Gulf of Mexico

The Gulf of Mexico continues to be a core area for Marathon, with promising development and exploration potential. We currently have significant interests in seven producing fields, of which Marathon operates four. We have rebuilt our inventory of prospects for future exploration activity in the deepwater Gulf of Mexico.

Following the Deepwater Horizon tragedy Marathon thoroughly assessed our capacity to manage a catastrophic offshore event. Marathon believes the Company and the industry are targeting the right issues to address offshore safety responsibly and effectively.

Droshky (Green Canyon 244):

Located in approximately 3,000 feet of water in Green Canyon Block 244, about 160 miles southwest of New Orleans, Louisiana, Droshky is a major subsea project consisting of four development wells tied back to the third-party Green Canyon 65 platform with dual, 18-mile flowlines. Marathon owns a 100 percent working interest in Droshky. Sanctioned in October 2008, first oil was achieved in July 2010.

Ewing Bank (Arnold, Lobster and Oyster, Blocks 963/873/917):

Located 130 miles south of New Orleans, this 1994 development serves as a production hub platform.

Gunflint (Mississippi Canyon Block 948)

The Gunflint prospect is located on Mississippi Canyon Block 948, approximately 160 miles southeast of New Orleans. It was drilled in about 6,100 feet of water, to a total depth of approximately 29,280 feet. The well encountered more than 550 feet of net hydrocarbon bearing sands in the Middle and Lower Miocene reservoirs. Marathon owns a 15.25 percent working interest in Mississippi Canyon Block 948.

Neptune (Atwater Valley Blocks 573, 574, 575, 617 & 618)

Discovered in 1995, Neptune was the first discovery in the Atwater Fold belt trend, approximately 120 miles off the coast of Louisiana. Marathon holds a 30 percent working interest in Neptune, which consists of five Outer Continental Shelf blocks. Production commenced in July 2008.

Ozona (Garden Banks Block 515)

The Ozona discovery is located in approximately 3,000 feet of water, about 175 miles southeast of Sabine, Texas. Marathon holds a 68 percent working interest in the Ozona Field, and serves as operator. Ozona was sanctioned for development in October 2008.

Petronius/Perseus (Viosca Knoll Blocks 786/830)

Marathon holds a 50 percent working interest in these blocks, approximately 130 miles southeast of New Orleans. The Petronius development consists of a compliant tower structure with production and drilling facilities. Petronius is capable of providing processing and transportation services to adjacent third-party fields.

Shenandoah (Walker Ridge Block 52)

Marathon holds a 10 percent working interest in the Shenandoah discovery located in Walker Ridge Block 52. This discovery encountered almost 300 feet of net pay. The well targeted the Lower Tertiary trend, is located in 5,815 feet of water and was drilled to a total measured depth of about 30,500 feet.

Stones (Walker Ridge Block 508)

In 2008, Marathon and our partners drilled a successful appraisal well. The well was drilled at a water depth of 7,500 feet to a total depth of 29,400 feet, with oil located in multiple reservoirs. This is a large potential development in the Paleogene trend. Marathon holds a 25 percent working interest.