AAPG Bulletin, Vol.92, No.2, 225-247, 2008
A three-dimensional insight into the Mackenzie Basin (Canada): Implications for the thermal history and hydrocarbon generation potential of Tertiary deltaic sequences
The stratal architecture of the Mackenzie Basin was reconstructed based on seismic and well data and used to define a three-dimensional model to reconstruct the so-far poorly known thermal and maturation history of the basin. To correctly account for the complex tectonic history of the Mackenzie Basin, episodes of uplift and erosion were implemented based on interpretations of original depositional surfaces. Our results indicate that the combined effects of basin inversion and low surface temperatures inhibited maturation from the late Miocene forward in all except the most deeply buried parts of the basin. This explains why upper Eocene and younger deposits are mostly immature despite their burial to more than 5000 m (16,400 ft). The specific history of the basin is shown to control the time intervals of potential hydrocarbon generation. Predictions of transformation ratios using a variety of published kinetics to account for source rock kinetic variability indicate that potential generation from Paleocene and older strata occurred mainly before the late Oligocene. The generation from Eocene strata, however, occurred mainly during the Miocene and, therefore, is interpreted to be a source for Oligocene and younger gas-rich reservoirs. These findings contribute to a better understanding of hydrocarbon systems in the Mackenzie Basin and are the basis for future studies of hydrocarbon migration and accumulation.