| Abstract |
Wairakei power station has been generating for 60 years and direct use applications for even longer. The long history of geophysical monitoring at Wairakei-Tauhara, New Zealand, has helped understand the causes of many reservoir processes and environmental effects of large scale development. Monitoring studies included changes in: groundwater level, subsidence, heat-loss from surface thermal features, micro-gravity, and microseismicity. Each of these data-sets has revealed the effects of subsurface physical processes that accompany extraction and reinjection of reservoir fluid. When interpreted together with downhole pressure and temperature data, incorporating subsurface boiling processes, the geophysical monitoring datasets provide a valuable source of information that can assist in the calibration of models (reservoir simulation) improving forward projections of reservoir behavior under modelled development strategies. In addition to power generation, the broader geothermal resources associated with the Wairakei-Tauhara Geothermal System have been supporting a wide range of direct uses. Examples are discussed, including the direct uses that have emerged through the period of the Wairakei power development, and the potential for expanded direct utilization from this energy resource. Careful reservoir management, informed by comprehensive monitoring has enabled reliable and sustainable resource use for both power generation and direct use. |