Athabasca Oil Sands Project (AOSP)

The AOSP is a joint venture among Marathon Oil Canada (20 percent), Shell Canada (60 percent) and Chevron Canada (20 percent). Shell is the operator. The AOSP's base project encompasses the Muskeg River Mine and the Scotford Upgrader. At full production, the mine's current gross production is 155,000 bpd of bitumen, a naturally occurring heavy oil.

Expansions

Given the significant resource base, the AOSP joint venture partners continue to look at options. Currently, the AOSP Expansion 1 project is under way. It includes construction of mining and extraction facilities at the Jackpine mine, expansion of froth treatment facilities at the Muskeg River Mine, expansion of the Scotford Upgrader and development of related infrastructure. Expansion 1 is anticipated to begin mining operations in the second half of 2010, and upgrading operations in late 2010 or early 2011. After Expansion 1 is complete, Marathon will have more than 50 mbpd of production and upgrading capacity in the Canadian oil sands.

Marathon's remaining land position will allow for further expansions and debottlenecking opportunities, providing Marathon with a secure production stream for decades.