Hydro-mechanical response of Opalinus Clay in the CO2 long-term periodic injection experiment (CO2LPIE) at the Mont Terri rock laboratory

• DOI: 10.1007/s40948-022-00442-x
• Publication Date: 2022-09-29T10:06:01Z
• Authors: Dario Sciandra; Iman Rahimzadeh Kivi; Víctor Vilarrasa; Roman Y. Makhnenko; Dorothee Rebscher
• Keywords: Poromechanics; Caprock; Bedding; Transverse isotropy; Bed; Classification of discontinuities

Abstract Guaranteeing the sealing capacity of caprocks becomes paramount as CO 2 storage scales up to gigaton scale. A significant number laboratory experiments have been performed with samples intact rock, showing that low-permeability and high-entry pressure excellent capacities contain deep underground. However, discontinuities, such bedding planes, fractures faults, affect rock properties at field scale, being same time challenging monitor in industrial-scale applications. To bridge these two spatial scales, Underground Research Laboratories (URLs) provide a perfect setting investigate field-scale under well-monitored environment. In particular, Long-term Periodic Injection Experiment (CO LPIE) Mont Terri laboratory, Switzerland, aims quantifying advance Opalinus Clay, an anisotropic clay-rich planes dipping 45° experiment location. assist design LPIE initial estimate system response, we perform plane-strain coupled Hydro-Mechanical simulations using linear transversely isotropic poroelastic model periodic injection for 20 years. Simulation results show pore changes resulting stress variations are controlled by behavior material, producing preferential along planes. cannot penetrate into Clay due strong capillary effects nanoscale pores, but advances dissolved resident brine. We find oscillations imposed well attenuated within tens cm, requiring close location monitoring boreholes respect interval observe signal. Article highlights permit examining caprock representative scale storage; transverse hydro-mechanical gain insight on response shaly injection; amplitude period long-term experiment.