Research And Application Of Fluid Flow Through Anisotropic Porous Media

Anisotropy is generally formed as result of orientation of asymmetric grains making upthe solid matrix of porous media and naturally fracture in porous media,Water injected maycause fingering and impact on recovery if anisotropy is not taken into account when planningwell pattern. Consequently, it is quite important to research on the theory of recognizing therelated anisotropic parameters and analyzing performance of reservoir. For this reason, thispaper completely study on theory of flowing through anisotropic media, as well as applicationduring field development.First of all, this paper derives pressure expressions of stable state about vertical well inanisotropic media with various boundary. Based on this, Formulae of pressure distributionfor five-spot pattern and nine-spot pattern have been established, the characters of isobariccontours and streamline are analyzed, and this equips optimum of well pattern with theoreticfoundation.Second, transient flow for vertical well and fractural well in porous media with arealanisotropy has been researched in this paper. The analytic solution for vertical well andsemi-analytic solution for vertical fractural well is developed by using image inversion,superposition principle, Laplace transformation, Fourier transformation, as well as theirinverse transforms, and storage and skin are taken into account. For vertical fractural well,influence of pressure and productivity is studied when the orientation of artificial fractureisn't in accordance with the direction of major permeability, it is fundamental to evaluatepotential and analyze well test data.For porous media with vertical anisotropy, this paper solves finite well-bore radiussolution based on point source (sink) solution, and this method is expanded to verticalfractural well with various boundary by using superposition principle. The feature of typicalcurves and related factors are investigated, and asymptotic expressions are made to interpretwell test data for various flow period during well test analysis.At last, this paper illustrates the identification of major permeability direction and relatedparameters of anisotropic medium, and the theory of dynamic analysis and optimization ofwell pattern are investigate by drawing support from stream tube model and spirit of vectorwell pattern. The numerical simulation must be used for complicate anisotropy.This paper not only improves the method of determining anisotropic parameters anddirection of major permeability, which are necessary for reservoir description and numericalsimulation, but also provides theory of dynamic analysis and optimization of well pattern, andthese are foundation to develop anisotropic reservoir reasonably and economically.