africa west coastBP has made its 17th and 18th discoveries on...

africa west coast

BP has made its 17th and 18th discoveries on ultra-deepwater Block 31 offshore Angola. The discoveries, Leda and Oberon, are in the southern portion of the block 258 miles (415 km) and 208 miles (335 km) northwest of Luanda, respectively.

Leda was drilled in a water depth of 6,791 feet (2,070 m) and reached a total depth of 19,379 feet (5,907 m) below sea level. This is the fifth discovery in Block 31 where the exploration well has been drilled through salt to access the oil bearing sandstone reservoir beneath. The well was tested at a rate of 5,040 b/d of oil through a 36/64ths inch choke.

Oberon-1 was drilled in a water depth of 5,328 feet (1,624 m) and reached a total depth of 11,883 feet (3,622 m). The well test results confirmed the capacity of the reservoir to flow in excess of 5,000 b/d under production conditions. The well was drilled by Transocean drillship GSF Explorer, which will continue to operate in Angola for BP through September of this year.

Tullow Oil has discovered a highly-pressured light hydrocarbon accumulation at the Tweneboa-1 exploration well in its Deepwater Tano license in 3,766 feet (1,148 m) of water offshore Ghana.

The well, drilled to a depth of 12,969 feet (3,593 m), encountered 69 feet (21 m) of net pay. The well is now being deepened to further assess the discovery and the up-dip limit of a potential deepwater fan system. The well was drilled by Ocean Rig semisubmersible Eirik Raude.

Offshore rig market

As with the rest of the world, the West Africa rig market has softened. Day rates for all rig types in the area have declined. Despite recent downward trends in the market, offshore rig demand will turn around and rise in the region through 2009 and into 2010, according to ODS-Petrodata's World Rig Forecast - Short Term Trends.

Kosmos Energy, which has pulled together US$750 million for the project, and its partners are executing a phased development plan for Jubilee, which is on the West Cape Three Points Block and adjacent Deepwater Tano Block. Kosmos, the technical operator for development of the Jubilee field and operator of the West Cape Three Points Block, expects first oil production to begin in late 2010. The company believes that phase-one development will produce over 300 million barrels of oil at a rate of 120,000 b/d.

The Jubilee development is based on conventional subsea technology located in around 4,265 feet (1,300 m) of water tied to a turret-moored floating production, storage and offloading vessel (FPSO). The phase-one development plan calls for up to 17 wells, comprised of up to nine oil producers, five water injection wells and three gas injection wells. Water, and possibly gas, injection wells are intended to enhance production and maximize oil recovery by maintaining reservoir pressure. The development process has been designed so that produced gas will be available for export to shore and/or reinjected into the reservoir, thereby eliminating gas flaring.

Kosmos estimates that the Jubilee field could potentially hold recoverable oil and gas reserves of between 650 million barrels and 2 billion BOE.