North Beechey Point / West Northstar

Off-shore, Western North Slope


  • Key Features
    • Project is adjacent to Beechey Point Unit (~100 MMBO) & to Northstar Unit (196 MMBO), and is 5 miles northeast of the Milne Point Unit (529 MMBO).
    • Project lies 4 miles south of the Sandpiper Discovery (12 MMBO) and 1.5 miles south of Shell/Eni/Repsol OCS Leasehold.
    • Long Island #1 Well: oil shows in Kuparuk conv. & SW cores (22-27 API); oil shows in Sag River & Ivishak.
    • North Star #1 Well: 3 zones in Ivishak tested 1,920/2,000/3,100 BOPD (41-52 API). Kuparuk test: 3% oil (30 API).
  • Leases
    • ADL 392149, 392150, 392151, 392152  (?/?/2022)

Geologic Summary by: D. T. Gross (6/25/2012)

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The Donkel/Cade North Beechey Point, West Northstar Project is comprised of four tracts totaling approximately 9,600 acres, located immediately offshore in the eastern Simpson Lagoon and western Gwyder Bay of the Beaufort Sea. The acreage surrounds the eastern portion of Cottle Island and lies just north of Long Island in State of Alaska waters, with depths up to 50’. The project area lies adjacent to two units, the Northstar Unit (196 MMBO) to the east and the Beechey Point Unit (~100 MMBO) to the south. The Milne Point Unit (529 MMBO) is 5 miles to the northwest and the Sandpiper Discovery (12-47-150 MMBO) is 4 miles to the north. Additionally, the North Beechey Point, West Northstar Project is only 11⁄2 miles south of the extensive 64-lease position held by Shell, ENI, and Repsol (40%, 40%, 20% respectively). Their leasehold encompasses the Federal OCS acreage that is closest to the northern borders of oil and gas units in the Colville River-Kuparuk-Prudhoe Bay area. Devon Energy held five Alaska State leases adjacent to the Donkel/Cade acreage to the northwest, immediately southwest of the Sandpiper Discovery, but allowed them to expire on 6/30/12 without drilling any wells.

The Northstar Unit is a joint State of Alaska and Federal unit that was formed in 1990 (Federal approval) based upon Triassic oil pays that were encountered in Shell’s 1984 discovery well (BF- 47 #1; ~ 5,000 BOPD) and a confirmation well (OCS-181 Seal Island #1; 4,903 BOPD; 39.5 degree API oil; 12.8 MMCFGPD). Four additional confirmation and delineation wells were drilled through 1986. To date, the unit has produced 154 MMBO from the “Northstar Pool” with only a 0.5 MMBO contribution from a single L. Cretaceous Kuparuk Formation completion. Though the Northstar Pool includes a 100’ U. Triassic Sag River transgressive sandstone and the mixed clastics/carbonates of the underlying Shublik Formation, their low permeability (<1% ave.) makes the L. Triassic Ivishak the superior reservoir with its 325’ of delta front sands (105’ net pay) averaging 15% porosity with 53 md permeability (Swi 54%). The 44 degree API oil has a column of 270-300’ and is trapped on the south side of a faulted anticline that has dip closure to the west, south, and east. With maximum throws of 200’, most faults within the field itself are not thought to interfere with communication between the fault blocks and a common oil/water contact is placed at 11,100’ SS. Of particular relevance to the North Beechey Point, West Northstar Project is the Northstar #1 well, drilled by Amerada Hess in 1986 as one of the Northstar delineation wells. Located just 1 mile east of the Donkel/Cade project acreage, the Northstar #1 (11,820’ MD(TVD)) tested three zones in Ivishak that flowed at rates of 1,920 BOPD,2,000 BOPD, and 3,100 BOPD (41-52 degree API). A test uphole in the Kuparuk determined it to contain 3% oil (30 degree API). Amerada Hess returned to the western portion of the Northstar Unit eight years later when it drilled the Northstar #3 well (10,000’ MD; 9,562’ TVD) in a location 2 miles southeast of the present day Donkel/Cade project acreage. Surprisingly, the well was only drilled down to a Kuparuk target which was determined through conventional and sidewall core analyses to be marginally gas productive. Despite oil saturations that averaged 4.8% in “Zone 4” at 9,561-93” MD, the Northstar #3 was plugged and abandoned, as was the previously suspended Northstar #1 well.

