Baldpate Field Exploration History, Garden Banks 260, Central Gulf Of Mexico

Okuma, Angelo, and Brian Boslaugh, Amerada Hess Corporation, Houston, TX

Abstract

Baldpate field is situated 195 miles southwest of New Orleans, Louisiana, in 1650 ft of water, in the central Gulf of Mexico. Proved and probable reserves are estimated at over 100MMBOE covering OCS Blocks 259 and 260.

Baldpate was discovered in 1991 by the Amerada Hess operated well, Garden Banks 260 #1, and penetrated 180 net feet of pay. Primary reservoirs were Pliocene turbidite sands having excellent reservoir quality, which were production teste d at a combined rate of 6496 BOPD and 24,525 MCFGD.

Rock property modeling revealed hydrocarbon-bearing sands will have a high amplitude negative reflection coefficient on the stacked section and an increased (more negative) amplitude with offset. Using a 3D time migrated volume, four ap praisal wells were drilled to evaluate the amplitude anomaly in down-dip, up-dip, and sub-salt positions. Even though the Baldpate reservoirs were visible on 2D and 3D seismic, two of the four wells were unsuccessful, proving the misleading nature of time migration and the justification for 3D pre-stack depth migration when imaging around complex salt bodies.

Four additional wells have been drilled to evaluate seismic amplitude anomalies in separate fault blocks north of Baldpate on Garden Banks 215 and 216. All of these wells have been successful. The Baldpate North accumulation will be dev eloped from the platform while the Penn State satellite field is produced via a subsea-tieback to the compliant tower.

Amerada Hess and 50% partner, Oryx Energy/Kerr-McGee, are developing the Baldpate reserves using a compliant tower, with the first oil coming on-stream in September 1998. Peak production from Baldpate and its satellite accumulations is expected to exceed 55,000 BOPD and 200 MMCFGD.