页岩气气田集输系统腐蚀控制技术研究与应用.

Objective In view of the serious corrosion problems faced to the gathering and transportation system of shale gas fields, systematic analysis and simulation evaluation were used to study the corrosion behavior and laws at different stages to clarify the main reasons for corrosion and countermeasures. Methods The main corrosion factors were systematically analyzed for the serious corrosion problems of gathering and transportation system in shale gas field, and according to the corrosion characteristics of the system, the shale gas development was divided into one drainage gas recovery stage and two stages of production, and the corrosion behavior and laws of different stages were studied by weight loss, SEM, EDS, XRD and other methods. Results The corrosion is dominant in the places where the sand content and fluid state change greatly, it was appeared as plough-type damage, and supplemented by electrochemical corrosion under the condition of flow velocity of 5-18 m/ s. As the flow rate decreased, the corrosion characteristics was changed by deposition of sand and flow back fluid, which makes it clear that the coexistence of SRB and carbon dioxide is the main reason for the perforation failure of gas gathering pipeline. The on-site working conditions of SRB film formation were simulated, a pitting corrosion rate of 5. 86 mm/a, it was equivalent to the part of the failure pipeline. Conclusions A feasible and practical corrosion control scheme was proposed, mainly including using erosion-resistant materials, increasing wall thickness, adding sterilization and corrosion inhibitors, and applying them to the shale gas field to reduce the failure of the gathering and transportation system by more than 90 % [ABSTRACT FROM AUTHOR]