罗家寨气田酸性气体偏差因子预测方法对比

METHOD OF Z-FACTOR PREDICTION FOR SOUR GAS IN LUOJIAZHAI GAS FIELD

文章采用SRK和DPR理论计算模型并结合不同的校正模型 ,对四川罗家寨高含硫气田的罗 7、罗 9井 ,计算了 80℃、10 3℃条件下压力在 9.0 14～ 4 5 .0 2MPa范围内气体的偏差因子 ,并与实验测试的结果进行了对比分析。试验测试结果表明 ,酸性气体偏差因子变化规律与常规天然气相似 ;试验与计算结果对比表明 ,计算酸性气体的偏差因子时必须对其临界参数进行校正 ,否者计算结果偏小 ;SRK状态方程在计算酸性气体偏差因子时误差较大 ,DPR计算方法能够满足工程计算的要求 ;随着温度的升高 ,硫化氢和二氧化碳对于体系的压缩因子的影响越来越小。

Luojiazhai gas field belongs to a gas field with high sulfur content. And the Wells Luo 7 and 9 are the representative gas wells with high sulfur content. With the theoretical calculation models of SRK and DPR and different correcting models, the Z-factors of gas are calculated when the temperature is at 80℃ and 103℃ and the pressure ranges from 9.014 MPa. to 45.02 MPa., and compared with the experimental results. The experimental results show the variation law of Z-factors for sour gas is similar with that for conventional gas. Comparing the calculating results with the experimental results shows the critical parameters must be corrected when calculating the Z-factors for sour gas. If not, the Z-factors will be smaller. With SRK, the error will be larger when calculating the Z-factors for sour gas. With DPR, the engineering calculation requirements can be met. The influence of H 2S and CO 2 on the compression factor of the system will decrease as the temperature rises.