| Title | Thermal Modeling of the Hot Dry Rock Geothermal Resource Beneath GEL99 in the Cooper Basin, South Australia |
|---|---|
| Authors | Graeme R. Beardsmore |
| Year | 2005 |
| Conference | World Geothermal Congress |
| Keywords | HDR, Australia, heat flow |
| Abstract | Radiogenic granites beneath the Cooper Basin are purported to be the most prospective hot dry rock resource in the world, but the remote location means that any economic development of the resource must factor in a significant cost of connecting to the national electricity grid. This cost cannot be easily reduced. The other major cost of development is drilling, so it is imperative to keep this cost to a minimum. As the energy potential of the rocks is directly proportional to their temperature, it is vital to target drilling at locations likely to yield the highest temperatures at the shallowest depths. The South Australian government has granted three Geothermal Exploration Leases for commercial ventures to explore in the Cooper Basin. GEL99 is one of those leases and is currently operated by Scopenergy Limited. A series of one-dimensional conductive heat flow models were developed from thermal conductivity profiles and bottom hole temperature data extracted from numerous petroleum exploration and appraisal wells in the GEL99 area. These heat flow estimates were then extrapolated vertically into the underlying crystalline basement to predict the temperature versus depth distribution at specific points in the region. The conductive heat flow at the top of the Warburton Basin sequence was found to be about 103±8 mWm2 beneath most of GEL99. The 220?C isotherm lies at a mean depth of around 4200-4300 m beneath most of the wells studied. Heat flow appears to be closely related to the nature of the basement rocks. |