三元复合驱注入段塞组合物理模拟实验研究

Physical modeling of ASP flooding slug combination

选取分子量为1200万、2000万的聚合物,通过室内物理模拟实验,研究三元复合驱注入段塞组合、浓度、大小对驱替效果的影响。实验结果表明:在化学剂用量相近时,高浓度小段塞的采收率比低浓度大段塞高,高分子量聚合物的驱油效果比低分子量聚合物更明显。不同前置和后续段塞优化驱油实验的结果表明,把聚合物、碱、表面活性剂拆分成双段塞(聚合物、碱+表面活性剂)分注比整个三元体系作主段塞单段塞合注采收率高;在碱、表面活性剂用量不变的情况下,注入的聚合物前置段塞(0.1～0.3 PV)增大对改善驱油效果有利,前置段塞聚合物浓度应不低于1.2g/L;后续段塞大小一般选择0.2PV,在聚合物浓度不变时,后续段塞大小变化在一定范围内对驱油效果影响不大。

A series of core flooding experiments with two types of HPAM, with molecule weight of 1.2×10~7 and 2.0×10~7 respectively, were conducted to investigate the effect of the combination mode, concentration and the size of ASP slug on displacing efficiency. When the amount of chemical matter is the same, the recovery of the higher concentration, smaller slug is higher than that of the lower concentration, larger slug; and the difference is more obvious as the HPAM with higher molecule weight is used. The increase of the preflush polymer slug (0.1-0.3PV) is beneficial to displacing efficiency. The post-pad slug can be chosen to be 0.2PV because it has no remarkable effect on the displacing efficiency. The results suggest that the two-slug injection mode (the polymer is separated from the ASP system) would be better than the single slug (alkaline, surfactant and polymer are in the same slug).