Study On Reservoir Heterogeneity Of Chang6and Its Effects On The Distribution Of Oil Layers In Wujiawan Area Of Zizhou Oilfield

Chang6formaion is the main producing formation in Wujiawan area of Zizhou Oilfield,which has been entered a period of stabilized production.This paper discuss thestratigraphic classification and correlation, sedimentary facies, fundamental character ofreservoir, the heterogeneity of reservoir and it is controlling of reservoir, using drilling,well logging combined with analytical data from190wells of Wujiawan area of ZizhouOilfieldChang6reservoir of the study area is belonged to delta front sub-facies, and thedominant sedimentary microfacies are underwater distributary channel and mouth bar. Therock type is fine feldspar sandstone. Cementing materials include self-generation chlorite,laumonlite, calcite and authigenice quartz. Pore types of the reservoir include intergranulardissolved pore, intragranular dissolved pore and residual primary pore. The intergranulardissolved pore mainly refers to laumontite dissolved pore, which is the mainly accumulatespace of the hydrocarlxin.This paper analysis the system control of reservoir in reservoir heterogeneity, and theconclusions are as follows:(1) in microscopic scale, the reservoir sand of Zizhou oilifeldWujiawan area with intergranular pores is the main storage space; Under the impact ofdiagenesis heterogeneity, petroleum distributed mainly distributary channel facies.(2) Invetrical, rhythmicity of oil saturation is accordant with which of the porosity andpermeability, within all the beddings, the homogenous massive one is most favorable topetroleum accumulation; thick sandstone type in the sand-shale assemblage is good, andthe interbed served as barrier for fluid flow.(3) In plane, the petroleum distribution iscontrolled by the sedimentary facies, in which the relatively homogeneous distributarychannel is the most favorable facies for hydrocarbon accumulation.