Research Of Pressure Sensitive Dual Porosity Fractal Reservoir Model Built With Fractal Theory

The fractal theory is a favorable and effective tool which for dealing with those assumed mass scales and with less-connectivity, even with exceedingly straggling distribution. Considerable theories and experimental study indicated that mass phenomenons in fluid flow through porous medium of reservoir has invariability scale, such as permeability distribution, porosity distribution and fracture network distribution in fracture reservoir, and so on. Based on the fractal theory, the fractal reservoir model has been widely studied and applicated.The permeability and porosity of pressure sensitive dual porosity reservoir are not only sensible function of pressure, but also present fractal character. Applicated the fractal theory on the pressure sensitive dual porosity reservoirs, build-up the non-linear flow models and explore the numerical resolution are very important to describe its' infiltrating distinction much more reasonable and develop the flow theory.This report combined fractal theory, fluid mechanics theory, reservoir engineering method and numerical simulation, and based on the dual porosity reservoir model presented by Warren-Root and the fractal flow model presented by Chang.J. and Yortsos.Y.C. By describing the fractal feature with parameter D_f andθ, quantification vary permeability with coefficient factor of compressibility of permeability, a new model of generalized radial flow in dual porosity fractal reservoir was built. Considering effect of wellbore storage, skin effect, apparent wellbore radius and the definite conditions of initial and boundary problem, six cases as finite reservoirs with constant pressure or sealed boundary and infinite reservoirs under production methods of constant rate or constantwellbore pressure obtained.By using these models, the dependency of pressure behavior on each parameter was analyzed and discussed in depth, and instruction was achieved. The conclusion of this paper can give definite direction and reference to development the pressure sensitive dual porosity reservoirs, and also has definite practicability on detecting and field application of well test analysis on hydraulic fracturing and reservoir development behavior.