Tubing are intended for a wide range of works from pumping out of oil and gas from a well cavity before production of various repair work. With their help on oil fields carry out raising of oil from a productive zone of layer to well head and also force water for maintenance of reservoir pressure. The main problem at operation of these pipes are refusals because of corrosion defeat. The main types of corrosion destructions of tubing connected with presence at the obtained environment of carbon dioxide and hydrogen sulfide are given in the paper. One of the ways of protection of an internal surface of tubing is the use of corrosion inhibitors – chemical reagents which introduction in small dosages on corrosion Wednesday significantly reduces metal corrosion rate. Results of experiments on corrosion inhibitor selection for protection of the oil-field equipment of one of fields of the Russian Federation are given in the paper.

In the territory of the Russian Federation within a year, in connection with change of atmospheric conditions, the soil moisture content, saturation of its different layers, temperature and a physical status of soil changes. Depth of freezing of soil is much lower than the bottom level of the pipeline. Freezing, defrosting and uneven rainfall of soil are adverse factors in these conditions. Apparently from the above, there are conditions of forming of corrosion cracking energized (CCE) connected with seasonal and long-term variability of water content of soil. At the same time manifestation of specific features of CCE, characteristic of the specific region, is possible. For studying the reasons and the nature of destruction of the main gas pipeline, in this work a studying of a focal zone is carried out. When determining stress corrosion cracking, first of all, the attention to existence of a fragile component in a break, arrangement of fragile cracks in the lower half-perimeter of a pipe and orientation of the fragile cracks along the forming pipe, which are the main signs of manifestation of corrosion cracking, was paid. On the basis of the received results it is proved that the studied cracks have the corrosion and mechanical origin, characteristic of corrosion cracking energized. Actions for prevention of destruction of gas pipelines are offered further.

Most of the structures, parts of machines in the process of operation are subjected to the action of cyclically changing loads, such changes can be judged by the fatigue of the metal. In addition to the influence of mechanical stresses during the service, corrosive environment affects metal structures, machine parts, which leads to the process of gradual accumulation of damage. Corrosive media leads to a decrease in durability. The paper presents results of fatigue tests on a sample of steel X70, selected from the focal zone of destruction of the main gas pipeline. The sample under investigation had numerous cracks typical for corrosion-mechanical destruction. It is shown that with an increase in the number of loading cycles, the electrode potential of the metal decreases, which leads to a decrease in its thermodynamic stability. With the growth of the crack, there is a decrease in the potential, which is not compensated by the relaxation processes. Results of the regression analysis showed that the correlation coefficient is r = 0.99, using the three-parameter logarithmic function.

The article addresses the issues of ensuring the reliability of tanks taking into account their life cycle by assessing and maintaining an appropriate level of quality. The work proposes: a structure that allows to assess the quality of such a complex technical system as a tank; Methodology, algorithm and formulas for evaluation of integral quality index.

Stress corrosion cracking (SCC) is one of the reasons of failure of main gas pipelines. SCC appears in the form of the single and multiple cracks arising on an outer surface of a pipe. In work different types of the analysis of destruction of the pipeline having multiple cracks are presented. For the purpose of studying of a number of features of SCC by authors various researches were conducted: electrochemical researches, potentiodynamic measurements at various temperatures. With the help of potentiometric studiesit is shown that at low temperatures process of formation of a passive film is at a loss, however, with temperature increase processes of oxidation of metals proceed much quicker, at the same time decrease of their thermodynamic opportunity is observed. The nature of temperature effect is defined on oxidation rate of metals by temperature dependence of a kinetic constant of chemical reaction that is expressed by the Arrhenius equation.