A proxy model for determining reservoir pressure and temperature for geothermal wells

•Wellbore simulation of geothermal wells.•Forecasting wellhead flowing properties of geothermal wells.•Coupling numerical reservoir simulation and wellbore simulation.•Using artificial neural network to estimate reservoir temperature and pressure from wellhead data. Estimating reservoir pressure and temperature is one of the challenges of geothermal reservoir engineering. A new proxy model has been developed to estimate reservoir pressure and temperature using wellhead pressure, temperature and non-condensable gas (NCG) amount. An exhaustive set of wellhead data covering a range of possible wellhead pressure, temperature and NCG data is used in a calibrated wellbore simulator, which is then used to create a knowledgebase to train an artificial neural network (ANN) model. The developed ANN model is tested using numerical simulation model results coupled with a wellbore simulator. It is observed that the ANN model can accurately estimate reservoir pressure and temperature for various production scenarios in liquid phase reservoir.