Geothermal: Increasing Production in Thin Geothermal Reservoirs

The Paris Basin is the largest geothermal district heating market in the world, with over 250,000 homes heated with geo-energy. However, further development of this resource is facing an uphill battle to deploy new heating plants in areas with sub-optimal reservoir properties and limited surface locations to locate geothermal plants. Drilling horizontal geothermal wells reduces the impact of drilling operations in densely populated urban areas. In this basin, there is also an East-West divide of good reservoir properties. The East has higher permeabilities and substantially more developments. And the best flow characteristics come from thin layers, which should be targeted to enhance heat recovery.

This case study discusses how placing a horizontal doublet in thin permeable layers, using Logging While Drilling (LWD) deep electromagnetic multi bed boundary mapping and borehole imaging technologies can be implemented to maximize reservoir exposure. 

The innovative well architecture for the geothermal doublet enabled the generation of approximately 15MW of heating capacity and provides hot water and heat to residents of about 8,000 homes with renewable energy. This project alone avoids the emission of 15,000 metric tons of CO2 equivalent per year.

As a result of the success of this approach, six other wells’ prospects have been identified around Paris in which this technology is planned to be deployed again, and other companies in Denmark, the Netherlands and Germany have shown interest to replicate this approach in Europe.