ME Mariner Energy Inc.

Mariner Energy, Inc. (NYSE: ME) today announced drilling success at the Lucius-1 ST-1 exploration well on Keathley Canyon Block 875. The sidetrack well was drilled to a total depth of about 20,600 feet in water depths of approximately 7,100 feet, logging almost 600 feet of high-quality oil pay with additional gas-condensate pay in thick Pliocene and Miocene sandstones. Mariner holds a 16.67% working interest in the project, with Anadarko Petroleum Company (NYSE: APC), the operator, holding 50% and Plains Exploration & Production Company (NYSE: PXP) holding a 33.33% working interest.

Scott D. Josey, Chairman, Chief Executive Officer, and President, said, "The Lucius discovery is further evidence of the significant value in Mariner's deepwater prospect inventory. We look forward to working with our partners in further appraisal of the field and evaluating development concepts for this very significant project."

The initial wellbore, Lucius-1, reached a target depth of about 20,000 feet in December 2009 and encountered more than 200 feet of net pay. Lucius-1 ST-1 was drilled as an updip sidetrack, approximately 3,200 feet due south of the discovery well.

At year-end 2009 Mariner owned interests in nearly 100 deepwater blocks. Following drilling activities at Lucius, the rig is expected to move to Green Canyon 903 to drill the first appraisal well at Heidelberg, where Mariner holds a 12.5% working interest.

About Mariner Energy, Inc.

Mariner Energy is an independent oil and gas exploration, development, and production company headquartered in Houston, Texas, with principal operations in the Permian Basin, Gulf of Mexico and South Texas. For more information about Mariner, visit the company's website at www.mariner-energy.com.

Important Information Concerning Forward-looking Statements

This press release includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. All statements, other than statements of historical facts, that address activities that Mariner assumes, plans, expects, believes, projects, estimates or anticipates (and other similar expressions) will, should or may occur in the future are forward-looking statements. Our forward-looking statements generally are accompanied by words such as "may", "will", "estimate", "project", "predict", "believe", "expect", "anticipate", "potential", "plan", "goal" or other words that convey the uncertainty of future events or outcomes. Mariner cautions that its forward-looking statements are subject to all of the risks and uncertainties normally incident to the exploration for and development, production and sale of oil and natural gas. These risks include, but are not limited to, price volatility or inflation, environmental risks, drilling and other operating risks, regulatory changes, the uncertainty inherent in estimating future oil and gas production or reserves, and other risks described in Mariner's latest Annual Report on Form 10-K and other documents filed by Mariner with the Securities and Exchange Commission (SEC). Any of these factors could cause Mariner's actual results and plans to differ materially from those in the forward-looking statements. Investors are urged to read Mariner's latest Annual Report on Form10-K and other documents filed by Mariner with the SEC.

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