The main aim is to carry out CO2 injection tests in an old geothermal doublet


The objective of the CO2-DISSOLVED_INJECTION project is to prepare and implement, for the first time, a series of dissolved CO2 injection tests (of the order of 3-5 kt in total) in a geothermal doublet to validate the technical feasibility of the operation. A geothermal doublet at the end of its lifespan will be sought as target among the sites in the Paris basin.

Two phases

This project has two main phases: a preparatory phase (18 months) in which the site will be selected, the technical operations designed and pre-dimensioned and the regulatory procedures with the administration will be started. This phase is funded by Geodenergies (October 2018 to March 2020).

At the end of this first phase, a « Go / No go » will decide if all conditions are met to move to the second operational phase (24 months).

The industrial purpose

The CO2-DISSOLVED_INJECTION project aims to achieve, at the end of the two planned phases, the validation of the core of the CO2-DISSOLVED concept put into practice, namely the CO2 injection loop enabling the dissolution of CO2 within the doublet injection well. This step is indeed essential before considering the construction of an industrial demonstrator that combines all technologies to capture, inject, and store CO2 whilst also recovering geothermal heat.

The industrial demonstrator, which we hope will be launched at the end of the operational phase of the CO2-DISSOLVED_INJECTION project, will be the last step before proceeding to a wider industrialization phase. We would then have a turnkey technological solution that can significantly reduce the carbon footprint of a given industrial sector, namely small CO2 emitters, which currently has no decarbonization solution.

The challenges

Validate the technical feasibility of injecting CO2 in dissolved form (3-5 kt) into a geothermal doublet no longer in operation. Several challenges exist:

  • Technical: demonstrate the CO2 injection technology, test the quality of dissolution in injected brine and check there’s no negative impact on the technical performance of the geothermal doublet
  • Environmental: specify the monitoring protocols for well integrity and CO2 dissolution
  • Economic: undertake a preliminary assessment of additional CAPEX / OPEX needed for CO2 injection operations
  • Regulatory: clarify any regulatory issues and establish administrative authorisation procedures in collaboration with the competent authorities
  • Societal: set up consultations with various stakeholders and work towards improving public perception


Dernière mise à jour le 15.04.2019