GRSG 35th Conference 2024 Abstract

Title: Geothermal field monitoring with satellite radar in New Zealand

Author: Nick Dodds

Organisation: SatSense

SatSense’s aim is to make ground movement data more accessible. As part of this mission, we have an ongoing partnership with GNS Science to continually process and update InSAR data over New Zealand. From a geological and deformation perspective, New Zealand presents a multitude of phenomena, including tectonics, volcanoes, landslides and coastal subsidence. However instead of natural movements, this talk will focus on induced surface deformation related to geothermal fields in New Zealand.

Injection and extraction of fluids in the subsurface for geothermal energy and mineral extraction purposes results in pore fluid pressure perturbations. These perturbations at depth result in ground motion at the surface that can be measured using InSAR. With satellite revisit times at days to weeks and a data archive spanning over a decade, InSAR can be used to measure both dynamic short-term and steady long-term surface movements related to geothermal operations and properties of the subsurface.

We present case studies from geothermal fields across New Zealand, where geothermal power accounts for 25% of the total energy supply. We show how movement at the surface can inform reservoir management and optimise geothermal energy recovery strategy. We show how InSAR can be used by operators to manage and report their subsidence footprint at scale. Finally, we present how monitoring movement at the surface can be used to manage related critical infrastructure such as pipelines.