Most of the Arctic, especially offshore, is essentially unexplored with respect to petroleum.
With those words, the US Geological Survey in late July released its assessment of undiscovered, technical recoverable resources north of the Arctic Circle, 66.56° N. Lat.
In fact, the Arctic is so unexplored that those conducting the assessment had to rely on a probabilistic methodology of geological analysis and analog modeling. The sparse seismic and drilling data in much of the Arctic meant that the usual tools and techniques used in USGS resource assessments, such as discovery process modeling, prospect delineation, and deposit simulation, were not generally applicable.
“The extensive Arctic continental shelves may constitute the geographically largest unexplored prospective area for petroleum remaining on earth,” USGS said.
Arctic resources
USGS concluded that the area north of the Arctic Circle has 22% of the world’s undiscovered, technically recoverable resources.
The region has 13% of the undiscovered oil, 30% of the undiscovered natural gas, and 20% of the undiscovered natural gas liquids (OGJ Online, July 24, 2008).
Of the Arctic’s estimated 90 billion bbl of undiscovered oil, 1,670 tcf of gas, and 44 billion bbl of NGL, 84% is believed to be offshore. These figures are the sum of the mean estimates for 25 provinces.
Eight other known provinces were not quantitively assessed because they were judged to have less than a 10% probability of having at least one significant accumulation of 50 million bbl of oil and oil-equivalent gas.
More than 70% of the undiscovered oil is estimated to occur in five provinces, and more than 70% of the undiscovered gas is believed to occur in three provinces.
The 400 existing oil and gas fields north of the Arctic Circle in Canada, Russia, and Alaska account for 40 billion bbl of oil, more than 1,100 tcf of gas, and 8.5 billion bbl of NGL.
Arctic oil and gas
USGS’s Circum-Arctic Resource Appraisal (CARA) excluded nonconventional resources such as coalbed methane, gas hydrates, oil shale, and tar sand.
It said the 400 known fields account for 240 billion boe, or 10% of the world’s known conventional petroleum resources.
The area above the Arctic Circle totals 8.2 million sq miles, 6% of the earth’s surface. Of that, almost 3.1 million sq miles is onshore and more than 2.7 million sq miles is on continental shelves in less than 500 m of water.
Oil provinces
Arctic Alaska is the top Arctic undiscovered oil province with 30 billion bbl of undiscovered oil, 221 tcf of gas, and 6 billion bbl of NGL.
Second is Amerasia basin with 9.7 billion bbl, 57 tcf, and 542 million bbl. The Amerasia basin extends north and northeastward from Arctic Alaska and north of the Sverdrup basin.
Third is East Greenland Rift basins with 8.9 billion bbl, 86 tcf, and 8 billion bbl.
Next is East Barents basins with 7.4 billion bbl, 318 tcf, and 1.4 billion bbl.
Fifth is West Greenland-East Canada with 7 billion bbl, 51.8 tcf, and 1 billion bbl.
Gas provinces
West Siberian basin is the top Arctic undiscovered gas province with 651 tcf, 20 billion bbl of NGL, and 3.6 billion bbl of oil.
East Barents basins is second with 318 tcf of gas, 1.4 billion bbl of NGL, and 7.4 billion bbl of oil.
Arctic Alaska is third.
Other provinces
Other Arctic provinces estimated at 5 million boe or more of undiscovered, technically recoverable resources are the Yenisey-Khatanga basin, Laptev Sea Shelf, Norwegian Margin, Barents Platform, and Eurasia basin.
Provinces with 1-5 million boe are North Kara basins and platforms, Timan-Pechora basin, North Greenland sheared margin, Lomonosov-Makarov, Sverdrup basin, Lena-Anabar basin, North Chukchi-Wrangel Foreland basin, Vilkitskii basin, and Northwest Laptev Sea shelf.
Those with less than 1 million boe are Lena-Vilyui basin, Zyryanka basin, East Siberian Sea basin, Hope basin, and Northwest Canada Interior basins.
The USGS did not yet report the results of individual assessment units in the provinces.
What it means
The assessment represents an appraisal of possible future additions to world oil and gas reserves from new field discoveries in the Arctic.
USGS said, “The study included only those resources believed to be recoverable using existing technology, but with the important assumptions for offshore areas that the resources would be recoverable even in the presence of permanent sea ice and oceanic water depth. No economic considerations are included.”