Enterprise's Corrib Gas Field Gets Second Successful Appraisal

Corrib Field, 70 km from Achill Island, off the west coast of Ireland, has passed its second appraisal. Well 18/25-1 is located in Block 18/25 in the Slyne Trough at a water depth of 350 meters, and is two km from the first appraisal well, 18/20-2z. It was drilled by the Sedco 711 semisubmersible rig to 3,741 meters total vertical depth subsea in the Triassic Sherwood sandstone. The well achieved test rates of up to 64 million cf/d gas through a 1 1/4 inch choke with a flowing wellhead pressure of 1,653 psi. This test rate was limited by the testing equipment.

Block 18/25 was awarded to Enterprise as part of License 2/93 in 1993. The Corrib discovery was made in October 1996. A 420 sq km 3D seismic survey was acquired over the area in 1997, which was followed by the successful test on the well 18/20-2z in 1998.

John McGoldrick, General Manager Ireland, commented: "This is the second good result we have had on Corrib. We have successfully delineated the southern end of the reservoir. The results will require further evaluation but have already demonstrated enough reserves to begin development feasibility studies, and enhance the prospectivity of our acreage in the area. The next step is to drill the Shannon prospect which lies some eight km south of Corrib, and we hope this will meet with even further success."

Co-venturers in Block 18/25 are: Enterprise Oil plc, the operator, with 45%, Marathon International Petroleum Hibernia Ltd, with 18.5%, Statoil Exploration (Ireland) Ltd, with 15%, Saga Petroleum Ireland Ltd, with 21.5%.

Enterprise has been active in Ireland since 1984 and currently holds 36 offshore blocks. The company is one of the most significant players in the Irish offshore industry.

Initial indications suggest that Corrib gas is of excellent quality being very dry and free of contaminants. Subsea development of the field is likely due to water depth. Feasibility studies on pipeline routes together with market assessments are currently underway. Currently, Kinsale Head is Ireland's sole source of indigenous gas, but it is in decline. Fifty percent of Ireland's needs (350 million cf/d) were met by imports in 1998).