NORTH SEA YIELDS OIL IN FIRST SALT DOME PLAY

BP Exploration has found as much as 660 million bbl of oil equivalent in a cluster of fields in the first diapir salt dome play in the North Sea.

Six fields in an area about 18 miles south of Forties field hold oil and gas/condensate reservoirs.

Reserves are split evenly between the two.

BP said appraisal of one of the fields, Mungo in Blocks 23/16a and 22/20, boosted development prospects for the area. Drilling is continuing on the prospect, which holds an estimated 130 million bbl of oil.

Elsewhere in the North Sea action, Shell U.K. Exploration & Production received approval to develop Nelson field in U.K. North Sea Blocks 22/11, 22/6a, 22/12a, and 22/7 at a cost of !21.1 billion ($1.8 billion).

SALT DOME HYDROCARBONS

In addition to Mungo, BP's salt dome play includes Monan field in Block 22/20 and Medan in Block 23/22a, which have about 60 million bbl of oil between them.

The first three discoveries in the area were Marnoch in Blocks 22/24a and b, a gas/condensate field with 170 million bbl of oil equivalent (BOE), Machar in Block 23/26a, predominately oil with associated gas and about 100 million bbl of oil equivalent, and Erskine, also in Blocks 23/26a and b, a 200 million BOE gas/condensate field.

John Browne, BP Exploration chief executive, said confirmation of Mungo brought reserves in the area to a level at which an integrated development scheme could be considered.

The fields are close together and adjacent to the Forties pipeline system.

Browne said, "We would expect these factors to produce an attractive development cost per barrel."

A phased development program is likely.

License holders in Blocks 23/16a and 22/20 are BP, Hamilton Oil GB plc, Ultramar Exploration, Ocean Exploration Co Ltd., Murphy Petroleum Ltd., Monument E&P plc, and Fina Exploration U. K.

In Block 23/22a BP's partners are Fina, Phillips Petroleum Co. U.K., Agip U.K. Ltd., Gas Council Exploration, and Ultramar.

In Blocks 22/24a and b the partners are Agip, Shell U.K. Ltd., and Esso U.K. plc. in Block 23/26b the partner is Texaco North Sea Ltd.

BP holds a 100% interest in Block 23/26a.

NELSON DEVELOPMENT

Nelson field has 450 million bbl of oil and 185 bcf of gas. It will be developed through a single drilling and production platform capable of handling a peak flow of 160,000 b/d of oil and 65 MMcfd of gas.

Work on the project began ahead of the formal approval. Shell has placed 300 million ($492 million) worth of orders.

Production is to start early in 1994.

Oil will move through a 15 1/2 mile, 20 in. line into the Forties pipeline system. Gas and NGL will be linked into the Fulmar gas line through a 30 mile, 10 in. line.

Nelson will require 36 wells. The current plan calls for 20 producers and seven water injectors from the platform and a subsea development 3.6 miles to the south consisting of eight production wells and three water injectors.

Shell will operate the first phase of the project. Enterprise Oil plc will take over all development drilling and operate the field when it starts production.

Interest owners are Enterprise in 22/11, Shell-Esso in 22/6a, BP-Mobil North Sea in 22/12a, and Total Oil Marine-Elf U.K. Ltd. in 22/7.

OTHER U.K. ACTIVITY

Among other activity off the U.K., BP tested 12.4 MMcfd of gas and 1,160 b/d of condensate through an 18/64 in. choke with a wellhead flowing pressure of 9,400 psi from its 30/2a-2 well in the Central U.K. North Sea.

The well was drilled to 14,842 ft. BP said the flow was restricted by high temperatures.

BP said the deep high pressure, high temperature well was a significant technical challenge and came in 25% under budget, representing savings of 92.5 million ($4 million).

BP's southern U.K. North Sea wildcat 49/1 lb, about 5 miles north of Audrey field, flowed 43 MMcfd of gas and 360 b/d of condensate through a 1 in. choke from Rotliegendes sandstone.
Block 49/11b is operated by Conoco (U.K.) Ltd., but the well was drilled by BP and financed by OMV (U.K.) Ltd., a unit of Austria's state oil company, to earn a 50% interest in the acreage. BP and Conoco are left with 25% each.
In the northern North Sea, Lasmo North Sea plc said four tests of the Upper Jurassic Brae at 13,250-13,896 ft in its 16/12a-14 wildcat on the Pine prospect in Block 16/12a produced a combined 12,766 b/d of oil.
The block lies between the Miller and "T" block development projects. It contains three other discoveries: North Birch, South Birch, and Elm. Further drilling is to begin immediately after the well is suspended to allow reentry later.
The final test flowed 5,130 b/d of 38' gravity oil and 2.54 MMcfd of gas through a 1/2 in. choke with 2,163 psi wellhead pressure.
Partners in the well are Sun Oil Britain Ltd., Hardy Oil & Gas (U.K.) Ltd., and British Gas Exploration & Production Ltd.
Ranger Oil (U.K.) Ltd. completed an appraisal of a 1976 discovery in Block 23/27, about 6 miles northeast of the Machar prospect. The well flowed 6,200 b/d of 38 gravity oil. It is to be sidetracked for further evaluation of the reservoir.
Elf Enterprise Caledonia received government approval to develop Chanter field in U.K. North Sea Block 15/17 as a subsea satellite to the Piper B platform, currently under construction. Production from the 3.2 million bbl Chanter oil reservoir is expected to begin in summer 1992, and a gas/condensate reservoir will begin production in 1996.
Amerada Hess Ltd. let contract to Rockwater Ltd., Aberdeen, for transportation and installation tie-in and testing of subsea structures in Scott oil field development in the U.K. North Sea during 1992 and 1993. The subsea system consists of three water injection manifolds, a pig receiver, a pipeline end manifold, and a production structure.
Hamilton Bros. Oil & Gas sold the entire production from Hamilton field in Block 110/13 in the U.K.'s share of the Irish Sea as fuel for a cogeneration plant planned by PowerGen plc at Connah's Quay, North Wales.

Deliveries are to start in October 1994 under a 27 year contract that is conditioned on U.K. government approval of a field development plan.

Hamilton faces government imposed restrictions in drawing up the development plan.

Because the field is in a major shipping lane, the project will be limited to a single platform.

Hamilton Oil Great Britain plc owns a 45% interest. Its partners are Ultramar Exploration Ltd. 30% and Monument Resources Ltd. 25%.

NORWEGIAN NORTH SEA

Off Norway, Den norske stats oljeselskap AS declared commercial Huldra gas/condensate field in North Sea Blocks 30/2 and 30/3.

Huldra, west of Veslefrikk oil field, holds reserves of 494 bcf of gas and 25 million bbl of condensate and could be developed as a satellite of an existing field in the area. Statoil said the earliest startup date would be fall 1995.

Statoil's partners in the field are Conoco Petroleum Norge AS, Total Marine Norske AS, Deminex (Norge) AS, Norsk Hydro Produksjon AS, and Svenska Petroleum Exploration AS.

Norsk Hydro AS, operator for Brage field in Norwegian North Sea Block 31/4, let a 145 million kroner ($20.7 million) contract to European Marine Contractors Ltd. to lay an 8 mile, 12 in. oil line from the Brage platform to the Oseberg field center and a 4 mile, 8 in. gas line to a connection on the Statpipe gas pipeline. Work is scheduled for completion by fall 1992. Brage is due to produce first oil in January 1994.