Tongonan Geothermal Field: Conquering the Challenges of 25 Years of Production

Abstract

Tongonan is one of only a few geothermal fields worldwide that has achieved a milestone of continued production for 25 years. Reservoir management has been a cornerstone in sustaining the field’s generation and in conquering the challenges since the commissioning of the first power plant in 1983.

Being one of the largest water-dominated systems, the series of challenges in its 25-year history, from the early workers first experience with injection returns and pressure drawdown to present day maintenance of optimum production, have been a source of lessons and the reason for the sound production and injection protocols that are set in place in the different geographical sectors of the field.

Technological knowledge and developments in geochemistry, tracer tests, stable and radioactive isotopes and reservoir engineering were crucial in analyzing and addressing these challenges. Likewise, experience and advances in well intervention techniques ensured optimum performance of production and injection wells in transmitting the energy to the surface and recycling of fluids back to the resource. With sound resource management, Tongonan Geothermal Field is poised for another 25 years of sustainable production.