一种碳酸盐岩凝析气藏储量的计算方法

碳酸盐岩凝析气藏地层压力下降到露点压力以下时,凝析油在地层及井筒内析出,井口产气量、产油量与井底产气量、产油量之间存在差异,导致储量计算存在困难。通过经验公式拟合得到露点压力,当地层压力大于露点压力时,将井口产油折成气,按单相气求取凝析气储量,再通过气油比折算凝析油储量和干气储量;当地层压力小于露点压力时,地层出现多相流,分别计算干气储量和凝析油储量;实例对比分析表明,该方法的计算结果准确可靠。

A method for calculating reserves of carbonate rock condensate gas reservoir

When the formation pressure of carbonate condensate gas reservoir drops below the dew point pressure,the condensate oil will be precipitated in formation and the wellbore,and then there will be the difference between the oil and gas production at the wellhead and downhole,which brings the difficulty for reserve calculation.Through empirical formula fitting,the dew point pressure can be obtained.When the formation pressure is greater than the dew point pressure,the wellhead oil will be folded into the gas,and the condensate gas reserve can be obtained by single-phase gas.Through oil-gas ratio,the condensate oil and dry gas reserves can be calculated.When the formation pressure is less than the dew point pressure,multiple flows will occur in the formation and then the dry gas and condensate oil reserves can be separately calculated.Through application results comparison,the calculation results with this method is accurate and reliable.