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

Artificial thermal maturation of petroleum source rocks is widely performed by either open-or closed-system pyrolysis. These experiments are performed usually on immature source rock or isolated kerogen samples to quantify petroleum generation potential and to calculate kinetic parameters. Here, we characterize a maturation series from the Triassic Montney and Doig formations in the Western Canada Sedimentary Basin (WCSB), in order to investigate the evolution of the source rock properties and their corresponding kerogen kinetic parameters as a function of the thermal maturity. Organic petrography determined the thermal maturity and the spatial distribution of organic matter particles. Rock-Eval Shale Play analyses were then applied to assess the presence of both free and sorbed hydrocarbons still contained in the sample as well as the hydrocarbon generation potential. Based on vitrinite reflectance values, three kerogen samples from the Doig Formation and one kerogen sample from the Montney Formation 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 of organic compounds that comprise the first two Rock-Eval peaks (Sh0 and Sh1) obtained during the improved thermovaporization. TD-GC-MS-FID analyses were carried out on rock samples sequentially from 100 degrees C to 200 degrees C and then from 200 degrees C to 350 degrees C in order to characterize the composition of hydrocarbons represented by each Rock-Eval Shale Play peak. Free and sorbed low-to-medium molecular weight aliphatic and aromatic hydrocarbons (