Characteristics And Simulations Of Porous Media In The Low Permeable Reservoir

Structure of porous media and multi-scale simulation of porous flow in less permeable reservoir are studied by flow mechanics in porous media, fractal geometry, percolation and renormalization group theory. Distribution of fingering and residual oil is comprehensively analyzed by experiment and computer simulation. Furthermore, a modified classical model to simulate multi-phase flow is presented. In general, this paper has carried out research as the following: Taking use of the principal theory and law of fractal geometry with the pore structural characteristics of the real reservoir sandstone, the stochastic fractal network models of spatial distribution of pores, the fractal distribution of pore radius and throat size as well as relevant frequency models are constructed actually. Through the test cores cast data, we can determine the range [ ] of coordinate number of pore throat, and by the usage of the coordinate number produced stochastically, paint the network with zone radius R by computer language, then, construct the fractal model of structure of porous media in less permeable reservoir, thus, resolve the uncertainty problems with the network simulation coordinate number and gain the fraction dimension of fractal network. Capillary pressure data are introduced to verify the above model and to determine the fractal dimension of throat size distribution, through getting a line with in double-log coordinate system. And the reverse of its slope is the fractal dimension Ds. The meaning of characteristic curve of real reservoir rock and the relation of multi-fractal characteristics of throat size and lithology are discussed. The flow mechanics in porous media, fractal geometry, percolation and renormalization group theory are comprehensively taken advantage to construct the fractal flow distribution model in less permeable reservoir. Moreover, Borland C language is used to encode the programs to calculate and match out the pressure curves in formation, displacement characteristic curves and build up the seeping field about macroscopical fractal network, to gain the saturation distribution with the residual oil. Then, comparing with the results calculated by classical seeping model, the exactness of fractal network models are verified exactly in the end.