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.