Corrosion Causes and Control Measures of Ground Gathering and Transportation Pipelines in a Gas Field

During the production process of a gas field, there were many perforations or pipe bursts in the ground gathering and transportation pipelines (including T connecters, elbows and flanges), which seriously affected normal and safe production. The influencing factors of pipeline corrosion in this gas field were studied by energy spectrum analysis of corrosion product composition in the pipelines, calculation of multiphase flow in the pipeline, validation of corrosion and erosion model, and flow field analysis of corrosion site. The results show that the perforation and bursting of pipelines and fittings were mainly caused by CO₂ corrosion and erosion corrosion. The inhibition effeciency of corrosion inhibitor decreased when the medium flow rate in the pipelines was high. By coupling the flow field with the corrosion data, the critical erosion velocity suitable for the engineering application of the gas field was determined. And the protection measures to control the corrosion of pipelines and fittings were proposed.