Mariner Energy announces deepwater Gulf of Mexico discovery

Mariner Energy has made a deepwater discovery on its Geauxpher prospect located on Garden Banks Block 462. The well, which lies in water depths of approximately 2,700 feet, was drilled to a total depth of 23,156 feet (measured depth).
Mariner estimates the field's gross proved and probable reserves on the block to be approximately 100 bn cf of natural gas equivalent. Development is underway with initial production expected as soon as year-end 2008.

Mariner is the designated operator at Garden Banks 462 and holds a 60 % working interest in the discovery. Apache Corporation holds the remaining 40 % interest. In November 2007 Mariner farmed into Geauxpher, providing the rig to test the prospect.
The Ocean America semi-submersible remains on location and a second well is planned to delineate the extent of the discovery. Mariner has identified additional potential on the block and expects to test these amplitudes over time.

Scott D. Josey, Chairman, Chief Executive Officer, and President of Mariner Energy said, "Our discovery at Geauxpher provides further evidence of the value potential in Mariner's deepwater prospect inventory. It is a credit to the capabilities of our commercial, exploration and development teams that identify and convert these opportunities into value for our shareholders."
"We appreciate the opportunity to work with Apache on this project."

Mariner also announced that it has expanded its deepwater prospect inventory, farming into the Heidelberg Miocene subsalt prospect with a 12.5 % interest.
Heidelberg is operated by Anadarko Petroleum on Green Canyon blocks 816, 859, 860 and 903. An exploration well is expected to spud on the acreage by year-end 2008.