Non-Isothermal Lumped Parameter Model for Two Phase High Temperature Geothermal Reservoirs

Abstract

Extensive works have been done on simulation of behavior of low-temperature geothermal reservoirs using lumped-parameter. However, there has not been much effort placed on using lumped parameter methods for high temperature - two phase geothermal reservoirs. In this paper, lumped parameter method to be applied for the high-temperature two phase geothermal systems. To account for these system a lumped parameter model is developed using Matlab software to provide a flexible means for assessing the behavior of reservoir. The model couples both energy and mass conservation equations and hence can be used to predict both temperature/enthalpy and pressure changes in the reservoir resulting from production, re-injection of a low temperature water into the system, and/or natural recharge. The method will be validated using results of reservoir simulation and high enthalpy geothermal field data. A computer program will be then used to perform sensitivity studies on reservoir size, porosity, aquifer recharge, and temperature of recharge fluid.