Session: OAC-01-01 Safety, Reliability, and Risk Management

Paper Number: 154478

154478 - The Analysis of Full-Life Cycle Service Reliability Evaluation for Large Diameter X80 Pipeline Girth Welds 

Abstract: 

The integrity of pipelines hinges on the strain capacity of girth welds, making it a pivotal factor in ensuring pipeline safety. The large-scale adoption of large-diameter X80 pipelines and the application of fully automatic welding technology have led to significant differences between the I-II composite fracture failure mechanism in fully automatic welded composite bevel girth welds and the traditional I-type fracture failure mechanism observed in manual welding or combination automatic welding with a single V-shaped bevel.Through statistical analysis of construction-phase data from a typical large-diameter X80 pipeline, this study investigates the probabilistic distribution patterns of uncertainties affecting girth weld failures. It identifies the optimal distribution types for uncertain parameters such as material mechanical properties, loads, and defects.By applying the Hamiltonian Monte Carlo-Subset Simulation algorithm, a reliability analysis was conducted on the strain capacity prediction model for large-diameter X80 fully automatic welded composite bevel girth welds, known as the CUP model. This research systematically explores the influence of material parameters (base material yield-to-tensile strength ratio, weld strength matching coefficient), defect parameters (crack depth, crack length, misalignment), and load parameters (strain capacity demand) on the reliability of high-grade steel pipeline girth welds with cracks.The results indicate that by varying the mean values and variance of the parameters involved in the reliability analysis and examining their effects on girth weld reliability, it was found that the reliability of girth welds with cracks decreases with increasing crack depth, crack length, and base material yield-to-tensile strength ratio, but increases with a higher strength-matching coefficient of the weld material.The findings of this research provide valuable insights, offering a reference and guidance for the reliability-based design of girth welds in high-grade steel pipelines.

Presenting Author: Han Zhang China University of Petroleum-Beijing

Presenting Author Biography: Zhang Han, a PhD student in oil and gas engineering, studying in China University of Petroleum (Beijing), his main research interests are structural safety of oil and gas storage and transportation facilities.

Authors:

Han Zhang China University of Petroleum-Beijing
Xiaoben Liu China University of Petroleum-Beijing
Yue Yang PipeChina Institute of Science and Technology
Jia Shao China University of Petroleum-Beijing
Jian Chen PipeChina Institute of Science and Technology
Pengchao Chen PipeChina Institute of Science and Technology
Hao Wang China University of Petroleum-Beijing
Hong Zhang China University of Petroleum-Beijing