| Title | Modelling the Ngatamariki Geothermal System |
|---|---|
| Authors | Jonathon CLEARWATER, John BURNELL, Lutfhie AZWAR |
| Year | 2012 |
| Conference | Stanford Geothermal Workshop |
| Keywords | Ngatamariki, modeling, TOUGH2, dual-porosity, New Zealand |
| Abstract | The Ngatamariki geothermal field is situated 17 km north east of Taupo. Mighty River Power has announced plans to build an 82 MW power station on the field. As part of the consent and planning processes, an extensive programme of drilling, testing and modelling was undertaken to provide understanding of the likely response of the field to a development. Analysis of the three new deep wells drilled by Mighty River Power in 2008-9 and the four wells drilled by the New Zealand government in the 1980s, together with recent MT surveys, showed a larger field than was originally defined by the early DSIR resistivity surveys. A conceptual model was developed to encompass the new data collected from the wells and the MT surveys. Modelling of the field was undertaken with a full-field dual-porosity numerical model together with a number of simpler process models. The challenge for the numerical modelling was to find parameter values for the model that would provide robust predictions of the field response to development. To help with this challenge, quick-running process models were used to test understanding of the flow processes and the sensitivity of the predictions to the model parameters. In this paper, we will describe the development of the various numerical models and discuss how the process model informed the full-field numerical model. |