A Single-phase Fluid Flow Pattern in a Kind of Fractured-vuggy Media

Abstract

The oil reserves of a fractured-vuggy carbonate reservoir are abundant. It is important to study the flow pattern in fractured-vuggy media for developing fractured-vuggy carbonate reservoirs. In this article, the curves of velocity vs. pressure gradient under different vug density have been drawn by completing the experiment of single-phase fluid flow. Using experimental data, the critical velocity at which the linear flow period changes to a non-linear flow period has been calculated by researching the relationship of the Reynolds number and the resistance coefficient. Based on the Darcy formula and the Forchheimer formula, the expressions of permeability and coefficients of the Forchheimer formula, which are function of vug density, have been calculated by fitting experimental data. A single-phase fluid flow pattern in fractured-vuggy media with different vug density has been built. Conclusions are as follows: With an increase of vug density, the pressure gradient at the same velocity decreases and the critical velocity increases. The flow pattern can be described by the Darcy formula when the velocity is smaller than the critical velocity and by the Forchheimer formula when the velocity is bigger than the critical velocity.