| Title | The History of the Ohaaki Geothermal Field - in 3D |
|---|---|
| Authors | C Massiot, G Bignall, S Alcaraz, H van Moerkerk, F Sepulveda, A Rae |
| Year | 2011 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Ohaaki Geothermal Field, New Zealand, 3D geological modelling, geothermal exploration, Leapfrog Geothermal |
| Abstract | Geothermal drilling of the Ohaaki Geothermal Field (New Zealand) started in 1965, and subsequently involved several phases of exploration, delineation and production/injection drilling, culminating in the commissioning of the Ohaaki Power Station in 1988. Since that time, exploration, development and monitoring activities have continued, with ongoing collation of geophysical survey and reservoir engineering data, and new geological insights from recent drilling operations. The acquisition of new geoscientific information demands a combined interpretation of the geothermal data sets which can be challenging. As such, 3D modelling has been increasingly used by Contact Energy Ltd. and GNS Science for geothermal data management, analysis and interpretation. To demonstrate the value of 3D modelling and data integration, five 3D geological models of the Ohaaki Geothermal Field have been constructed, for five different stages of field development, using Leapfrog Geothermal 3D visualisation and modelling software. Comparison of the respective 3D models with (historical) interpretations made at each development phase highlights the utility and effectiveness of 3D geological modelling in producing robust and consistent interpretations. We demonstrate how 3D geological models and numerical interpolations can be easily updated and refined, with testing of alternative interpretations accompanying revision of the conceptual and geological models. As a result of increased efficiency and reliability, 3D models can be used on a routine basis to assist in the development of drilling strategies and to advance data integration for field management. |