Water soluble corrosion inhibitor for inhibiting carbon steel CO2 corrosion and its preparation method

Abstract

The invented corrosion inhibitor includes following percentages (weight) of constituent; rosin amine 10-40%, element acid 5-30%, thiourea and ramification of thiourea 5-30% and solvent 10-50%. According to molecular design method, the corrosion inhibitor is prepared by adopting macromolecular compounds, small molecule compounds and negative ions with specific adsorption. Thus, the inhibitor restrains the corrosion of pipeline made of carbon steels in wider temperature region and the environment containing CO2, no matter the surface of the pipeline is clean or covered by the film of corrosion product. The invention corrosion inhibitor provides the features of wide suitable area, small use level, high efficiency, easy to produce, avirulence and non-peculiar smell as well as complete water-solubility.

Description

technical field [0001] The invention belongs to the anti-corrosion technology of metal materials, in particular to a method for inhibiting carbon steel CO 2 Corrosion water-soluble corrosion inhibitor and preparation method thereof, it is especially suitable for CO in oil field 2 Corrosion inhibition. Background technique [0002] CO 2 Corrosion is one of the forms of corrosion encountered in oil and gas field exploitation and gathering and transportation pipelines. Dry CO 2 The gas is not corrosive, but CO 2 After being dissolved in aqueous solution, it is more corrosive than hydrochloric acid solution with the same pH. With the development of ultra-deep wells and the increase of water content in the late stage of oil and gas well production and the popularization and application of three-injection oil recovery technology, CO 2 Corrosion is a growing problem. Many oilfields in my country, such as Tarim, Changqing, Sichuan, North China and other oilfields, are already...

AI Technical Summary

Problems solved by technology

[0004] in CO 2 In a corrosive environment, especially at high temperature, the surface of the carbon steel material of the pipeline is often accompanied by a corrosion product ferrous carbonate film, which has a great influence on the corrosion inhibition performance of the injected corrosion inhibitor, while the previous Corrosion inhibitors do not take this into consideration, and both on-site and laboratory corrosion inhibitor performance evaluation tests usually use steel samples with clean surfaces

In fact, the corrosion product film formed on the surface of the material has a great influence on the corrosion inhibition performance of the imidazoline corrosion inhibitor. On the surface of the metal material covered with the ferrous carbonate film, the corrosion inhibition rate of the imidazoline corrosion inhibitor is greatly reduced, or even completely fail

This is why imidazoline corrosion inhibitors are used in oil fields, but CO 2 The main reason why the corrosion problem has not been solved