Oil of 44° gravity flowed at an unstimulated, sustained rate of 5,010 b/d with 14.3 MMcfd of associated gas with limited drawdown at the Cameia presalt oil discovery in Block 21 offshore Angola, said Cobalt International Energy Inc., Houston.
The drillstem test flow rate at the Cameia-1 well, drilled to 16,030 ft in in 5,518 ft of water, was restricted by surface equipment, facility, and safety precautions and “confirmed the presence of a very thick, continuous, high quality reservoir saturated with light oil,” Cobalt said.
James W. Farnsworth, Cobalt’s chief eExploration officer, said, “Based upon our analysis of the test data, if not limited by the test equipment on the rig, we believe the well would have the potential to produce in excess of 20,000 b/d.” As yet undrilled deeper targets provide upside potential, he added.
An extensive wireline evaluation program confirmed the presence of a 1,180-ft gross continuous oil column with over a 75% net to gross pay estimate. No gas-oil or oil-water contact was evident on the wireline logs of what the company said is a “world-class quality carbonate reservoir.”
Cobalt called the discovery “extraordinary” and said it will immediately start an appraisal program.
Cobalt previously planned to drill its Bicuar-1 exploratory well after completing Cameia-1, but given Cameia-1’s exceptional results the company, its partners, and the concessionaire have agreed to immediately begin drilling to appraise Cameia and probe the deeper objectives.
The Diamond Offshore Ocean Confidence semisubmersible will spud the Cameia-2 appraisal well in February and drill to 16,000-18,000 ft in 100-120 days.
Cobalt’s partners in Block 21 and Cameia-1 include Sonangol Pesquisa e Producao SA 20%, Nazaki Oil and Gaz SA 30%, and Alper Oil Ltd. 10%.
The Cobalt group is one of several exploratory efforts aimed at prospects off Angola that are geologically similar to giant oil discoveries off Brazil (OGJ Online, Dec. 21, 2011).