Leakage and diffusion of high-pressure gas pipeline in soil and atmosphere: experimental and numerical study

ABSTRACTPersonal safety and environmental issues, such as fires and explosions, have climbed to the top of the list of concerns due to the rupture of a high-pressure gas pipeline. Analysis of the diffusion characteristics of methane leaks in soil and air is essential for engineering maintenance and the prevention of secondary mishaps. The primary contribution of this paper is the design and establishment of a full-scale experimental system to simulate small-hole leakage of high-pressure gas pipeline in order to observe the leakage and diffusion behavior of methane in soil and atmosphere under various leakage pore sizes and pressures. The results show that, near the leakage hole, the high-pressure jet dominates the action, whereas near the surface, lateral diffusion and accumulation dominate for an extended period of time. When the diffusion reaches a stable state, the vertical and horizontal diffusion distances are 0.76 m and 1.05 m, respectively, and the maximum temperature difference at the leakage hole is 8.7°C; Under the conditions of leakage holes of 0.5 mm, 1.0 mm, and 1.5 mm, the surface leakage radii are 0.4 m, 0.8 m, and 1.4 m, respectively. The leakage aperture is the main factor affecting the diffusion of methane in soil; A small hole leakage rate model for high-pressure gas pipelines was established based on experimental data, with an average error of 9%; The response time and steady time in the process of methane concentration growth have an exponential relationship with horizontal distance from the leakage hole and a power function relationship with vertical distance and leakage rate. The average relative errors of the calculation formula are 16% and 12%, respectively. This work can provide a basis for the hazard assessment of small hole leakage and diffusion in buried gas pipelines, and also provide data support for the theoretical and numerical models of high-pressure gas flow in soil and atmosphere.KEYWORDS: High pressureburied gas pipelinesoil and atmosphereleakage diffusionfull-scale experiment AcknowledgementsThis work is supported by the National Natural Science Foundation of China (No. 52174062). We are grateful for permission to publish this study.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by the National Natural Science Foundation of China [52174062].Notes on contributorsHongye JiangHongye Jiang is currently an associate professor at the School of Petroleum and Natural Gas Engineering at Southwest Petroleum University and the director of the Oil and Gas Storage and Transportation Institute. He mainly engages in teaching and graduate training. His research interests include safety and integrity management of oil and gas storage and transportation systems, and corrosion of oil and gas pipelines.Zhengyi XieZhengyi Xie is a master's student majoring in oil and gas storage and transportation engineering at Southwest Petroleum University. He mainly studies the mechanism and consequences of oil and gas pipeline leakage diffusion, with a focus on safety and integrity management of oil and gas storage and transportation.Youlv LiYoulv Li is a lecturer at the School of Petroleum and Natural Gas Engineering at Southwest Petroleum University, with a research focus on corrosion rate and integrity management of oil and gas pipelines.Minghua ChiMinghuawei Chi graduated from Southwest Petroleum University with a major in Petroleum and Gas Storage and Transportation Engineering and is currently studying at Sichuan University. His research focus is on the propagation and suppression of flames and explosions, while also focusing on issues such as mechanical response of oil and gas pipelines.