Analysis of Carbon Sequestration and Enhanced Geothermal Energy

Environmental impacts of CO2 emissions can be mitigated by storing CO2 underground and by using renewable sources of energy like geothermal. Geological Carbon Sequestration (GCS) can store a large amount of carbon while renewable sources are being developed. GCS involves compressing CO2 and injecting it deep underground for permanent storage. To reduce risk, it is important to be able to estimate the location of the CO2 plumes after injection as well as in the distant future. Our research is to use a new, efficient global optimization algorithm, Stochastic RBF, to estimate parameters of a process-based CO2 simulation model (TOUGH2) from monitoring data and to use the simulator with the estimated parameters to estimate the plume locations. Our initial research indicates this is effective even with few locations for monitoring. In future research we will further advance the optimization algorithm and expand the analysis to include economic and environmental issues under uncertainty.

It is important to maintain the sustainability of Enhanced Geothermal Systems (EGS). After prolonged use, an EGS will experience thermal breakthrough caused by the cooling of the rock mass. A sustainable operational use of EGS is to let the depleted reservoir naturally recover by halting the use of the reservoir and meanwhile, “farm” energy out of another nearby reservoir. Analytical and numerical models have been developed by the Cornell group that elucidate the recovery process. This understanding can be used to develop strategic operational methods to ensure sustainable use of EGS.