Seismic surveys of the Bering and Chukchi seas west of Alaska have revealed the presence of five basins that may contain large volumes of oil
"These are only seismic studies," Dr. Charles D. Masters of the U.S. U.S. Geological Survey said yesterday. "Not a single exploratory well been drilled to confirm the oil-bearing potential of these basins."
Dr. Oswald W. Girard Jr. of the agency said geologists have been known for five years that the basins could contain oil. One, named the Navarin Basin, could contain as much as 7 billion barrells of oil and will be put up by the federal government for leasing bids by oil companies in December 1982.
"Since no exploration has been done of this region, it's impossible to say whether there is any oil in this basin," Girard said. "On the basis of our seismic data, we can say there is a 5 percent probability that there is oil in the Navarin Basin."
Five percent is the highest probability factor geologist normally will give to even the mose promising potential oil field that has not been explored. g
Measuring 200 miles long and 100 miles wide, the Navarin Basin lies in water 1,500 2,000 feet deep, about 300 miles north of the Aleutian Islands and 400 miles west of the Alaskan coast. The basin lies beneath the Bering Sea, with about one-third of it extending into waters claimed by the Soviet Union.
What the seismic studies reveal are huge articlines, or fault traps, on the basin floor, where thousands of feet of sedimentary rock have folded over from volcanic or earthquake activity. Oil explorers look for these anticlines because they often serve as traps for oil that has worked its way up from deep sediment, where it had formed from marine fossils millions of years ago.
The studies revealed the presence of two potential oil-bearing basins in the Chukchi Sea, which lies at the entrance to the artic Ocean and is covered by pack ice throughout the winter. Exploratory drilling in these two basins might not take place for years, because of the difficulty of conducting such operations in the winter months