Strategies to Improve Reinjection Facility Management in Maibarara Geothermal Power Facility, Batangas, Philippines

Abstract

Maibarara Geothermal Inc. (MGI) operates the 32 MW Maibarara Geothermal Power Facility (MGPF) in Batangas, Philippines. Reinjection is a critical component of geothermal operations, ensuring the sustainability of the reservoir by returning spent geothermal fluids back into the reservoir and in meeting environmental regulations on zero RI surface discharge. MGPF employs a cold reinjection scheme that integrates thermal ponds and Alvenius lines connected to the reinjection well. To enhance the efficiency and reliability of this system, the frequent need for pipe cleaning due to scaling and clogging in the enclosed Alvenius pipelines had to be addressed. To mitigate this issue, we replaced the Alvenius pipes with open concrete canals along the reinjection line. This strategic modification allowed for easier monitoring, quicker maintenance access, and a reduced likelihood of flow restrictions. Moreover, the open concrete canal design facilitated greater exposure of the brine to ambient temperature conditions, which further helped in cooling the brine before being reinjected into reinjection wells. As a result, this improvement not only streamlined operational workflows but also optimized reinjection performance and enhanced the overall efficiency and sustainability of the system.