AAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
Geological Setting and Petroleum Potential of the Paleozoic Hudson Platform, Northern Canada
(1) Geological Survey of Canada - Quebec, Natural Resources Canada, Quebec City, QC, Canada.
(2) Canada-Nunavut Geoscience Office, Iqaluit, NU, Canada.
(3) Geological Survey of Canada - Calgary, Natural Resources Canada, Calgary, AB, Canada.
(4) Ontario Geological Survey, Sudbury, ON, Canada.
(5) Manitoba Geological Survey, Winnipeg, MB, Canada.
(6) Geography, Laval University, Quebec City, QC, Canada.
The Hudson Platform covers 600,000 km2 and represents the largest Paleozoic sedimentary basins in Canada. The Hudson Platform encompasses parts of Manitoba, Ontario and Nunavut, with two thirds of the area covered by waters of Hudson Bay. The Platform contains the large Hudson Bay Basin and the smaller satellite Moose River and Foxe basins.
The Hudson Platform is the least studied intracratonic basin in North America; its surface area rivals that of other intracratonic basins although it is characterized by a thinner preserved sedimentary succession. The succession of the Hudson Platform consists of Ordovician to Cretaceous strata, with a maximum preserved thickness of about 2500 m in Hudson Bay. The Paleozoic succession includes Late Ordovician to Late Devonian shallow marine carbonates, reefs and thin mudstones with thick Upper Silurian evaporites. Paleozoic strata are unconformably overlain by thin, erosional remnants of Middle Jurassic and Early Cretaceous non-marine and marine sandstones, mudstones and lignite seams.
The hydrocarbon potential of the Hudson Platform is poorly constrained and the area is currently viewed as a frontier prospect. In a first phase of exploration (1970-1980), over 46 000 line-km of seismic reflection data were acquired and 5 exploration wells drilled. Most of the seismic profiles and all of the exploration wells are located in a relatively small area in the central part of the bay. A limited number of onshore wells have also been drilled. Although bitumen was been reported in some wells, all were dry and the area was abandoned by exploration companies in the 1980s.
The Geological Survey of Canada and its partners are carrying out a re-evaluation of the petroleum systems and energy resource potential of the Hudson Platform. Early results indicate that many prospective petroleum reservoir and trap types, including hydrothermal dolomites and reefs are present. Upper Ordovician oil shales are widespread with TOC values up to 35% (average of 15%). Thermal maturation data and basin modeling suggest that oil window conditions have been reached. New high resolution bathymetric surveys in Hudson Bay have led to the recognition of circular sea-floor depressions similar to fluid or gas-escape pockmarks, possible evidence of hydrocarbon migration. New hydrocarbon systems data suggest that large areas of the Hudson Platform are prospective for oil accumulations.