Sour Gas Field Development And The Inside And Outside Of The Wall Corrosion And Prevention Techniques In Long-distance Analysis

There is rich CO₂ in Chinese central and western oil and gas fields. With the effect of the acid gases and the working environmental, the oil and gas pipelines are subject to severe corrosion in the mining and long-distance transportation. The corrosion in the development of oil and gas fields and transportation will either bring disastrous accident or cause environmental pollution. So the study of the corrosion of the pipelines for the acid gas field development and long-distance transport has a certain practical significance.With the electrochemical analysis of the corrosion film in the inside of the N80 tube steel and gather lines, it had been found that the corrosion film which in the surface of the N80 tube steel has a protective effect for pipes. The corrosion scale can protect the substrate from the further corrosion. It evidently appeared a double-layer structure, the outer film was thin and the inner film was compact and thin, and it had strong combination with the substrate.The electrochemical characters of CO₂ corrosion on N80 steel and the novel alloy 09Cr2AlMoRe were studied in comparison, the results showed that the cathodic and anodic polarization resistances of novel alloy were bigger than these of N80 steel, indicating an evident corrosion prohibiting of the novel steel.Five inhibitors were selected, and the corrosion protection effect on N80 steel were evaluated by electrochemical technique, a type inhibitor was finally selected, which can effectively inhibit the oxide carbon corrosion on N80 steel.The electronic properties of the passive film on X80 steel in simulated soil environment were investigated, the influence of the factors including formation potential, formation temperature, chloride ions concentration on the electronic property of the passive film was analyzed.The rear earth element Ce was added into carbon steel, the influence of Ce content on the electronic property of the passive film on carbon steel was studied in simulated soil environment, the results showed that the protection capability of the passive film on the substrate was enhanced with the addition of Ce.