This paper presents a simplified mathematical model for describing the water block mechanism and its influences, based on Darcy's formula and relative permeability curve and capillary pressure curve.

Based on the Darcy's law of the infiltration of ground-water, this paper has deduced the theoretical formula for the inclined shaft water-make calculation in the different aquifer.

In oil and water phases, fluid percolation obeys Darcy's law. According to this, the formula for calculating producing pressure differences of the interwell fluid units could be established.