Oil-rock interaction controlling oil migration and accumulation in porous shale reservoir: Insights from varied lacustrine basins in China.

Shale oil has emerged as a critical energy resource in China, yet its occurrence and enrichment mechanisms in shale reservoirs remain poorly understood, especially in diverse lacustrine basin types. A particular challenge is the oil-rock interaction, which could govern nanopore evolution, hydrocarbon distribution, mobility dynamics, and compositional fractionation. This synthesis integrates measured and compiled data to elucidate oil-rock interaction mechanisms regulating these parameters. Incorporating measured and compiled data, comparative analysis demonstrates stark contrasts between saline and freshwater basins in mineral composition, pore structures, and associated oil-generation and migration behaviors. Oil-rock interactions, mediated by van der Waals forces, hydrogen bonding, and π-π stacking, vary substantially across mineral types: clay minerals demonstrate strong adsorption capacities, enhancing hydrocarbon enrichment but constraining mobility; whereas brittle minerals promote free-oil accumulation. These findings establish a mechanistic framework for shale oil sweet spot formation. We further propose an innovative method based on non-hydrocarbon compositional similarity between wellhead oil and core extracts to identify productive intervals, revealing substantially greater contributions from thick shale sequences than previously recognized. The study highlights critical knowledge gaps and proposes future directions integrating interdisciplinary approaches and AI-driven quantification, offering theoretical and practical guidance for shale oil exploration optimization in China.