大庆长垣南部敖包塔油田扶余油层致密油储层成岩作用OA

Current research on the reservoir-controlling factors of Fuyu reservoir in Aobaota oilfield of southern Daq-ing Placanticline mainly focuses on sedimentary facies,while insufficient analysis of diagenetic control on reser-voirs hinders the establishment of sweet-spot evaluation index system.Based on experimental data such as thin-sec-tion identification,whole-rock analysis,scanning electron microscopy and clay X-ray diffraction,charts for diage-netic facies classification with cementation porosity reduction rate and compaction porosity reduction rate as the core are established to clarify sweet spots for exploration,development and well deployment.The results show that the main diagenesis types include compaction,cementation and dissolution,with compaction being the primary factor in porosity reduction,followed by cementation.Compaction exhibits strong screening effect,eliminating frag-ile pores while preserving pathways with high compaction resistance and good connectivity.Cementation demon-strates strong differentiation,with localized pore precipitation leading to highly uneven pore radius distribution.5 types of diagenetic facies are identified in Fuyu reservoir in studied area,with strong compaction-extremely weak cementation facies prioritized for target sweet-spot area and weak compaction-strong cementation facies being avoid-ed.The research provides significant guidance for reevaluating the main controlling factors of tight oil sweet spots in Aobaota oilfield of southern Daqing Placanticline and supporting the establishment of sweet-spot evaluation index system.