11 Jan 2022 10:55

Chukotka shelf could be as promising as Alaska oil fields, RAS experts say

MOSCOW. Jan 11 (Interfax) - The Chukotka shelf should be factored into the forecast of the oil and gas potential of the Far Eastern sector of the Russian Arctic, as it could turn out to be as promising as oil fields in Alaska, experts from the Russian Academy of Sciences' Vernadsky Institute of Geochemistry and Analytical Chemistry said in an article published in the journal Geologia i Nedropolzovaniye (Geology and Subsurface management).

Russia's continental shelf, with an area of more than 6 million square kilometers, is the largest in the world, the experts said. Its initial recoverable energy resources are forecast at about 100 billion tonnes of oil equivalent, 80% of which are concentrated in the Arctic. The Far Eastern shelf has great potential. The basin of the shelf of the East Siberian and Chukotka seas extends from the Anzhu Islands in the west to the coast of Alaska in the east, amounting to half of the continental margin of Asia.

"In the Eastern Arctic, the giant North Chukotka marginal shelf rift, which developed primarily in the Cretaceous and Cenozoic - the North Wrangel-Geraldskaya ridge, specifically the West Wrangel and East Siberian rise, and the Eastern periclinal of the De Longa anticlise, is of greatest interest in terms of oil and gas potential. About 60 oil and gas fields were discovered in Northern Alaska. Most ore concentrated along Point Barrow. Two of the largest oil fields and many small oil fields are located in structural stratigraphic traps. The oil potential of Northern Alaska is estimated at about 30 billion cubic meters of oil and about 160 trillion cubic meters of natural gas," the experts said.

"Alaska, the most explored part of the United States, holds 40% of America's undiscovered reserves. Oil reserves in Alaska amount to 0.896 billion barrels. Proven oil reserves in the U.S. total 28.4 billion barrels, of which almost a third are in Alaska. Northern Alaska, including the northern slope and neighboring Beaufort Sea shelf and Chukotka continental shelf, holds more than 30 billion barrels (4.8 billion tonnes) of oil. This geologically complex region, which includes prospective horizons from Jurassic to Tertiary deposits, remains the frontline for development," the article said.

The carbon isotopic composition of oil from fields in Alaska and Chukotka shows the similarity of their parameters. The northern slope of Alaska, including the neighboring Beaufort Sea shelf and Chukotka continental shelf, is one of the remaining oil development fronts and is seen as the most promising for discovery of oil and gas resources. The sedimentary mantle of the Anadyr depression was formed by terrigenous rock from the Late Cretaceous, Paleocene and Neogene periods that is as much as 6-7 km thick. The basement rock is Mesozoic, the experts said.

"The completed comparative analysis of fields in Alaska and Chukotka is of interest for the forecast of the oil and gas potential of the Far Eastern sector of the Russian Arctic. The obtained results show that the oil fields of Alaska and Chukotka are of similar significance," the experts said.