稠油热采中隔热油管的漏磁检测方法

Magnetic flux leakage detection method of insulated tubing during heavy oil thermal recovery

针对稠油热采过程中隔热油管内、外管缺陷检测和判别存在的问题,提出了一种直流励磁方式下的隔热油管漏磁检测方法。基于直流励磁漏磁检测原理及麦克斯韦方程组,采用有限元仿真软件对隔热油管的检测结构进行仿真,建立了内、外管缺陷检测的试验系统,分析了隔热油管内、外管缺陷Bx、By分量的大小及分布特点。研究结果表明:直流励磁方式下的漏磁检测方法能够实现隔热油管内、外管缺陷的检测,同时能够判别30%深度以下的内、外管缺陷信号。

Some problems exist in the defect detection and judgment of the inner and outer pipes of insulated tubing during the heavy oil thermal recovery. This paper proposes a magnetic flux leakage（MFL） detection method of insulated tubing under DC exciting mode. Based on the principle of DC exciting magnetic flux leakage detection and Maxwell＇s equations, the detection structure of insulated tubing is simulated using the finite element simulation software. The experimental system detecting the defects of inner and outer pipes is established. The values and distribution characteristics of Bx and Bycomponents of the defects of inner and outer pipes are analyzed. The research results show that the MFL detection method under DC exciting mode can realize the detection of inner and outer pipes defects and distinguish the defects signals beneath 30% depth.