Session: MF-08-01/10-01 Development of Stress Intensity Factor Solutions (Joint with C&S) and Pipeline Integrity

Paper Number: 61647

Start Time: Wednesday, July 14, 2021, 09:00 AM

61647 - Prediction of Ultimate Load of Pipeline With Defects Based On Material Hardening 

Submarine pipelines are important facilities for offshore oil and gas development, and it is of great significance to ensure their safe and efficient operation.The existing pipeline ultimate load evaluations and researches lack the consideration of pipe characteristics and failure mechanism, there are certain errors, and the types of defects involved are relatively single.In order to give full play to the potential of pipes, consider the strain hardening effect of pipeline steel during the true failure process of submarine pipelines, and study the influence of different types of defects on the ultimate bearing capacity of the pipeline. This paper uses the twin shear stress yield criterion and based on the Ramberg-Osgood material strain hardening model to derive a formula which is used to predict the ultimate load of the defect-free X60 submarine pipeline.Using finite element method to study common defects including flat-bottomed rectangle, flat-bottomed ellipse single-point external defect, single-point internal defect, axially adjacent and circumferential adjacent double-point external defects on the ultimate load of X60 submarine pipeline.A formula for predicting the ultimate load of the submarine pipeline with a flat-bottomed rectangular single-point external defect was fitted, and the accuracy of the formula was verified by comparison with real data.On the basis of this formula, the ultimate load prediction formulas of X60 submarine pipeline with different types of defects were fitted, and the formulas were verified to have excellent accuracy, which provided a basis for the safety assessment of X60 submarine pipeline.

Presenting Author: Zhuoyu Fang China University of Petroleum(Beijing), Pipeline Technol & Safety Res Ctr

Authors:

Zhuoyu Fang China University of Petroleum(Beijing), Pipeline Technol & Safety Res Ctr
Shaohua Dong China University of Petroleum(Beijing), Pipeline Technol & Safety Res Ctr