Optimisation stochastique de la stratégie d’injection en vue de la pré-évaluation de sites candidats au stockage géologique

Abstract

Geological carbon sequestration (GCS) has been identified as having the potential to reduce increasing atmospheric concentrations of carbon dioxide (CO 2 ). However, a global impact will only be achieved if GCS is cost-effectively and safely implemented on a massive scale. This work presents a computationally efficient methodology for identifying optimal injection strategies at candidate GCS sites having uncertainty associated with caprock permeability, effective compressibility, and aquifer permeability. A multi-objective evolutionary optimization algorithm is used to heuristically determine non-dominated solutions between the following two competing objectives: 1) maximize mass of CO 2 sequestered and 2) minimize project cost. A semi-analytical algorithm is used to estimate CO 2 leakage mass rather than a numerical model, enabling the study of GCS sites having vastly different domain characteristics. The stochastic optimization framework presented herein is applied to a feasibility study of GCS in a brine aquifer in the Michigan Basin (MB), USA. Eight optimization test cases are performed to investigate the impact of decision-maker (DM) preferences on Pareto-optimal objective-function values and carbon-injection strategies. This analysis shows that the feasibility of GCS at the MB test site is highly dependent upon the DM's risk-adversity preference and degree of uncertainty associated with caprock integrity. Finally, large gains in computational efficiency achieved using parallel processing and archiving are discussed.

Analytical solutions for aquifer thermal energy storage

“…When considering aquifer energy storage in the context of intermittent renewable energy sources, approximate solutions such as those provided herein can form a valuable tool both for screening and ranking purposes, and also as proxy-solutions in system-level tools [see e.g., Cody et al, 2015;Bachu, 2015;Celia et al, 2011] for examples from CO 2 storage). On a theoretical level, such analytical solutions form the building blocks on which other physical processes can be preliminarily assessed (pressure buildup due to injection, thermally induced mechanical stresses, extent of altered geochemical conditions due to salinity and temperature change).…”