3D Conceptual and TOUGH2 Modelling of the Waiotapu Geothermal Field, New Zealand
Author: Irfan Narendrotomo
Year: 2021
Supervisors: Juliet Ann Newson , Chelsea Arlette M. Cervantes
Abstract:
The Waiotapu geothermal system is a liquid dominated, high-temperature system located in the Taupo Volcanic Zone (TVZ) in the North Island of New Zealand. Seven exploration wells were drilled in Waiotapu in the late 1950s, which were drilled to around 500 m - 1100 m depth. Although Waiotapu has seven deep exploration wells that reached a high temperature reservoir, these wells are considered non-production because they are protected by the Waikato Regional Council, the environmental regulator of most of the Taupo Volcanic Zone. Two main fault structures affect the geothermal system of the area which are the Paeroa and Ngapouri faults that extend from northeast to southwest of the thesis project area.This thesis aims to analyze and study the characteristic reservoir of the Waiotapu geothermal system and its surroundings through 3D conceptual modeling and numerical modeling. The conceptual model is created using existing data obtained from surface and subsurface exploration. Leapfrog Geothermal software was used to build the model. This 3D conceptual model was used as the basis of a numerical TOUGH2 model. The numerical model was calibrated to measured well temperature and the result of this calibration shows the temperature, permeability, and fluid flow distribution of the system. Modeled results indicate that the Waikite area has a heat distribution connectivity from the Waiotapu geothermal system through the Paeroa and Ngapouri faults.The inflow comes from north-east of Maungakakaramea,