-
Date submitted2022-09-30
-
Date accepted2024-11-07
-
Date published2025-02-25
Carbon dioxide corrosion inhibitors: current state of research and development
Among the methods of corrosion control in the oil and gas production industry the leading place belongs to inhibitor protection, since there is no need for technological and technical changes in the existing equipment. The combination of high variability of inhibitor composition with changing conditions of its application and low capital investments makes it an indispensable reagent at oil and gas fields. The main classes of compounds used as active bases of carbonic acid corrosion inhibitors for the protection of oil and gas equipment are described. Classical organic active bases containing heteroatoms (oxygen, sulfur, nitrogen) are examined. Special attention was paid to alkylimidazolines and other nitrogen-containing compounds as the most frequently used as active bases of carbonic acid corrosion inhibitors in Russia and abroad. A wide range of possibilities to achieve the desired properties of corrosion inhibitors by varying the substitutes has been demonstrated. Nowadays, in addition to the traditional requirements for corrosion inhibitors, their safety for the environment is equally important. The information on prospective research and development aimed at improving the environmental characteristics of the reagents used is given. Plant extracts, synthetic and biological polymers involved in traditional corrosion inhibitors or used as new independent compounds are considered. It is shown that the effectiveness of corrosion inhibitors significantly depends on the pH of the medium, temperature, partial pressure of СО2, flow rate, and other factors.
-
Date submitted2018-08-30
-
Date accepted2018-10-26
-
Date published2019-02-22
Study of bearing units wear resistance of engines career dump trucks, working in fretting corrosion conditions
- Authors:
- Ju. Olt
- V. V. Maksarov
- V. A. Krasnyy
The occurrence of fretting corrosion on nominally fixed surfaces of high-loaded parts of mining machines and mechanisms is considered. Examples of wear and damage of critical parts, bearing assemblies of engines of dump trucks in fretting conditions are given. The mechanisms of fretting corrosion when using wear-resistant coatings are considered. It is noted that when choosing protective thin-layer coatings that provide an increase in the fretting-resistance of surfaces of tightly contacting parts, it is necessary to take into account both their wear resistance and the ability to resist shear. At the same time, the thickness of such coatings allows preserving, during operation, those provided during the assembly of the tension, without disturbing the maintainability of the nodes. The results of research of fretting wear of a number of coatings on a special installation are given. The mechanisms of wear of a number of thin-layer coatings based on friction-mechanical brazing, polymer fluorocarbon composition, solid lubricant coating using scanning electron microscopy were studied. Recommendations on the use of the studied thin-layer coatings for high-loaded parts of mining machines operating in fretting corrosion conditions have been developed. The aim of the work was to study the effect of a number of thin-layer coatings on the wear of highly loaded connections of the mechanisms of mining machines, in particular bearing assemblies of quarry dump trucks operating under fretting corrosion conditions.
-
Date submitted2015-08-25
-
Date accepted2015-10-24
-
Date published2016-04-22
The modern technology of drilling and casing of well during the exploration of gas hydrates
- Authors:
- N. I. Nikolaev
- Lyu Tyanle
In the paper, the perspectives of exploration and completion of gas hydrate fields and the drilling problems in the gas hydrates of the northwest china are studied. It has been established, that the main reasons of complications in the Muli field are the secondary hydrate formation on the walls of the well and drilling assembly and ice formation inside the set cement during the well drilling and completion in permafrost. It has been shown, that in the areas with permafrost during the drilling of the layers containing gas hydrates, temperature and pressure changes can lead to the dissociation of hydrates. At the same time, pressure increase in the annular space due to the gas release, can lead to the secondary formation of gas hydrates, drill string stuck, ceasing of drilling fluid circulation, which is the reason of serious trouble in the wellbore. The results of the research on the development of drilling fluids compositions, which lower the drilling troubles of permafrost, are presented. Comparative experiments have been conducted to evaluate the effectiveness of thermodynamic and kinetic inhibitors, which prevent the repeated hydrate formation. It has been established, that the kinetic inhibitors have the clear advantage: they have good inhibiting effects even with low amounts of additives. In the laboratory conditions, the researches have been conducted to evaluate the phase equilibrium of gas hydrates during their reaction with the water solutions, containing kinetic inhibitor PVP. A thin clay drilling mud has been developed on the water base, providing the holding of the temperature in the level of –2 °С and its effectiveness for the gas hydrate fields in the PRC has been shown. Casing effectiveness of unstable rocks during the drilling in the conditions of negative temperatures inside the well largely depends on their physical-mechanical properties, composition and the technical indicators of cement materials. The authors suggest the composition of quick-setting cements based on aluminum binding materials. It has been established, that the analyzed compositions have the ability to considerably improve the results of cementing.