HOUSTON, Mar. 26�A successful appraisal well both confirmed earlier commercial expectations of the deepwater Gunnison prospect in the Gulf of Mexico and extended its reservoir boundaries more than a mile to the west of the original discovery, two of the partners in that project said Monday.
The Garden Banks 668 No. 2 well, drilled 1 mile to the west, and a follow-up sidetrack, drilled updip 1.5 miles, confirmed the lateral extent and continuity of reservoirs encountered in the discovery, said officials of both Kerr-McGee Corp. in Oklahoma City and Nexen Petroleum USA Inc., Calgary.
�These are important wells,� said Charlie Fischer, executive vice-president and chief operating officer of Nexen Inc., formerly Canadian Occidental Petroleum Ltd., and parent of the Nexen Petroleum subsidiary.
The wells �confirmed our seismic model of the area, giving us confidence in our original estimate of Gunnison area reserves in the 150-250 million equivalent bbl range. This will make development of Gunnison an attractive commercial project,� he said.
However, officials at Kerr-McGee, which is operator with 50% interest in Garden Banks Blocks 667-669 to Nexen�s 30%, say more appraisal drilling is needed before they begin planning development and production. �The remaining 2001 drilling program in the Gunnison area is designed to further evaluate � and refine potential development options,� said Luke R. Corbett, chairman and CEO of Kerr-McGee.
In addition to the Gunnison discovery, those blocks also contain the Durango and Dawson prospects.
The Garden Banks 668 No. 2 has been suspended as a potential future production well, officials said.
The 17,000-ft discovery well was drilled by Noble Drilling Corp.�s upgraded semisubmersible rig, the Noble Amos Runner, in 3,150 ft of water in Garden Banks Block 668 and encountered 275 ft of net pay in three main zones (OGJ Online, June 5, 2000).
A subsequent 19,147-ft sidetrack encountered an oil column with some 350 ft of net pay about a quarter-mile north of that discovery.
Another appraisal well, the Garden Banks 668 No. 3, is being drilled 2.5 miles west of the discovery. A planned sidetrack of that well will test the separate Durango satellite prospect in the adjacent Garden Banks Block 667.
Following that completion, the same rig is expected to drill the Garden Banks 668 No. 4 to appraise the northerly downdip, officials said.
�We have a very attractive acreage position within the Gunnison sub-basin and see significant additional upside in the larger area,� said Fischer. �In addition, with interests in more than 100 blocks throughout the deep water of the Gulf of Mexico, we have one of the largest acreage holdings in this region and are well positioned to expand upon our success there. This year Nexen anticipates drilling six to eight more exploration wells in deep water.�
Kerr-McGee holds interests in more than 25 blocks in the greater Gunnison area. Corbett earlier said those holdings provide an �opportunity to develop yet another core area in this high-potential trend.�
The third partner in the Gunnison prospect is Cal Dive International Inc. with 20% interest.