The Beechey Point Unit was formed in 2009 with Brooks Range Petroleum Corporation (BRPC) as its operator. It contains 30 leases covering 52,879 acres that hold oil accumulations peripheral to the northern edge of the Prudhoe Bay Unit. According to the Alaska Division of Oil and Gas, the Beechey Point Unit “lies north of the northwest to southeast trending, down-to-the-north, Prudhoe fault that separates the Prudhoe Bay field from deeper, more complexly faulted structures to the north”. The primary exploration targets are sandstones in the L. Triassic Ivishak Formation of the Sadlerochit group and the U. Triassic Sag River Formation, as well as the L. Cretaceous Kuparuk River Formation. The unit was divided into five Exploration Blocks, each of which is required to have been tested by an exploration well by 2019, (North Shore EB, West Shore EB, Northwest Shore EB, East Shore EB, and Offshore EB). Undeveloped oil discoveries in the area date back to the 1969 Hamilton Brothers Storkersen #1 well (future Dewline Unit), but the Beechey Point Unit approval was based upon the 2007 BRPC North Shore #1 well being sidetracked in 2008 and encountering 70’ of oil in the Ivishak. A DST that flowed at a rate of 2,092 BOPD led to the well being certified Capable of Producing in Paying Quantities (CPPQ). In 2010, BRPC drilled wells within two of the Exploration Blocks and suspended both. In the North Shore EB, the North Shore #3 well (11,414’ MD; 10,601’ TVD) was drilled into a Sag River – Ivishak target that displayed 4-way closure and was reported to have 11 MMBO in reserves. Two miles to the northeast in the Offshore EB, the Sak River #1A well (12,716’ MD; 9,396’ TVD) proved up 4.5 MMBO in reserves in the Kuparuk. Presently the plan for the North Shore Development Project is to produce oil from several relatively small, isolated hydrocarbon accumulations within the 15,000-foot horizontal drilling radius of their drilling pad. The Ivishak and Sag River sands will be produced from each prospect using horizontal drilling technology and long-reach wells to recover between 5 and 10 million barrels of oil, (22% porosity, 39 degree API). In the West Shore EB (ADL 39509 lease), BRPC has proposed a well location that is just one mile southwest of the plugged and abandoned BPX West Gwyder #1 well, drilled in 2000 to a depth of 11,030’ MD (10,513’TVD) and which had poor to locally fair/good oil shows in the Tertiary, Kuparuk, Jurassic Sands, and Ivishak.

The now-dissolved Sandpiper Unit was less than a mile to the north of the North Beechey Point, West Northstar Project in Federal OCS waters of the Beaufort Sea. The unit was formed over a L. Triassic Ivishak Formation oil discovery that was found by two wells drilled by Shell and AMOCO in 1986and which had surface locations on an artificial island constructed in 49’ of water. The Sandpiper #1 well was drilled to 12,575’ MD and tested two zones below 11,910’ MD in the Sadlerochit Group (Ivishak Fm.) that flowed from 500 to 2,500 BOPD (40-52 degree API) and 18.5 MMCFGPD. Sandpiper #2 also encountered the oil pay and both wells were certified as being Capable of Producing in Paying Quantities, leading to the formation of the Sandpiper Unit in 1992. The OOIP was reported to be 450 MMBO and values for the recoverable reserves have ranged between 47-150 MMBO, though later assessments have been lower. The unit operatorship transferred from BP to Murphy Oil in 1999 and the predicted field production rate was changed from 12,000 BOPD down to 8,000 BOPD with expectations for the oil to be processed at the Northstar Unit facilities. Three delineation wells were planned for the 2000 drilling season but were never spudded. It is not certain why but it appears that the combined effects of oil prices in the mid $20’s, the necessity of constructing an island pad north of the barrier islands, and the expectation that the Northstar Unit would be capacity-constrained until 2005 led to the abandonment of the Sandpiper Unit and the relinquishment of its leases upon their expiration in April, 2001. However, Sandpiper was determined to be a “significant discovery” by the ADOG in 2000 and by the MMS in 2001. In 2003 at the first lease sale in the area since 1998, ConocoPhillips acquired three tracts over the Sandpiper discovery. In 2009, ConocoPhillips retained these three federal leases even as the company was in the process of dropping over 100,000 acres of leases as part of the shift of their exploration focus to the Chukchi Sea. At the time, the 15,000 gross acres of the Sandpiper prospect were estimated to hold between 20 million and 70 million barrels of oil. Though they spent $4 million on the lease bonus bids, ConocoPhillips did not do any drilling at Sandpiper and today the acreage remains unleased despite being surrounded by the Shell/ENI/Repsol lease position to the north and the Devon leases to the south. This situation may be related to a 2009 DOE North Slope report that stated that the development of the Sandpiper discovery would be dependent upon the development of discoveries nearer to shore at Gwyder Bay and areas north of the Kuparuk Field. It predicted that it would be 2015, at a minimum, before development would begin at Sandpiper with the construction of a production/drilling pad north of the barrier islands.

Aside from those wells previously discussed, there are three key wells related to the North Beechey Point, West Northstar Project. One of the earliest wells in the area is the Plaghm Beechey Point #1, drilled by Placid Oil in 1971 between the future Milne Point Unit and the Northstar Unit at an onshore location 2 miles WSW of the Donkel/Cade project acreage. Despite having its planned total depth changed from 11,500’ to 13,000’ on 12/24/70, the well reached a TD of only 11,922’ MD(TVD) on 1/12/71. Unfortunately, it was not a success and neither sidewall cores nor conventional cores were taken before the well was plugged and abandoned. Cement plugs were set in the 8,911’ of openhole at the Top Kuparuk Formation (L. Cret.; 8,132- 232’ MD), Top Sadlerochit Group (L. Triassic; 10,499-599’ MD), and Top Lisburne (Miss.; 11,158-258’ MD).

