金属油气管道点蚀缺陷安全评估及预警系统研究

油气金属管道在油气输送过程中因为载荷和腐蚀介质等因素的影响下，很容易萌生缺陷而引发重大安全事故。点蚀与多坑蚀缺陷是存在周期最长、最普遍、最有可能产生穿孔的高危缺陷，因而对金属管道工作过程中的在线检测与安全评估一直是油气输送技术领域研究的重点和热点。本文考虑了多个点蚀及点蚀之间的相互作用，根据美国石油协会的API-579的技术标准，研究点蚀占比对剩余强度的影响，建立对金属管道点蚀缺陷剩余强度的统一评价模型，也称无缝表征评价函数；然后将无缝表征模型和场指纹法（FSM）管道腐蚀监测技术相结合，运用FSM技术获得的管道腐蚀三维模型获取点蚀占比、剩余壁厚等在役管道参数，通过无缝表征模型评价管道安全并构建面向全域生产管线的安全评估决策及安全预警系统。该评估系统完善了FSM技术对点蚀缺陷的安全评估，同时也实现了无缝表征模型计算中的在线评估。油气田现场试验表明这个安全评估系统具有一定的实际应用价值。

Study on Safety Assessment and Early Warning System of Pitting Defects in Metal Oil and Gas Pipelines

In the process of oil and gas transportation, under the influence of load, corrosive medium and other factors, oil and gas metal pipelines are prone to sprout defects and lead to major safety accidents. Pitting and pitting defects are the most common and high-risk defects with the longest period, which are most likely to produce perforation. Therefore, online detection and safety assessment in the process of metal pipeline work has always been the focus and hot spot in the field of oil and gas transportation technology. Based on API-579, this paper studies the influence of pitting ratio on the residual strength, and establishes a unified evaluation model for the residual strength of pitting defects of metal pipelines, also known as the seamless characterization evaluation function. Then, the seamless characterization model and field fingerprint method (FSM) pipeline corrosion monitoring technology are combined to operate The three-dimensional model of pipeline corrosion obtained by FSM technology is used to obtain the in-service pipeline parameters, such as pitting ratio, residual wall thickness, etc., to evaluate the pipeline safety through seamless representation model, and to build the safety assessment decision-making and safety early warning system for the whole production pipeline. The system not only improves the safety assessment of FSM technology for pitting defects, but also realizes the online assessment in the calculation of seamless representation model. The field test of oil and gas field shows that the safety assessment system has certain practical application value.