Mariner Energy Commences Production From Its Geauxpher Field

HOUSTON, May 27 /PRNewswire-FirstCall/ -- Mariner Energy, Inc. (NYSE: ME)
announced today the startup of production from Geauxpher, a deepwater
development in the Gulf of Mexico on Garden Banks Block 462.

Geauxpher lies in water depths of approximately 2,700 feet more than 150 miles
from the Louisiana coast. The development includes two wells with current
gross production of approximately 115 million cubic feet of natural gas
equivalent per day (MMcfe/d). The wells are connected via a 40-mile subsea
tieback to a third-party operated platform on Garden Banks Block 72.
Production from the wells to pressurize the flowline to the platform commenced
April 15, 2009, and sales commenced May 15. Mariner holds a 60% working
interest and operates the Geauxpher field. Apache Corporation holds the
remaining 40% working interest.

With the startup of the Geauxpher field, approximately half of Mariner's
current daily production of 390-400 MMcfe/d comes from oil and gas fields
located in deepwater. In another joint venture with Apache, Mariner is
currently drilling an exploration well on the Arden prospect on Garden Banks
Block 949. Mariner operates the well, which is expected to reach its targeted
depth over the next two to three months, and holds a 50% working interest.

"We are realizing production from Geauxpher less than a year after its
discovery, which is exceptional for a deepwater project of this magnitude and
a tribute to the expertise of our deepwater team. Even more impressive, first
production could have occurred as early as last fall but for disruptions
caused by Hurricane Ike," said Scott Josey, Chairman, Chief Executive Officer,
and President of Mariner Energy. "The Geauxpher project has been an excellent
collaboration with Apache, and we are pleased to be partnering with them again
on our Arden prospect."

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 and the Gulf of Mexico. For more information about
Mariner, visit the company's website at www.mariner-energy.com.

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. Forward-looking statements provided in this press
release are based on Mariner's current belief based on currently available
information as to the outcome and timing of future events and assumptions that
Mariner believes are reasonable. Mariner does not undertake to update its
guidance, estimates or other forward-looking statements as conditions change
or as additional information becomes available. 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 the Annual Report
on Form 10-K for the fiscal year ended December 31, 2008, as amended, and
other documents filed by Mariner with the SEC. Any of these factors could
cause Mariner's actual results and plans of Mariner to differ materially from
those in the forward-looking statements. Investors are urged to read the
Annual Report on Form 10-K for the year ended December 31, 2008, as amended,
and other documents filed by Mariner with the SEC. This press release does
not constitute an offer to sell or a solicitation of an offer to buy any
securities of Mariner.

SOURCE Mariner Energy, Inc.

Patrick Cassidy, Mariner Energy, Inc., +1-713-954-5558, ir@mariner-energy.com