Blake extension opens development path

June 1, 1999
In the UK Central North Sea, Talisman has proven an extension of the British Gas operated Blake discovery into block 13/29b. The 13/29b-6 appraisal well tested 3,950 b/d of 32° API oil from a thick section of Lower Cretaceous Captain sands. However, another exploration well - 13/23a, 8 km west of Blake - came up dry.

In the UK Central North Sea, Talisman has proven an extension of the British Gas operated Blake discovery into block 13/29b. The 13/29b-6 appraisal well tested 3,950 b/d of 32° API oil from a thick section of Lower Cretaceous Captain sands. However, another exploration well - 13/23a, 8 km west of Blake - came up dry.

BG and its partners had been struggling to justify a standalone development for Blake. Now they are leaning towards subsea facilities tied back to the Ross Field FPSO, 5 km to the south of the Blake extension. Ross produced its first oil in April - the Bleo Holm floater is leased by Bluewater. Oil and gas production is building up to around 40,000 boe/d as water injection gets under way. Gas is piped 25 km to the Frigg UK export line.

The newbuild hull had an extended stay of 22 months at UIE's yard in Clydebank, Glasgow. Latest estimates put the Åsgard A production ship at NKr 7.5 billion, compared with the budgeted figure of NKr 5 billion, while the Åsgard B gas production semisubmersible has spiralled from NKr 8.4 billion to NKr 11 billion. Statoil chief executive Harald Norvik blamed changes in the project's scope and unrealistic cost targets. Åsgard is the world's largest undertaking with 57 development wells.

Floater pioneer Amerada Hess has also faced problems with two projects in the UK sector. Over-optimistic reservoir estimates - forced an early end to production from the Durward/ Dauntless fields, which yielded just 11 million bbl of oil since coming onstream in August 1997. The FPSO Glas Dowr is now on the market for relocation. Production from Amerada's Fife area fields has also been suspended for four months, while the Uisge Gorm FPSO undergoes repairs stemming from an over-pressured cargo tank.

Licensing changes for sagging UK sector
Phillips has issued the FEED contract for its Jade development in the UK central sector to Amec. Jade is an HP/HT gas condensate field, discovered in 1996 in 260 ft of water, just nine miles north from the Judy platform. Phillips and its co-venturers have decided on a dedicated unmanned platform for Jade (jacket and topsides weighing 4,700 tons) which will be linked to the Judy installation by a 16-in. multiphase pipeline. Reserves are around 100 million boe, requiring perhaps four development wells.

The eventual award of the platform may forestall closure at one of several UK yards which are rapidly running out of North Sea work. Barmac has already laid off hundreds at its two sites in Scotland. A similar pattern is emerging in Norway, where Kvaerner is contemplating a closure next year. The future at Aker Maritime's yards is also uncertain, with major shareholder Aker RGI considering selling off the division altogether.

The UK's situation is more dire, with no major developments in prospect barring an oil price surge. The government has unveiled new measures which include:

  • Rounds offering unlicensed blocks every two years (including West of Shetland)
  • More flexibility over fallow block programs
  • One-month approval targets for fast-track development plans, with a slimmed-down, 15-page application document to cut costs.

Location of Jade in relation to the main J-block discoveries.

Click here to enlarge image

Gas export schemes taking shape
Owners of the Frigg Norwegian pipeline are planning a new venture to step up Norwegian gas exports to Scotland. The venture, Vesterled (Viking for "westward"), would invest in a new line carrying gas processed from the Norsk Hydro-operated Heimdal platform north to Elf Norge's Frigg platform. Currently, two export lines extend from Frigg to St Fergus on Scotland's east coast. According to Total Oil Marine, supplies via the new line could flow to St Fergus in 2002.

Also in the Norwegian North Sea, Norway's Gas Supply Committee has submitted Hydro's Tune Field to cover shortfalls in gas export contracts to mainland Europe. Tune, with reserves of 20 bcm, has been allocated 2.9 bcm/yr from 2002-2006 through existing trunklines, dipping to 2.5 bcm from 2007onwards. A PDO is expected this month for the field involving a four-slot template tied back to Oseberg via twin flowlines.

Saga is claiming that the recently issued PDO for its Borg Field (ex-H Central) would break even at $8.10/bbl. The 75 million bbl oilfield would output 15,000 b/d during a first development phase through a previously tested well, with oil heading to the Gullfaks C platform for processing by way of the Tordis subsea facilities. A second phase could bring further tie-ins to Gullfaks C, doubling production during 2001. The cost of the project is estimated at NKr 800 million.

Elsewhere in the sector, production from Elf's Frigg gas condensate satellite Lille Frigg was terminated early due to production/oil price problems. The subsea facilities, plus those at East Frigg and the entire Froey platform (Elf), are already being marketed for re-use by Netherlands-based WEB Platform Brokers. Froey's installation, which only came onstream five years ago, is expected to be available from next year or 2001. Production has been below expectation with some of the wells hit by clogging or scale formation.

Further awards off Denmark, Ireland
Two newcomers have been awarded offshore acreage under Denmark's open door licensing procedure, which applies to waters east of the mature Central Graben. Some of the blocks won by service company Gustavson adjoin the Skagerrak area just north of the median line with Norway. This zone has been closed off to drilling for environmental reasons.

According to analysts Wood Mackenzie, Gustavson is investigating potential Jurassic structural types (Haldager and Gassum sandstones) which may contain hydrocarbons that migrated south from the Farsund basin.

South-west of this acreage, US independent Anschutz was granted 13 blocks of which the southernmost four extend into the Ringkoebing Fyn High and the Horn Graben. Anschutz's chief exploration target is Rotliegendes gas - again, unproved so far in Denmark, although common elsewhere in the North Sea. Elf Petroland, for instance, has just disclosed another discovery in block K5a, drilled to a total depth of 4,140 meters, which flowed 750,000 cu meters/day from a Rotliegendes play.

Off western Ireland, two licences were the sum total arising from the second Porcupine Basin round. The new licences, operated by Agip and Elf, cover blocks in quadrant 43 and 44, 200 km offshore, in waters 1,100-2,500 meters deep. No wells are thought to have been pledged.

However, there could be some activity in the shallow North Celtic Sea Basin, where Dublin-based Providence Resources has issued tenders to develop the Helvick oil and Ardmore gas accumulations in Block 49. An integrated scheme embracing another prospect in block 50.11 is also a possibility.