The Gulf of Alaska continental shelf has proven to be one of industry's major disappointments in hydrocarbon exploration during the last decade. Eight of the nine major structures leased for 560 million dollars in the 1976 OCS Sale 39 have been drilled without finding commercial hydrocarbons. Thermal immaturity of the potential source rock, extreme depth of as yet untested potential reservoirs, and problems caused by overpressured shales have all contributed to the lack of success.

Stratigraphy and structure are the result of the northwestward movement of the Gulf of Alaska microplate. Movement is primarily in conjunction with the Pacific plate although there is minor oblique subduction beneath it. Progressive deformation from the northwest toward the southeast is the result of collision with the North America plate. OCS Sale 39 was located in the area of growing anticlines and active deformation. OCS Sale 55, held in 1980, and the subsequent reoffering sale in 1981 were on the relatively undeformed southeastern part of the plate. Prospective horizons in this area lie at much shallower depths, but the lack of significant structures and unknown thermal maturity of the source rocks tend to downgrade prospects in the area which is untested to date.

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