Resource Assessment Review of the Daklan Geothermal Prospect, Daklan, Philippines

Abstract

Among resource assessment approaches, the “volumetric” also known as “stored heat” method is the most practical approach and generally suitable for estimating the capacity of a geothermal prospect even in its initial stages of exploration and development. The results from this method are usually optimistic because of the use of fixed parameters and at the same time conservative because heat recharge is not considered. Probabilistic analysis is usually coupled with volumetric method to account for the uncertainties encountered in calculation. Review and analyses of the existing exploration data from Daklan geothermal prospect shows a relatively modest sized geothermal resource. The Monte Carlo simulation shows that the most likely resource area can support is a conservative 30-35 MWe development for 25 years. It should be noted however, that the exploration wells revealed a low permeability reservoir. But because of the high bottomhole temperatures ranging from 240-290C encountered in the wells drilled, further studies are needed to be done in the area to fully delineate the extent of the geothermal resource and identify permeable targets.