A Study on Pressure and Temperature Behaviors of Geothermal Wells in Single-Phase Liquid Reservoirs

Abstract

In this study, a non-isothermal reservoir simulator that is capable of rigorously simulating (or forwarding) both pressure and temperature behaviors of single-phase liquid-dominated geothermal systems is presented. The model is based on solving the mass and energy balance equations for the reservoir simultaneously. The model is also capable of simulating heat losses from the reservoir to the strata enabling realistic simulations of temperature to be made in the well. All equations are solved in a fully implicit manner using the well-known Newton’s method for handling the non-linearity. The model is 2D (r-z) cylindrical and hence provides realistic descriptions of wellbore pressure and temperature behaviors. The transient behaviors of especially temperature, which is the main focus of the study, and various sensitivities of formation and well properties on the pressure and temperature responses have been studied by using the model developed. The synthetic examples considered in this study have shown that the wellbore temperature shows the most significant sensitivity to rock thermal conductivity among the other parameters, such as porosity, skin and permeability, considered for this investigation.