Corrosion Risks Assessment Management of Natural Gas Pipelines Based on TPI Management Mode

Abstract

In order to clarify the goals of corrosion management of natural gas pipelines, achieve key, orderly, visual and dynamic management of indicators at all levels and get rid of trivial management, the TPI management was used to manage the corrosion block index of natural gas pipelines. Firstly, clarify the management objectives of the corrosion block of natural gas pipelines, and achieve the activity decomposition of the management objectives. Secondly, through the independent-coupling analysis of the risk and the Gray evaluation theory, it proposes the Gray consequence grade equation and the Gray risk matrix, which determines the TPI indicators, and develops an economic rating system. The results of the study indicate that the pipeline is in a critical stage and require the implementation of the targeted management. In addition, the risk value of the outer wall corrosion is the highest in the target activity, and the TPI indicators of the entire TPI system of the Nature Gas pipelines corrosion are as follows: the integrity of the outer protective layer, outer coating thickness, soil pH, soil salinity, soil sulphur, residual stress, sudden stress, design stress, SCC sensitivity, material mechanical strength, material corrosion resistance, inner coating thickness, protection potential, pigging quality, H2S content and CO2 content. And it establishes an economic evaluation model according to the TPI system.