低渗透油藏注表面活性剂提高采收率技术研究及应用

Research and application of surfactant injection to enhance oil recovery in low permeability reservoir

低渗透油藏水驱开发后仍有大量原油残留在地层孔隙中,注表面活性剂能够有效提高低渗透油藏水驱开发后的采收率。以新型双子表面活性剂GSK-1为主要处理剂,并结合非离子表面活性剂AEO,研究出了一套适合低渗透油藏的表面活性剂驱油体系,室内评价了其综合性能。结果表明,该驱油体系具有良好的乳化性能,乳状液放置120min后析水率仍低于30%,稳定性较好;驱油体系还具有良好的润湿反转性能,储层岩心经过浸泡48h后,其表面接触角可以由110.3°降低至50.4°;在天然岩心水驱后继续注入0.5PV的表面活性剂驱油体系,能使采收率继续提高15%以上,驱油效果较好。现场应用结果表明,区块内5口采油井采取表面活性剂驱油措施后,日产油量显著提升,平均提升幅度均在2倍以上,达到了良好的增油效果。

A large amount of crude oil remains in the formation pores after water drive development of low permeability reservoir.Surfactant injection can effectively improve the recovery of low permeability reservoir after water drive development.Taking the new Gemini surfactant GSK-1 as the main treatment agent and combined with the non-ionic surfactant AEO,a set of surfactant oil displacement system suitable for low permeability reservoir was studied,and its comprehensive performance was evaluated in laboratory.The results showed that the oil displacement system has good emulsifying performance.After the emulsion is placed for 120 min,the water separation rate is still less than 30%,and the stability is good;The oil displacement system also has good wetting reversal performance.After soaking the reservoir core for 48 hours,the surface contact angle can be reduced from 110.3° to 50.4°;After water flooding of natural core,continue to inject 0.5PV surfactant flooding system,which can continue to improve the oil recovery by more than 15%,and the oil displacement effect is good.The field application results showed that after surfactant flooding measures are taken in 5 production wells in the block,the daily oil production is significantly increased,and the average increase range is more than twice,reaching a good oil increase effect.