摘要
途经环境敏感地段的埋地油气管道周围铺设膨润土垫,可以减小管道泄漏对周边环境造成污染的风险,但也可能对管道阴极保护电流散流产生屏蔽作用。为了研究膨润土垫对管道阴极保护电流的屏蔽程度,建立了异性土壤结构下管道电位计算模型。基于边界元法,对铺设膨润土垫前后不同阴极保护电流下的管道电位分布、管道自然电位一定时阴极保护范围随土壤电阻率的变化关系进行了计算。选取工程中已铺设膨润土垫的1 500 m管段进行建模计算和现场测试,计算和测量在距管道首端200 m处的管道注流点电位变化,计算结果与测量结果具有较高的吻合度,从而验证了算法的准确性。
Laying geosynthetic clay liner around buried pipeline that passes through environmental sensitive area can reduce the risk of contamination of the surrounding environment caused by pipeline leakage, but it may generate shielding effect on the pipeline cathodic protection current flow. In order to identify the severity of such shielding effect, a calculation model of pipeline potential under the anisotropic soil structure is established. With the boundary element method, the pipeline potential distribution under different cathodic protection current is calculated before and after laying geosynthetic clay liner, and the change of cathodic protection scope with soil resistivity is analyzed at a given natural potential. A 1 500 m pipeline section where geosynthetic clay liner has been laid is selected for modeling and field test, and the potential changes at flow injection point that is 200 m from pipe head end are calculated and measured. It is found that the calculation results and the measurement results coincide well, verifying the accuracy of the algorithm.
出处
《油气储运》
CAS
2014年第9期995-999,共5页
Oil & Gas Storage and Transportation
关键词
油气管道
膨润土垫
阴极保护
边界元法
oil/gas pipeline
geosynthetic clay liner
cathodic protection
boundary element method
