Abstract
Improved matrix-fracture interface fluid transfer functions for naturally fractured reservoirs are formulated and the associated parameters are determined by experimental data. Hindered-fluid transfer across the matrix-fracture interface due to skin effect is considered. Applications for single phase oil or gas production by pressure depression and oil production by immiscible displacement are accomplished by means of dimensionless phenomenological equations. Analytical solutions are derived for special boundary conditions involving the typical laboratory tests and reservoir simulation to represent the various matrix block shapes. The present analytical solutions involve the skin effect, anisotropic porous matrix, properly scaled variables, and full-time solutions and asymptotic solutions for early- and late-time periods. These solutions are obtained after proper linearization of the porous matrix fluid transfer model for one-, two-, and three-dimensional Cartesian matrix blocks, circular-cylinder and annular shaped matrix blocks, and spherical matrix blocks. The characteristic parameters of the transfer functions, namely the diffusion coefficient, skin coefficient, and skin thickness, are determined by conforming special analytical solutions to experimental data involving fluid exchange between matrix and fracture by imbibition.
