Experimental assessment of the hydro-mechanical behaviour of a shale caprock during CO2 injection

Abstract The presented experimental study focuses on the hydro-mechanical characterisation of a shale caprock (Opalinus Clay) in contact with carbon dioxide. objective this paper, consists evaluation material's sealing capacity terms entry-pressure, mechanical behaviour and sensitivity transport properties to chemo-mechanical effects induced by gaseous liquid CO2 injection. Two types Opalinus Clay core samples are tested; shaly carbonate-rich. has been evaluated OPA according stepwise residual methods compared results from mercury intrusion porosimetry. obtained differences associated different involved physical processes discussed literature data. Injection tests carried out saturated unsaturated conditions have revealed that sub-critical propagation water material is not generation fractures. On other hand, capillary forces affecting beside capacity. impact chemical permeability both analysed long-term injection tests, where no significant variations measured during exposure time investigated. challenges related type analysis laboratory scale experiments illustrated new insights when subjected non-wetting fluid highlighted.