Corrosion Study On Gathering Pipelines In Sulfur-bearing Gas Fields In Eastern Sichuan

With the expansion of the oil and gas field exploitation and the increasing of the construction of the pipeline in recent years, the related corrosion problems are becoming more and more serious. Corrosion of pipelines will not only damage to pipeline, leak, cause safety accident, but also can cause environmental pollution, and harm people's health and property safety, bringing huge economic losses. At the same time, it caused the bad social influence.In this paper, we study the main cause of the corrosion through the analysis of the main kind of sour natural gas pipeline internal corrosion. Through analyzing the pipeline of region temperament, corrosion section sampling and sampling of pigging content, and degree of corrosion on the samples and the reason analysis, we know that the corrosion reason is H2S and CO2 corrosion in pipeline.Samplings of pipeline are carried out, which are used to study the corrosion law of east of Sichuan area by laboratory experiment. Found:(1) Through the experiment of 20 steel pipeline and X52 steel pipeline, corrosion are uniform corrosion, which correspond to east of Sichuan within the main test results. (2) Through simulations, they proved three glycol aqueous solution was corrosive, and corresponding to different water medium corrosion rate have obvious difference.(3) Under the condition of simulated condition, we obtained 5-50 days period of H2S and CO2 corrosion rate and water infiltration time affect corrosion.Through sampling analysis and experimental study, we analysis the root cause of corrosion of east of Sichuan area is H2S-CO2 corrosion; Direct reasons are the flow of medium containing H2S and CO2, and the gas collecting lines convey natural gas without dehydration, glycol serious loss, poor dewatering device and its filtering effect, which affect the dehydration effect.Through to the east of Sichuan area within the corrosion reason research, we put forward to strengthen dehydration unit operation, and determine suitable pigging period and injection of corrosion inhibitor of measures to control the internal corrosion. Through the internal corrosion study of east of Sichuan area and control measures are put forward, they have the very vital significance to slow down the gas pipeline internal corrosion, and prolong the service life of pipeline, and guarantee pipe network economic operation.