Triassic oils and potential Mesozoic source rocks, Peace River Arch area, Western Canada Basin

Abstract

Triassic oils and their potential Mesozoic source rocks in the Peace River Arch region (Western Canada Basin) have been examined using various analytical techniques. Triassic oils are divided into two groups, 1 and 2, on the basis of biomarker composition. Triassic outcrop samples from the Rocky Mountain Foothills are mature to overmature, and contain Type II/III organic matter with TOC's ranging from 0.1 to 15.0 wt% and HI values up to 445. Subsurface core samples from the Triassic Montney Formation are mature to overmature with TOC's (rarely) up to 2.8 wt% and HI values up to 398. The Triassic Doig Formation has good to excellent source potential and moderate to high maturity, with TOC values over 5.0 wt% and HI values commonly in excess of 300. The Jurassic “Nordegg Member” ranges from early mature to overmature, with TOC's as high as 23.5 wt% and HI values greater than 600 where maturity is low. Oil-source rock correlations are established, based on biomarker signatures, between the Group 1 oils and the Doig Formation. Group 2 oil was sourced by the “Nordegg Member”