Abstract: Effective well radius combined mathematical models are suggested for non-Newtonian power-law fluids with the low-velocity non-Darcy flow in the fractal reservoir.The formation models consist of internal regions and external regions.Porous medium flow in the fractal network of the internal regions obeys the low-velocity non-Darcy law of the non-Newtonian power-law fluids while the one in the external region obeys the Darcy law of the non-Newtonian power-law fluids.The initial and the three outer boundary conditions of infinite,finite with constant pressure and closed boundary are given according to the polymer flooding in a fractal reservior.Solutions of the well test models in Laplace space are obtained.The relationship between the dimensionless pressure and time is studied by using the Stehfest numerical inversion.The dynamic feature of the pressure and parameter effect are disscussed.This method can be used to predict formation permeability,skin factor and reservoir pressure of non-Newtonian fluids such as the polymer fluid flow and locate the polymer flooding frontier.

Key words: fractal reservoir, non-Newtonian power-law fluids, non-Darcy flow, combined mathematical model, dynamic feature of pressure