裂缝渗流条件下页岩相似材料的电化学试验研究

Electrochemical Study on Shale Similar Materials under Fracture and Seepage

为了研究裂缝发育和水体渗流作用对页岩的电化学规律,基于制作的A~D 4组页岩相似材料,分别采用1~4倍单位炸药对其进行爆破致裂,并对4组页岩相似材料进行电化学测试。分析试验结果发现:①渗流试验开始前,A、C和D 3组页岩相似材料的Nyquist图和Bode图性态一致性较强、B组的一致性较弱;②渗流试验开始后,随着渗流作用时间的延长,A~D 4组页岩模拟材料的Nyquist图和Bode图均产生了变化;③相同渗流时间条件下,4试验组阻抗模值的大小关系为A>B>C>D。研究表明:渗流和裂缝能够改善页岩相似材料的Nyquist图和Bode图的性态,渗流时间越长、裂缝越是发育,页岩相似材料阻抗的降低程度越大。

In order to study the electrochemical characteristics of shale under fracture development and water seepage,four groups of shale similar materials(A~D)were prepared.The four similar shales were cracked by 1~4 times of unit dose explosive.Four groups ofthem were electrochemical tested.The results are as follows:①Before the start of seepage test,the Nyquist diagram and Bode diagram of group A,C and D have strong consistency,while the consistency of group B is weak.②After the start of seepage test,the average Nyquist diagram and Bode diagram of four group have changed with the extension of seepage action time.③Under the same seepage time,the relationship between impedance modulus values of four test groups is A>B>C>D.The results show that seepage and fracture can improve the properties of Nyquist diagram and Bode diagram of shale similar materials.The longer the seepage time and the more developed fractures,the greater the reduction of impedance of shale similar materials.