Abstract:

Shale oil resources in the Subei Basin show significant potential. The second and fourth members of the Funing Formation (hereafter referred to as Funing Member 2 and Funing Member 4) are the main target layers for exploration. These layers are characterized by substantial thickness, wide distribution, high content of brittle minerals, well-developed laminated structure, and favorable organic matter types, with typical geological features, including low to medium total organic carbon (TOC), complex tectonics and lithology, and developed faults/fractures. Since 2011, Jiangsu Oilfield has strengthened basic research and exploration practices, leading to the establishment of the theory of differential enrichment of shale oil in complex fault blocks with low to medium TOC. Key technologies for exploration and development have been integrated and innovated, green and low-carbon development models have been explored, and significant breakthroughs have been achieved in shale oil exploration of Funing Member 2 and Funing Member 4 in the Gaoyou Sag. However, there are still many challenges, such as an unclear understanding of the patterns of shale oil enrichment and high yield, insufficient adaptability of engineering technologies, undefined technical policies for cost-effective development, and high development costs. Main approaches to achieving large-scale production and cost-effective development of shale oil include: deepening the fundamental research on the main controlling factors of shale oil enrichment and high yield, tackling main challenges and advancing key technologies, optimizing integrated organizational management and operation mechanisms, and maximizing the drilling success rate in high-quality reservoirs, the utilization rate of shale oil reserves, and the recovery efficiency to further reduce costs and improve efficiency.

Key words: Subei Basin, Gaoyou Sag, shale oil in complex fault block, exploration progress, research direction