Midway along the southern border of the North Beechey Point, West Northstar Project, the Sohio Long Island #1 well was drilled in 1984 to a depth of 11,600’ MD(TVD) from an icepad constructed on the western end of the Long Island. Though unsuccessful in finding economic hydrocarbons, the well did have numerous oil shows in the L. Cretaceous Kuparuk Formation (8,980’ MD; 8,939’ TVD), the U. Triassic Sag River Sand (11,078’ MD; 11,037’ TVD), and the L. Triassic Ivishak Formation (11,265’ MD; 11,224’ TVD). Of the four conventional cores cut in the well, the two deeper cores in the Kuparuk had extensive oil shows. Core # 4 (9,158-218’ MD) showed the Kuparuk B to be composed of shales and very thin, fine-grained sandstones that had scattered brown staining, dull gold fluorescence, and milky cuts. Core #3 (9,042-102’ MD) was cut in a Kuparuk C sandstone that was fine-medium grained, had strong petroliferous odors, and displayed continuous brown oil staining, dull gold fluorescence , and strong milky cuts down to its base at 9,091’ MD. Though no conventional cores were cut in the deeper strata, the single sidewall core recovered from the Sag River Sand (11,120’ MD) was of a very fine-grained sandstone with brown oil staining, yellow-gold fluorescence, and a milky cut. The SWC’s recovered from the Ivishak showed it to be composed of friable, fine to medium grained sandstones interbedded with claystones. A single SWC from the upper portion of the formation (11,277’ MD) displayed yellow-gold fluorescence and a milky cut.

The third well lies 4 miles to the west-northwest of the Donkel/Cade project acreage. The Jones Island #1 well was drilled in 1993 by ARCO Alaska to a depth of 15,153’ MD (11,767’ TVD) in the Jones Island Unit that included what is now the western half of the project acreage. The well was deviated 11⁄2 miles to the NNE from a icepad surface location midway between Bertoncini Island and Jones Island in 21⁄2 feet of water. Texaco had permitted a well in this area previously, but their permit for the Jones Island #1XX expired in 1986. The ARCO well encountered “basement” at 15,000’ MD (11,614’ TVD) at the base of the Permo-Triassic Kavik Formation and thus the older Carboniferous Eschooka Formation, Lisburne Group, and Endicott Group were not encountered. The primary exploration target of the Jones Island #1 well was the L. Triassic Ivishak Formation, with a secondary target in the L. Cretaceous Kuparuk Formation. After drilling its section, it was decided not to stop and log the Kuparuk. No sidewall cores were taken in the Kuparuk (12,370’ MD; 9,065’ TVD) when the openhole was later logged, but the driller’s report does note that when drilling the deeper section it was “difficult reaming thru the Kuparuk sands and silts”, thus confirming their presence. The well’s sidewall cores in the underlying U. Triassic Sag River Sand had a good oil show (14,318’ MD; 10,933’ TVD) and the Triassic Shublik Formation (14,377’ MD; 11,007’ TVD) and L. Triassic Ivishak Formation (14,505’ MD; 11,130’ TVD) had numerous very poor to fair oil shows. Despite the oil shows, ARCO chose not to run porosity and permeability analyses on the cores, reported that the Jones Island #1 well encountered “no significant hydrocarbons”, and plugged and abandoned the well. This may have been because the attempts to take fluid samples in the Sag River failed due to low permeability and because the sandstones and conglomerates of the Ivishak often had either a kaolinite(?) or a carbonate matrix.

In summary, the North Beechey Point, West Northstar Project sits amid major oil production and discoveries. An exploration well that was drilled on the very edge of the project acreage displayed good oil shows and reservoir quality sands in the equivalent stratigraphic intervals of these fields. The L. Cretaceous Kuparuk Formation has production at the Milne Point Unit to the west (233 MMBO cum.), in a single Kuparuk completion at the Northstar Unit to the east (0.6 MMBO cum.), and has reserves assigned to it in the Offshore Exploration Block of the Beechey Point Unit to the south (4.5 MMBO). The U. Triassic Sag River Sand is also productive at Milne Point and Northstar, and is part of the reserves being assigned to the Northshore Development Project in the Beechey Point Unit to the south. Though not productive to the west of the Donkel/Cade project, the L. Triassic Ivishak is the major contributor to the 153 MMBO of cumulative production at Northstar to the east, was assigned recoverable reserves of 47-150 MMBO at the Sandpiper Discovery to the north, and has had tens of millions of barrels of reserves assigned to it thus far at Beechey Point to the south. Additional oil reserves may be found in the project area in Triassic Shublik sands such as those that are part of the Northstar Pool production or in Tertiary Schrader Bluff sands much like those that are productive at the Milne Point Unit (67 MMBO cum.).