Abstract: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, the influence of pitting ratio on the residual strength is studied, and a unified evaluation model for the residual strength of pitting defects of metal pipelines, also known as the seamless characterization evaluation function is established. 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 based on by FSM technology is used to obtain the in-service pipeline parameters, such as pitting ratio, residual wall thickness, etc., which are applied 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.