[3] The field is an anticlinal structure on the downthrown side of a major salt diapir associated growth fault and produces from 25 Pliocene-Pleistocene delta-front sandstone reservoirs at depths from 1290 to 3600 m.[4] The structure was located with reconnaissance reflection seismology 2D lines recorded from 1966 to 1970, coupled with well data defined lithofacies and isopach maps indicating large delta systems.
[4] Relative amplitude seismic profiles reveal "prominent hydrocarbon indicators" such as bright spots and flat spots, and seismic facies analysis show shingled, oblique and sigmoid reflections typical for delta-front sandstones.
Production at the oil field, deep in the Gulf of Mexico off the coast of Louisiana, was supposed to have declined years ago.
And for a while, it behaved like any normal field: Following its 1973 discovery, Eugene Island 330's output peaked at about 15,000 barrels per day (2,400 m3/d).
[5]However, Richard Heinberg provides his own figures: Production from Eugene Island had achieved 20,000 barrels per day (3,200 m3/d) by 1989; by 1992 it had slipped to 15,000 bbl/d (2,400 m3/d), but recovered to reach a peak of 30,000 bbl/d (4,800 m3/d) in 1996.
[6]The source of additional oil was analyzed as migrating through faults from deeper and older formations below the probable Jurassic and Early Cretaceous age.
[8] As of 1999[update] the owners of the block leases (numbers in parentheses) are Chevron Corporation (313), Royal Dutch Shell (331), Ecee, Inc (330), Palo Petroleum (337).