Reservoir simulation of the Alto Peak geothermal field, Leyte, Philippines

Abstract

This study deals with the development of a numerical model for the Alto Peak geothermal field in Leyte, Philippines. Formation temperature and pressure profiles were estimated from heat-up surveys of five directional wells in this field. These profiles are indicative of an upflow zone beneath the New Alto Peak crater and an outflow to the south. The reservoir seems to be closed in the east. No conclusive data was gathered on the extent of the reservoir to the north and northwest. A three-dimensional grid of the reservoir was created to serve as input for the numerical simulator TOUGH. Several parameters of the TOUGH input were varied iteratively until a satisfactory match was reached between the measured and simulated temperatures and pressures of the wells. The steady state of the resulting best-fit model was able to replicate most of the prominent features of the observed temperatures and pressures. The current model, however, should be calibrated against production data before future predictions can be made.