Abstract: After nearly 40 years of exploration and development,the production of He-43 block in Xianhezhuang oilfield declined year by year.To enhance oil recovery,the fine reservoir description of first and second member of Shahejie formation has been carried out and its reservoir geological model has been established.Through tectonic characteristics analysis,a number of small faults have been newly found which plays an important role in analyzing residual oil reservoir potential.After detailed analysis of the fault and sand body in the process of hydrocarbon accumulation and the effect of sedimentary facie on reservoir thickness,the main controlling factors of reservoir formation in this area has been determined,namely faults and sedimentary facie.Through the reservoir controlling factors analysis,new reservoir understandings have been formed.Through sedimentary facie and distribution characteristics analysis,the hydrocarbon distribution characteristics of this area have been determined.Therefore,the above mentioned research results are of great significance for He-43 block river potentialities and stable yield.