Numerical Simulation Of Co_2 Subgrade Of Oxygen - Type Overally Gas Storage

Underground gas storage can be optimized gas supply system to ensure that the supply is stable and reliable, the accident emergency reserve, etc., the world’s oil supply tension, oil prices volatile international background, the underground gas storage has the more important significance. The construction of underground gas storage, the biggest initial investment is to maintain reservoir volume, pressure, prevent water intrusion cushion gas. Cushion gas storage volume accounts for30%～70%of total volume of gas storage,1/3to2/3of total investment, when a waste gas storage, a considerable amount of cushion gas can’t be out of the ground, this will lead to a lot of "dead money" deposits. So with cheap carbon dioxide instead of the more commonly used gas as cushion gas of gas storage, can save a lot of the initial investment. Because of the special properties of CO2and cushion gas as gas storage ideal gas, will greatly reduce the cost of building warehouse, saving a lot of money, and realize effective geological storage of carbon, and for the development of national economy and national energy security to make greater contributions.This article make aquifer underground gas storage on carbon dioxide cushion gas seepage are studied, the spread of the underground gas storage in China in the future with a carbon dioxide gas cushion layer reservoir construction and operation and so on provides the theoretical basis, has important practical value. The main results are as follows:(1) Outlines the domestic and foreign research development status quo of aquifer underground gas storage, this paper discusses the CO2as the cushion gas.(2) The comprehensive literature at home and abroad, according to the operation mechanism of gas storage, combined with the two phase flow theory, set up to describe the mathematical model of aquifer underground gas storage operation, namely the CO2and gas diffusion percolation model.(3) The gas-water two-phase flow of slightly compressible fluid seepage equation is decomposed into the pressure equation and the saturation equation, the simultaneous equation of gas concentration, the two-dimensional plane flow is only considered to find the solution by finite element method.(4) Write the numerical simulation to solve the model, set up a perfect solving program, the calculated results visualization. With single well numerical simulation gas storage operation, can get different moment of reservoir pressure, water saturation and concentration of carbon dioxide and gas distribution, on the basis of the analysis of the process of injection-production dynamic change of the important factors.