Study On Reservoir Distribution Of Shahejie Formation Of Paleogene System In Gudao Area

Paleogene formation in Gudao area is an important target stratum for new proved reserves in old oil area,while the exploration degree has been relatively low.Due to the unclear understanding of the distribution of formation and the corresponding reservoirs,there is a lack of systematic understanding of the distribution of oil and gas to,which hugely restricts the next step of rolling development.Therefore,the sequence stratigraphy and reservoir distribution of Gudao area are studied in this paper.Starting from the sedimentary genesis,the genetic types,characteristics and distribution of reservoirs are ascertained.Combined with the present situation of oil and gas distribution,the distribution of favorable areas is pointed out.The following results are achieved:(1)The Paleogene sequence stratigraphic framework of Gudao area is established,which shows that the sequence patterns of east slope and west slope are different.The former was gentle,with the strata gently overlying on the uplift.The latter was relatively variable and convergent to the uplift.(2)Different tectonic settings and sequence stratigraphic patterns are proposed,which control the development of different sedimentary sandbodies.The eastern slope is a slope-type gentle slope zone,and braided river delta deposition are mostly developed from Es3 to Es2,the shallow lake deposition is mainly developed in Es1.The west slope is slope-break gentle slope zone.From the Es3 to Es1,the LST fan deltas with gravity flow characteristics,TST and HST braided river delta,carbonate beach bar are developed respectively.(3)Combined with the prediction results of seismic properties,the distribution of sedimentary facies and the evolution law of sedimentary environment on the east slope and the west slope were analyzed,and the vertical and horizontal distribution characteristics of the reservoir were revealed,and the distribution range of sandstone on the west slope is wider than that on the east slope.(4)Combined with reservoir rock types and physical characteristics,four favorable reservoir development areas on the east and west slopes are predicted.