Artificial thermal maturation of source rocks at different thermal maturity levels: Application to the Triassic Montney and Doig formations in the Western Canada Sedimentary Basin

International audienceArtificial thermal maturation of petroleum source rocks is widely performed by either open- or closedsystempyrolysis. These experiments are performed usually on immature source rock or isolated kerogensamples to quantify petroleum generation potential and to calculate kinetic parameters. Here, we characterizea maturation series from the Triassic Montney and Doig formations in the Western CanadaSedimentary Basin (WCSB), in order to investigate the evolution of the source rock properties and theircorresponding kerogen kinetic parameters as a function of the thermal maturity. Organic petrographydetermined the thermal maturity and the spatial distribution of organic matter particles. Rock-EvalShale Play analyses were then applied to assess the presence of both free and sorbed hydrocarbons stillcontained in the sample as well as the hydrocarbon generation potential. Based on vitrinite reflectancevalues, three kerogen samples from the Doig Formation and one kerogen sample from the MontneyFormation at different thermal maturity levels were selected for analysis of bulk kinetic parameters(e.g., activation energy distribution, frequency factor) using programmed open-system pyrolysis.Additionally, we evaluated the type of hydrocarbons and determined the molecular composition oforganic compounds that comprise the first two Rock-Eval peaks (Sh0 and Sh1) obtained during theimproved thermovaporization. TD–GC–MS–FID analyses were carried out on rock samples sequentiallyfrom 100 C to 200 C and then from 200 C to 350 C in order to characterize the composition of hydrocarbonsrepresented by each Rock-Eval Shale Play peak. Free and sorbed low-to-medium molecularweight aliphatic and aromatic hydrocarbons (