Probabilistic evaluation of a corrosion danger to main pipelines in the condition of stress- corrosion

摘要

Stress corrosion cracking (SCC) is very important for the Russian oil-and-gas industry due to a fact that a number of SCC failures of Russian carbon steel main pipelines have increased for last several decades. All the factors supervising SCC process of main pipelines destruction can be classified as necessary or sufficient. Factors which can be a separate cause for SCC refer to sufficient factors. Necessary SCC factors define intensity of SCC corrosion process. Conceptual principle of SCC diagnostics is the multifactor analysis of conditions of a main pipeline laying and operation including an estimation of influence of electrochemical protection. Influence of each sufficient and necessary factor should be considered separately and in common. The quantitative result of this estimation is called "index of SCC danger". Rate of growth of obtained SCC defects is defined using special diagrams in dependence of content of hydrogen-containing inorganic compound in ground and existing level of polarization potential.