The general formula and application for the elastic two-phase method with stable and variable rate of gas wells

Abstract

For the gas flow controlled by the closed boun&dary， after the completion of gas testing and shut-in to obtain the original formation pressure， the pressure draw down curves can be divided into three stages： unsteady state， transit state and pseudo-steady state. The pseudo-steady state is called elastic two-phase state， and the pressure within the well control range of the elastic two-phase state decreases at a constant velocity. This article established the general formulas for the stable rate and variable rate elastic two-phase method of gas wells， based on the stable rate elastic two-phase method represented by pressure first power， pressure square and pseudo pressure proposed by Chen Yuanqian， and the variable rate elastic two-phase method represented by pressure first power proposed by Blasingame. The practical application shows that the general formula provided in this paper are practical and effective.

Keywords

• gas well
• stable rate
• variable rate
• pseudo-pressure
• pressure one power
• pressure squared
• elastic two-phase method