Marathon Oil U.K. Ltd. and partners have gauged the first reported hydrocarbon strike in St. George's Channel between Wales and Ireland.
Marathon completed two tests of its 103/1-1 frontier wildcat, drilled in 318 ft of water to target formations below 7,500 ft.
The first test of 124 ft of Jurassic perforations flowed at a stabilized rate of 21 MMcfd of gas, 120 b/d of 42 gravity liquid hydrocarbons, and 55 b/d of water through a 72/64 in. choke with 800 psi flowing tubing pressure. Analysis showed most of the water was from drilling fluids.
A second test included the first interval and another 15 ft of perforations about 75 ft below the original pay. It flowed 19 MMcfd of gas, 70 b/d of liquid hydrocarbons, and 215 b/d of water through a 60/64 in. choke with 986 psi flowing tubing pressure. Analysis showed most of the produced water was formation fluid.
A Marathon official said the company is encouraged by the find-but cautious.
No further drilling is planned this year, due to the working window imposed by environmental restrictions on the license. Further drilling can take place starting in mid-1995 at the earliest.
Seismic surveys are under way and expected to be finished early in December.
Drillsite is 24 miles off the coast of Wales, 26 miles off Ireland, and about 100 miles northeast of Marathon's Kinsale Head and Ballycotton gas fields off southern Ireland.
Marathon was awarded seven blocks in the St. George's Channel in the 14th U.K. licensing round of 1993. They are Blocks 102/10, 103/1, 103/6, 106/27, 106/18, 106/19, and 106/23.
Block 103/1 interests are operator Marathon 60%, Seagull U.K. Ltd. 20%, Santos Europe Ltd., Guildford, U.K., 12.5%, and Oranje-Nassau Petroleum Search By 7.5%.
Copyright 1994 Oil & Gas Journal. All Rights Reserved.
Issue date: 11/07/94