The Study On The Diagenesis And Diageneticfacies Characteristics Of Chang 6 Reservoir In Heshui Area

Due to the influence of sedimentation, diagenesis and tectonism, the micro-pore structure of the Chang 6 reservoir in Heshui area is heterogeneity, the law of the oil-water percolation is complex. On the basis of the research of sedimentary facies and sand body distribution characteristics, using the methods of casting thin sections, scanning electron microscopy to research the diagenesis characteristics of Chang 6 reservoir in Heshui area, high pressure mercury injection, constant speed mercury penetration, nuclear magnetic resonance (NMR) and oil-water relative permeability are uesd to study the micro-pore structure and percolation characteristics of the typical diagenetic facies. Basically achieved the following conclusions:The main diagenesis types of Chang 6 reservior in the research area are compaction, cementation and dissolution. The main diagenetic stage is in the stage A of the middle diagenetic phase, part into the stage B of middle diagenetic phase. The diagenetic ficies of Chang 6 reservior in the research area:the illite cementation-integranular pore diagenetic facies, the illite cementation-feldspar dissolution diagenetic facies, chlorite cementation diagenetic facies, the carbonate cementation+illite cementation diagenetic facies, the illite cementation diagenetic facies and the carbonate cementation diagenetic facies. Different types of diagenetic facies have different microscopic pore structure characteristics:the illite cementation-integranular pore diagenetic facies and the illite cementation-feldspar dissolution diagenetic facies have the bigger throat radius, the smaller pore-throat ratio and the the higher coordination number. Otherwise, the carbonate cementation+illite cementation diagenetic facies and the chlorite cementation diagenetic facies have the smaller throat radius, the greater pore-throat ratio and the smaller coordination number. Different types of diagenetic facies have different percolation characteristics:the movable fluid saturation of the illite cementation-feldspar dissolution diagenetic facies is high and the oil-water interference degree is smaller, the movable fluid saturation of the carbonate cementation+illite cementation diagenetic facies and the chlorite cementation diagenetic facies is low and the oil-water interference degree is greater. Different types of diagenesis and diagenetic facies have different influence on reservoir property:after compaction and cementation, the reservoir physical property become worse, after dissolution, the reservoir physical property become better. The reservoir physical property of good diagenetic facies is better, the reservoir physical property of bad diagenetic facies is worse.