Study On Design Carbonate Reservoir Gas Injection To Optimize Throughput

In view of the problems of high water cut and low production of oil wells in the late development of M area,the water and gas injection in the field has been carried out,and the remarkable results have been achieved.In view of the phenomenont of large differences in the different effect of gas injection,the dynamic static association analysis method and numerical simulation method are used to analyze gas injection well in order to determine the main controlling factors of gas injection effect.New understanding of fractured non-continuous medium is got and the scene well selection principle is summed up.Aiming at the main controlling factors of gas injection effect,5 typical models are designed to carry out the research on the optimization of injection production parameters based on the field geological model.The implementation of gas injection measures in the future field has important guiding significance.The main research and achieved four aspects of the results and understanding:The formation of fractured vuggy non-continuum deepen understanding based on gas injection effect: matrix development so that the reservoir in terms of energy can be divided into low edge water reservoir and strong edge water reservoir;near well bore fracture cave development is divided into bad,good,good,excellent,septal interlayer enable seam hole in the shaft direction development types under homogeneous,the upper part of the development of the lower development is poor and the upper part of the development of lower growth is good;matrix development will leads to very close distance seam cave are isolated from each other.Through the development of before and after gas injection wells of different types of viscosity,oil saturation,water gas saturation research,deepen summarized three mechanism of nitrogen injection: gravity displacement at the top of the remaining oil,dissolution of the viscosity,increase formation energy.Among them,oil bearing small and storage layer at the top of the closed the gas injection well gravity different mining attic oil mechanism dominated;production layer is thicker,dissolving,reduction in viscosity mechanism plays a role more;no bottom water reservoir gas injection empowerment effects is obvious.Determined from the well conditions,geology and dynamics of gas injection well selection principle: well condition well selection principle,wellhead and well bore with gas injection pressure requirements;geological well selection principle: reservoir is connected with bottom water;circumferential borehole exist unused reservoir;well week physical;vertical growth is relatively homogeneous,without a valid interlayer;wellbore direction to avoid water height;dynamic well selection principle: the production decline rate is slow;seismic profiles on the circumferential borehole exist,beaded structure;at the beginning of operation,high yield;gas injection before the water rising approximately linearly;in front of the gas injection had effective measures of precipitation.Establishment of five kinds of typical model,respectively for medium oil and gas injection rate,stuffy well time and liquid production rate of four kinds of injection production parameters of optimization and obtain the following understanding: The greater the energy of the water body,gas injection medium tend to CO2;different types of reservoir gas injection rate is larger,cycle oil increase effect is better,but from an economic point of view,optimal injection of different reservoir volume is different;different reservoir gas injection effect is not sensitive to stuffy time well;strong bottom water reservoir can be taken larger liquid production rate,no bottom water or weak bottom water reservoir with smaller fluid production rate of production.