Mississippian Lacustrine Horton Formation Source Rocks from Nova Scotia and New Brunswick, Eastern Canada: A Major Shale Gas and Oil Shale Resource Plays

P.K. Mukopadhyay(Muki)
Global Geoenergy Research Ltd., Halifax, NS, Canada

Based on regional geology, geochemical fingerprinting, and heat flow histories related to major faults, selected Mississippian Horton Group lacustrine shales and siltstones (usually 100-500 m in thickness; with variable organic facies with kerogen Types II, II-III, III) from various basins of Nova Scotia and New Brunswick, Eastern Canada have been identified as major Oil Shale and Shale Gas Resource Plays. These basins include the Cumberland, Windsor, Antigonish, Western Cape Breton and Moncton. The organic shales in these basins are similar to the Mississippian Barnett Shale in the Fort Worth Basin of Texas. Calculations of the methane generation potential of the Mississippian Horton group shales range from 75 to 300 scf/ton.

The current work has also documented the influence of regional maturity (Ro: 0.7 to 2.5%), specificity of organic facies (ratio of the lacustrine versus terrestrial organics), the mineralogy (ratio of quartz, clays, and carbonates), regional stress and fracture patterns on the amount of both adsorbed and free gas or the extractable hydrocarbons within these unconventional shale resources from the basins of Nova Scotia and New Brunswick. Preliminary evaluation of the gas composition and the micro-fracture patterns within the shale network indicates the presence of moderately high free gas compared to the adsorbed gases especially at a vitrinite reflectance (Ro) above 2.2%. The proposed regional resource assessment potential of the Mississippian Horton Group shales based on petroleum system analysis illustrates the location of the boundary zones between gas cell and oil cell zones within this unconventional resource play.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas