深层气藏储层具有较明显的压力敏感性,岩石渗透率随有效应力的增大而降低,这将对气井的产能产生较大影响。在气藏开发过程中,由于边底水的侵入和凝析水在井底的聚集出现气、水两相渗流,增大了气相的流动阻力,也会降低气藏的产能。因此,在气、水同产两相渗流规律的基础上考虑储层敏感性效应的影响,通过建立广义拟压力函数定量描述压敏储层条件下气、水两相渗流过程,采用数值积分计算任意压力下对应的拟压力值,确定深层压敏气藏产水气井的流入动态方程,并结合实例分析了储层渗透率压力敏感程度和水、气比对气藏产能的影响。结果表明,该模型合理可靠,可以用于深层压敏气藏产水气井产能的预测。
Deep gas reservoir has pronounced pressure sensitivity where rock permeability decreases with the increase of effective stress, causing low productivity of gas wells. In the development process of gas reservoirs, twophase flow of gas and water exist due to intrusion of bottom and edge water and accumulation of condensate water in the bottom hole, which increases resistance to gas flow and reduces productivity of gas reservoir. Considering the sensitivity effect of reservoir on the basis of the gas water two-phase flow law, through establishment of generalized pseudo-pressure function1 gas and water two-phase flow process in the pressure-sensitive reservoir conditions, is quantitatively described in this paper. Corresponding pseudopressure value under any pressure is calculated by using numerical integration method to determine inflow performance equation of gas-water well in deep pressure-sensitive gas reservoir, combined with case analysis of the impact of pressure-sensitive degree of reservoir and ratio of permeability and water on productivity of gas reservoir. Results show that this model is reasonable and reliable, and it can be used for production forecasts of water-gas well in deep pressure-sensitive gas reservoir.