H-CUBE Project - Hydrodynamics, Heterogeneity, and Homogeneization in CO2 Storage

The integration of heterogeneity for assessing multiphase flow in porous media is a discipline developed since many years in petroleum reservoir simulation, hydrogeology and subsurface hydrology. The consideration of geological storage of carbon dioxide as a potential mitigation technology to reduce greenhouse gas emission into the atmosphere offers a new context for research developments on this topic. The role of geological heterogeneity distribution will be crucial on the CO2 plume migration and also on the pressure print extension. On one hand, CO2 storage reservoir characterisation should benefit from all scientific results published in the oil/gas engineering context: developed geostatistical tools, proposed strategies for uncertainty analysis, etc. On the other hand, CO2 storage context differs from petroleum as, for instance: a) the involved space and time scales are greater in the CO2-storage domain than in the hydrocarbon industry, b) the amount and availability of data is generally much more limited in CO2 case studies, and c) the use of flow simulation in CO2 storage studies is not for predicting the flow path from an injection well to producing ones, but for estimating the reservoir capacity performance, and safety (overpressure), d) the supercritical CO2 fluid properties differ from hydrocarbon one. As a consequence, new challenges arise and specific developments are still required for correctly assessing the hydrodynamic of CO2 geological storage. The main goal of the project H-CUBE is to provide appropriate theoretical and numerical models for accurate evaluation of the hydrodynamic behaviour of a CO2 storage complex and surrounding area. Particular emphasis will be placed on the determination of the CO2- brine flow with buoyancy forces and dissolution effect in saline aquifers with a methodology for assessing heterogeneity of the geological formations at several scales. This will consist in performing deeper studies on the impact of heterogeneities onto CO2 flow behaviours from near well injection zone (meter scale) to basin scale (~100km), in developing new techniques for optimizing the flow behaviour simulation (up-scaling and homogenisation techniques) and characterisation (proposal of appropriate reservoir descriptors), and in proposing suitable modelling and statistical workflows for assessing uncertainty analysis in function of the envisaged geological contexts. The project is decomposed in four main work packages that are described in this paper.