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蒸发气混相注入和凝析气混相注入已在世界大量油藏中得以应用。这些注入气的特性往往通过实验室分析及组分模拟得到。本文研究了①多次接触混相驱油的物理过程;②应用Coats关系模拟气-油相对渗透率随界面张力的变化,以及预测原油采收率相关误差的可能性;③气/油非平衡效应在预测原油采收率及气油比方面的重要性。通过使用一款商业组分模拟器达到了上述研究目的,即基于性能完善的玻璃珠人造岩心进行实验,预测了多次接触混相注入的特征。利用在外界条件下能展现上临界点的三元液态体系研究了凝析气驱与蒸发气驱。凝析气法与蒸发气法驱油十分高效,注入1PV驱替液可采出90%的原油储量。与非混相驱替相比,突破时采出程度与总采收率分别提高8%和20%。然而,无论是凝析气驱还是蒸发气驱(假设是在平衡条件下),组分模拟均过高预测了原油采收率。进一步的模拟证实了产生这种误差的原因有可能是在接近混相时Coats相关系数不能够精确地描述相对渗透率特征,或是由于产生的流体处于非组分平衡状态,或者两种原因都存在。
Evaporative gas-phase injection and condensate gas-phase injection have been applied in a large number of reservoirs in the world. The characteristics of these injected gases are often obtained through laboratory analysis and component simulation. In this paper, ① the physical process of multi-phase miscible flooding is studied. ② Coats relationship is used to simulate the change of relative permeability of gas-oil with interfacial tension and the possibility of predicting the error related to oil recovery. ③ The non-equilibrium effect of gas / oil The importance of predicting crude oil recovery and gas / oil ratio. The above research goal was achieved by using a commercial component simulator, which was based on experiments performed on a well-established glass bead artificial core to predict the characteristics of multiple-contact, mixed-phase injections. The condensate gas drive and the evaporative gas drive are studied by using the ternary liquid system which can show the upper critical point under the external conditions. Condensate gas and evaporative gas method is very efficient oil displacement, injection of 1PV displacement fluid can produce 90% of the reserves of crude oil. Compared with non-miscible flooding, the degree of recovery and total recovery of breakthrough increased by 8% and 20% respectively. However, neither the condensate drive nor the evaporative gas drive (assumed to be under equilibrium conditions), the compositional simulations are all too high to predict oil recovery. Further simulations confirm that the reason for this error may be that the Coats correlation coefficient can not accurately characterize the relative permeability near the mixed phase or because the resulting fluid is in a non-component equilibrium or both .