|
Appraisal drilling extends BP’s Mad Dog field in Gulf Well, three sidetracks encounter 300 feet of net oil pay on Gulf of Mexico field’s untested southwestern flank; BP, other owners consider options Ray Tyson Petroleum News Houston Correspondent
The BP-operated Mad Dog field in the deepwater Gulf of Mexico, already a sizeable discovery by Gulf standards, appears to house a much larger oil accumulation than initially thought.
An appraisal well and three sidetracks confirmed “significant hydrocarbon pay” on the previously untested southwestern flank of the producing Mad Dog field, according to Unocal, a partner in the Mad Dog project.
“We are pleased with the results of this appraisal program which has extended the limits of the Mad Dog field,” Joseph Bryant, Unocal’s president and chief operating officer, said March 22.
Well penetrations individually encountered up to about 300 feet of net oil pay in the early Miocene section and found hydrocarbons some 700 feet deeper on the western flank of the structure than previously encountered, the company said.
The appraisal well was drilled to a measured depth of 22,890 feet from Green Canyon Block 826 to down dip targets in adjacent Block 825, Unocal said, adding that the blocks are situated in about 5,000 feet of water. Discovery could warrant own facility The discovery apparently is large enough to warrant its own production facility, or could be tied back to the existing Mad Dog platform, Unocal indicated.
Unocal said prior to the March 22 announcement that additional exploration drilling at Mad Dog could prove up as much as 450 million barrels of oil equivalent reserves. Unocal and its partners also may test the deeper tertiary zone that underlies Mad Dog.
The Mad Dog field, located on Green Canyon Block 782, was discovered in 1998 and began producing in January 2005. The field currently yields about 30,000 barrels of oil per day from two wells, but is expected to increase over the next year as additional wells are completed and brought online. The facility is designed to process about 100,000 barrels of oil and 60 million cubic feet of gas per day.
Construction of Mad Dog’s spar components and topsides began in 2002 in Pori, Finland and Morgan City, La. The overall capital cost of the project was estimated at about $1.5 billion. Three discoveries on Atwater Fold Belt trend The new discovery at Mad Dog again demonstrates the prolific nature of the Atwater Fold Belt trend, which in addition to Mad Dog has given rise to BP-operated discoveries Holstein and Atlantis.
Unocal owns a 15.6 percent working interest in the Mad Dog project. Operator BP owns a 60.5 percent interest. Australia’s BHP Billiton holds a 23.9 percent share.
Meanwhile, the Unocal-leased Discoverer Spirit drillship has moved from Mad Dog to drill Unocal’s highly prospective Knotty Head prospect on Green Canyon Block 512, which drew some of the highest bids in last year’s Central Gulf of Mexico lease sale. Knotty Head is located just north the of the giant Tahiti discovery operated by ChevronTexaco.
The ship is then scheduled to drill a third appraisal well at Unocal’s big St. Malo discovery on Walker Ridge 677. Following St. Malo, the drillship will be sub-leased to another company. Unocal’s commitment to the Discoverer Spirit terminates in September, Unocal said.
| 