关键词: 凝析气井, 油气两相流, 产能方程, 非达西流, 拟压力积分, 凝析油堵塞

Abstract: The main purpose of this work is to derive an analytic formula describing pseudo-steady state flow of gas-condensate under reservoir condition and consider correctly the effect of condensate on well deliverability.Liquid dropout naturally occurs with reservoir depletion below the dewpoint,which differs from dry gas. It is unresolved to account for the effect of condensate on deliverability.Condensate is generally viewed as an immobile phase so that the dry gas flow equation is frequently used to analyze gas condensate well productivity and testing.An accurate evaluation of well productivity and testing is extremely important for the planning and development of gas condensate reservoir.Therefore,there is the strong need to develop a new and rigorous equation to express more closely the gas-condensate flow in porous media.In this paper,the foregoing problem is expected to be resolved.On the basis of the detailed description of flow performance of gas condensate,a definite solution problem of gas condensate two phase flow is formulated. Subsequently the corresponding analytic formula is derived under pseudo steady state.The detailed solution procedures are described.Then a more representative and rigorous overall deliverability equation desired is obtained through introduction of non-Darcy flow.Additionally,the calculation methods of the parameters (two phase pseudopressure integral and two phase non-Daccy flow factor D) involved in the equation and the calculating example are discussed briefly.The calculated results show that the binomial equation used in the dry gas condition is unsuitable for modelling deliverability of gas condensate well due to its overpredictions.

Key words: gas condensate well, two-phase flow, deliverability equation, non-Darcy flow, pseudo-pressure integral, condensate blockage