Coupled multiphase flow and elasto-plastic modelling of in-situ gas injection experiments in saturated claystone (Mont Terri Rock Laboratory)

摘要: Abstract Understanding gas migration in host rock is one of the most important issues to consider final disposal radioactive waste deep geological formations. In order investigate transport water-saturated argillaceous rock, constant pressure injection tests on samples from Mont Terri Rock Laboratory (Switzerland), as well pulse with a stepwise increasing pressure, were carried out. During migration, desaturation and hydraulic mechanical interaction can be observed. To simulate porous media, coupled multiphase flow method within FEM code family OpenGeoSys (OGS) was developed including van Genuchten function for relationship between capillary water saturation, approach Mualem relative permeability both phases, an elasto-plastic deformation model. Two approaches applied, taking into consideration change by pore deformation, respectively. Both are based experimental observations allow significant increase when exceeds minimal stress. The material parameters model determined using measured data laboratory experiments under well-defined test conditions. With calibrated parameters, in-situ experiment simulated. Good agreement numerical results achieved.