Engineering methods for predicting productivity and longevity of hot-dry-rock geothermal reservoir in the presence of thermal cracks. Technical completion report

摘要

Additional heat extraction from geothermal energy reservioirs depends on the feasibility to extend the main, hydraulic fracture through secondary thermal cracks of the adjacent hot rock. When the main, hydraulic fracture is cooled sufficiently, these secondary thermal cracks are produced normal to the main fracture surface. As such, both the heat transfer surface area and heat energy available to the fluid circulating through the main, hydraulic fracture system increase. Methods for predicting the productivity and longevity of a geothermal reservoir were developed. A question is whether a significant long-term enhancement of the heat extraction process is achieved due to these secondary thermal cracks. In short, the objectives of this investigation are to study how the main, hydraulic fracture can be extended through these secondary thermal cracks of the rock, and to develop methods for predicting the productivity and longevity of a geothermal reservoir.