Geothermal reservoir modeling and calibration in a coupled thermo-hydro-mechanical perspective - a case study for DEEP Geothermal Project in Saskatchewan, Canada

ABSTRACT: Geothermal offers a low-emission, reliable and sustainable source of base-load energy, yet efficient reservoir management is challenging. Understanding the Thermo (T), Hydro (H) and Mechanical (M) interactions can help create sustainable strategies and ease energy extraction. In this study, a geological regional-scale THM model is created using PETREL, based on geological data from 11 wells close to the DEEP geothermal project. Geostatistical modelling was challenging as only 11 wells are available for such a large area. The depositional directions are used as secondary data for stratigraphic modeling. The permeability was populated using Machine Learning techniques based on 9 well logs as input data and calibrated with pulse-decay tests. A Mechanical Earth Model (MEM) was set up using a combination of empirical equations and calibrated using laboratory and field data. The minimum horizontal stress in the sandstone reservoir was found to be lower (~41 MPa) compared with caprock shale. Two open geothermal loop tests were history matched using INTERSECT which confirm fractures are induced for improved transmissibility in the sandstone reservoir without causing caprock failures.