IMAGE-D8.1: Selection of exploration techniques

The field integration workpackage (WP8) is dedicated to integrate all existing and new data derived from new exploration techniques to provide predictive models for site characterization and well-sitting. The objective of this workpackage is to provide a systematic approach for the assessment of an optimum location of geothermal production and injection wells. For that, it aims at provide recommendations to the use of existing and novel exploration techniques developed and tested in the WP7 in order to highlight the favorable key situations identified in the WP6. 

Patterns and situations favourable to enable geothermal exploitation can be classified according to the two main factors: heat and fluid flow and accumulation: 

- Heat factor: patterns that enable positive heat anomaly, i.e. that result in having higher temperature at one given depth than in a classic situation of normal geothermal gradient; 

- Fluid factor: patterns that enable fluid flow and that may be favourable to expect final sufficient flow (after enhanced processes) for a viable exploitation. 

The most important key situations take into account for the geothermal exploration of deep basin and basement are the presence of a plutonic intrusion, a thermal blancket, a convective transfert system, a fracture pattern like joke, ramp, tip and fracture intersections. 

Theorically, these key situations are not scale-dependent but in an exploration context, different scales have to be considered: the European scale, the regional scale and the local scale. The size of geological objects considered for each scale is crucial for the selection of the exploration methods. A synthesis of the exploration methods versus key situations at the different scale is provided in this report. There are therefore no golden rules to select the best exploration techniques for a given geothermal project in a sedimentary basin but rather a wealth of techniques that must be tailored based on their technical feasibility, spatial resolution, delivery time and costs.