-
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 submitted2022-03-25
-
Date accepted2022-09-06
-
Date published2022-12-29
Autoclave modeling of corrosion processes occurring in a gas pipeline during transportation of an unprepared multiphase medium containing CO2
The problem of selecting a method for ensuring the reliability of the unprepared fluid transport facilities of an unprepared fluid in the presence of carbon dioxide is considered. Carbon dioxide corrosion is one of the dangerous types of damage to field and main pipelines. It has been shown that dynamic autoclave tests should be carried out during staged laboratory tests in order to determine the intensity of carbon dioxide corrosion and to select the optimal method of protection. A hypothesis about the imperfection of the existing generally accepted approaches to dynamic corrosion testing has been put forward and confirmed. A test procedure based on the use of an autoclave with an overhead stirrer, developed using elements of mathematical modeling, is proposed. The flows created in the autoclave provide corrosive wear of the sample surface similar to the internal surfaces elements wear of the pipelines piping of gas condensate wells. The autoclave makes it possible to simulate the effect of the organic phase on the flow rate and the nature of corrosion damage to the metal surface, as well as the effect of the stirrer rotation speed and, accordingly, the shear stress of the cross section on the corrosion rate in the presence/absence of a corrosion inhibitor. The given results of staged tests make it possible to judge the high efficiency of the developed test procedure.
-
Date submitted2021-04-30
-
Date accepted2021-11-30
-
Date published2021-12-27
Methodology for testing pipeline steels for resistance to grooving corrosion
- Authors:
- Viktor I. Bolobov
- Grigoriy G. Popov
The methodology for testing pipeline steels is suggested on the assumption that for the destruction of pipes in field oil pipelines by the mechanism of grooving corrosion the simultaneous fulfillment of such conditions as the occurrence of scratches on the lower generatrix of the pipe, eventually growing into a channel in the form of a groove, emulsion enrichment with oxygen, presence of pipe wall metal in a stressed state, presence of chlorine-ion in the oil-water emulsion is required. Tests are suggested to be carried out in 3 % aqueous solution of NaCl with continuous aeration by air on bent plates 150×15×3 mm, made of the analyzed steel, the middle part of which is under the action of residual stresses σ res , close to the level of maximum equivalent stresses σ eqv in the wall of the oil pipeline, with the presence of a cut on this part on the inner side of the plate as an initiator of additional mechanical stresses. Using the value of the modulus of normal elasticity of the analyzed steel, the degree of residual strain of the elastic-plastic body from this material, corresponding to the value σ res ≈ σ eqv is calculated, based on which the plates are bent to the required deflection angle, after which the cut is applied to them. After keeping the plates in the corrosive medium for each of them the increase in depth of the cut as a result of corrosion of the walls by the corrosive medium is analyzed, from which the rate of steel K by the mechanism of grooving corrosion is calculated taking into account the duration of tests. Corrosion rate values for two pipe steel grades determined by the suggested procedure are given. The comparison of K values obtained leads to the conclusion about the higher resistance to grooving corrosion of 09G2S steel.
-
Date submitted2021-03-10
-
Date accepted2021-05-21
-
Date published2021-09-20
Influence of heat treatment on the microstructure of steel coils of a heating tube furnace
- Authors:
- Vladimir Yu. Bazhin
- Bashar Issa
Transportation and refining of heavy metal-bearing oil are associated with the problems of localized destruction of metal structures and elements due to corrosion. In the process of equipment operation, it was revealed that premature failure of steel coils of heating tube furnaces at oil refineries and petrochemical plants was associated with insufficient strength and corrosion resistance of the steelwork. The study of the effect that structure and phase composition of 15KH5M-alloy steel elements of heating furnaces at oil refineries have on the corrosion properties, associated with mass loss and localized destructions in the process of heat treatment, allows to develop protective measures and determine heating modes with a rate-limiting step of oxidation. The rate of various corrosion types of 15KH5M steel is used as an indicator to assess the effectiveness of the applied modes of coil heat treatment in order to increase their corrosion resistance and improve their operational characteristics. Conducted experiments on heat treatment of certain steel coil sections allowed to determine rational heating modes for the studied coils, which made it possible to reduce their mass loss and increase corrosion resistance of working surfaces in the process of operation. Proposed heat treatment of steel coils at specified intervals of their operation in the tube furnaces creates conditions for their stable performance and affects the degree of industrial and environmental safety, as well as reduces material costs associated with the repair and replacement of individual assemblies and parts of tube furnaces.
