【摘要】 深层和超深层气藏的开发已成为气藏开发最重要的领域之一。由于气藏埋藏较深,普遍存在高温高压的特点,气藏气体偏差因子的计算直接影响单井井底流压、产能和动态储量的计算准确度,从而影响开发技术对策的制定。然而目前计算偏差因子和井底流压的方法众多,不同的气藏,计算方法的适用性存在差别。针对双鱼石茅口组高温高压气藏,通过BB法、HY法、DPR法、DKA法、LXF法和ZGD法6种偏差因子计算方法的计算结果与实验实测值进行对比,结果表明:①在气藏条件下HY法和DAK法计算准确性最高,最大偏差约为2.5%,其中DAK法计算结果最为接近实验值,并且在8 MPa至123 MPa压力范围内,平均偏差约为0.6%。②基于实验测试和计算结果确认DAK法适用于该气藏的天然气偏差因子计算。③在此研究基础上,对温压耦合模型进行改进,建立了新的气藏井底流压计算模型。对比现场测试压力和模型计算值,改进的温压耦合模型计算结果偏差最低,仅为-1.593%,具有较高准确性,研究结果表明针对类似于双鱼石这类高温高压气藏,DAK法和改进的温压耦合模型具有较强适用性。更多还原

【Abstract】 Developing deep to ultra-deep gas reservoirs has become one of the most important domains in reservoir development. Due to greater burial depth, they are commonly characterized by high temperature and pressure, bringing about big difficulty in predicting gas deviation factor accurately. To measure this factor also affects directly calculation accuracy of single-well bottomhole flowing pressure, production capacity, dynamic reserves, and consequently making development technical countermeasures. So, it’s particularly important to select an optimal calculation method. In this study, some results obtained from six methods to calculate deviation factor(i.e., BB, HY, DPR, DKA, LXF and ZGD) were compared with those measured values by taking some HTHP gas reservoirs of Maokou Formation in Shuanyushi block as examples. Results show that the calculation accuracy of HY and DAK methods is the highest under HTHP, and the maximum deviation is about 2.5%. The result from DAK method is the closest to experimental value, and its average deviation is about 0.6% at pressure of 8-123 MPa. After comparison, it’s confirmed that DAK method is most available for those HTHP gas reservoirs. Furthermore, one temperature-pressure coupling model was modified, and another model to calculate bottomhole flowing pressure was also established. In addition, the on-site measured pressure and the value obtained from these two models were compared. It is indicated that, the deviation calculated from the modified model is the lowest, only-1.593%, also showing that this one has higher accuracy available for deep to ultra deep gas reservoirs.更多还原