Cobalt International Energy, Inc. ("Cobalt") (NYSE:CIE) today announced it has completed drilling operations on the North Platte #4 appraisal well. The preliminary results are encouraging and indicate that the well encountered approximately 650 feet of net oil pay, which is greater than the approximately 550 feet of net pay found in the North Platte #3 appraisal well. The North Platte #4 initial appraisal results also indicate high quality Inboard Lower Tertiary Wilcox reservoirs on the eastern flank of the North Platte field. Cobalt is currently evaluating log data, fluid samples and pressure information and is preparing for a geologic sidetrack to further analyze the extent of the eastern flank of the field. The geologic sidetrack is expected to be completed in the first quarter. Timothy J. Cutt, Cobalt's Chief Executive Officer said, "This well result is an important milestone in the appraisal of the full potential of the North Platte field. The confirmation of high quality reservoir on the large eastern flank of the field is encouraging." An update to the resource potential will be provided following the sidetrack operations. Cobalt, as operator, owns a 60% working interest in North Platte, and TOTAL E&P USA, Inc. owns the remaining 40% working interest. About Cobalt Cobalt International Energy, Inc. (NYSE: CIE) is an independent exploration and production company active in the deepwater U.S. Gulf of Mexico and offshore West Africa. 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 federal securities laws, including 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," "may," "will," "aim," "estimate," "continue," "intend," "could," "expect," "plan," and 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 disclaims any obligation or undertaking, 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.