低渗油藏表面活性剂驱油体系优选

The optimization for surfactant oil displacement system in low permeability reservoirs

针对低渗油藏渗流阻力大、注水压力高及水驱采收率偏低的问题,通过性能评价,优选一种适合该类油藏的表面活性剂驱油体系。以研制的阴非离子型表面活性剂(GJ剂)为主剂,其它表面活性剂为助剂,分别考察其油水界面张力、润湿性、防膨性、洗油效率、驱油效率。结果表明,GJ+YJ体系与原油界面张力为6.15×10-3mN/m,该体系可使油湿岩片接触角由76.80°降低至48.83°,防膨率达66.63%,洗油效率为61.28%,驱油效率提高11.80%。因此,GJ+YJ体系在低渗油藏改善水驱效果中具有良好的应用前景。

According to the problem emerging in low permeability reservoir of great filtrational resistance,hight injection pressure and low water displacement efficiency,a compounded surfactant was optimized for EOR by properties evaluation.The surfactant combination system including GJ as main agent and other surfactant as accessory ingredient was evaluated by interfacial activity,wettability,anti-expandability and displacement efficiency.The results show that oil displacement system of GJ＋YJ which can reduce interfacial tension to 6.15×10-3 mN/m,change contact angle of oil-wet rock from 76.80 ° to 48.83 °.And expandability rate is 66.63%,enhanced displacement efficiency is 11.80%.GJ＋YJ is able to improve the waterflooding of low permeability reservoir and has a good prospect application in this reservoir.