Erosion Characteristics of Oil Pipeline During CO₂ Flooding Process

The addition of CO₂ and sand particles during the transportation of crude oil pipelines can exacerbate the erosion damage to the pipe wall. A study was conducted on the issue of pipeline erosion and wear, and the effects of bending angle, sand particle size, and flow rate on the erosion characteristics of pipe walls were numerically investigated based on computational fluid dynamics methods. The results show that with the change of bending angle of the bent pipe, the erosion rate changed in an inverted “U” shape. When the bending angle was around 90 °, the wall erosion rate was the highest. At the same time, there was a positive correlation between sand particle size, flow rate, and wall erosion rate. Adopting a spiral pipe series connection treatment for the connection section between the straight pipe and the elbow of the pipeline, and optimizing the design of the wall surface, could effectively reduce the degree of wall erosion and improve the safety and transportation efficiency of the crude oil pipeline. Reaches a highest value when the bending angle is roughly 90 °. Meanwhile sand particles size and flow rate are positively correlated with wall erosion rate. Additionally, a wall optimization design is employed, and the spiral pipe series processing is adopted for the connection section of the straight pipe and the elbow, which can effectively reduce the erosion of the wall and provide a theoretical guidance for safe and efficient transportation of crude oil pipeline.