| Shahejie Formation is an important production layer in Gudong oilfield. It has been exploited beyond 10 years, and needs to be descript finely. Based on the front line of subject and the problem that should be dissolved the thought of study is put forward, that is building geology model and dynamic analysis to found simulation model, then the distribution of remaining oil is pointed through geology analysis and simulation. This paper emphasizes the combination between the static state and dynamic state, and the combination between reservoir description and simulation.Through the study on the tectonics, sedimentation, reservoir bed and fluid model, the static geology model is constituted. Based on the forecast method of production, the reserves, recovery ratios and energy status are analyzed. Three dimensional geology model and simulation model are building with Petroleum Workbench. This paper stresses the validation of the geological model and providing accurate distribution of remaining oil. The new simulation thought is brought forward in building model and history matching times.Following conclusions are gained through the study on geology status, dynamics, simulation and distribution of remaining oil.(1) Palaeogene system developed on burial hill and had been crossed by many faults. Thus it has many beds and looks like an anticline. The second fault, Gudong fault crossed the formation from north to south. East part ascended, and west part descended. East part had been divided into 5 blocks by some third faults. Also west part had been divided into 4 blocks. The second, third and four stage faults in the block have good sealing. Based on micro tectonics study, it has been proved that the distribution of remaining oil exist in several heaves, such as little oil block with high focus, small convex, and little heave of nose formation.(2) Shahejie Formation in Gudong oilfield had been contrasted. It has 6 sand, or 22 sediment timing cells. Delta had been developed on east of Gudong oilfield, and lake system on west. Sandbody of micro sedimentary facies in bock have been determined.(3) On the basis of well, drilling core and test data, second well interpretation model of physical property of reservoir bed had been built. The standard plate of reservoir bed and net thickness had been set down. In the practice, the model and standard plate had been proved effect.(4 )Property of reservoir bed indicates that oil mostly exists in biolithe, coarse and fine sandstone and most pore is primary pore. The heterogeneity shows that oil is controlled by microfacies and faults in the plane, and barriers exist between the sandbody of adjacent timing cell in the vertical. The structure of Shahejie Formation reservoir displays faulted and stratiform. Reservoir of 7-block is divided into four hydraulic unit (E, G, F, P) on the basis of well data and drilling core.(5) From the depression to Gudong burial hill, the property of crude oil becomes bad (density and viscosity increases) and total salinity of oil-field water decreases. This indicates close fluid system changes to half-close. With the depth increases, the property of crude oil becomes bad and total salinity of oil-field water increases. The property of fluid changes little with time.(6) The calculation results indicates that the geological reserves is 1496× 104t, which is less 464 X I04t than the reserves calculated on 1987, but exceeds 150×104t than the reserves calculated on 1994. Because building model in detail and restudy of the parameter, the result is more truthfulness.(7) The calculation method of reserves and recovery ratio for Shahejie formation reservoir has been selected. The recovery reserves of waterflooding is 747.2478× 104t the geological reserves is 1337.022 X 104t. The result of energy analysis in typification reservoir indicates that the effective water body is 68 times; the recovery ration of natural water drive is 31%; the pressure will drop in the condition that the production rate is 1544260m3/a and the injection-produc...
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