Behavior and Thermal Stresses of a Geothermal Reservoir on an Oblique Fault Plane

Abstract

The heat extraction through a geothermal reservoir on an oblique fault plane in a hot dry rock is consid ered. The fault is modeled mechanically as a frictional contact interface of two elastic bodies. During the heat extraction, the surface of the reservoir is cooled by the fluid and the thermal contraction of rock occurs. For the purpose of clarifying the behavior of the reservoir and the leakage of fluid through the fault, the analysis is attempted on the basis of the two dimensional theory of quasi-static thermoelasticity. It is concluded from numerical results that a geothermal reservoir can be created on an oblique fault plane and the opened region of the plane increases gradually with time during the heat extreaction. It is also found that the large thermal stresses on the fault plane outside the opened region tend to stop the leakage of fluid through the fault plane.