孔隙率对埋地超临界CO2管道泄漏扩散的影响

长输管道中的超临界CO2流体一旦发生泄漏并扩散到周围环境中，将会造成极大的经济损失并对生命体构成潜在的生理危害。文章针对不同土壤孔隙率下埋地超临界CO2管道发生小孔泄漏初期的扩散规律展开研究。根据我国土壤特点选用0.35、0.45、0.55、0.65四种孔隙率，结合我国国内某油田超临界CO2埋地管道的输送工况参数，依据相关的基础理论建立三维土壤-管道模型，使用FLUENT专业模拟软件，模拟埋地CO2管道发生泄漏初期CO2在不同孔隙率的土壤中扩散情况，通过分析计算得到其以均匀扩散为主的扩散规律。以所选最大孔隙率为例，以5%为CO2危险浓度，确定以泄漏口为中心的2 m范围内的地表为危险区域，相关结论为施工人员提供技术参考。

Influence of the porosity on the leakage and diffusion of the buried supercritical CO2 pipeline

Once the supercritical fluid of CO2 transported in the pipeline leaks and diffuses into the surrounding environment, it will pose potential physiological hazards to humans and animals and cause huge economic losses. Based on the influence of soil porosity on the initial diffusion law of buried CO2 pipeline, small pore leakage are studied. We chose the porosity rate of 0.35, 0.45, 0.55, 0.65 according to the soil characteristics of our country and combine the parameters of the transportation condition of the supercritical CO2 buried pipeline in a domestic oil field. Basic on the relevant theories, the three-dimensional soil-pipeline model was established and the professional simulation software FLUENT was used to simulate the diffusion of buried CO2 pipeline in soil with different porosity at the initial stage of leakage. We obtain that the main form of diffusion is uniform diffusion. Taking the selected maximum porosity as an example, with 5% as CO2 hazardous concentration, the surface within 2 m centered on the leakage port is determined as the hazardous area, and the relevant conclusions provide technical reference for the construction personnel.