Based on the core，seismic，logging and experiment data，the control factors of sedimentary environment were analyzed，and the numerical simulation of reservoir sedimentary process was carried out to quantitatively characterize the reservoir distribution and evolution at different stages. The study results show that the initial parameters of numerical simulation of carbonate reservoir sedimentary process have a great influence on the reservoir distribution，and main parameters include accommodating space change，carbonate productivity，etc. In the vertical direction of BU Oilfield，the MB21 Member of Mishirif Formation can be divided into 6 layers includingⅠ-Ⅵ. High-energy sedimentary belt and low-energy sedimentary belt appear alternately. The lithology of high-energy sedimentary belt is mainly grain limestone on the top of LayerⅠ，while the lithology of low-energy sedimentary belt is mainly micrite limestone with micro-fracture on the bottom of Layer Ⅵ. The research results provide the geologic basis for the water injection development scheme of bottom injection and top production in BU Oilfield. Four wells have been drilled to build up the formation pressure and to alleviate the local pressure deficit，and the daily production rate of the Oilfield has increased by nearly 19%，and increases to 0.94×104 m3/d.