Evaluation of the destruction danger of the main pipelines in dependence on the shape of the surface crack defects

Abstract

The conditions of the corrosion-fatigue cracks of given shape spread in the pipe wall for systems "pipe metal – environment" are defined on the basis of analytical and numerical evaluation of kinetics and the corrosive-fatigue crack defects. The strength and fracture risk of the operated oil and gas pipes are evaluated on the basis of the index of the pipe element resistance to the crack growth. The relationship between the ultimate form of the half-elliptical corrosive-fatigue cracks and the speed of their development is established for the systems "pipe metal – environment".
The criterion dependence of the initial and the critical form of cracks, which gives the opportunity to evaluate the danger of the detected defects and to interpret the results of technical diagnostics of the studied main pipelines, is suggested.