Theoretical Analysis on the Bending Springback of Flattened Oil and Gas Pipelines

Abstract

Oil and gas pipeline leakage incidents occur from time to time, causing environmental pollution, property damages and other serious consequences. Flattening the oil and gas pipelines to stop the flow can effectively reduce losses. The extrusion device can quickly arrive at the incident scene and flatten the pipeline within a short time using hydraulic power or mechanical force so as to stop the flow. However, due to the springback problem, a small amount of oil or gas will still leak. Therefore, studying the bending springback of flattened oil and gas pipelines is very essential to solving the oil or gas leakage problem. This paper analyzes the theories related to flattening and closure of oil and gas pipelines. Springback is an inevitable result of the elastic redistribution of the internal stress in a flattened pipeline. Regarding the bending springback problem of flattened steel pipelines, based on the assumptions of plane strain, this paper applies the plate bending theory and establishes a theoretical model for the bending springback process of flattened steel pipelines and obtains the factors affecting the bending springback of flattened pipelines. At the same time, it uses the model in conjunction with the experiment to analyze the relationship between the springback of a flattened pipeline and the closure efficiency.