Lithologic and Fracture Response to Geophysical Logs in the Andesite, Metamorphic, and Diorite Intrusive Rocks in Two Geothermal Wells in the Philippines

Abstract

Geophysical logging in geothermal wells is still at its infancy when compared to oil and gas industry. Many geothermal developers are still hesitant to apply this technique in its standard well evaluating because of lack of experience and limited information in the geothermal environment. But there are some fields where these are successfully applied, e.g. in Iceland and Cerro Prieto. This paper presents the analysis of geophysical logs in two geothermal wells at Palinpinon and Acupan geothermal fields. Results of the logs in both wells indicate that they can be used successfully in evaluating well permeability and lithology. Fractures and contacts can be identified, however, distinguishing fractured zones which are potential producer and injector should have to be confirmed form flow meter and temperature logs. This is because many fractures can be identified from geophysical logs notwithstanding whether one is permeable or not.