Offshore Europe Banner Saga adds to Halten Bank gas pool

Elf has added to its Piper area empire through the newly flowing satellite Iona.

Well 6406/2-3, drilled by Transocean Arctic to a planned T/D of 5,400, is one of the deepest on the Norwegian shelf. The new discovery, provisionally called the A structure but since renamed Kristin, lies in Jurassic formations and extends at its northern end into Statoil-operated block 6506/11, the licensees of which co-financed the well costs. Reservoir pressure is described as very high.

Two years ago, Saga discovered on the same block Lavrans (ex-B-Structure), estimated to hold 80 bcm of gas, 150MM bbl of condensate and 10MM tons of NGLs.

The latest find comes too late to impact upcoming gas allocations from the ?sgard area, although Lavrans had been under review. It coincides with a hectic period for Saga. Having just acquired the North Sea assets of Santa Fe, it has now entered a deepwater alliance with Total to issue joint applications for new acreage along the Atlantic Margin, from the Shetlands (where Total is believed to have a recent gas discovery) down to western Ireland. The two will also pool expertise and resources in deepwater exploration and development.

Concurrently, Saga's Vigdis Field has come onstream five months early. Twelve subsea wells will output 100,000 b/d at peak to the specially modified Snorre platform, seven km away.

Landmark projects lift construction sector

Kverner has landed EPIC contracts for two of the North Sea's outstanding development projects, ?sgard B and Siri. This follows a quiet spell workwise in the North Sea for the engineering contractor, but the awards compensate for missing out on the Troll C semisubmersible platform to Umoe Haugesund.

Particularly ?sgard. The $1 billion contract for what will be Norway's first floating gas production platform is also the sector's costliest. Following a period of integrated engineering and project management between Kaverner and Statoil, on the lines of their partnerships on Sleipner West and Norne, topsides construction will start at the Kverner Rosenberg yard, Stavanger, next March. The topsides and hull, measuring 115 x 96 meters, will weigh 45,000 tons without the operating deck load, and will be able to export 38 million cm/d of rich gas and 94,000 b/d of condensate. On top of this, 41,000 bbl of partly stabilized crude will come onboard daily for transfer to the ?sgard A production ship.

Siri, operated by Statoil, is Denmark's major oil discovery of recent times. The EPIC contract, valued at $230 million, will involve development through a manned production jack-up situated on a steel storage tank on the seabed, with a loading buoy and flowlines allowing gas and water reinjection. At one point a floater looked likely for this marginal discovery, in 60 meters of water, but Statoil may have been swayed by the performance of the jackup on the Yme Field - also a short-term production project. At this stage Statoil says production from Siri (due onstream late 1998) could last anywhere from five to 12 years. Another non-Danish operator, Amerada Hess, is also expected to announce field development plans in the sector shortly.

Rig demand continues upwards

Rig utilization rates in the North Sea reached 100% last year, according to Edinburgh analysts Wood Mackenzie, despite an 8% hike in the marketed fleet to 81 units. In 1997, demand for semis could outstrip supply by almost one rig-year; jackup requirements, by contrast, are expected to slip back as the year passes. Deepwater semis currently command $130,000/day in the North Sea, while heavy duty jackups average over $98,000, with HP/HT work fetching the highest price.

Bruce gets an extension

Confirmation of government approval for BP's Bruce Phase 2 enlivened a latterly quiet UK development scene. An extra 728 bcf and 61MM bbl of oil and condensate in the western area will be drained through two eight-well subsea manifolds linked by a bundled pipeline to facilities on a new steel platform. This itself will be bridge-linked to the extant Bruce platforms, in 122 meters of water, and will feature a high pressure gas compressor for reservoir reinjection, thereby aiding oil and condensate recovery. Four of the wells should be drilled and tied back to the manifold by summer next year, allowing first production in October 1998, peaking at 450 MMcf and 45,000 bbl of liquids per day. Phase 2 will bring total spending on Bruce to #2.85 billion.

Elsewhere in the UK sector, operators continue to re-evaluate long-dormant small discoveries, thanks to the wonders of floating production technology. East of the Shetlands, Conoco reveals that Maclure (22MM bbl) and Sorby (gas/condensate) are both in line for standalone FPSO or FPSO tieback developments. Texaco has chartered the semi Northern Producer to produce its 20MM bbl Galley Field in block 15/23a, ideally by the end of this year. Oil will be piped to the Tartan platform. Enterprise, however, decided after long deliberations that the 10MM bbl Sedgwick in block 16/6 didn't really warrant its own floater; instead, the crude will be directed 2 km to the West Bre manifold as a subsea tieback.

Just one new UK start-up to report: Elf's Iona, initially at 4,400 b/d, through deviated wells drilled from the Saltire A platform. Further reservoir tests over the next few months should boost production, which heads to Flotta via the Piper B minimal facilities platform. Development and operating costs are estimated at #27 million.

Spar bidders approach deadline

Shell UK Expro has narrowed to six the consortia bidding to decommission the Brent Spar. The usual, heavyweight contractors have been detailed to develop 11 different ideas for re-using the Spar's components or scrapping them onshore. Five of the groups must also progress their ideas for raising the Spar from the water safely - the hardest task.

Commercial bids are due in end-April. Following analyses by Shell and independent review specialists over the next few months, a new disposal solution may be submitted to the UK government by year-end. Assuming this is approved, decommissioning could ensue in spring 1998. It may be that several of the ideas are merged into one solution. Shell claimed it was costing #20,000 a month to keep the Spar stationed off Erfjord, Norway.

Among the notions for raising the Spar, three involve a vertical lift whereby water in the tanks would be replaced by compressed gas, to prevent the hull from collapsing from the outside sea pressure. This operation could be controlled remotely to reduce safety risks. Another idea involves placing a lifting cradle under the Spar, connected by cables to jacks on barges moored alongside. These cables would be jacked upwards to raise the Spar vertically.

Amoco, which has also commissioned exhaustive studies concerning the approaching demise of the North West Hutton platform in UK block 211/27, has decided instead to try to increase production through enhanced recovery techniques, under an alliance with Schlumberger. Wintershall, however, is proceeding with the removal and dismantling of its Dutch sector K-13B and K-10C gas production platforms. The job should be awarded and under way by this summer. The platforms and jackets are not huge, however, weighing respectively 970 tons and 1,640 tons in water depths up to 28 meters.

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