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Pioneer adding Torok pool at Oooguruk Primary, secondary production from offshore expected to yield 10 million barrels; onshore core area will add another 58 million Kristen Nelson Petroleum News
Pioneer Natural Resources Alaska is permitting development of Torok, the shallow oil formation at its Oooguruk development offshore Alaska’s North Slope.
Pioneer brought Oooguruk into production in June 2008 and puts gross production potential at 120 million to 150 million barrels from the Kuparuk and Nuiqsut formations.
Now the company is moving to add another one-half to one-third more production potential, with an initial 68 million barrels of primary and secondary recovery from the shallower Torok formation. Torok will be produced both from the existing Oooguruk offshore drill site and from proposed onshore drill sites in the Colville River Delta.
Pioneer, the Oooguruk operator, holds a 70 percent working interest in the field; Eni Petroleum US LLC holds the remaining 30 percent.
Pioneer is applying to the Alaska Department of Natural Resources for unit expansion and for a Torok participating area.
Pioneer is also applying to the Alaska Oil and Gas Conservation Commission for rules to operate the Torok pool.
Torok long known Torok was discovered at the Colville 1 well in 1965, and was also identified in exploration wells drilled in the 1980s and 1990s, Mike Morgan, Pioneer Natural Resources Alaska reservoir engineering technical advisor, told the commission at an April 26 hearing. The Torok sand has been identified in more than 20 wells. The Oooguruk Torok is 200 to 250 feet thick and is composed of thinly bedded alternating sands and shales, with half-inch to six-inch beds common.
When Pioneer drilled the Ivik, Oooguruk and Natchiq exploration wells in 2003, the company was looking for all three horizons — Kuparuk, Nuiqsut and Torok.
Torok is a lower Cretaceous turbidite, Morgan said, with local analogs at Tarn, Meltwater and Nanuq.
A well drilled from the Oooguruk production island last year, the ODST-45A, tested the Torok at more than 1,000 barrels per day and has produced some 170,000 barrels to date, Morgan said.
A 1986 exploration well, the Colville Delta 3, has the lowest known Torok oil at 5,150 feet true vertical depth.
Pioneer is proposing that the Oooguruk-Torok oil pool be defined as the accumulation correlating to the 4,991-5,272 foot measured depth interval in the ARCO Kalubik No. 1 well.
Morgan said that preliminary data from ODST-45A well studies indicate that the oil has an API gravity of 24 degrees.
Large prospective area The Torok core development area is in the southwestern area of the existing Oooguruk unit, extending southward into the area proposed for unit expansion.
The core area is some 8,000 acres. One thousand acres can be developed from the offshore drill site, with an estimated 50 million barrels of original oil in place; 10 million barrels are expected to be recoverable at a combined primary and secondary recovery rate of 20 percent.
The onshore core area, some 7,000 acres, has an estimated 290 million barrels of OOIP, and at a 20 percent recovery rate is expected to produce 58 million barrels.
Rates of recovery are expected to average 4,000 to 9,000 barrels per day.
Torok will be developed with 25 horizontal wells. Water and gas (when available) will be used for secondary recovery.
Phased development has begun with the pilot project from the offshore drilling island; work from the onshore Nuna drill site is the next step.
The total Torok prospective area, as defined by 3-D seismic, is some 23,000 acres with an estimated 690 million barrels of OOIP.
AOGCC Commissioner Cathy Foerster noted that the Torok prospective area appeared to extend into the drill site 3-S area in the Kuparuk River unit and asked if there had been any discussions with ConocoPhillips about development of that area.
Dale Hoffman, Pioneer’s senior staff landman for Alaska, said there had been just preliminary conversations.
Facilities Facilities for Torok development would include one or two onshore drill sites, Nuna 1 and 2, on the Colville River Delta; roads connected to drill site 3-S in the Kuparuk River unit; a small pig-launching and receiving pad; and flowlines to existing infrastructure at the Oooguruk tie-in pad.
Phased development for Torok includes the T45A test from Oooguruk Island, a 3,800-foot lateral, and a three-well pilot to be drilled in 2010-12.
Onshore drill site permitting includes 2010-11 field studies; 2011 permitting and regulatory applications; and 2011-12 permitting and regulatory approvals.
Conceptual engineering for facility design is slated for this year, followed by final design and long lead purchases in 2013, the beginning of onshore drill site construction in 2014 and first onshore production in 2015.
Onshore development drilling will begin in 2012-13 with predevelopment wells and testing, followed by development drilling beginning in 2014.
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