Research On Reservoir Architecture Of Delta-front

Most of the Es₂⁷-Es₂⁸ in Liang 60 fault block is a delta front deposit.It was in the development period that water accounted for a high proportion of rock pore.So,It is an important part of the research to describe reservoir characteristics finely and search for remaining oil distribution area.Reservoir architecture is an effective method to depict the internal structure of reservoir and predict remaining oil distribution area.Therefore,It is of great significance to research reservoir architecture of the Es₂⁷-Es₂⁸in Liang 60 fault block.In this paper,the core,logs,analysis and test data are used to research reservoir architecture of delta front deposit.Firstly,based on the theory of high-resolution sequence stratigraphy,It was established of isochronous stratigraphic framework of the target segment.Within isochronous stratigraphic framework,theory of sedimentary petrology was used to research sedimentary microfacies.The method was used to research reservoir architecture of vertical period,lateral boundary and plane fitting.Finally,It was established in the Es₂⁷-Es₂⁸ in the Liang 60 fault block of structure model,reservoir architecture model,intercalation model and petrophysical model.According to the study,the Es₂⁷-Es₂⁸ in Liang 60 fault block was divided into 2 middle-term base-level cycles and 5 short-term base-level cycles.Source of research area mainly came from Northeast direction.Research area mainly fell on 6 microfacies:underwater distributary channel,underwater natural dike,estuary bar,sheet sand,distal bar,interdistributary.estuary bar are characterized by a large thickness and a continuous distribution of the sand body.Reservoir of the Es₂⁷-Es₂⁸ in the Liang 60 fault block was divided into 19 periods of forth level reservoir architectural unit and 70 periods of third level reservoir architectural unit.The boundary marks of single estuary bar were identified that included elevation difference,mud between sand,thickness difference between sand bodies,characteristic of“thick-thin-thick”,and filling modes of inner accretion layering of estuary bar included progradation along the source direction and lateral accretion.Negative cycle is a feature of forth level reservoir architectural unit.Single estuary bars are lobe and wide ribbon on the plane.It was divided into 3 vertical modes of separation,superimposition and cutting,and included 3 planar types of separation,lapping and cutting.Quantitative characteristics of reservoir was analysed in key architecture units,including Sandstone thickness,ratio of thickness to width,occurrence and physical properties.Finally,fine 3D geological models were established.