The current stage in the development of promising gas and gas condensate fields in the Russian Federation is associated with facilities whose production includes carbon dioxide. Such objects include the Urengoyskoye oil and gas condensate field (Achimov deposits), the Bovanenkovskoye oil and gas condensate field, and the Kirinskoye gas and condensate field. The presence of CO2 in the produced gas, in combination with moisture condensation and a number of other factors, stimulates the intensive development of local corrosion processes. The main factors that influence the development of corrosion at infrastructure facilities and its localization in the presence of CO2 are considered. It is noted that when assessing the degree of aggressiveness of the environment, it is necessary to consider not only the CO2 content, but also other basic operating parameters that can affect corrosion. During the exploitation of gas fields, the conditions of moisture condensation that contribute to corrosion arise, which occurs when a temperature gradient arises and the produced gas is rapidly cooled. Higher temperatures increase both the amount of precipitated moisture and, accordingly, the rate of local corrosion. Simulation tests have shown that the development of local forms of corrosion (pitting, ulcers) are possible even at low CO2 partial pressures (from 0,025 MPa and above) in the presence of condensed moisture.

This article presents the results of studies in the field of synthesis of water-soluble salts of oligomethylene aryl sulfonates synthesized using aromatic hydrocarbons contained in the gas oil fraction of the catalytic cracking process of oil as raw materials. Based on the synthesized various salts of oligoaromatic sulfonic acids (sodium, potassium, ammonium salts), solutions of various concentrations (35; 75; 150; 200 mg/l) were prepared and their effect on the vital activity of sulfate-reducing bacteria at a temperature of 30…32 °С for 7…14 days was studied. It was found that complex salts synthesized on the basis of oligomeric sulfonic acids of aromatic hydrocarbons of the gas oil fraction (N-1, N-2, N-3) at a concentration of 150 mg/l exhibit more than 90%, and at a concentration of 200 mg/l, 100% bactericidal effect and completely inhibits the growth of bacteria. It was revealed that the synthesized salts of sulfonic acids exhibit a relatively higher antimicrobial activity against SRB than the industrial bactericidal inhibitors AMDOR-IK-7 and AMDOR-IK-10 taken as a reference. Based on the studies, it was found that the synthesized salts of oligosulfonic acids completely inhibit the growth of sulfate-reducing bacteria at much lower concentrations compared to the industrially used bactericidal inhibitors taken as a reference. In particular, at a concentration of 150 mg/l, the bactericidal effect is more than 90% against 75…80% for the standard.

The article presents a study of the protection degree of a model inhibiting solution samples in order to select the optimal inhibitor for protecting the annular space of the underwater crossing of the “Pavlodar- Shymkent” main oil pipeline across the Irtysh river built by the pipe-in-pipe method. In order to determine the corrosion rate of pipe steel we used witness coupons made of 17G1S steel similar to the steel of the pipeline in operation. Gravimetric and electrochemical methods were used to study the inhibitory properties of inhibiting solutions consisting of corrosion inhibitors Rancor 1101, CRW 82590, VpCI 337, ForeRP 40, and water from the Irtysh river. We carried out comparative analysis of the corrosion rates of pipe steel and the protection degree of inhibitor solutions at various concentrations. Any of inhibitors in concentrations from 50 to 750 ppm, in static mode, do not provide a protective effect, at which steel 17G1S shows increased resistance in a corrosive environment of water samples from the river Irtysh (reduction of the average corrosion rate to 0.005 mm/year according to GOST). Comparing the protective ability of corrosion inhibitors in a corrosive environment from water samples from r. Irtysh, it has been exhibited that the Baker Hughes inhibitor CRW 82590 shows the best protective ability, in static mode during gravimetric studies 80,38% (500 ppm) and 82,52% (750 ppm), in static mode during electrochemical studies 85,90% (500 and 750 ppm).

The study is examines the assessment of the corrosion-protective properties of zinc-rich coating based on water sodium silicate (ZRC) using the Electrochemical Impedance Spectra (EIS) with AutoLAB PGSTAT204N. The system consists of three electrodes: Ag/AgCl reference electrode in 3 M solution of KCl, auxiliary electrode – Pt (8x8 mm) and working electrodes for determination potential (Ecorr) and impedance measurement, salt spray test method and natural teszzt method at Dam Bay Marine Research Station, Nha Trang, Khanh Hoa, Viet Nam. ZSC can provide good cathodic protection when zinc content is 70% by weight or more. ZSC with a mixing ratio of High Modulus Liquid Sodium Glass / Zinc Powde : 25/75 by weight (working title – TTL-VN) has good corrosion protection after 16 cycles salt spray test and after 18 months natural test in seawater. The paint film has basic parameters as adhesion – 4,41 MPa, flexural strength – 2 mm, pendulum hardness – 0,62 conventional units and initial coating potentia l – 0,96 V Ag/AgCl.

Compositions based on hydroxyethylidene diphosphonic and nitrilotrimethylenephosphonic acids with alkali earth metals (Ca, Mg) are studied as corrosion inhibitors. It is found that the studied compositions are not inferior to their zinc counterparts as regards their corrosion inhibition efficiency and can be used in two-circuit cooling systems

In this investigation we studied the temperature dependence of the protection effect of St3 steel against corrosion in 0,04% CH3COOH solution-kerosene system by gravimetric method of leucine (derivative of aliphatic monoamino monocarboxylic acids – AL-MAMCA: with the general formula CH3-CH(CH3)-CH2-CH(NH2)-COOH). Previously at 20 ºC we investigated this corrosion process in various two-phase acid and neutral electrolyte solutions in hydrocarbon systems and revealed a good protection effect of leucine. On the basis of the obtained data, the activation energy in the corrosion process of St3 steel has been calculated without and in the presence of the leucine in the aggressive system shown by analytical and graphical methods (graph of dependence of lgK on 1/T). It was found that the addition of leucine to the aggressive system in terms of corrosion causes a significant increase in the activation energy of St3 steel in the corrosion process, and thus complicates the process of this undesirable process. It has been shown that in parallel with the increase in the temperature of the aggressive environment in terms of corrosion, the previously physically adsorbed leucine molecules on the surface of St3 steel are gradually replaced by chemically adsorbed ones, thus further strengthening the metal – inhibitor bond