Optimization Of The Daqing Oil Field Outside The Metal Tank Anti-corrosion Coating Structure

With the development of oil field exploitation and the prolongation of running time of metal conservation pots, the corrosion and aging of metal conservation pots become more serious. It is important to set up and perfect the evaluation method for properties of surface anticorrosive coating, to select and develop an anticorrosive material with excellent properties and lower cost, and to optimize the anticorrosive construction for conservation pots in DaQing oil field.In this paper, the corrosion mechanism of metal surface caused by air was proposed based on the principle of corrosion process of metal enclosed by the thin surface electrode. After conducting the survey of air environment in DaQing oil field, and according to the climate features in DaQing, the factors which affect the air corrosion in DaQing were analysized, the evaluation method for the function of surface anticorrosive coating was set up, providing a theory instruction and method for developing and optimizing the construction of composite anticorrosive coating for conservation pots. On the basis of analysis results of air corrosion in DaQing oil field and the present state of surface anticorrosion, incorporating with the function mechanism of surface anticorrosive coating and the factor which affects the anticorrosion property, the technological and economical standard that the container and the coating must conform to were proposed, and the thickness, construction and material for surface anticorrosive composite coating were designed. Six new type of surface anticorrosive coatings were applied to the conservation pots, their stability to medium, climate-resistance, chemistry-resistance and electric conduction were determined according to the national standards. The priority of each factor was determined and the anticorrosion properties of each coating were estimated finally. The coating with superior properties was applied in clean water pots, transfer oil tanks, etc, of No.3 oil extraction field and tested the properties on spot. The change of the attachment force of coating, electric conductivity and ratio of powder with time were investigated. The comprehensive anticorrosion properties and the property superiority of each coating were determined finally. The spot determined anticorrosive properties of each coating were also compared with that determined in the laboratory, to inspect the accuracy of the experiment results.The popularization and application conditions of the five optimized anticorrosion coatings used in metal conservation pots in DaQing were summarized, and the application prospect was predicted from the points of technological and economical views.