前置液酸压缝中酸液指进的物模与分形研究

针对前人以有机玻璃平行板形成模拟裂缝，模拟指进现象与实际的酸液指进在物理化学背景上存在明显差异的问题。采用与地层矿物类型相近的大理石板和双层钢化玻璃板相结合的方式构成裂缝壁面，利用真实的盐酸作为驱替液，实现了酸岩反应条件下酸液指进的模拟，发现了前人研究中未曾报道的酸岩化学反应和酸液自身重力综合影响下的酸液指进行为。采用分形维数对酸液指进的复杂形态进行定量描述，发现所得的酸液指进形态的分形维数分别为1.86、1.75、1.75和1.81,表明酸液指进形态具有明显的分形特征。为分形理论在酸压设计研究中的应用提供了直接支持。

PHYSICAL SIMULATION AND FRACTAL FEATURES OF ACID FINGERING IN PAD ACID FRACTURING TREATMENT

The phenomenon of acid fingering in pad acid fracturing treatment directly affects acid distribution, effective distance, fracture conductivity. It is more complicated and difficult to study than other fingering phenomena. Previously, acid fingering was simulated in a model that consists of two lucite plates, which failed to simulate acid fingering with acidrock reaction. Based on previous study, one marmoreal plate and one doubledeck toughened glass plate, rather than two transparent glass plates, are used as the fracture walls. Acid fingering is successfully simulated with acidrock heterogeneous chemical reaction. Some new phenomena, which are not mentioned in existing literature, are discovered. The acid fingering patterns are characterized by fractal dimension, which is 1.86, 1.75, 1.75 and 1.81 respectively. Which illustrates that the fingering pattern is evidently fractal and directly supports the applications of fractal theory in acid fracturing design.