低渗透油藏用纳米乳液性能评价与应用

Performance evaluation and application of nanoemulsion suitable for low permeability reservoirs

结合低渗透油藏驱油技术特点,研究了纳米乳液降低界面张力能力、耐温抗盐能力、改变岩石润湿性能力和驱油效果。试验结果表明,纳米乳液质量浓度为1 000 mg/L时,与原油的界面张力能够达到10-3mN/m数量级,并且表现出较强的耐温抗盐和改善岩石润湿性的性能,质量浓度为2 000mg/L的纳米乳液的水溶液能在岩心水驱的基础上进一步将采收率提高20%以上。该纳米乳液产品已在江苏油田井组应用,取得了显著的驱油效果。

Combined with the characteristics of oil displacement technology in low permeability reservoirs,the ability of nanoemulsion to reduce interfacial tension,to resist temperature and salt,to change rock wettability,and to improve oil displacement effect are studied.The test results show that when the mass concentration of nanoemulsion is 1000 mg/L,the interface tension between the crude oil and water can reach the order of 10-3 mN/m.The nanoemulsion shows strong performance of temperature resistance and salt resistance,which can improve rock wettability.The aqueous solution of nanoemulsion with mass concentration of 2000 mg/L can further improve the recovery by more than 20%on the basis of core water flooding.The nanoemulsion product has been applied in the well group of Jiangsu Oilfield,and has achieved remarkable oil displacement effect.