Abstract: With wellbore after-flow and skin effect taken into con-sideration, an effective well radius mathematical model is pro-posed for unsteady flow of fluids in fractal reservoirs. Nonlinear fractal geometric theory is applied to the dynamics of flow in the model. Features of the fractal reservoir are described with tow
fractal parameters (df,θ), where df describes the geometric fea-tures andθdepicts the connectivity of the fractal network of the reservoir. Laplace transform is used to obtain the analytical so-lutions and long-time/short-time asymptotic solutions of the model. And analyses are made on the character and effects of pressure behavior and the parameters.

Key words: fractal reservoir, mathematical model, ana-lytical solution, pressure behavior