The Research Of Sedimentary Facies And Reservoir Prediction In The First Member Of Dainan Formation In Huangjue Area Of Gaoyou Sag

The Huangjue area is the major oil exploration in Gaoyou sag.According to the exploration level of upper and middle formations are high in Huangjue oilfiled.The first member of Dainan formation are more faults,large depth of burial,poor physical property and thin monolayer thickness,so the output of generally conventional test oil is lower.Therefore,to research the sedimentary system and distribution regular of advantage sand body,and then to study the reservoir prediction and research the distribution of advantage reservoir.It can provide geological basis for the next phase of oil and gas exploration.grounding on stratigraphy of equence stratigraphy and theory of sedimentlogy,making full use of drilling,well logging,seismic explanation and selecting the typical section,the E₂d₁ section of Huangjue area are divided into two sand groups and eight sub layers by the logging stratigraphy,sedimentary cycle and closed cross-sections.On the based then the formation framework of the research area is established.The study of sedimentary environment of E2d1 is carried out through rock observation,log response,sizing analysis and the predecessors'research based on formation framework built.The results show that the dereliction fan delta is the major sedimentary system in Huangjue area.The fan-delta front is the main depositional body,and it may be subdivided into underwater distributary channel,sheet sand,mouth bar and flood plain.The reservoir is mainlv the sand-body of fan-delta front branch channel,and sand body was distributed bandedly and extended alongsource area.It has typical character of channel sand body.The variance of reservoir quality is obviously in underwater distributaries channels.Through analyzing the evolvement of sedimentary in every layer,it is found that the lake area is gradually enlarging,fan body size increases and upgrowth retrogradation and normal cycle of E₂d₁.Though the study of micro-features of reservoir,we can see that it is middle porosity and low permeability reservoirs.In terms of geologic mode of sandbody extending along channel in Huangjue area,combined with fine seisnic interpretation,combinning the well datas and seismic datas,predicting the distribution of by the method of wave impedance inversion.Based on sedimentary facies study and reservoir prediction,the favorable reservoir distribute is evaluated and analyzed.