Cross-technology convergence in shale gas development: Insights from international patent network and machine learning

Understanding technological convergence patterns in transitional energy sources is critical for strategic innovation governance during the global sustainability transition. This study examines cross-technology convergence in shale gas innovation through analysis of 17,929 patents filed across major jurisdictions between 2000 and 2023. Based on semantic topic modeling (Top2Vec), IPC co-occurrence networks with machine learning methods, we map the structure technological integration and compare innovation strategies across countries. Three core findings emerge: (1) shale gas innovation forms a highly interconnected global network with established cores in hydraulic fracturing, environmental mitigation, and processing, alongside emerging clusters in microseismic monitoring and purification technologies; (2) systematic cross-country differences reveal distinct innovation strategies: the United States operates as a broad integrator, China and Japan as focused specialists, and Europe as collaboration-centric; (3) integration breadth correlates most strongly with patent recency, documentation scope, and moderate family size, though modest predictive performance (R² = 0.36) reflects the complex, non-linear dynamics of technological convergence. These findings inform targeted policies for transitional energy governance, including monitoring critical network bridges, strategically funding emergent clusters, and tailoring collaboration mechanisms to national innovation postures.