BOEM approves Hilcorp geohazard survey

Alan Bailey

for Petroleum News

The Bureau of Ocean Energy Management has approved Hilcorp Alaska’s application to conduct geohazard surveying over federal leases in the Cook Inlet this summer. The surveying would encompass four lease blocks about halfway across the inlet, to the west of Kachemak Bay. Hilcorp has indicated an interest in drilling up to four exploratory wells in federal lands in the lower Cook Inlet. Federal regulations require a geohazard evaluation over the entire area within 1.5 miles of a well site, before drilling can begin.

In an Aug. 11 letter confirming the permit approval BOEM said that the agency had conducted an environmental assessment of the proposed operations and had reached a finding of no significant impact. The agency consulted with the National Marine Fisheries Service and the U.S. Fish and Wildlife Service with respect to the requirements of the Endangered Species Act. Hilcorp has obtained letters of authorization from both of these agencies for the incidental take of whales and sea otters.

BOEM has listed a series of measures that Hilcorp must take to prevent unacceptable environmental impacts. For example, vessels must reduce speed when within 900 feet of marine mammals and must not operate in a manner that may separate some members of a group of animals from the animal group.

Hilcorp has previously indicated an intention to bring a jack-up drilling rig to Cook Inlet for Cook Inlet exploratory drilling. The company has expressed a particular interest in testing the Blackbill prospect, discovered by ARCO’s Raven No. 1 well in 1982. The prospect is situated about halfway across the inlet. An offshore 3D seismic survey conducted by Hilcorp in 2019 found that the prospect, with oil in a Cretaceous reservoir, is associated with a 65,000-acre, four-way closure in the rock strata.

The federal offshore leases that Hilcorp is exploring lie north of the Augustine-Seldovia Arch, a geologic structure to the south of which the Tertiary strata hosting the producing Cook Inlet oil and gas fields thin out. However the Cretaceous rocks associated with the Blackbill prospect are part of the older Mesozoic sequence that underlies the Tertiary.

- ALAN BAILEY