A STUDY OF THE GEOELECTRIC EFFECT ON THE PROCESS OF HYDRAULIC FRACTURING EXPERIMENTS

In the paper,the geoelectric effects associated with the pressurization measured and recorded by electric instruments in sites of hydraulic fracturing experiments are summarized,and some significant results corresponding to rock failure are also obtained as follows:(1)With the increase of pressure,the resistivity rises distinctly. Affer the pressure has exceeded a half of rock critical stress,the resistivity drops rapidly; and during the release stress,the resistivity gradually rises again.(2)The self-potential centered on the pressure hole and the electric potential in the wells ZK2 and ZK14 change with the pressurization,all reflect strongly the correlation between the percolated electric field and the pore pressure gradient.