The Bacman Geothermal Field, Philippines: Geochemical Changes and Operational Challenges After Ten Years of Production

Abstract

After ten years of production, the Bacman geothermal field has undergone geochemical changes and operational challenges unique to the field. The geochemical response of the reservoir to exploitation was distinct but rather benign. There was no indication of detrimental reservoir processes as experienced in other producing Philippine geothermal fields such as injection returns or groundwater intrusions. Acidic inflows were contained in a small and shallow portion of the field. Reservoir-related and other problems encountered are generally near wellbore and at very manageable levels. Results of the geochemical monitoring for the past ten years showed that most production wells have attained stable chemistry. Sound reservoir management strategy, intensive and pro-active geochemical monitoring, and the application of practical and innovative solutions to operational problems encountered resulted to a well-managed, stable, and sustainable resource.