考虑相变的凝析气井产能方程

凝析气井生产过程中,出现反凝析后储层表现为油气多相渗流特征,单相气井的产能方程已不适应凝析气井。在凝析气藏稳态理论基础上,建立了考虑相态变化的凝析气井多相流产能方程,在产能方程中引入油气两相拟压力函数,并可以计算凝析气藏中压力剖面,从而计算随压力分布的合理储层参数。结果表明,随地层压力的不断降低,由于凝析油的析出,降低了气相渗透率。考虑相变的凝析气井产能方程的计算结果小于单相气井的产能方程,并且差值不断增大。

Deliverability equation study of gas condensate well considering phase change

During the production of condensate gas well,the formation is characterized with oil-gas multiphase seepage after retrograding,where deliverability equation for dry gas well isn't adapted to condensate gas well.On the basis of stable state theory of condensate gas reservoir,multiphase flow deliverability equation of gas condensate well was developed which gave consideration to phase change.The new equation made use of oil and gas two-phase pseudo pressure function and pressure orthography was calculated,so the distribution of the reasonable reservoir parameter along pressure grad could be calculated.The research shows that the productivity resulted from multiphase flow deliverability equation of gas condensate well is less than that from deliverability equation for dry gas well because formation pressure gradually depressing results in retrogradation,which reduces gas relative permeability.The difference of the two equations increases with pressure depression.