Research on Transient Flow Regulation With the Effect of Quadratic Pressure Gradient

Abstract

During the course of reservoir engineering calculations and derivation of fluid equations, the nonlinear term of fluid state equation are often ignored under the assume of slightly compressible fluid. But this would cause great error in the long-lasting well testing and then it would lead to the incorrect understanding to the actual reservoir. The authors studied the transient seepage flow regulation with the effect of quadratic pressure gradient, induced the seepage equation by remaining the quadratic pressure gradient, meanwhile considering the well bore storage and the effect of skin factor, obtained Laplace space analytic solution with dimensionlessness and Laplace transformation, and then the type curves were established by use of numerical inversion. At last, relative error curves intuitively show that the quadratic pressure gradient and skin factor are of great impact to transient flow regulation and great errors would occur if they were ignored. In conclusion, the quadratic pressure gradient and skin factor must be taken into consideration in both transient flow and well-testing analysis.