在凝析气藏的开发过程中,当井底流压降到露点后近井带发生反凝析,形成的凝析油聚集区会降低凝析气井的产能。目前的凝析气藏产能方程通常采用产量修正后的干气藏产能方程或采用带有凝析气藏拟压力函数的产能方程。其中,干气藏产能方程未考虑凝析油聚集对凝析气渗流的影响,得出的凝析气井产能方程误差较大;凝析气藏拟压力函数方法求取拟压力函数过程复杂,实际应用不广泛。为此,统计得出了凝析气相对渗透率与压力的关系,简化了凝析气藏拟压力函数,最终得出凝析气井产能预测新方法。实例应用表明,所提出的凝析气井产能方程预测产量更符合实际,对现场合理配产提供了依据。
In the development of condensate gas reservoir, retrograde condensation happens in near borehole area when bottom hole flow pressure drops to dew point, and the resulted condensation accumulation zone would reduce the productivity of condensate wells. Current condensate reservoir productivity equation commonly applies dry reser- voir productivity equation with productivity modification or productivity equation with condensate reservoir pseudo- pressure function. The former fails to consider the impact of condensate accumulation on condensate seepage, so the derived productivity equation for condensategas well has relatively big error; and the latter is not widely applied due to the complicated derivation of pseudo-pressure function. Phase relation between the relative permeability of condensate and pressure is obtained through statistic, pseudo-pressure function of condensate reservoir is simplified, and a new productivity prediction method for condensate gas well is developed. It has been proved in practice that the productivity equation prediction for condensate gas well conforms to reality, and can provide criteria for rational production allocation in the field.