Complex Network-based Analysis of Structural Changes in Offshore Natural Gas Markets

The natural gas market is a key component of the global energy market, and significant changes in the natural gas market during the 2021–2023 period also affected the global energy market. This study discusses changes in the structure of the global natural gas market during the 2021–2023 period using the complex networks method. First, the market network was constructed for the 2021–2023 period, and the evolution of the natural gas market structure during the period was simulated using the Topsis model and the association analysis model. The importance ranking of each node of the complex network and the membership of the associations were calculated to observe reactions to the changes in the market structure during the period. Second, the market network was shocked randomly and intentionally using the destructive evaluation model, and the impact of the shock on the network was assessed by calculating indicators, such as connectivity efficiency and maximum connectivity subgraph after the shock, which reflected change in market structure stability. The results of the study show the following:（1） During the period, the market developed from a predominantly European orientation toward regional polycentricity, with intense competition between regions. The U.S. maintained its leading position in the liquified natural gas（LNG） market, Europe’s position generally declined, and emerging markets, such as Africa and the Middle East rose.（2）The Russian association was split up, LNG chose to deepen cooperation with Asia, however, the association shrank gradually and the pipeline gas association was split up; it has since recovered. The U.S. community has continued to expand and maintain this trend.（3） The stability of the natural gas market structure first declined and then stabilized during the period under study, and the natural gas market structure will continue to change in future; however, the magnitude of the change will decrease.