CO2 Storage

THMC for CO2 Storage

Nowadays, greenhouse effect is a global concern for human society. Carbon dioxide is the largest greenhouse gas contributor. However, the energy demand is still primarily satisfied by burning fossil fuels, which produces about 30 billion tonnes of carbon dioxide that are released into the atmosphere.

CO2 capture and storage (CCS) has gained global interest due to its potential to reduce the impact of CO2 on climate change. CO2 sequestration in deep geological formations is one of most suitable solutions for CCS so far. Three main geological formations provide potential to store CO2 (cf. figure below): depleted oil or gas reservoirs, saline formations, and coal seams. During the early storage phase (10yrs-100yrs) for CO2 sequestration, injected CO2 is mainly trapped by structural or stratigraphic mechanisms such as under a low-permeability caprocks. Chemical trapping, such as mineralization, offers a very long-term storage capacity (>1000yrs). The influence, on the surrounding environment, of mechanical and chemical changes as well as heat effects during CO2 injection are not well-known. Related research is experiencing rapid worldwide growth in order help us understand this inter-disciplinary topic.

The goal of the chair is to aid site selection and risk mitigation by investigating potential induced seismicity that may be cause by CO2 injection. Unfortunately, other injection operations (such as waste water injection and geothermal energy) have already produced significant seismic events. While there has never been a felt seismic event induced by CO2 geosequestration, the similarity of the operations associated with CO2 geosequestration and waste water injection mean that this topic warrants our attention. The current focus of the research is to perform numerical modelling which takes care to account for the acute differences present between lithologies in the subsurface as these differences result in various seismic responses to stress and pressure changes.

The chair ”Gaz Naturel” points towards the understanding of complex modelling issues then enhancing the assessment of field studies so as to provide benchmarks for developing reliable solutions to geoenviromental problems.

CO2 sequestration process

Infographie: Pascal Coderay