-
Date submitted2018-05-21
-
Date accepted2018-07-14
-
Date published2018-10-24
Increasing the wear resistance of adapters and drill pipes by elec-tromechanical processing
The directions of the research on increasing the wear resistance of drill pipe locks, threaded joints and casing drill string have been defined: application of drill pipes from the nose-resistant surfacing to the lock with Russian and foreign materials (hardbanding); hardening of the surface layer of drill pipe locks by electromechanical processing; hardaning of the external and internal locking thread of drill pipes by electromechanical processing. Comparative tests of the wear resistance of various hardening materials (hardbanding) of Russian and foreign production and the drill pipe lock without surfacing have been made. The recommendations for increasing the wear resistance of threaded joints by the method of electromechanical processing are developed, which determine the ways of increasing the resource and reliability of drill pipes and sub-assemblies, the formation of unique properties of parts, reducing the labor-capacity of manufacturing and restoring parts, increasing the efficiency of enterprises and organizations, protecting the environment and creation of competitive products. The materials of the article are of practical value for specialists of various fields engaged in the issues of increasing the reliability of technological equipment. The production success of using wear resistant surfacing technology on the body of a drill pipe joint is due to the possibility of using relatively simple and mobile welding equipment, carrying out work in the places of use of a drilling tool or temporary (permanent) production bases with a small transport arm from the field, re-depositing surfacing materials restoration of drill pipe locks; a wide and growing list of companies that receive accreditation for the production of these works.
-
Date submitted2018-01-23
-
Date accepted2018-02-25
-
Date published2018-06-22
Influence of post-welding processing on continuous corrosion rate and microstructure of welded joints of steel 20 and 30KHGSA
- Authors:
- A. M. Shchipachev
- S. V. Gorbachev
Welded joints of structure steels have lower corrosion resistance in comparison to base metal. To increase corrosion resistance of welded joints and heat-affected zone they use longtime and energy-consuming methods of thermal and mechanic processing. The article covers the possibility of using the superplasticity deformation (SD) effect for processing of welded joints. The effect of SD is that metals and alloys with a small grain size (of the order of 10 μm) under conditions of isothermal deformation at a certain temperature acquire the ability for unusually large plastic deformations while reducing the deformation resistance. Grain-boundary sliding during superplasticity provides a high degree of structural homogeneity. If the metal does not have the small grain size, then during isothermal deformation at appropriate temperature the SD effect will not be fully manifested but will cause relaxation of residual micro and macro strains, recrystallization, which can be used during processing of welded joints to ensure their full strength. There have been carried out the investigation of processing methods impact - SD, thermal cycling and influence of post-welding treatment on corrosion rate and microstructure of steels 20 and 30KhGSA. It is shown that after deformation in superplasticity mode there is low corrosion rate and more favorable microstructure in the studied samples of steel. Post-welding processing of welded joints in SD mode provides low tool loads and low energy costs.
-
Date submitted2015-10-11
-
Date accepted2015-12-13
-
Date published2016-08-22
The specifics of operating minor deposits (as given by the examples of gas condensate deposits of the Northern Caucasus)
- Authors:
- R. A. Gasumov
One of the most important directions in upgrading well productivity in the process of mining hydrocarbons consists in fighting with salt formation and salt deposition. Solving that problem becomes especially actual when operating deposits that are in their final stage of exploitation in complex mining and geological conditions accompanied by deposition of salts in the well foot area of oil bed and their sedimentation on the sub-surface and surface equipment. It provokes a drop in well productivity and results in off-schedule repair works. Specifics are considered of exploiting minor gas condensate deposits of the Northern Caucasus that are operated under complicated mining and geological conditions of anomalously high bed pressures, high temperatures, strong depressions on the beds and inflow of mineralized water from water saturated seams. Processes are studied of salt deposition from heavy hydrocarbons in the well foot and the bed area surrounding it. Water sample analyses data from different wells have demonstrated that the main salts carrier is the associated water, and the principal sedimenting agents are corrosion products, as confirmed by the results of microscopic studies. The dynamics is presented of salt deposition in the “well foot – wellhead – separator” system retrieved from the results of studies of reaction products in the well foot zone of oil bed. It is demonstrated that the efficiency of struggling with salt deposition in the course of mining hydrocarbons depends on comprehensive approach to the problem, the principal thrust lying with prevention of such deposition. Possible ways are considered to prevent precipitation of ferric compounds in the course of operating gas condensate wells, a way is suggested to intensify gas inflow.
-
Date submitted2009-08-08
-
Date accepted2009-10-26
-
Date published2010-02-01
Relationship between wear resistance of cutting bit body of mining tool and distribution of hardness along the cutting bit
- Authors:
- M. P. Talerov
In present article the courses of low wear resistance of rotary cutting bit body and also the courses of one-sided wear are described. The results of hardness of the cutting bit body from various manufacturers are represented here. In summary a conclusion was made that the utilization of thermal treatment after pressing removes specific structure that can be the course of one-sided wear genesis.