Experimental and Numerical Research on the Tightness and Stability of Cavern Roofs for Underground Salt Cavern Oil Storage in High-Impurity Salt Mines
摘要
The underground salt cavern oil storage method is a well-established technique used in various countries, and using salt cavern sediment voids for oil storage and other energy (natural gas and hydrogen ) is the emerging trend for high-impurity salt mines. The sediment particles at the cavern's base support its structure, but the cavern roof's integrity must be evaluated for tightness and stability. To address this, we conducted a series of experiments (breakthrough pressure experiments, rock salt permeability and porosity experiments, and rock structure experiments) on the cavern roof's breakthrough pressure, permeability, porosity, and microstructure using oil-immersed rock salt samples, along with constructed a 3D geological model that accounts for different sediment content (large sediment and less sediment), different cavern roof shape (arc-shaped and flat-shaped), and different oil wellhead pressure (0 MPa, 2 MPa, 4 MPa, and 6 MPa). The experimental results indicate that most rock salt samples exhibit excellent tightness, with permeability ranging from 6.6