Numerical Investigation of Pressure Transient Responses of a Well Penetrating a Deep Geothermal Reservoir at Super-Critical Conditions

Abstract

Numerical simulations were carried out to predict pressure transients in a hypothetical deep geothermal well which penetrates a reservoir at super-critical conditions. Production at about 4000 m depth was assumed. In many cases, two-phase conditions develop due to high temperature and production-induced pressure decrease. Several cases in which single-phase conditions are maintained were studied in detail. Pressure transients are influenced by the reservoir temperature distribution - in particular, a temperature distribution with subcritical conditions at the well but supercritical conditions farther away causes a characteristic nonlinear pressure response whlch is influenced by the large compressibility and small kinematic viscosity near the critical point.