Study on the Erosion Law and Erosion Prediction Model of Pipe Columns During Gas Storage Reservoir Injection and Production Processes

There are few studies on erosion problems in gas storage environments. High-speed gas-carrying sand in gas storage wells can cause pipeline erosion and subsequent failure. To this end, a numerical model of gas/liquid/solid three-phase erosion under high temperature and high-pressure conditions in gas storage was established. The model combines the laws of conservation of mass, momentum, and energy, as well as the force model of solid particles. Using the established mathematical model of erosion, numerical simulations were performed to study the erosion process of the column under different parameters during gas injection and extraction to find the main factors affecting column erosion. Subsequently, a prediction model was established based on the determined main factors to estimate the maximum erosion rate of the column. The results show that during the extraction process, the maximum erosion rate is exponentially related to the extraction rate, and the erosion intensifies when it is greater than 1 million m³/d. It is linearly related to the particle mass flow rate and the well inclination, and it tends to decrease when the particle size is greater than 3 mm. The erosion law during gas injection is similar to that during extraction, but the erosion during gas injection is more severe. The comprehensive influence of various parameters on the maximum erosion rate was studied by orthogonal experiments, and an erosion prediction model was established by nonlinear regression using the least squares method.