Evolution of the Reinjection System in a Compact Operating Geothermal Field: the Maibarara Experience

Abstract

Reinjection of separated brine is a major concern of the Maibarara Geothermal Field. The development plan for the Maibarara Field is compact where the production wells, steamfield, power plant and reinjection wells is situated in a 7-hectare area. Maibarara System was originally designed for an infield hot reinjection where separated brine will be injected into a very hot reservoir ( more than 300°C) at an injection temperature of 162°C. Reinjecting hot brine into a hot reservoir in Maibarara, however, proved to be difficult, thus, a cold reinjection system was implemented. Through time, the cold reinjection system evolved due to the response to reservoir exploitation, steam production strategy and the capacity of the injection wells at different injection temperatures. This paper will describe the reinjection challenges that Maibarara encountered and evolution of the reinjection systems in managing brine reinjection.