Fast screening for detection of heavy corrosion in insulated pipe using pulsed eddy current

保温管和钢结构广泛应用于石油天然气管道、石油化工装置平衡、建筑物钢支撑结构和大型液体储罐等领域。绝缘金属管道、压力容器和结构部件的退化可能是以下原因的结果：1)现有运输介质内的内部腐蚀过程；2)外部来源，如曝气水或含有腐蚀性污染物的水，这些污染物已被引入厚(达51毫米)的隔热屏障中。其他可能发生腐蚀的区域包括地面碳钢储罐，其绝缘层厚度可达6至10毫米。目前的超声波探伤技术只能对拆除保温层后的壁厚进行局部测量。PEC已被证明有能力在存在导电铁磁材料的情况下进行大起飞时的检查。该项目将：1)开发脉冲涡流(PEC)技术，包括优化的探头设计，用于在大提离时快速检测绝缘导电管道的一般腐蚀。2)展示此类技术的能力和局限性。3)建立了PEC对壁厚、提升力和渗透率变化响应的理论模型，并与实验室测量结果进行了验证。4)针对目标检测条件优化探头设计，并使用开发的模型帮助识别可能影响测量精度的参数。这项工作对检测服务提供商非常重要，因为如果不拆除绝缘材料，目前无法对管道进行本地检测。开发有助于生命周期管理的技术并提高对化学加工、油气和液体运输以及安全壳行业腐蚀条件的评估能力，将支持加拿大工业在这些领域的表现。HQP将接受培训，以便进入这一快速增长的在职检验领域的劳动力队伍。

Insulated pipe and steel structures arise in a large number of applications including oil and gas pipeline,balance of plant in the petrochemical industry, steel support structures for buildings and large liquid storagecontainers. Degradation of insulated metal piping, pressure vessels and structural components may be theresult of 1) internal corrosive processes, arising within the existing transport medium or 2) external sourcessuch as aerated water or water with corrosive contaminants that have been introduced into thick (up to 51 mm)insulating barriers. Other areas where corrosion may occur include above ground carbon steel storage tanks,where insulating layers can be 6 to10 mm thick. Current ultrasonic inspection technology is only capable oflocalized wall thickness measurements after insulation removal. PEC has a demonstrated capability to performinspection in the presence of conducting ferromagnetic materials at large lift-offs. This project will: 1) Developpulsed eddy current (PEC) technology, including probe design that is optimized for rapid inspection ofinsulated electrically conducting pipe at large lift-off for general corrosion. 2) Demonstrate capabilities andlimitations of such technology. 3) Develop theoretical models of the response of PEC to changing wallthickness, lift-off and permeability and validate these against laboratory measurements. 4) Optimize probedesign for the target inspection conditions and assist in identifying parameters that may affect measurementaccuracy using the developed models. This work will be important to inspection service providers who cannotcurrently perform local inspection of pipe without expensive and time consuming removal of insulation.Development of technologies that will assist in lifecycle management and improve assessment capability forconditions of corrosion in chemical processing, oil and gas and liquid transport and containment industries willsupport the performance of Canadian industry in these areas. HQP will be trained to enter the workforce in thisrapidly growing area of in-service inspection.