A calibrated maturation modeling study of several offshore wells was conducted in the vicinity of the Amauligak field, Canadian Beaufort Sea, an area of thick permafrost (500-1100 meters). Presence of permafrost, indicates that present day downhole temperatures are not in equilibrium (transient state) and may never have been in equilibrium since the onset of glacial conditions. Therefore basin models in regions of present day (or near present day) permafrost (high latitudes) must include a model for near term surface temperature history and must
be evaluated at time increments of order 50,000 years or less in order to account for the transient state and achieve an accurate heat flow model for the region. Failure to properly model temperature history results in an overestimation of present day heat flow and an incorrect calibrated paleo-heat flow model for the basin.
A constant basal paleo-heat flow was found to be adequate to account for observed vitrinite and apatite fission track data in six calibration wells. Heat flow values ranged from 0.85 to 1.05 heat flow units. Peak hydrocarbon generation rate occurred from 30-10 million years after which it decreased due to a hiatus and/or uplift and erosion from 10-5 million years. At 5 million years, rates increased to present day. At present, the Richards Formation source-rock is generating oil and gas at some depth interval in the fault blocks studied.
AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994