Abstract: The remaining oil exists as discontinuous phase in the ultra-high water cut period, which is greatly influenced by microscopic force. Taking the residual oil in the droplet as the object of study in the ultra-high water cut period, the micro mechanical cause of oil droplet in the capillary model is analyzed, and it is clarified that the capillary force is the main force formed by the residual oil. The model of two hole pore structure is selected to establish the critical condition model of the oil droplet transfer tunnel radius, and the mechanism of choosing the remaining oil droplet capillary channel is studied. Quantitative analysis results show that the driving force and the viscous force have a great impact on the minimum boundary value of the channel radius passing the oil droplet. The results can provide theoretical guidance for analyzing the conditions of remaining oil in ultra-high water cut period and enhancing oil recovery.

Key words: Ultra-high water cut period, Microscopic remaining oil, Mechanical cause, Pore selection mechanism

摘要： 特高含水期剩余油多以非连续相存在,微观作用力影响明显。以特高含水期孤滴状剩余油为研究对象,对毛细管模型中油滴的微观力学成因进行分析,明确毛管力是孤滴状剩余油形成的主要微观作用力;选取双孔孔隙结构模型建立油滴运移孔道半径临界条件模型,研究剩余油滴选择毛细管孔道的机理,定量化分析结果表明, 驱动力和黏滞力对油滴通过的孔道半径最小界限值的影响较大。该结果可为分析特高含水期剩余油动用条件及提高采收率提供指导。

关键词: 特高含水期, 微观剩余油, 力学成因, 孔道选择机理