formula under the condition of planar one-dimensional and radial steady state percolation which obey Darcy's law. The percolation of gas obeying the binomial theorem, multi-point steady state well testing and the determination of the absolute open flow potential of gas well (3)Unsteady state percolation of gas, the basic assumptions and mathematical models, The pressure distribution formula of constant rate gas well in infinite formation, and pseudo-steady state percolation of a gas well when producing in limited formation and the application of binomial law in unsteady state percolation of gas Teaching focuses The basic differential equation of gas percolation, the concept and calculation of pseudo pressure and pseudo-time. Steady state percolation of gas. The distribution formula of pseudo- pressure and the production formula under the condition of planar one-dimensional and radial steady state percolation which obey Darcy's law. The percolation of gas obeying the binomial theorem, multi-point steady state well testing and the determination of the absolute open flow potential of gas well. Unsteady state percolation of gas, the basic assumptions and mathematical model Teaching difficulti The basic differential equation of gas percolation, the concept and calculation of pseudo- pressure and pseudo-time Chapter 6 Foundation of water/oil displacement theory The basic contents and requirements (1) Piston like displacement of oil by water. the theory of planar one-dimensional and radial piston like displacement of oil by water, and the shrinkage of oil edge (2)Theoretical foundation of non-piston like displacement of oil by water, Basic assumptions and mathematical models. The differential equation of saturation distribution of planar one- dimensional and radial non-piston like displacement of oil by water. Saturation distribution formula is obtained using the method of characteristics, and the determining method of front and average saturation Changes of the flow resistance and production in the process of displacement of oil by water Teaching focuses: The theory of planar one-dimensional and radial piston like displacement of oil by water. The differential equation of saturation distribution of planar one-dimensional and radial non-piston like displacement of oil by water. Saturation distribution formula is obtained using the method of characteristics eaching difficulties The theory of planar one-dimensional and radial piston like displacement of oil by water. The displacement of oil by water. Saturation distribution formula is obtained using the method or like differential equation of saturation distribution of planar one-dimensional and radial non-piston like characteristics Chapter 7 Percolation theory of oil-gas two phases(dissolved gas drive) The basic contents and requirements (1) The continuity equation and the basic differential equation of oil-gas two-phase percolation (2)Oil-gas two-phase steady state percolation. The concept and calculation of the production gas- il ratio and the pressure function, and the production formula of oil-gas two-phase steady state (3)Unsteady state percolation of gassy fluid. Method of alternation of steady state. The calculation and prediction of average oil saturation, the production gas-oil ratio and oil pre Teaching focuses The continuity equation and the basic differential equation of oil-gas two-phase percolation Oil-gas two-phase steady state percolation. The concept and calculation of the production gas-oil percolation. Unsteady state percolation of gassy fluld ula of oil-gas two-phase steady state ratio and the pressure function, and the production for Teaching difficulties The continuity equation and the basic differential equation of oil-gas two-phase percol The calculation and prediction of average oil saturation, the production gas-oil ratio and oil