PhD student Yeftamikha Siahaan and Dr Eylem Kaya presented research on non-condensable gas reinjection at the International Indonesia Geothermal Convention & Exhibition 2024, highlighting emissions reduction in geothermal operations.

PhD student Yeftamikha Siahaan and key researcher Dr Eylem Kaya presented advances in geothermal non-condensable gas reinjection, their reactive transport modelling applications at Ngā Tamariki Geothermal Field, New Zealand, at the International Indonesia Geothermal Convention & Exhibition (IIGCE) 2024, highlighting the growing global importance of emissions reduction in geothermal operations.

At the Ngā Tamariki geothermal field, where NCG reinjection is currently underway and planned to increase, our research programme is working closely with Mercury NZ to better understand these subsurface processes. By collaborating from the very early stages of field trials, Mercury NZ has shared operational experience and data that allow our team to apply reactive transport modelling to investigate how NCG reinjection may alter reservoir chemistry, mineralogy, and flow behaviour over time.

These models help assess potential impacts on permeability and fluid pathways and provide an evidence-based framework to support risk mitigation and long-term reservoir sustainability. The outcomes directly contribute to Mercury NZ’s decision-making around NCG reinjection strategies, ensuring emissions reduction is achieved without compromising reservoir performance.

The strength of this industry–research collaboration was recognised internationally at the International Indonesia Geothermal Convention & Exhibition (IIGCE) 2024, where a paper presented by Yeftamikha Siahaan received the Best Paper Award in the Resource Management Category. Due to strong industry interest, the work was also selected for a second presentation in the Value Creation Session, delivered by both Kaya and Siahaan. This recognition highlights the growing importance of combining field experience with chemical modelling to assess the impact of NCG reinjection in geothermal reservoirs.