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Too early to tell Kuparuk sands bust for Pioneer at NW Kuparuk; Jurassic could be prolific Kay Cashman Petroleum News Publisher & Managing Editor
Remember Alpine! That’s the response of Alaska Oil and Gas Division Director Mark Myers to pessimistic comments about the Northwest Kuparuk exploration results released by Pioneer Natural Resources.
The Dallas-based independent said that preliminary results from this winter’s drilling at the Beaufort Sea prospect north of the Kuparuk River oil field did not find a commercial extension of the productive Kuparuk C sands: “Although all three of the wells found the sands filled with oil, they were too thin to be considered commercial,” Pioneer said March 31. (See Petroleum News bulletin of March 31.)
But the company did hit its secondary target, Jurassic sands, at all three wells — the Ivik, Natchiq and Oooguruk: “Deeper, beneath the Kuparuk sand, we encountered thick sections of oil-bearing Jurassic-aged sands,” Pioneer spokeswoman Susan Spratlen told Petroleum News. “The issue is determining the permeability, how much oil there is and what the recovery factor will be.”
Jurassic holds promise, Myers says
The prolific western North Slope Alpine field is producing from Jurassic sands.
“ARCO would have walked away from the Alpine field several years ago because of its permeability problems. But our … ability to find and produce the more challenging, low permeability reservoirs has increased dramatically,” Myers said.
Permeability is a standardized measure of how easily a fluid, such as oil, will flow through a given unit of rock.
“In the area from north of Kuparuk all the way to the Alpine field and into NPR-A there are a series of three upper Jurassic-aged sandstones that are known to contain oil … staggering amounts of oil. The Alpine sand being youngest, the Nuiqsut and the Nechelik,” Myers said.
Myers did not know which Jurassic sands Pioneer had encountered in its drilling at Northwest Kuparuk but, according to public records, the Jurassic sands are generally thick and very laterally extensive in the area where Pioneer drilled its three wells, whereas the Kuparuk sands are extensive in the Kuparuk field but sparse elsewhere and they vary in thickness over short distances.
“The issue has always been finding reservoir quality, not finding oil,” Myers said.
There are two ways of dealing with the permeability problems that are common in many of the reservoirs in the central North Slope, he said — drill vertical wells and fracture them or drill horizontal wells like they’ve done at Alpine, exposing a lot of the reservoir to well bore.
Spratlen said Pioneer was testing just one of the Northwest Kuparuk wells, the Ivik, because “the three wells were similar enough to just test one at this time.” She said the Ivik, a vertical well bore, had been fractured. It flowed at a sustained rate of approximately 1,300 barrels per day and had been shut in for a pressure build-up test. Myers is optimistic “I am optimistic about it, although it’s way too early to tell,” Myers said. “Pioneer and Armstrong’s people are very bright technically. … They really understood the risks.”
When asked if Natchiq was still working on a design for a standalone processing facility for Northwest Kuparuk, Spratlen said yes.
“But we have not completed our testing of the Ivik well. In a month or two we will be in a better position to answer more specific kinds of questions,” she said.
But as far as Alaska is concerned, Ken Sheffield, president of Pioneer Natural Resources Canada and in charge of Pioneer’s Alaska assets, said the company is still very committed to its operations here, which at this time involve only the Northwest Kuparuk prospect in partnership with Armstrong Resources, an affiliate of Denver-based Armstrong Oil and Gas.
“We intend to continue to look at other possibilities in Alaska,” Spratlen said. Pioneer opens Alaska office Pioneer was the first independent oil and gas company not partnered with one of the major North Slope producers to drill an exploration well on the North Slope.
The company bought into the Northwest Kuparuk prospect, which had been developed by its partner Armstrong Resources, in late October.
Pioneer has since opened a small, 1,000 square foot office in Anchorage at Pacific Office Center, 301 K Street, Suite 200.
Landman Pat Foley, Sheffield said, is manning the office.
“It’s just the basics, a two-room office. It’s a place to hang our hat when we’re in Alaska,” Sheffield said.
Pioneer executives said in February that they will open a full-fledged office in Anchorage if they have a commercial find at Northwest Kuparuk. Sheffield, they said, would move from Calgary to Anchorage if that happened.
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