Above: Project Location Map. View enlargement

Torrens Energy understands that for an area to be prospective for ENHANCED geothermal SYSTEMS, three key factors are needed:

• an active heat source which is generally radiogenic granite;
• insulating sedimentary cover over the heat source; and
• proximity to infrastructure and market.

Torrens Energy has secured the rights to explore in areas that have confirmed high heat flow, which have sedimentary rock cover with known insulating properties, and are located on the national power grid.

Torrens has been granted 27 GELs, over five project areas encompassing 21,681km² of highly prospective ground in South Australia and Victoria.

The geological setting is the Torrens Hinge Zone which is where insulating sedimentary rocks of the Adelaide Geosyncline overlap the radiogenic basement rocks of the eastern margin of Gawler Craton.

Industry Positioning

Torrens Energy is an upstream geothermal resource explorer, focused on discovery, delineating and testing the viability of geothermal resources on-grid. Downstream the Company plans to participate in the renewable energy generation business through development partnerships with power industry leaders such as AGL Energy Limited.

The Company aims to deliver a pipeline of geothermal prospects by applying its unique heat-flow methodology (3D-TFM), further refined by seismic surveys and intermediary validation drilling, to bring targets to deep drill-ready status.

Technical Innovation

Torrens Energy recognised the need to develop cost effective and robust broad-scale exploration techniques to map hot spots over some 20,000 km² of regional prospective geology.

Against a backdrop of technical challenges, the result has been development and deployment of the 3D-TFM methodology, transforming the Australian geothermal sector in terms of site selection for enhanced geothermal systems.  This has positioned Torrens Energy as a leader in the use of innovative geothermal exploration science.

This unique approach combines advanced three-dimensional temperature modeling with the three-dimensional geological framework, to identify both favourable insulators and rocks suitable for creating underground heat exchangers, thereby allowing for the rapid identification of quality geothermal targets.

The development of this effective modeling was partly funded by the Australian Government Renewable Energy Development Initiative (REDI), a clear example of where industry innovation and public resources can deliver an outcome of significant national benefit.

Temperature Modeling

Temperature prediction at depth by conductive heat-flow modeling using measurements recorded in shallow boreholes is an industry-standard method. The method is based on the thermodynamic principle that thermal energy, measured as conductive heat flow, remains constant at depth.

Above: Seismic representation of heat flow-drilling at approximately 15km spacing. View enlargement

The schematic representation (right) shows heat flow-drilling at approximately 15 kilometer spacing, enabling high resolution heat mapping over large areas and providing geological control for three-dimensional modeling of temperature.  In Australian examples where wells have been drilled to target depths, temperature modeling has been found to reliably predict the temperature gradient to within 5% of the actual value.

Given the fact that a major obstacle facing geothermal commercialisation in Australia is the high cost of the supporting power infrastructure, the exploration undertaken by Torrens Energy on the national power grid is one of the most important geothermal developments in Australia.

Project Detail:  Parachilna | Port Augusta | Other