硬脆性泥页岩微裂缝模拟研究

Simulation of Micro Cracks in Hard Brittle Shale

针对硬脆性泥页岩微裂缝封堵实验中裂缝尺寸较大的问题,采用化学腐蚀的方法,系统研究了石英玻璃岩心对应力的敏感情况和化学腐蚀中HF浓度、酸液比例、温度和时间对制造出的缝宽影响。结果表明:石英玻璃半圆柱应力敏感性很弱,随着加泄压次数增多,应力敏感不存在;在腐蚀的单因素实验中,随着HF浓度、HF在酸液中比例、温度、反应时间的增加,制造的缝宽变大,电阻值减小,缝宽与电阻值有良好的拟合关系;正交试验中,在20℃时,5 wt%HF∶5%H2SO4=1∶2超声反应20 min后,缝宽为1.317μm,表面呈部分凹坑状,得到的微裂缝对进一步研究纳米材料的封堵性能具有重要意义。

Aiming at the size of sealing microfracture is larger than hard brittle shale, chemical corrosion method was used to study the stress sensitivity of quartz glass core and the concentration of HF, acid ratio, temperature and the reaction time on the impact of manufacturing width. The result showed that the sensitivity of quartz glass semi-cylindrical weak, after multiple treatment, the stress sensitivity does not exist. In the single factor experiment, with the increase of HF concentration, the proportion of HF in the acid solution, temperature and the reaction time, the manufacturing width becomes larger, the resistance value decreased, crack width and resistance fitting relationship good; In orthogonal experiment, 5 wt%HF：5 %H2SO4=1：2 ultrasonic reaction after 20 min, the slit width is 1.317 μm, the surface was concave part. The micro cracks have important significance for further research on the sealing performance of nano materials.