Traditional correlation analyses based on whole-rock data have limitations in discerning pore development determinants in shale oil reservoir, given the complex lithology of shale formations and intricate interdependencies (multicollinearity) among geological variables. In this study, mercury injection capillary pressure and digital analysis of scanning electron microscopy were employed to examine the macropore structures of both whole rocks and their constituent lithologies for the Upper Triassic Chang-7 shale of the Ordos Basin. Variations were observed among clay shale (shale primarily consisting of clay-sized mineral grains), massive siltstone and silty laminae within the Chang-7 shale. Through the combination of correlation analysis and scanning electron microscope digital technique, it was demonstrated that total organic carbon content primarily controls the level of macropore development, while lithology primarily governs macropore types and structures. Although quartz and pyrite exhibit correlations with macropore volume, they do not emerge as primary factors; instead, they appear interconnected to total organic carbon. Due to detrital mineral framework preservation during compaction, larger macropores are more developed in massive siltstones and silty laminae than in clay shale. Additionally, silty laminae, situated closer to the source rock and influenced by organic acids, exhibit a higher abundance of larger dissolution pores, potentially favoring shale oil development. This study overcomes traditional method constraints, disentangling multi-correlations, and providing new insights into shale macropore development mechanisms, potentially advancing shale oil exploration and production.

Conventional petroleum exploration targets have become increasingly complex recently. Although geological research of unconventional oil and gas resources has received much attention in recent years, such resources also face many complex geological and scientific problems. In this context, the 8^th International Symposium on Hydrocarbon Accumulation Mechanisms and Petroleum Resources Evaluation was held in Beijing from 21 to 23 October, 2022. Experts presented and discussed their latest research findings on this topic relating to both conventional and unconventional oil and gas resources. They also discussed various development strategies for the petroleum industry taking into account the global objectives of “carbon peaking and carbon neutrality” to mitigate the impacts of climate change. Six significant theoretical advances and some new technologies were introduced at this conference. These advances related to the “Whole Petroleum System” theory, shale oil and gas exploration, deep and ultra-deep petroleum exploitation, clean energy issues, and alternative types of unconventional oil and gas resources. In response to these technological advances, four major current challenges were identified. These challenges related to the petroleum industry’s ongoing growth and development in the context of carbon-neutrality goals, the evolution of hydrocarbon laws relating to petroleum accumulations and their exploitation, organic and inorganic effects on petroleum generation and accumulation mechanisms, and artificial intelligence applications related to hydrocarbon prediction.