Measurement Research of Borehole-to-Surface Electric Potential Gradient Method in Monitoring Hydraulic Fracture

As the main measures to improve oil and gas production, hydraulic fracturing has been widely applied in modern oil industry. By means of lower resistance properties of fracturing fluid, borehole-to-surface electric potential gradient method analyses the gradient change before and after fracturing, and reveals extensions orientation of fracturing fluid in the underground. Consequently, the aim of inferring fracture azimuth is fulfilled. This paper analyses the influence law between launch current, detecting depth, polar distance and potential gradient making use of the vertical line power three-dimensional finite difference method. The study provides theoretical guidance for measurement method of field test to determine oil well fracturing fracture trend.