Regional Geology And Hydrocarbon Potential of the Canadian Arctic Islands

Abstract

Abstract The geology of the Canadian Arctic Islands, with its major structures, favorable hydrocarbon source rock and extensive reservoirs, suggests that giant oil and gas fields similar to those of the Persian Gulf, North Africa and Prudhoe Bay will also be found in the High Arctic of Canada. This potential has attracted multimillion dollar expenditures and future commitments by the natural resources industry and the Canadian Government. The total hydrocarbon province of the Canadian Arctic Islands is centered around the elongate east-west Mesozoic Sverdrup Basin, with a complex of older Paleozoic arches and basins to the south and a younger Cenozoic shelf basin to the north. The Mesozoic and Cenozoic rocks are predominately terrigenous clastics consisting of sandstones and shales which attain cumulative thicknesses of over 30,000 feet. The Upper Paleozoic sediments include shelf carbonates, evaporites and thick terrigenous clastics which also have cumulative thicknesses- of over 30,000 feet. The Lower Paleozoic rocks are predominantly shelf carbonates evaporites and basinal pelagic sediments which may reach combined thicknesses of over 20,000 feet. Several major arches, anticlines, faults and evaporite domes are indicated from surface geology, and many more are being located by geophysical methods. The major Palesozoic reservoirs are:the Lower Triassic Bjorne sandstone formation which occurs along the southern margins of the Sverdrup Basin with thicknesses of over 2,000 feet; the Upper Triassic Heiberg Formation, a regressive sandstone extending over most of the Sverdrup Basin with measured thicknesses of over 4,000 feet; and the Lower Cretaceous Isachsen sandstone formation which is over 4,000 feet thick in the deeper portions of the Sverdrup Basin and is expected to be a major target within the Cenozoic coastal basin. The major Paleozoic reservoirs are coarse terrigenous sandstones and marine carbonate clastics. The Siluro- Devonian and Permo-Pennsylvanian carbonate reefs exhibit thicknesses of several thousands of feet and are widely distributed along Paleozoic interbasinal arches or platforms. Natural gas in major quantities has been found in wells drilled on Melville and King Christian Islands, and many other favorable indications of hydrocarbons are present on the surface throughout the Islands. It appears to be only a matter of time until the potential of the Canadian Arctic Islands will be realized. INTRODUCTION THE GEOLOGY of the Canadian Arctic Islands, with its major structures, favorable hydrocarbon source rock and extensive reservoirs, suggests that giant oil and gas fields similar to those of the Persian Gulf, North Africa and Prudhoe Bay will also be found in the High Arctic of Canada. This potential has attracted multi-million-dollar expenditures and future commitments by the natural resources industry and the Canadian Government. In this paper, the authors will present some highlights of the potential and speculate where this potential might be found. The interpretations are based mostly on published information from the Geological Survey of Canada. Detailed references to publications are not included in the text; however, a general list is appended. Of the three basic requirements for the accumulation of major economic hydrocarbon deposits trap, hydrocarbon source rock and reservoir rock.