油气藏流体-CO2体系相行为的实验测定与计算

利用高压相平衡实验装置 ,对某油田F6 6A井和F30井的原油在油藏温度下注入不同量的CO2 (注入CO2 与油藏流体的摩尔比为 0～ 2 .0 0 )时的PVT关系进行了测定 ,共取得PVT数据点 16 5个 ,泡点压力点和体积系数点各 11个。实验结果表明 ,由于原始油样的组分结构和组成不同 ,其注气体系相行为有较大的不同。F6 6A井油藏原油的饱和 (泡点 )压力随着CO2 注入量的增加近似呈线性增加 ,而F30井的饱和压力和CO2 注入量之间呈二次曲线关系 ,上升速度比F6 6A井缓慢 ,注气体系的体积系数的增加速度与CO2 注入量近似呈直线关系。对油藏流体中各组分进行适当组合合并为假组分后 ,用PR和SRK状态方程对所测注CO2 原油体系的相行为进行了预测。结果表明 ,PR状态方程的预测精度优于SRK方程 ,但两者均不能用于计算高CO2 注入量时油藏流体的相行为

EXPERIMENTAL STUDY ON THE PHASE BEHAVIOR OF RESERVOIR FLUID-CO2 SYSTEM

Using a high pressure PVT apparatus, the phase behaviors of reservoir fluid from wells of F66A and F30 with different injection content of CO 2 have been measured at the reservoir temperature. The results of 165 data of PVT, 11 data of bubbling pressure and 9 data of volume coefficient have been gotten. The experimental results show that the two kinds of oil samples have different phase behavior due to the different component and composition. For the F66A well fluid, the bubbling pressure is proportional linearly with the injection content of CO 2 , and it is quadric for F30 well fluid. The volume coefficients are also proportional linearly with the injection content of CO 2 for both samples, but the volume coefficient of fluid from F30 well is more than that of F66A fluid. The PR EOS and SRK EOS are used to predict the phase behavior of reservoir\|CO 2 system. The predictive accuracy of PR EOS is higher than that of SRK EOS for the two oil samples, but they are not suitable for predicting the phase behavior of reservoir fluids with high injection content of CO 2.