Research status of multi-field coupling model in deep energy exploitation： A case study of hot dry rock

Abstract:

With the decreasing of shallow energy resources of the earth and the gradual transformation to deep energy development， China’s hot dry rock geothermal resources have great potential， but the development and research is still in its infancy. Deep energy exploitation will inevitably face the problems of high temperature， high stress， high permeability pressure and hydrochemical environment. Therefore， the multi-field coupling effect of rock THMC （temperature field+seepage field+mechanical field+chemical field） is the focus of current research. In this paper， the method and development process of the multi-field coupling model are introduced， and the application in deep energy exploitation is summarized， especially the multi-field coupling problem in the Enhanced Geothermal System （EGS） and related experimental studies. The results show that the research on crack propagation， chemical stimulation measures and mechanical parameters in EGS is the key research problem. Moreover， the urgency and necessity of deep energy development are emphasized， which provides an important reference and guidance for future research and practice.

Key words:deep energy;multi-field coupling model;enhanced geothermal system;hot dry rock;experimental studies