Geothermal Exploration of Paleozoic Formations in Central Alberta, Canada

This study explores Paleozoic formations in the Central Alberta Basin with regard to their usability as geothermal reservoirs. A 3D geological model is developed based on stratigraphic picks of more than 7000 wells from the Alberta general well data file. Spatial distribution and thickness of deep formations is analysed by the 3D model. Porosity and permeability distribution is mapped in four Devonian carbonate formations–Cooking Lake, Leduc, Nisku and Wabamun –by data from about 50,000 core analyses. Since logging data of the promising Cambrian Basal Sandstone are rare, porosity and permeability are measured with probe permeametry and helium pycnometry on cores. First results give an average porosity of 11.1 % and an average permeability of 1.4 mD. Formation temperature of Cambrian and Devonian strata is estimated by a newly calculated geothermal gradient and the reservoir depth range derived from the 3D model. Temperatures in the Cambrian Basal Sandstone formation range from 62°C in the shallower northeast to 121°C in the deeper southwest, surface temperatures in the Devonian strata are between 19° - 87°C. Especially for district heating this temperature range seems sufficient to exploit but also industrial applications for oil sands extraction can be an option for geothermal use in Alberta.