| With the increasing demand of natural gas in the Yangtze River delta, the existing Jin Tan gas storage cannot meet the emergency and season peak-shaving supply of natural gas, so Liu Zhuang gas storage is built. Gas is injected in the new gas storage since September2001. Based on the geologic feature and production history of Liu Zhuang gas storage, numerical simulation was conducted in this article, hence the reasonable injection-production volume and period gas injection scheme were proposed. Main research achievements are as follows:(1) The sealing ability of cap rock was analyzed from microcosmic and macroscopic based on the systematic literature review and the combination of reservoir physical property and structural trap characteristics. In addition, the sealing ability of fault was researched by quantitative and qualitative analysis.(2) The production history overview of Liu-Zhuang oil-gas field was introduced and the gas storage reserves was calculated by the combination of dynamic and static method according to the production performance data. Then, based on the huge literature review, development situation of Liu-Zhuang reservoir, the bound of operating pressure was verified. Hence, the work gas and cushion gas volume with different pressure range were obtained. Besides, the dynamic pressures of10injection-production wells in north and south broken dish were analyzed, especially for the pressure sensitive phase in the ending of gas injection, and the expansion ability of wave and oil ring was calculated.(3) According to the nodal analysis, the downhole was selected as nodes to divide the system into two parts-inlet flow and outlet flow. With the established node model of vertical conduit inlet flow and outlet flow of stratal filtrate, the curves of dynamic characteristic were drawn, then the reasonable injection-production volume was put forward.(4) Numerical simulation model of Liu-Zhuang gas storage was established by three dimensional three-phase black oil model in Eclipse, and the history of production well and injection well was matched accurately. With the variation analysis of gas saturation before and after gas cap injection, the methodology and steps were proposed to avoid the gas fingering. Furthermore, the influence of physical property such as permeability and porosity on the multicycle injection and production with the combination of theoretical and actual models was analyzed.(5) The formation capacity and tectonic position of9injection-production wells was studied, which provided the information to determine the ratio of single well injection (production) volume to total injection (production) volume. Then the optimum allocation of injection (production) was selected by numerical simulation as well as the nodal analysis results. Finally, the operation scheme of multicycle injection and production was proposed and the production dynamic of water and gas was analyzed. |
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