The Sakhalin-1 Project is an oil and gas development on the northeast shelf of Sakhalin Island. It was declared commercial in October 2001. The Project area is comprised of the Chayvo, Odoptu and Arkutun-Dagi fields. Total recoverable reserves are estimated to be 2.3 billion barrels of oil and 17.1 trillion cubic feet of natural gas. Exxon Neftegas Limited, an affiliate of Exxon Mobil Corporation, is the operator. The Sakhalin-1 Project is one of the most ambitious, world-scale projects developed by international oil and gas industry to date, and represents one of the largest single foreign direct investments in Russia. Project benefits to Russia include direct revenues to the Russian state estimated at over US$ 50 billion over the life of the Project.