Eni made a new hydrocarbon discovery in the US Gulf of Mexico deepwater. The exploration well Heidelberg-1, located in Green Canyon block 859, some 210 kilometers (130 miles) off the Louisiana coast, led to the discovery.

Heidelberg-1, which has been drilled in a water depth of 1628 meters (5340') and a total depth of approximately 9,163 meters (30,062'), encountered more than 60 meters (200') of net hydrocarbon-bearing sand.
Well data are now being collected and evaluated to assess the size of the discovery.

Eni owns a 12.5% working interest in Heidelberg. Partners are Anadarko Petroleum Corporation (Operator with 44.25%), Mariner Energy, Inc. (12.5%), StatoilHydro (12%), Cobalt International Energy, L.P. (9.375%), and ExxonMobil (9.375%).

The Heidelberg discovery is on trend with recent discoveries at Tahiti, Caesar, and Tonga and is located 25 kilometres (15 miles) south of Eni's Tahiti West exploratory well in GC 639, which is expected to resume drilling in the first quarter of 2009 for similar-age targets.

In the USA, Eni owns lease interests in 403 blocks in the Gulf of Mexico and is among the leading producers with a daily net production capacity in excess of 100,000 barrels of oil equivalent (60% operated). Eni is also present in Alaska, where it owns interests in 173 leases between offshore and the North Slope and is currently advancing with the development of the operated Nikaitchuq project.