AGREEGAS

The AGREEGAS project aims at characterizing the biogeochemical processes responsible for the clogging of very low-enthalpy geothermal doublets. In the Centre-Val de Loire region, some installations exploiting swallow waters are faced with major malfunctions leading to costly maintenance operations, or even the shutdown of the exploitation. The main cause is the development of iron and manganese oxy-hydroxide deposits in the heat exchangers and sometimes in the well screens. The diagnostics carried out on these installations suffer from a lack of data and the lack of remediation actions leads, in some cases, to the abandonment of the exploitation. The objective of the project is to better understand these clogging mechanisms leading to operating issues and to propose, on the one hand, recommendations based on a better characterization of these environments for new doublets and, on the other hand, remediation solutions for doublets already in operation. For this purpose, on-site and laboratory investigations will be carried out in order to predict and anticipate these clogging processes. The focus will be on the development of economically viable remediation solutions, which will then be tested on site. The project consortium includes academic experts in water chemistry and micro-organisms (BRGM, ISTO, University of Tours), project owners, and sector representatives.