【作者】 李辉；

【导师】 范海明；

【作者基本信息】 中国石油大学(华东) ， 油气田开发工程， 2020， 硕士

【摘要】 根据稠油粘度大、流动性差等性质,采取不同稠油开采方法,其中,稠油乳化降粘开采技术具备经济、所需能量少等特点。目前,胜利油田整装油藏普遍进入特高含水阶段,随着开发的不断深入,储层非均质性进一步加剧,注入水发生无效窜流,开发起来难度增大。研制单一的乳化降粘体系,能在高效乳化润湿基础上,有效遏制无效窜流。由于稠油的粘度较大,在现场实现机械搅拌的难度较大,并且对于流动性差的稠油,储层对稠油的剪切速率不会太高,因此提出了自扩散乳化降粘的方法,使稠油在适当的表面活性剂(乳化剂)体系和少量的机械能(如轻微的摇动、搅拌或超声波等)的共同作用下就能够发生乳化,从而达到降低稠油粘度的效果。在一定的实验条件下,制备不同体系,观察不同体系与稠油随时间推移的自扩散乳化和破乳情况,并对体系进行分类。针对不同类别体系,开展界面张力分析、粒径分析、和稳定性分析等实验,从而研究体系的形成机制。进行室内岩心化学驱替实验,评价不同类别体系的驱油效果,并从微观上观察体系与稠油乳化过程。根据实验结果将体系分为三大类:第一类体系既可以与稠油发生自扩散乳化,又能在观察时间24h内实现破乳;第二类体系可以与稠油发生自扩散乳化,但是在观察时间24h内不能实现破乳;第三类体系与稠油不能发生自扩散乳化。最终结合现场实际情况和实验结果表明:使用微力,在实验温度为50℃,油水比1:9,乳化剂浓度为0.3%的实验条件下,7种表面活性剂(DF-21、B6、B16、B18、B19、B29和B31)单组分体系可以使胜利油田稠油实现自扩散乳化,在24h内实现破乳完全。加入稠油自扩散乳化体系,稠油的降粘率达70%以上,并且油水界面张力大大地降低。三类体系均可使稠油的采收率增加,其中,一类体系采收率增幅最大,超过了20%,还可使油相相对渗透率增加7.7倍,说明该类体系也是具有良好的相渗调节作用。从微观可视化实验中也可以证明稠油可与一类体系产生乳状液增加油相的流动能力。更多还原

【Abstract】 According to the characteristics of heavy oil high viscosity and poor fluidity,different heavy oil extraction methods are adopted.Among them,heavy oil emulsification and viscosity reduction extraction technology is economical and requires less energy.At present,Shengli Oilfield’s packaged oil reservoirs generally enter the extra-high water cut stage.In addition,as the development continues,the heterogeneity of the reservoir further intensifies,and the influent channeling of injected water is invalid for extracting oil,then the development of oilfield benefits becomes more difficult.Therefore,we can develop a single emulsification and viscosity reduction system to effectively curb invalid channeling on the basis of efficient emulsification and wetting.Because of the high viscosity of heavy oil,it is difficult to achieve mechanical stirring in the field,then we proposed the method of self-emulsification and viscosity reduction to be emulsify and reduce the viscosity of heavy oil with a suitable surfactant and a small amount of mechanical energy(such as slight shaking,stirring or Ultrasound,etc.).Under certain experimental conditions,we prepare different systems,observe the selfemulsification and demulsification of different systems and heavy oils over time,and classify the systems.For different types of systems,experiments such as interfacial tension analysis,particle size analysis,and stability analysis are conducted to study the formation mechanism of the system.Carry out laboratory core chemical displacement experiments to evaluate the oil displacement effect of different types of systems,and observe the emulsification process of the systems and heavy oil from a microscopic perspective.According to the experimental results,systems are divided into three types: the first type of system can be self-emulsification and demulsification(which can be achieved within the24 h of observation time);the second type of system can be self-emulsification with heavy oil,but it cannot be demulsified within 24 h of observation time;the third type of system cannot be self-emulsification with heavy oil.Finally,combined with the actual situation on the live situation and the experimental results,it was shown that: under the experimental conditions of applying micro-power,at 50℃,an oil-water ratio of 1:9,and a surfactant concentration of 0.3%,seven surfactants of single-component systems(DF-21,B6,16,B18,B19,B29 and B31)can make the Shengli Oilfield’s heavy oil achieve microdynamic self-emulsification and demulsification to the ground within 24 h.Adding heavy oil self-emulsifying system,the viscosity reduction rate of heavy oil is more than 70%,and the oil-water interfacial tension is greatly reduced.All three types of systems can increase the heavy oil recovery.Under the first type of system,the recovery of heavy oil increases the most,which exceeds 20%.In addition,it can increase the relative permeability of oil phase by 7.7 times,indicating that this type of system also has a good effect on the regulation of oil phase permeability.From microscopic visualization experiments,it can also prove that the first type of system can emulsify heavy oil and then increase the flow capacity of the oil phase.更多还原