Apr. 2012 - Anadarko completes the Mercury-2 appraisal well in Sierra Leone. The well encountered water-bearing reservoirs with oil shows. The Mercury-2 well, drilled 7 miles (12 kilometers) northwest of the Mercury-1 oil discovery, targeted an area where the extensive 3D seismic coverage indicated a high probability of finding thick reservoir quality sandstones. It intersected over 886 feet (270 meters) of reservoir quality sandstones which were water bearing with oil shows at this location. The Discoverer Spirit (UDW drillship) drilled Mercury-2 to a final depth of 16,870 feet (5,142 meters) in a water depth of 5,955 feet (1,815 meters).

Mar. 2011 - Anadarko has finalized plans for its 2011 drilling campaign in the Liberian Basin. To perform this program, the company intends to mobilize the Discoverer Spirit drillship to West Africa to drill an appraisal well on its Mercury field, located about 7 miles (11 kilometers) west of the Mercury discovery well offshore Sierra Leone in Block SL-07B-10. The company also plans to drill the Jupiter exploration prospect on the same block later in the year, which the company operates with a 65% working interest. Anadarko will also drill the Montserrado exploration well on Block 15 (operated by Andarko with a 57.5% working interest) offshore Liberia. Further to the east, on Block 10, Anadarko recently acquired 593,053 acres (2,400 square kilometers) of 3D seismic data. Processing of the survey is expected to take about six to nine months, and with the acquisition of this data, Anadarko will have 3D seismic information covering virtually all of its acreage in the Liberian Basin, stated the company.

Nov. 2010 - Anadarko made a discovery in the Mercury-1 exploratory well offshore Sierra Leone, encountering about 135 net feet (41 meters) of oil pay in two Cretaceous-age fan systems. Drilled to a total depth of 15,950 feet (4,862 meters) in about 5,250 feet (1,600 meters) of water, the well hit about 114 feet (35 meters) of light sweet crude oil with gravity between 34 and 42 degrees API, with no water contact in the primary objective. An additional 21 net feet (6 meters) of 24-degree gravity crude was encountered in the shallower secondary objective. Anadarko stated the wellbore is being preserved for possible re-entry, drillstem testing or a down-dip sidetrack to further delineate the reservoir's areal extent, quality and deliver ability. Mercury is located on offshore Block SL-072-10 about 40 miles (64 kilometers) southeast of the Venus discovery, which Anadarko operates with a 65% interest. Partners on the block include Repsol Exploration Sierra Leone (25%), and Tullow Sierra Leone B.V. (10%). Once operations are complete at the Mercury well, Anadarko plans to mobilize the drillship to Ghana to accelerate the appraisal program at the Owo and Tweneboa fields, anticipated to commence in 2011.