*Formulation of Corrosion Inhibitors DOI: http://dx.doi.org/10.5772/intechopen.88533*

*Water Chemistry*

in construction failure.

corrosion materials.

**2. Inhibitors for acid solution**

concentration of running water can save a lot of industrial water. In circulating cooling water, in order to avoid corrosion and scaling of equipment, it is often necessary to add water stabilizer. Also, in the process of crude oil and natural gas collection, the current drilling and oil recovery technology requires fracturing and acidification of limestone oil and gas fields with high concentration of hydrochloric acid solution. As the 15–28% hydrochloric acid solutions are often used in the oil wells, the corrosion problem of tubing and oil production equipment is serious in deep well acidification technology due to the high temperature in the well. Therefore, metal materials and products are subjected to various environments during production, storage, transportation, and use. Metal products are easy to vary from different degrees of corrosion. Corrosion problems in tubing and oil production equipment are serious, sometimes causing fracture accidents, resulting

Corrosion inhibitor is an anticorrosion chemical; it can be added to the corrosive environment to cause physical and chemical interaction with the metal surface, thereby significantly reducing the corrosion of the metal material. At the same time, the use of the corrosion inhibitor does not require special equipment, nor does it need to change the properties of the metal. Compared with other anticorrosion methods, corrosion inhibitors are easy to use, cost-effective, and widely used in industrial production and social life. Therefore, it is widely used in various industrial processes, such as pickling, cooling water systems, acidification of oil and gas wells, water injection in oil fields, storage and transportation of metal products, and so on. With the advancement of society and the enhancement of human environmental awareness, the development and application of corrosion inhibitors have received more and more attention. In recent years, countries around the world have paid great attention to the research and application of corrosion inhibitors, which can be used alone or in combination with other anti-

Herein, in view of the current requirements, the characteristic formulation of corrosion inhibitors in acid solution, near-neutral solution, alkaline solution, and oil and gas systems is discussed. The types of pickling inhibitors in different kinds of acid media, inhibitors for the cooling water, alkaline solution, and oil and gas

In various corrosive media, acidic gases and liquids are of strong corrosive medium. The rate of metal corrosion in acidic medium is much faster than that in other media, especially in sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, hydrofluoric acid, citric acid, and sulfamic acid, which are commonly used in pickling and removing iron oxide, descaling and decontaminating of boiler equipment, and so on. In addition, high level of H2S and CO2 in oil and gas wells is also the corrosive acidic medium. Since acid has a corrosive effect on metal equipment, especially the corrosion effect of inorganic acid is more serious, and the released hydrogen will diffuse into the interior of the metal, causing hydrogen embrittlement of the equipment to be washed. In addition, as a large amount of acid gas will generate, it will deteriorate working conditions inevitably. Therefore, a suitable corrosion inhibitor should be added during pickling to inhibit the corrosion of the metal in the acidic medium, reduce the amount of acid used, improve the pickling effect, and prolong the service life of the thermal equipment. **Table 1** shows the commonly used corrosion inhibitors in corrosive

systems are principally talked about in details, respectively.

**154**

acidic medium.

**Table 1.** *Operating conditions and properties of some common corrosion inhibitors.*
