Broken Hill Proprietary Co. Ltd. (BHP), Melbourne, on Monday revealed that the Atlantis-2 appraisal well in the US Gulf of Mexico found a further 200 ft of net oil pay, in addition to the oil-bearing Miocene sands reported in July (OGJ Online, July 18, 2000). This additional zone brings the total net pay to over 500 ft.
Operator BP drilled the appraisal well to 18,600 ft TD in the Atwater Foldbelt ultradeepwater area of the gulf. Interests in the well are BP, 56%, and BHP, 44%.
Atlantis-2 was drilled on Green Canyon Block 743 in 6,675 ft of water with the dynamically positioned drillship C.R. Luigs, owned by Global Marine Inc. A sidetrack will now be drilled from the existing Atlantis-2 wellbore to secure further data on the lateral extent and nature of the reservoirs, which will be important in determining the resource volumes, says BHP.
The Atlantis-1 discovery well was drilled in 1998 on Green Canyon Block 699, 3 miles to the northeast of the appraisal well; it also encountered oil-bearing Miocene sands.
BHP said Atlantis is one of three joint BHP-BP discoveries in the Atwater Foldbelt. These include Neptune, in which BHP owns a 42.5% interest. First discovered in 1995, Neptune is 16 miles northeast of Atlantis.
Another joint discovery is Mad Dog, in which BHP holds a 23.9% interest. Mad Dog is a similar distance to the southwest of Atlantis. Net pay of 440 ft has been reported at the field, which was discovered in 1998.
A second appraisal well on Mad Dog will start drilling within a few weeks, says BHP.