Study On Wellhead Magnetic Flux Leakage Detection Device Of Conventional Drill Defects

It is necessary to conduct periodic or temporary flaw detection of drilling tools during the drilling process, which helps to detect defects of drilling tools to avoid downhole drilling tools’ accidents. However, the detection method or the technique can’t meet the actual demand at present.Wellhead magnetic flux leakage detection device could conduct drill-site detection for conventional drilling tools by means of the linear motion of drilling tools while tripping. Drill-site detection could save the time to transport drilling tools to the workshop for detection, which is good for timely detection of drilling tools’ defects, so as to avoid further drilling accidents or complex caused by continued using the defective tools.Based on the systematic analysis of the defects of drilling tools, summarize types and causes of various defects of drilling tools. The structure of wellhead magnetic flux leakage detection device was determined through investigations into domestic and foreign detection technology, which mainly includes detection system, measurement & control system and propel system. Meanwhile, the component of each system was determined according to the requirement of work environment. Detection system includes probe body and mud removal device; measurement & control system includes control circuit and microcomputer control subsystem; propel system includes wellhead transport rail and mobile base. According to the design of magnetic circuit and analysis of magnetic through the finite element simulation using ANSYS software, the influence of magnetic parameters to detection sensitivity of the probe is found, and determine the geometric scope of the probe, furthermore, the structure of probe was optimized through the orthogonal experiment. Wellhead magnetic flux leakage detection device was successfully developed while studying for master’s degree. The device could conduct drill-site detection for drilling tools, which is a useful means of early detection of drilling tools’ defection.