Lianshuang Dai
Deputy Director of Production Department
China Oil & Gas Pipeline Network Corporation
Dr. Dai Lianshuang has over 15 years of experience in the oil and gas storage and transportation industry. Working at China National Petroleum and Natural Gas Pipeline Group, he focuses on asset integrity and intelligent research. A Tianjin University PhD, he has led projects, published papers, and won awards in material and oil&gas transportation fields.
Participates in
TECHNICAL PROGRAMME | Energy Infrastructure
Pipelines, Storage and SPRs
Forum 08 | Digital Poster Plaza 2
28
April
12:30
14:30
UTC+3
Driven by escalating energy demands and technological progress, the use of high-grade steel in oil and gas pipelines has grown steadily. In the past 15 years, X70 and X80 steel pipelines, spanning over 60,000 kilometers, have enabled the development of a new pipeline system featuring large diameters, high strength, and high pressure. However, their extensive adoption has been marred by persistent challenges, especially the girth weld fracture failures. For example, PHMSA data shows that 10+ leakage incidents occurred in newly built high-grade steel pipelines from 2009–2010. Malaysia reported X70 pipeline weld fractures in 2014 and 2018; China recorded three consecutive X80 pipeline weld failures from 2017–2019; and Canada issued a 2020 advisory on this critical issue.
Through a decade of in-depth analyses and rigorous material testing, the authors have elucidated the root causes of cracks in semi-automatic and manual welds, clarified the softening/embrittlement mechanisms in automatic welds' heat-affected zones, and determined the combined effects of low matching, pre-strain, and geometric discontinuities. This research established a theoretical framework for predicting brittle fracture failures in high-grade pipeline welds. The framework offers practical guidance for improving new pipeline construction quality, managing in-service weld risks, and supports the future application of X90 and higher-grade pipeline steels.
Through a decade of in-depth analyses and rigorous material testing, the authors have elucidated the root causes of cracks in semi-automatic and manual welds, clarified the softening/embrittlement mechanisms in automatic welds' heat-affected zones, and determined the combined effects of low matching, pre-strain, and geometric discontinuities. This research established a theoretical framework for predicting brittle fracture failures in high-grade pipeline welds. The framework offers practical guidance for improving new pipeline construction quality, managing in-service weld risks, and supports the future application of X90 and higher-grade pipeline steels.
