ARCO has disclosed combined potential reserves totaling about 1.75 billion bbl in two recent Alaska discoveries.
If ARCO's estimates are confirmed, the strikes would be the biggest oil discoveries off the U.S. and biggest in the U.S. overall since discovery of Prudhoe Bay and Kuparuk River oil fields, also in Alaska, in 1968-69.
ARCO said its Sunfish discovery in Alaska's Cook Inlet has the potential to contain as much as 750 million bbl of gross oil reserves if the structures are filled and ARCO's geologic concepts are demonstrated.
In addition, ARCO's Kuvlum discovery in the Beaufort Sea involves a structure that could hold 1 billion bbl or more of gross oil reserves, the company said. If deemed commercial, Kuvlum would be a daunting development project because of heavy ice floes and other severe conditions in the deepest arctic waters yet to see full scale commercial oil development.
ARCO disclosed the details at a security analysts meeting in New York last week.
SUNFISH
The Sunfish discovery, made in 1991, occurred in an area many explorationists believed was played out, ARCO said.
ARCO's 1 Sunfish flowed 1,100 b/d of oil and 1 MMcfd of gas through a 24/64 in. choke with 1,100 flowing tubing pressure from Miocene Tyonek at 12,160 ft (OGJ, Nov. 4, 1991, p. 39).
With a 1992 delineation well, ARCO confirmed Sunfish sands as commercial and found hydrocarbons in the North Foreland sand, age undisclosed. The 1 North Foreland, 11/2 miles south of 1 Sunfish, flowed a combined 3,610 b/d of oil and 3 MMcfd of gas through chokes ranging from 24/64 to 36/64 in. from three zones.
ARCO 60% and Phillips Petroleum Co. 40% this year acquired almost 130,000 acres south and west of the Sunfish discovery with high bids totaling $66 million in state Sale 75 (OGJ, Feb. 9, p. 40).
"We believe the discovery at Sunfish extends over this newly acquired acreage on the South Cook Inlet anticline," said ARCO Alaska Pres. H.L. Bilhartz. "We now believe we have identified enough economically recoverable oil at Sunfish to justify development, although several additional wells will be required to solidify the scope of those plans."
KUVLUM
The $40 million Kuvlum discovery well, drilled last summer, flowed 3,400 b/d of oil (OGJ, Oct. 19, 1992, p. 40). Under producing conditions, Bilhartz said, the rate could be greater than 10,000 bid.
"Data from the single discovery well indicate that the size of the structure could make Kuvlum the largest domestic oil discovery since Prudhoe Bay and Kuparuk were discovered decades ago," Bihartz said.
"The prospect, in which ARCO has a 50% interest, could contain at least 1 billion bbl or more of gross reserves. Although the prospect is a large one, its size does not match that of Prudhoe Bay. In the extreme case, where the structure is full and the sands are thicker - a case we give less than a 1% probability - the structure could contain 6 billion bbl of oil."
ARCO is operator for a six company group with interests in the 35,582 acre Kuvlum prospect, about 15 miles off the Arctic National Wildlife Refuge.
OTHER ALASKA STRIKES
ARCO also cited three other significant Alaskan discoveries it made since 1988.
Its Point McIntyre strike in the Prudhoe Bay area is expected to start production later this year. ARCO, BP Exploration, and Exxon Corp. approved a $700 million development plan for Point McIntyre last year, agreeing to share production facilities with nearby Lisburne field (OGJ, Mar. 25, 1992, p. 30).
ARCO plans further drilling in the Colville High area west of Kuparuk River field, where it drilled the Fiord and Kalubik strikes last year (OGJ, Dec. 28, 1992, p. 28).
ARCO 1 Fiord flowed 1,245 b/d of oil from two intervals, and its 1 Kalubik flowed 1,610 b/d of oil from two intervals. Partner in both wells is Union Texas Petroleum Alaska.
"It is apparent from this year's drilling that it will take at least one more winter drilling season in the Colville High area to further evaluate the 1992 discoveries."
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