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Grey Owl expanded
DNR approves 32% size increase of Savant's eastern North Slope unit
Kay Cashman Petroleum News
On Jan. 31, Derek Nottingham, director of the Alaska Department of Natural Resources' Division of Oil and Gas, signed the approval of a proposed expansion of the Grey Owl unit, or GOU, that was submitted on Feb. 21, 2024, by Savant LLC, which owns 100% of the working interest in the GOU. The division deemed the expansion application complete on Oct. 28 and published public notices Nov. 10, with comments due Dec. 9. No comments were received.
The proposed expansion sought to incorporate 17 state leases originally omitted from the Sept. 20, 2023, GOU formation decision and increases the unit by approximately 24,164 acres (32%) to a total size of roughly 74,447 acres, up from 50,283 acres.
The GOU is located on the eastern Alaska North Slope.
The expansion application was signed by Glacier Oil & Gas COO David Pascal.
The expansion area is approximately 20 miles south-southwest of Glacier subsidiary Savant Alaska's Badami unit.
The GOU is roughly 26 miles due east of the Dalton Highway and the Trans Alaska Pipeline and approximately15 miles due west of the Canning River and western border of the Arctic National Wildlife Reserve. The Sadlerochit Mountains in ANWR are approximately 20 miles to the southwest of the GOU and roughly 30 miles to the south are the Brooks Range Foothills.
Exploration efforts within the GOU and immediate surrounding area have been limited, and between 1969 and 1990 included only three wells. Regionally, however, Lagniappe Alaska LLC showed renewed interest in the area by drilling the King Street 1 exploration well in 2024, located 15 miles to the north of the GOU. Bill Armstrong's Lagniappe Alaska is returning to the eastern North Slope this winter to drill the Sockeye-2 well on state acreage approximately 8 miles southeast of Badami, within the Lagniappe-operated oil and gas lease block.
Exploration targets for the proposed GOU unit expansion area are sandstones in the Canning formation interval of the Late Cretaceous and Early Tertiary Brookian sequence.
According to state statute, "a unit must encompass the minimum area required to include all or part of one or more oil or gas reservoirs, or all or part of one or more potential hydrocarbon accumulations."
Savant has submitted confidential geological, geophysical and engineering data, which demonstrate that the area approved for unit expansion includes all or part of an oil, gas reservoir and potential hydrocarbon accumulations.
The division found that the proposed expansion of the GOU promotes conservation of all natural resources, promotes the prevention of economic and physical waste and provides for the protection of all parties of interest, including the state.
The effective date of the GOU expansion is retroactive to Sept. 20, 2023 "based upon the updated interpretation of available seismic data and regional subsurface mapping across the broader region and near-by analogs," the division said.
Two wells Although Savant committed to just one well in the five-year period, the division in its decision calls for Savant to "drill and test two exploratory wells which, combined with any associated studies, sufficiently demonstrate to the Division that all approved potential hydrocarbon accumulations are viable reservoir targets within the five-year unit term of Sept. 20, 2023, through Sept. 20, 2028."
But the first exploration well called for remains the same in the exploration plan attached to the expansion application -- Savant shall evaluate an initial exploratory well (GO-1) through flow testing in the winter season of 2026-2027.
And the division calls for drilling an additional well that sufficiently tests the approved potential hydrocarbon accumulations not tested in the GO-1 well.
OR Savant has the option of drilling a single well that sufficiently tests all approved potential hydrocarbon accumulations.
Seismic in area The first 2D regional seismic data was acquired in this area of the eastern North Slope during the mid- to late 1960s at the time of the Prudhoe Bay discovery.
In the early 1990s, an additional 2D seismic survey was conducted, which covered the eastern part of the North Slope coastal plain.
The only 3D regional seismic survey overlapping portions of the GOU and its expansion area -- the proprietary Shaviovik 3D survey -- was conducted in 2001 by WesternGeco and Fairweather Geophysical on behalf of Phillips Alaska (now ConocoPhillips Alaska).
Wells in the GOU The West Kavik Unit 1 well, located within the GOU, was spud in February 1969 by Texaco Inc.
Although the well originally was designed to target both the Ellesmerian Ivishak and Lisburne formations, it was drilled vertically to 16,613 feet true vertical depth that reached the Lisburne formation carbonates and was ultimately plugged and abandoned in January 1970. The Ivishak sandstones, comprised of a lower quality facies than that produced at Prudhoe Bay, yielded no moveable hydrocarbons. The Lisburne carbonates were tested by DSTs 1-3, each one failing to recover any oil. However, further up section, the Brookian Canning formation, situated stratigraphically above the Lower Cretaceous Unconformity, successfully tested gas with associated oil from stacked turbidite reservoirs. DSTs 4-6 were conducted in the Canning formation, with DST 4 (9,690 feet to 9,790 feet TVD) being the only test to register measurable amounts of oil. Although gas flowed to the surface for more than 30 hours, no oil made it to the surface. However, a 55-foot oil column was reported on top of watery, gas cut mud at 2,261feet depth in the borehole when the testing tool was pulled. Further up hole, DSTs 7-8 failed to recover any hydrocarbons from the Brookian Sagavanirktok formation. No further drilling occurred in the area until the mid-1980s.
1980s and later wells The Alaska St J 1 well, located approximately 8 miles east of the GOU, was spud in March 1984 by Exxon Corp., vertically drilled to 13,655 feet TVD. It reached the Brookian Canning formation and was plugged and abandoned in June 1984.
The objective of this well may have been to determine the existence of a stratigraphic trap within a thick Canning formation sequence.
Although no testing was conducted, two cores were collected in the lower part of the Canning formation. Core 1 was collected between 12,310 feet and 12,341 feet TVD with 22.5 feet recovered. The dominant lithology was siltstone; no oil or gas shows were identified. Core 2 was collected between 12,668 feet and 12,704 feet TVD with only 9.5 feet recovered, consisting primarily of siltstone and very fine- to fine-grained sandstone with poor porosity and permeability and no oil or gas shows.
No further drilling occurred in the area until the early 1990s.
The Gyr 1 well, located approximately 5.5 miles south of the GOU, was spud in February 1990 by ARCO Alaska Inc. It was directionally drilled to 8,005 feet TVD, reached the uppermost Canning formation shales with some minor sandstone, and plugged and abandoned in April 1990. This well was meant to test a sub-thrust structural trap to evaluate Brookian Sagavanirktok topset sandstones below the main frontal thrust of the Brooks Range Foothills. The only oil show encountered, however, was in the Canning formation at 7,740 feet TVD, and it was not tested. Water wet stacked sandstones within the Sagavanirktok topsets were also encountered and one 31-foot conventional core was collected between 5,463 feet and 5,494 feet TVD within the Sagavanirktok formation. Core analysis yielded a maximum porosity of 14.1%, and associated permeability of 71 measured depth with lithologies consisting of sandstone, silty claystone, pebble conglomerate, and silty sandstone.
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