一种预测超高压气藏压缩因子的新方法

天然气压缩因子的实验测定费用昂贵且耗时长，而应用经验关联式和状态方程求解又复杂且适用范围受限，计算精度和实用性难以确定。为此，根据Standing Katz天然气压缩因子图版，结合收集到的近1 000个实验数据点，采用最小二乘法拟合建立了高压天然气压缩因子的解析模型。与DPR、DAK、Brills、Ehsan等具有代表性的经验关联式和SRK状态方程的计算结果进行对比，所建模型计算得到的气藏压缩因子在高压及超高压条件下具有较高的精度，可满足工程计算的要求。

A new approach to predicting the compressibility factor of ultra high-pressure gas reservoirs

The experimental test for determining the compressibility factor of natural gas costs high and consumes a lot of time. Besides, it is complicated to achieve solutions with empirical correlation and state equations which are only applicable to a limited range, so this brings about great difficulties in ensuring the calculation accuracy and practicability. To this end, based on the Standing Katz deviation factor plate, the least squares fitting is used to establish an analytical model for high pressure natural gas compressibility factor with reference to almost 1000 acquired experimental data points. Compared with the calculated results of typical empirical correlations such as DPR, DAK, Brills, Ehsan, etc. and SRK state equations, the compressibility factors from this established model are of relatively high accuracy for reservoirs at high or ultra high pressure, which meets the requirement for engineering calculations.