适合特低渗透油藏注水井降压增注的纳米乳液体系研究

Study on nano-emulsion system for depressurization and augmented injection of water injection well in ultra-low permeability reservoirs

针对海上某特低渗透油藏注水井普遍存在注入压力升高以及注水量降低的问题,开发了一种适合特低渗透油藏注水井降压增注的纳米乳液体系,并通过室内试验对其各项性能进行了评价。结果表明:该纳米乳液体系具有良好的分散稳定性以及较低的黏度,能够确保施工过程的顺利进行;纳米乳液体系还具有良好的界面活性和防膨性能。此外,储层段天然岩心使用模拟注入水驱后继续注入纳米乳液体系,可以使岩心驱替压力降低率达到35%以上,具有良好的降压增注性能。

In view of the problems of increasing injection pressure and decreasing water injection volume in water injection wells of an offshore ultra-low permeability reservoir.A nano-emulsion system suitable for depressurization and augmented injection of ultra-low permeability reservoirs has been developed,and its performance has been evaluated.The results show that the nano-emulsion system has good dispersion stability and low viscosity,which can ensure the smooth operation of the construction process.The nano-emulsion system also has good interfacial activity and anti-swelling property.In addition,the natural core of the reservoir is injected into the nano-emulsion system after simulated injection water injection,which can reduce the core displacement pressure by more than 35%.