Handling the Problem of Rapid Reinjection Returns in Palinpinon-I and Tongonan, Philippines

Abstract

Rapid return of reinjection waters is a genuine problem facing geothermal development, especially in "wet steamfields" such as those found in the Philippines. If left uncontrolled and unabated, it leads to quenching of individual production wells, and ultimately to significant reductions in power generation. In the geothermal industry steamfield management and power generation business, unforeseen or unprogrammed reduction in power output have immediate impacts and drastic consequences. This underscores the importance of proper steamfield management, especially on the problem of rapid reinjection returns.
All geothermal development in the Philippines are in liquid-saturated reservoirs, which has made the country the leader in wet steam technology. A major concern of wet steam development is reinjection management. The Philippine National Oil Co. - Energy Development Corp. (PNOC-EDC) has been in the Philippine geothermal business for over 25 years, mainly as steamfield developer and manager. Its experience in injection management has been diverse, beginning with in-field injection to scattered disposal of separated brine, which commonly have scaling potentials and problems of their own. The advent of stricter environmental laws has resulted in PNOC-EDC disposing not only of separated waters but power plant condensates as well. Nonetheless, the company's sound, dynamic and responsive injection strategy and overall steamfield management in the four production fields it has developed, has enabled it overcome these problems, resulting in sustained geothermal operations and power generation.