Black Shales and Shale Gas in Southwestern Ontario, Canada

Terry R. Carter¹, Lee Fortner¹, and Tony Hamblin^2
1Ontario Ministry of Natural Resources, London, ON N6E 1L3 [email protected], [email protected]
²Geological Survey of Canada, Calgary, AB T2L 2A7, [email protected]

Exploration for unconventional natural gas sourced from black shales has been the hottest natural gas play in the western United States for several years, with recent expansion of the play into Canada and the eastern United States. Ontario has been largely overlooked in this flurry of activity despite the presence of the same organic-rich shale strata which are the subject of intensive exploration efforts in neighbouring states and provinces.

A recent report by the Geological Survey of Canada has identified the Collingwood/Blue Mountain (Utica), Kettle Point (Antrim) and the Marcellus shales, all located in southwestern Ontario, as having the best potential for discovery of commercial quantities of shale gas. The Collingwood/Blue Mountain black shales are generally thermally mature, range from 2 to 50 metres in thickness, with TOC from 1 to 11%, at depths ranging from outcrop to over 800 metres. The Marcellus usually occurs as subcrop beneath glacial drift and is marginally mature to mature, averages 6 metres in thickess, with average TOC ranging from 4 to 13%. The Kettle Point formation shales subcrop beneath glacial drift and are thermally immature, average 28 metres in thickness to a maximum of 108 metres, with TOC values from 3.6 to 15%.

Water well and petroleum well records document the occurrence of natural gas in glacial drift wherever these formations form the local bedrock, strongly suggesting the presence of biogenic natural gas. Dry, thermogenic gas may be also present where these rocks are buried to greater depths.

AAPG Search and Discovery Article #90095©2009 AAPG Eastern Section Meeting, Evansville, Indiana, September 20-22, 2009