The Study Of Dolomite Physical Properties And Its Control Factors In Longwangmiao Formation In Northeast Sichuan Basin

Based on carbonate petrology,reservoir geology and the predecessors' results,using the microscope,the cathodoluminescene microscope,carbon and oxygen isotope,observing the core and outcrops,mastering the sedimentology of Sichuan basin and the study area of the northeast of Sichuan basin,the paper focus on the petrographic character,spatial type,physical properties,diagenesis of dolomite of Longwangmiao Formation,seize the main factors that control the physical characteristics.The result shows that sedimentary model of Longwangmiao Formation in Sichuan basin is gentle slope,developing inner gentle slope,outer gentle slope and the slope-basin from west to east.The sedimentary facies in the study area mainly include inner gentle slope,which contains mixed product tidal flat,grain beach and flat phases.The dolomite types of Longwangmiao Formation include particle and grain dolomite.Spatial types include intergranular dissolved pore,intergranular hole,cracks.Constructive diagenesis include dolomitization,dissolution and cataclasis,destructive diagenesis include compaction and recrystallization,preservation diagenesis include cementation.The factors that control physical characteristics of dolomite of Longwangmiao Formation include palaeogeomorphologic plateau,granule deposit,quasi-atmospheric fresh water corrosion,penecontemporaneous dolomitization and epigenetic karst.Lacking strong quasi-atmospheric fresh water corrosion and epigenetic karst is the reason that physical characteristics worse than the middle area in the Sichuan basin.The palaeogeomorphologic plateau can influence the others and it is the fundamental factors.