东海某气田天然气偏差系数实验及计算模型评价研究

为准确计算东海某高含CO₂气田天然气的偏差系数，进而提高气藏工程、采气工程和地面工程设计研究的可靠性，首先采用加拿大DBR-PVT仪进行192组高含CO₂天然气的偏差系数实验分析，然后采用ASPEN HYSYS软件中的BWRS、PR和SRK等12种状态方程进行对应的192组模拟计算，探讨偏差系数的主要影响因素，评价软件状态方程计算偏差系数的准确性。结果表明:实验范围内，压力和CO₂含量对偏差系数的影响较大，温度对偏差系数的影响较小，偏差系数随压力的增加先减小后增大；PR和Sour PR状态方程计算高含CO₂天然气的偏差系数精度最高，平均相对误差1.09%，最大相对误差5.74%。因此，当天然气CO₂含量较高时，建议采用PR和Sour PR状态方程计算偏差系数。

Study on Gas Deviation Factor Experiment and Calculation Model Evaluation of A Gas Field in East China Sea

In order to accurately calculate the deviation coefficient of natural gas in a high-CO₂ gas field in East China Sea, and further to improve the reliability of gas reservoir engineering, gas production engineering and surface engineering design, 192 groups of the high-CO₂ content gas deviation factor experiments were carried out with the Canadian DBR-PVT instrument. Then 192 sets of corresponding simulation calculations were carried out using 12 state equations such as BWRS, PR and SRK in ASPEN HYSYS software. The main influencing factors of the deviation factor were discussed, and the accuracy of calculating deviation coefficient by software state equations was evaluated. The results show that within the experimental range, pressure and CO₂ content have great influence on the deviation factor, while temperature has little influence on it. The deviation coefficient first decreases and then increases as the pressure rises. The PR and Sour PR state equations have the highest accuracy in calculating the high-CO₂ content gas deviation factor, with the average relative error of 1.09% and the maximum relative error of 5.74%. Therefore, when the CO₂ content of natural gas is high, it is recommended to use the PR and Sour PR state equations to calculate the deviation factor.