Characterizing Deep Basin Siliciclastic Reservoirs for Geothermal Use Near Hinton, Alberta

Abstract

Hot water for geothermal power is commonly sourced from magmatically heated reservoirs found near the earth’s surface. In sedimentary basins, however, significantly elevated temperatures may be present in aquifers as shallow as 2000 meters. The development of deep basin sedimentary rocks as geothermal reservoirs has not been widely studied in the Western Canadian Sedimentary Basin and is the subject of this investigation. The area of interest lies in the western-central region of the Alberta basin, located within 50 kilometres of Hinton, Alberta. The area excludes foothills strata that have undergone orogenic deformation.

The investigation aims to develop a static 3-D model displaying regional reservoir zones where flow parameters (permeability, porosity, reservoir pressure) are optimal and the temperatures are high. The static model incorporates borehole, wire-line, core, DST and well log data to determine geometry and flow parameters of the formations. The marginal-marine Viking formation and the continental Mannville Group have wellbore and production information that establish the sediments as suitable water-bearing reservoirs and also provide a high number of data control points for the model. These Early Cretaceous formations occur at a depth range between 3000 - 4000 metres. Corrected bottom hole temperatures (BHT) at these depths range between 100 - 150 degrees Celsius (sufficient for direct-use heating). The primary exploitable facies include shoreface sequences (Viking) and incised valleys (Viking and Mannville). The subsurface data is assembled in Petrel to build isopachs, estimate total reservoir volumes and estimate the total energy reserves. Incorporation of flow data additionally constrains the petrophysical analysis and narrows the possible targets where existing oil and gas wells could be retrofitted to produce hot water at significant flow rates. Further development will extend the static model to a dynamic one, which can describe variation in flow rates and pressure at the well head and in the surrounding reservoir as water is pumped out. The dynamic model will also account for injection wells where cold water is re-injected and how fluid mixing and restoration of fluid pressure affects flow rates of the reservoir.

AAPG Datapages/Search and Discovery Article #90323 ©2018 AAPG Annual Convention and Exhibition, Salt Lake City, Utah, May 20-23, 2018