Cobalt said it is currently evaluating the results and called early results there “very encouraging”.
The well, which was spud on 29 August, is located in Block 21of the Kwanza basin in about 5000 feet of water.
It was drilled by the Diamond Offshore semi-submersible Ocean Confidence, which experienced mechanical difficulties while drilling, causing a two- to three-week delay
Joseph Bryant, the company’s chief executive officer, suggested in November that a discovery of about 150 million barrels would be considered commercial, although the prospect could hold as much as 1 billion barrels.
Cobalt’s partners are Sonangol P&P, Nazaki Oil & Gas and Alper Oil.
After Cameia-1 is completed, Cobalt will move the Ocean Confidence to drill the Bicuar pre-salt prospect, also in Block 21.
The announcement of Cameia-1 success came as Cobalt signed a production sharing contract and became the operator of Block 20 in Kwanza, located directly south of and adjacent to Block 21.
Cobalt will hold a 40% interest in the block, with Sonangol holding 30%, BP on 20% and China Sonangol International Holding Limited owning the remaining 10%.
Cobalt plans to drill its first well on Block 20 in 2013.
The spate of good news for Cobalt translated into a spike in its stock price. Shares were trading up more than 36% on Tuesday afternoon at $13.81 per share on the New York Stock Exchange.