陆相断陷湖盆复合沉积体系储层成岩作用及发育模式OA

Taking the clastic rock reservoirs of the Lower Cretaceous Bayingebi Formation in the Guaiz-ihu Depression of the Yin'e Basin as the research object.This study comprehensively applied technical methods,including core observation,thin section identification,scanning electron microscopy(SEM),and fluid inclusion thermometry,to research the diagenesis and reservoir development mechanism of clastic rocks in the Bayingebi Formation of the Guaizihu Depression.The results indicate that the study area developed the complex sedimentary system of delta-gravity flow.In the delta sedimentary system,sandstone lithofacies of debris flow genesis and traction current genesis are developed;while in the grav-ity flow sedimentary system,sandstone lithofacies of slide-slump genesis,sandy debris flow genesis,and turbidity current genesis are developed.There are significant differences in the reservoir diagenetic facies corresponding to different lithofacies.In the delta plain facies,the reservoir diagenesis system of debris flow genesis is closed,and the secondary pores caused by the dissolution of organic acids in the early stage are easily filled by calcite in the later stage,resulting in the overall development of calcite strong cementation diagenetic facies.The clastic rock reservoirs of the delta front facies dominated by traction flow genesis have strong material recycling capacity,secondary pores are not easy to be filled by the later calcite cements,and the diagenetic facies are mainly of medium compaction-strong dissolution facies,and the quality of the reservoirs is good.In the gravity flow sedimentary system,sandstones near slopes and faults are prone to sliding-slump,resulting in a high degree of mixing of detrital particles and plastic muddy matrix,so that the overall compaction resistance is poor,and the diagenetic facies are mostly of the strong-compaction facies and pseudo-matrix plastic deformation-filling facies,making the reservoir quality poor.The sandstones far away from slopes and faults are mostly of sandy debris flow and turbidity current genesis,which reservoirs quality is good.In the sandy debris flow genesis clastic rock reservoirs are mainly determined by medium compaction-strong dissolution facies,the physical property is best.In turbidity current genesis clastic rock reservoirs,the feldspar and quartz particles dis-tribute centrally as bands,and combined with the chlorite coating attached to the particle edges,the o-verall compaction resistance of the reservoir is greatly improved,which makes the muddy matrix hard to intrude into the sandy layer,and the reservoir physical properties is only less than sandy debris flow genesis.