Some aspects of the thermal regime and hydrodynamics of the western Canadian sedimentary basin

Abstract

Summary Approximately 65 000 bottom-hole temperatures from about 36 000 wells in the Prairies Basin of western Canada have been used to investigate the thermal regime there. Both lateral and depth variations in temperature gradients and heat-flow densities occur, and these are related to the hydrodynamics which is controlled by the topography. The vertical heat-flow density in the Mesozoic-Cenozoic formations is less than in the Palaeozoic formations in recharge areas, but is greater in discharge areas. A zone in which heat flow is approximately constant with depth exists in the central part of the basin between recharge and discharge areas. It is clear that basin-wide redistribution of heat by groundwater motion takes place. The relationship between geothermal gradients and hydrocarbon occurrences is studied for southern Alberta and it is found that the mean geothermal gradient in the Mesozoic and Cenozoic sediments is greater for areas where Mesozoic gas and oil pools exist than for areas where they do not occur.