Enhanced oil recovery and flow mechanisms in shale reservoirs: Toward cross-scale, low-carbon, and field-oriented development

Shale oil and gas development is shifting from single stimulation methods toward integrated recovery strategies that combine flow-mechanism understanding, enhanced oil recovery, and carbon utilization and storage. Based on the discussions in Session “Shale Oil and Gas Flow Mechanisms and Enhanced Oil Recovery” of the second “International Geo-Energy Frontier Forum”, this work summarizes recent advances in thermally assisted CO₂ huff-n-puff, supercritical CO₂ flow and multiscale CO₂ foam simulation, in-situ upgrading and thermal conversion, micro/nanobubble injection, dual geological-engineering sweet-spot identification, and shut-in optimization. The major bottleneck is no longer the lack of individual stimulation methods, but the insufficient integration among pore-scale mechanisms, fracture-matrix interactions, field-scale simulation, and carbon storage accounting. Future research should focus on mechanism-informed pilot design, lithology-specific upscaling models, CO₂-thermal-chemical coupled processes, and standardized evaluation workflows linking recovery efficiency with carbon sequestration performance.