Gulf of Mexico - Shelf

In the past several years, Mariner has increased its drilling activities on the Gulf of Mexico shelf. As of December 31, 2007, Mariner held interests in 235 blocks on the Gulf of Mexico shelf. The Gulf of Mexico shelf properties comprise 39%, or 324 Bcfe, of our proved reserves as of December 31, 2007. In 2007, net production in the Gulf of Mexico shelf was approximately 65.8 Bcfe or approximately 66% of the company's annual production.

Among independent E&P companies, Mariner Energy is one of the largest leaseholders in the Gulf of Mexico. The "blue" blocks indicate current leaseholdings (as of January 2008).