Study On Corrosion Mechanism And Anti-corrosion Measures Of Gathering And Transferring Pipeline Of ZT Block In A Gas Field

The gas in the gas field of a gas field is high in hydrogen sulfide and carbon dioxide acid corrosive gas.In the process of heating and transportation of moisture,the complex and harsh corrosive environment with high acidity and high sulfur content can easily cause corrosion failure of metal pipes.This is a safe production of gathering pipelines.Operation poses a great threat.In order to put forward effective anti-corrosion measures,the corrosion mechanism of the gathering pipeline must be studied,and on this basis,the corresponding anti-corrosion scheme should be proposed.In this paper,based on the investigation results of the corrosion status of on-site transmission pipeline network,taking P303-P302 gathering pipeline as the research object,the field conditions are simulated,and the H₂S/CO₂ partial pressure is quantitatively evaluated using the high temperature and high pressure dynamic corrosion weight loss method and the grey correlation analysis method.,temperature,flow rate and other factors on the corrosion rate;the use of metallographic microscopy,scanning electron microscopy,energy spectrum analyzers and other instruments,the test piece surface macro morphology and corrosion product film morphology components were measured and analyzed,qualitative assessment of each The effect of corrosion factors on corrosion and the type of corrosion to determine the corrosion mechanism.Studies have shown that hydrogen sulfide and carbon dioxide participate in the corrosion of gathering pipelines.Compared with carbon dioxide,hydrogen sulfide is the dominant controlling factor in the corrosion of the gathering pipelines.The presence of carbon dioxide contributes to the synergistic effect of corrosion to a certain extent;the temperature passes through the impact gathering.The film formation mechanism of pipeline corrosion products affects the corrosion behavior,and the corrosion product film is the most sensitive to temperature;the flow rate mainly affects the mass transfer process and erosion of corrosive media in the gathering pipeline.Under the corrosive conditions of the gathering and transmission pipeline,chemical reactions occur between the corrosive media and the desublimation reaction produces elemental sulfur that causes sulfur deposition and initiates under-scale corrosion of the pipeline.In view of the corrosion mechanism in the gathering and transmission pipeline,the corrosion inhibitor and anti-sulfur pipe were screened and evaluated by combining the dynamic corrosion weight loss method with the electrochemical method.The results show that:HC-Y-01 continuous filling corrosion inhibitor corrosion effect.The best,the recommended concentration of 120mg/L;super 13Cr pipe corrosion resistance to hydrogen sulfide,strength and weldability to meet Engineering needs,low sensitivity to on-site operating conditions SSC.And for the corrosion and corrosion mechanism of on-site gathering pipelines,the economic and effective anti-corrosion measures are proposed.