A failure analysis method for long-distance natural gas pipelines

Abstract

The invention discloses a method for analyzing the failure of a long-distance natural gas pipeline, which includes step 1, aiming at the corrosion and thinning condition of the long-distance natural gas pipeline, and obtaining its corrosion rate in the natural gas transportation process through experimental methods and theoretical methods; 2. Predict the effective wall thickness and ductile crack arrest toughness of long-distance natural gas pipelines by corrosion rate; 3. Calculate the ratio of the number of ductile crack extension pipe sections to the total number of connected pipe sections by probability analysis method; 4. Calculation of natural gas length Fifthly, according to the failure risk probability and bearable risk probability of the long-distance natural gas pipeline, analyze and judge the failure of the pipeline, and predict the allowable service life of the pipeline. The method of the invention has simple steps and is convenient to implement, can be effectively applied in failure analysis of long-distance natural gas pipelines, provides reliable guidance for safety inspection, maintenance and maintenance of long-distance natural gas pipelines, has remarkable effect, and is easy to popularize.

Description

technical field [0001] The invention belongs to the technical field of natural gas long-distance pipeline detection, in particular to a method for analyzing the failure of a long-distance natural gas pipeline. Background technique [0002] Natural gas long-distance pipelines play a pivotal role in my country's West-East Gas Transmission Project. During the operation of the natural gas long-distance pipeline, under the combined effect of environmental corrosion, external force damage, welding defects and material processing and construction defects, it will bring different degrees of failure risk to the pipeline. For long-distance natural gas pipelines, the pipeline failure caused by corrosion and thinning damage mode is one of the most typical failure modes, which seriously damages the safety of the pipeline. In the current long-distance oil and gas pipeline standards, the failure judgment principle for pipeline corrosion and thinning is mostly the allowable stress criterio...

AI Technical Summary

Problems solved by technology

For long-distance natural gas pipelines, pipeline failure caused by corrosion thinning damage mode is one of the most typical failure modes, which seriously damages the safety of pipelines

In the current oil and gas long-distance pipeline standards, the failure judgment principle for pipeline corrosion and thinning is mostly the allowable stress criterion, that is, the first strength theory. In special cases, it also includes the second, third and fourth strength theories. The stress criterion can achieve accurate prediction of short-term failure of the pipeline, but it will no longer be accurate for long-term prediction or conditions with high risk of failure

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