Abstract:

This paper has revised Forchheimer Equation by dividing the curve into two segments linearly,established mathematical models of unsteady and Non-Darcy high-speed flow through porous medium, double medium and triple medium in composite reservoirs,and gained their solutions and their corresponding long time asymptotic solutions. The unsteady Darcy flow and the Darcy flow in composite reservoirs through porous medium, double medium and triple medium are special cases of their own.

It is realized from long time asymptotic solutions that there are two steps at the pressure curve of triple medium，one step at the
pressure curVe of double medium，and no step at the curve of
pressure porous medium.The pressure curve will become T一shaped when the production of oil well is very- high.