Research On The Stability Of Cavern In Bedded Rock Salt Based On Permeability And Time Dependent Behavior

Based on the feature of Chinese bedded rock salt, the crack propagation principles of rock salt with interface and rock salt with impurities is studied in this paper from microscopic point of view in the assistance of SEM, and analyzed reason from the view of energy; The distribution principles of pore structure of rock salt with different components and the effects of pore distribution to permeability of rock salt through combination of CT and mercury testing was studied.The tightness of cavern was analyzed from macro and physical view.; As the low permeability of rock salt, two kinds of rock salt permeability testing were tested in different confining pressure and different permeability pressure, obtained the variation of permeability and brief analyzed the calculation for permeability of low permeability rock salt; Proposed the minimum operation pressure and cavity spacing of reservoir when consider the static stability and long-time stability but not consider the interface strength, and discussed the effects of different interface strength to cavern stability in assistance of FLAC 3D software; Analyzed the gas permeability random in rock salt in different period based on damage area and interface permeability characteristics in long time condition and combined with result of long-term creep through building the porosity-fracture permeability model in COMSOL software, provided the reference for running of cavity storage.