Study on the deformation and failure laws of surrounding rock under reduced roof thickness in Salt Cavern Gas Storage.

Under the premise of guaranteeing the stability of the gas storage reservoir, reducing the thickness of the salt layer on the top plate of the gas storage reservoir can improve the utilization rate of the salt layer in the construction section and increase the vertical height of the gas storage reservoir cavity, creating a larger gas storage space. The mechanical planar model of the casing-cement sheath-surrounding rock in the top plate of the salt cavern gas storage reservoir yields the elastic-plastic theoretical solution for the stress and deformation of the well wall surrounding rock. Based on this, a three-dimensional mechanical numerical model of the top plate is constructed to compare the effects of various top plate thicknesses on the surrounding rocks of the gas storage reservoir and to analyze the stress and deformation behavior of the wall surrounding the rock of the top plate of the reservoir in the cementing section and bare wells under the long-term injection and extraction cycle.