Self-polishing antiseptic antiscale coating and preparing method thereof

Abstract

A self-polishing antiseptic antiscale coating sequentially comprises an inert metal layer, an active metal layer and a hole sealing layer from interior to exterior, and the inert metal layer, the active metal layer and the hole sealing layer are sequentially prepared on the inner wall and the outer wall of an oil pipe or a casing pipe or a ground pipeline. A preparing method of the self-polishingantiseptic antiscale coating comprises the steps that firstly, a hot spraying method is adopted, and inert metal is sprayed to the outer wall of the pipeline to serve as the inert metal layer; secondly, the hot spraying method is adopted, and active metal is sprayed to the exterior of the inert metal layer to serve as a middle layer; and thirdly, a brush coating method is adopted, an alloy with the material being macromolecules or passivation liquid is brushed to the exterior of the middle layer to serve as a surface layer of a composite coating; and in hypersalinity water, the coating can becorroded layer by layer, attachment of scales and corrosion products is difficult, and the characteristics of self-polishing, corrosion preventing and scale preventing are achieved.

Description

technical field [0001] The invention belongs to the technical field of oil and gas field corrosion and protection, and in particular relates to a self-polishing anti-corrosion and anti-scaling coating and a preparation method thereof, which are mainly used for anti-corrosion and anti-scaling of oil pipes, casing pipes or the inner or outer walls of surface pipelines. Background technique [0002] With the deepening of exploration and development of oil and gas fields, the environment faced by oil and gas extraction is getting worse and worse, especially the emergence of high salinity water, high carbon dioxide and hydrogen sulfide content, which makes the oil and gas field wellbore and ground corrosion and scaling problems Increasingly prominent, including occurring on the inner and outer walls of tubing, casing, and surface pipelines. Some pipelines or wellbores need to be inspected or pigged once in only one month of production, which has a great impact on production and h...

AI Technical Summary

Problems solved by technology

[0004] At present, the anti-corrosion coatings of oil well pipes or surface pipelines in use are mainly organic coatings. However, during the application process, it was found that friction and collision of oil pipes will inevitably occur during the downhole process, resulting in damage to the coating and exposed metal. The electrochemical corrosion phenomenon of "big cathode and small anode" is easy to appear during downhole service, which will accelerate the perforation failure of the pipe string

At present, the commonly used coatings, no matter how many layers of structure, the outermost layer is basically a passivation layer or a dense layer, which mainly relies on blocking the entry of corrosive media to achieve the purpose of anti-corrosion. There is no self-polishing effect, and the scale layer is easy to adhere to the surface, and As the adhesion increases, the roughness increases and scaling becomes easier, therefore, it is difficult to achieve the dual purpose of self-polishing, anti-corrosion and anti-scaling

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