Reservoir Characteristics And Oil Accumulation Factors Research Of Chang6-chang9 In Zhifangbei-shunning Oildom

Zhifangbei-Shunning area where has a low structure is as some nose-shaped uplifts on north-west dip monocline.The Chang 6 ~Chang 9 oil-bearing formation of Yanchang Formation belongs to the tight reservoir with low porosity and low permeability.Both in longitudinal and flat,Reservoir feature and the relationship with oil Reservoir is very complex.with core datas?mud logging datas?logging datas,analysis datas of Reservoir feature of Zhifanggoubei-Shunning oildom chang 6~chang 9 formation and control of oil and gas are found It is considered that the sandstone lithology of Reservoir feature is mainly feldspar sandstone and the filling in sandstone reservoir is clay heterobase andCarbonate cementatio,The research finds that Main pore types of chang 6~chang9 reservoir is residual intergranular pore and corrosion pore.which the pore structure is complex.The pore throat combination in sandstone is mainly small hole and.micro throat.Using the technology of micro CT and nuclear magnetic resonance,It is considered that the pore diameter of 10 ?m or more is the largest contribution to porosity and The larger the proportion of pore diameter above 100 m,the greater the pore connectivity.The main pore diameter is less than 100 nm in the study area,the higher the porosity of the pore throat above 100 nm,the better the physical condition of the reservoir and the greater the saturation of mobile fluid.The heterogeneity of chang 6~chang 9 reservoir in the study area is relatively strong.Large scale underwater distributary channel sand bodies in the study area provide favorable conditions for high quality reservoirs.There is also a great correlation between reservoir distribution and porosity and permeability.The Property of Oily good is better than that of poor oil The relationship between diagenesis and oil-bearing property of the reservoir shows that the better the dissolution,the better the oiliness.The stronger the reservoir heterogeneity,the worse the Oiliness.