Safety of oil loading/unloading operations in underground water-sealing oil storage with significant elevation

During oil loading/unloading operation, the vertical pipe between ground surface and bottom of underground water-sealed oil storage with significant elevation may subject to spilling and slack flow conditions. If it happens, oil flow may generate significant impacts to the bottom of the vertical pipe. Consequently, it is necessary to equip the feeding vertical pipe with throttling plate, which can reduce impact force up to 20%-34%. Based on energy conservation principles and design codes of throttling plate, mathematical model for oil loading/unloading processes can be established to the determine position, thickness, the number of holes, hole diameters and other parameters related to the throttling plate. In addition, software TLNET can be deployed to simulate the shut-up and restart processes of underground water-sealed oil storage and then to analyze the changes in transient pressures. With the time in pump restart and shut-up at 2 minutes, the maximum transient pressure along the pipeline shall be lower than 1.9 MPa, which is lower than designed pressure-bearing capacity of the pipeline. Consequently, operation safety of oil storage will not be threatened.