Cobalt International Energy Inc., the deep-water oil explorer with wells in the U.S. Gulf of Mexico and West Africa, surged the most since its 2009 initial share sale amid plans to prolong drilling on prospects that may hold 2 billion barrels of crude.
Cobalt rose 22 percent to $11 at the close in New York, the biggest gain since the company first sold shares to the public two years ago.
Cobalt extended its $360,000-a-day lease on Diamond Offshore Drilling Inc.’s Ocean Confidence rig by as much as two weeks to mid-March 2012, the rig owner said today in a U.S. Securities and Exchange Commission filing.
The vessel, which has been under lease to Cobalt since July, is being used to search for crude in the Cameia and Bicuar prospects in Angolan waters, the Houston-based company said last month in a presentation on its website. The fields lie 23,000 feet (7,010 meters) to 26,000 feet beneath the sea surface and contain at least 1 billion barrels of oil each, according to the presentation.
Lynne Hackedorn, a Cobalt spokeswoman, didn’t return a telephone message left at her office.
Cobalt’s previous exploration successes have included the Heidelberg and Shenandoah discoveries in the Gulf of Mexico co-owned by Andarko Petroleum Corp.