M8 well, spudded in July, is being used as a testbed for trials of a coarser mud system developed by BP and Baroid: this comprises particles of varying size to reduce losses into the formation. Although the system worked satisfactorily on the M7 well, BP found that the well bore needed more thorough cleaning prior to completion than when using conventional fluids. Experimental rotary direction steering tools are also being applied on M8 as well as a new technique that involves floating the 9 1/2-in. casing to the top of the reservoir section to reduce friction resistance.
In Norway, Statoil has set a personal horizontal offset record - 7,337 meters - with the Gungne well drilled from the Sleipner A platform. Total measured depth is 8,561 meters with a maximum angle of 88 degrees. A 512-meter, pre-drilled and pre-perforated liner has been set 8,000 meters from the platform, which Statoil claims is a world best. These measures have enabled the well to flow 2-3mcm of gas and 12,500 b/d condensate, on par with the main Sleipner East wells, despite earlier misgivings about Gungne's production potential.
Saga steps up drilling campaign
Saga is set to double its Norwegian sector drilling and intervention activity in the coming year, with up to seven rigs on its payroll. Transocean Arctic kicked off the current exploration campaign, targeting the high-pressure A structure that straddles two Halten Bank production licences. Scarabeo 5 could also be contracted for exploratory assignments in the deepwater Voering plateau.
Late this year, Saga aims to spud its first slim-hole well on Snorre, following equipment tests at the Ullrigg drilling and well center at Rogaland Research in Stavanger. Multi-lateral branches up to 700 meters long are planned from existing wells on Snorre to boost water injection in the poorest flowing reservoir zones, thereby sustaining oil production levels.
Another improved recovery scheme planned for Snorre next year involves using foam to steer gas flows through the reservoir. Saga tested the technique this summer on the P-18 well, out of service since 1994 due to high gas cut. Under the new measures, the well has flowed successfully and steadily.
According to Saga, pumping foam around the injection well causes improved spread of the injected gas, in turn pushing more oil towards the production wells. The technique will be applied as part of a water-alternating-gas scheme in the central fault block, south-west of the Snorre platform, with the aid of funding from the European Union.
Gas deals sustain Southern Basin
Shell/Esso have discovered a gas accumulation named Corvette, 8 km south of the Indefatigable Field in the UK southern sector. The two companies plan to drill further prospects in this and the Sole Pit area under a fast-track production initiative using existing pipelines.
An older discovery to the north is Conoco's Boulton, which is a strong candidate for a subsea development through the Caister Murdoch complex, probably with three production wells. The project looks imminent now that Eastern Natural Gas has signed up for $150 million of supplies during the field's estimated 16-year life.
Another contract recently concluded for a pipeline in this sector, the Interconnector, involves British Gas exporting 20 bcm over 10 years to Wingas, the joint venture between Wintershall and Gazprom. Construction of the Interconnector is about to get under way, with first gas due to land in Zeebrugge in fall 1998. Earlier this year Wingas also contracted 1bcm/yr from Conoco through the same pipeline. All the gas is destined for the German market.
Another German marketer, Verbundnetz Gas, recently negotiated a six-year extension on Norwegian gas supplies from the Oseberg Group of companies, maintaining annual deliveries of 4 bcm until September 2016.
MAST oilfields transferred to Canada
Canadian oil companies have been busy again in the North Sea. Talisman Energy has acquired BP's stakes in the Beatrice, Buchan and Clyde Fields which currently generate 37,000 b/d. Talisman's share will be close to 20,000 b/d, on top of its existing share in Buchan.
The fields are part of the MAST asset group, all mature production units which have collectively undergone various production extension programs. But BP was keener to sink its resources into new developments, of which it has plenty in the North Sea and the Shetland area. Talisman will become operator of the three fields next January: earlier this year it also bought out BP's interest in the Ross prospect.
PanCanadian North Sea has acquired interests in 22 blocks and part blocks from Oryx UK, through agreeing to fund $55 million of exploration and appraisal costs. The company also plans further UK farm-ins and acquisitions.
In the Dutch sector, it has done a similar deal, financing the drilling of exploration well L/16a-3, operated by Continental Netherlands Oil, in return for 50% of this block and 37% of Continental's block K/18b. The well was targeting a Lower Cretaceous sandstone oil prospect in the west of the block, which in the event turned out dry.
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