大尺寸可视化酸液指进模拟装置研制及应用

Development and Application of Large Scale Visible Physical Simulation Device for Acid Fingering

裂缝中的酸液指进是酸压过程中发生的重要现象,目前多采用模拟手段进行研究。然而现有物理模拟实验与实际酸压过程缺乏必要的相似性。鉴于此,建立相似准则并确定相似比例尺,研制出了大尺寸可视化物理模拟装置并进行了模拟实验。与前人类似装置相比,该模拟装置具有三板双缝的结构特点,不仅可考察不同黏度差、密度差以及不同注酸流量、不同温度下的指进行为,还可进行酸岩反应、酸液滤失和不同裂缝倾角影响下的中低压酸液指进可视化模拟。模拟实验发现酸液指进形态复杂,需要在定性研究的基础上,对其演化规律进行定量表征。

In pad acid fracturing,low viscosity acid leads to a fingering phenomenon in the high viscosity pad fluid and has agreat influence on the result of acid fracturing;judging from former studies,it can only be analyzed through simulation.However,present models differ significantly from the real acid fracturing process.In view of this,a large-scale physical visible acidfingering simulation device was designed and manufactured based on similarity criterions and similarity scales presented by theauthor.Compared with the physical acid fingering simulation devices of predecessors,this simulation device structure featuredthree plates and double slits capable of studying fingering behaviors under different viscosities,densities,and temperaturesand performed acid rock reaction,acid fluid loss as well as low-and medium-pressure acid fingering visual simulation underdifferent fracture inclinations.Simulations of acid fingering were performed,and it was found that acid fingering forms wereso complex that quantitative description based on qualitative research was required to reveal the evolution rule.