Cobalt International Energy, Inc. (“Cobalt”) (NYSE:CIE) today announced that its Aegean #1 exploratory well on Keathley Canyon Block 163 in the U.S. Gulf of Mexico had reached objective total depth of 34,701 feet MD (33,751 feet TVD) after having drilled through the targeted Inboard Lower Tertiary formation. The targeted zones did not encounter commercial hydrocarbons and operations are underway to plug and abandon the wellbore. Cobalt, as operator, owns a 60 percent working interest in Aegean. TOTAL E&P USA, INC. is Cobalt’s partner in Aegean, with a 40 percent working interest. About Cobalt Cobalt is an independent exploration and production company focusing on the deepwater U.S. Gulf of Mexico and offshore Angola and Gabon. Cobalt was formed in 2005 and is headquartered in Houston, Texas. Forward-Looking Statements This press release includes “forward-looking statements” within the meaning of the safe harbor provisions of the Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934 — that is, statements related to future, not past, events. Forward-looking statements are based on current expectations and include any statement that does not directly relate to a current or historical fact. In this context, forward-looking statements often address Cobalt’s expected future business and financial performance, and often contain words such as “anticipate,” “believe,” “intend,” “expect,” “plan,” “will” or other similar words. These forward-looking statements involve certain risks and uncertainties that ultimately may not prove to be accurate. Actual results and future events could differ materially from those anticipated in such statements. For further discussion of risks and uncertainties, individuals should refer to Cobalt’s SEC filings. Cobalt undertakes no obligation and does not intend to update these forward-looking statements to reflect events or circumstances occurring after this press release, other than as required by law. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release. All forward-looking statements are qualified in their entirety by this cautionary statement.