低渗透油藏表面活性剂降压增注效果影响因素  

Factors effecting decompression and augmented injection by surfactant in low permeability reservoir

作　　者：祝仰文[1,2] 孟红丽[3] 马宝东[2] 施雷庭[1] 刘丽娟 叶仲斌[1] 罗平亚[1] 

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,四川成都610500 [2]中国石化胜利油田分公司勘探开发研究院,山东东营257015 [3]中国石化胜利油田分公司滨南采油厂,山东滨州256600 [4]深圳百勤石油技术有限公司,广东深圳518000

出　　处：《油气地质与采收率》2016年第1期74-78,共5页Petroleum Geology and Recovery Efficiency

基　　金：国土资源部专项项目"山东胜利油田低渗透油藏综合利用示范基地建设"(YKC0720);中央财政支持地方高校发展专项资金"石油与天然气工程国家一级学科"(P014)

摘　　要：表面活性剂通过降低油水界面张力和乳化作用实现低渗透油藏降压增注。通过宏观和微观方法研究界面张力和乳化速率对降压效果的影响,并分析界面张力和乳化速率的协同作用。结果表明,当界面张力小于5.25 m N/m时,能够实现降压作用,且随着界面张力的降低,其降压效果越显著;界面张力下降,采收率上升,但当其降低到10^(-1)m N/m时,表面活性剂提高采收率的增幅有限;界面张力达到10^(-2)m N/m时,表面活性剂仍无法完全解除水流通道中残余油的附加阻力。当表面活性剂的乳化速率大于0.11 m L/min时,有降压作用,进一步提高乳化速率,从而提高降压率,但当表面活性剂的乳化速率大于0.42 m L/min时,对降压率的影响程度减弱;对采收率增幅的影响为乳化速率加快,采收率增幅加大,当表面活性剂的乳化速率大于0.21 m L/min时,继续增加乳化速率对采收率增幅的影响不大。因此,表面活性剂用于降压增注的表面活性剂形成乳状液的时间短,能够使油水充分乳化,迅速扩大波及面积后再降低界面张力、提高洗油效率,可以更有效地降低驱替压力,提高采收率。Surfactant can achieve the purpose of decompression and augmented injection in low permeability reservoirs by reducing interfacial tension and emulsification. The effect of emulsification rate and interfacial tension on the decompression was studied through macroscopic and microscopic methods. The synergy between the interfacial tension and emulsification rate were analyzed. The results show that decompression can be reached when the interfacial tension is less than 5.25 m N/m,and the effect is more significant with the reduction of interfacial tension. If the interfacial tension reduces,oil recovery may increase;but when the interfacial tension decreases to 10^(-1)m N/m,impact on the oil recovery is limited. When it arrives at 10^(-2)m N/m,the surfactant cannot completely eliminate the additional resistance of residual oil in the flow channel yet. When the emulsification rate of the surfactant is greater than 0.11 m L/min,decompression effect is obvious. More pres-sure drop appears with the emulsification rate improving. But when it is greater than 0.42 m L/min,it has little effect on the pressure. The oil recovery increases with the emulsification rate improving until l0.21 m L/min. But when it is higher than0.21 m L/min,higher emulsification rate has smaller effect on the oil recovery. Therefore,the emulsification rate of suitable surfactant system should be as short as possible and thus let oil emulsified completely to gain rapid expansion of sweep area.Then the interfacial tension is reduced to improve displacement efficiency at lower pressure and thus,higher oil recovery.

关 键 词：低渗透油藏 降压增注 表面活性剂 界面张力 乳化速率 

分 类 号：TE357.432[石油与天然气工程—油气田开发工程]