Involvement of preliminary regional fluid pressure evaluation into the reconnaissance geothermal exploration—Example of an overpressured and gravity-driven basin

• Proposal for regional hydrodynamic data analysis in preliminary geothermal studies.
• The noval approach is based on basin-scale pore pressure evaluation.
• The application is demonstrated for a gravity driven and overpressured basin.
• Key point is the definition of the upper boundary of overpressured region.
• Workflow for application in thermal water production and reinjection.

The paper proposes the involvement of preliminary regional hydrodynamic analysis for the reconnaisance phase water-based geothermal exploration in sedimentary basins. This approach is based on basin-scale pore pressure evaluation, it complements the usual reservoir and temperature analyses. Understanding of subsurface pore pressure distribution is beneficial not only in planning thermal water production but also in reinjection. The method is demonstrated for a sedimentary basin characterized by overpressured and superimposed gravity-driven flow. The key point of the approach is the understanding of regional pressure regimes and the delineation of the boundary of overpressured and gravitational flow domains.