桩106稠油油藏低气液比氮气泡沫驱实验研究

针对桩106普通稠油油藏水驱开发后期提高采收率的需要,同时为了克服常规泡沫驱注气成本和注入压力过高的问题,开展了低气液比氮气泡沫驱实验研究.泡沫驱油体系筛选实验结果表明:构建的泡沫驱体系0.2wt%DS2+0.5wt%Na2CO3具有良好的起泡性能(起泡体积570ml,析液半衰期590s),同时具有大幅度降低油水界面张力(1.4×10-3mN/m)和较强的乳化能力(最小乳化转速275r/min).岩心物理模拟实验表明,低气液比条件(0.2∶1—0.5∶1)下的氮气泡沫驱不但能够在水驱基础上提高采收率22%—30%,而且还可以防止气体的过早突破,从而起到较持久的调驱作用.低气液比泡沫驱是提高普通稠油油藏水驱开发后期采收率的一种经济有效的方法.

Experimental Study of Nitrogen Foam Flooding with Low Gas/Liquid Ratio for Zhuang106 Heavy Oil Reservoir

In light of development of Zhuang106 heavy oil reservoir after water flooding,and in order to decrease the cost of gas injection and high injection pressure of conventional foam flooding,an experimental study on nitrogen foam flooding with low gas/liquid ratio was investigated.The results showed that the selective foam system 0.2wt% DS2 +0.5wt% Na2CO3 not only had good foaming performance(The foam volume is 570ml and half life period is 590s),but also could significantly reduce interfacial tension(1.4×10-3mN/m)and had strong emulsifying capacity(The minimum emulsification rotation speed is 275r/min).Core physical simulation showed that nitrogen foam flooding with low gas/liquid ratio of 0.2∶1—0.5∶1,not only enhanced oil recovery of 22%—30%,but also to prevent premature gas breakthrough,which played the role of a more lasting profile control and flooding.The above results demonstrate that foam flooding with low gas/liquid ratio is a promising economical method for improving heavy oil recovery after water flooding.