The Research On Sedimentary Microfacies And Forcasting Perspective Of Putaohua Oil Reservoir In Gulongbei Areas,Daqing Oilfield

According to the sand body changes quickly and the understanding of thickness and distribution is not clear in Putaohua oil reservoir in Gulongbei areas,the control of the facies belt and sand body to the oil rich area of the reservoir needs to deepen two major geological problems,carry out research on the division and comparison of fine stratigraphy,sedimentary microfacies and reservoir properties,to has a deeper understanding of the sedimentary microfacies and the distribution of sand bodies in the Putaohua oil formation in Gulongbei areas,a comprehensive study of reservoir understanding,single factor deepening and multi cause combination,finally selected favorable exploration area.First of all,based on the principles of sequence stratigraphy,comprehensive core,logging curve and seismic reflection level,we have determined the top and bottom interfaces of Putaohua oil layer,and divided 3 upper sequence,middle and lower sequence group and 8 small layer interfaces.Secondly,using sandstone thickness,petrological analysis and heavy mineral analysis to identify two provenances and their control areas in the northeast and west of the area;using mudstone color,sedimentary structure,bedding and core phase analysis,it is determined that the grape flower oil layer belongs to the delta front sedimentary environment,and identifies 8 types of sedimentary microfacies,such as underwater distributary channel,inter channel,estuarine dam,mat shape sand,turbidite sand and front edge mud,and determine that microfacies are mainly underwater distributary river channel,channel control sand body distribution,and the sand body is not large area,its section is lenticular and plane is striped,the vertical main channel and the branch channel interweave and overlap;by analyzing the distribution characteristics of sand bodies,the thickness of microfacies and the oil-bearing property,the oil-bearing dominant reservoirs and microfacies are determined.Thirdly,through the analysis of core cast thin film and scanning electron microscope data,the reservoir pore and throat type are determined;By analyzing the plane distribution characteristics of the grapevine oil layer and its small layers,and combining the total thickness of the oil sand and the number of layers,pore structure,porosity and permeability,and the coefficient of drilling,the relationship between the porosity and permeability of the reservoir and the oil-bearing property of the microfacies and the physical property of the reservoir is determined.Finally,comprehensive structure,microphase and physical property are used to determine the control factors of regional reservoir formation and local reservoir formation,and the optimization criteria for favorable blocks are established,and a number of favorable development blocks are selected.