Fracturing Effect of Electrohydraulic Shock Waves Generated by Plasma-Ignited Energetic Materials Explosion

Abstract

Electrohydraulic shock waves (ESWs) are widely applied to many fields such as sterilization, lithotripsy, food processing, and so on. Based on high-pulsed power technology, electrical explosion is increasingly utilized to generate shock waves with steep fronts and short duration. In order to further magnify the shock waves, we have proposed a new technique by using energetic materials (EMs) loads. This paper investigated the fracturing effect of the ESWs generated by plasma-ignited EMs explosion. During the ESWs fracturing process, a large-scale triaxial stress pressurizing equipment and a dynamic strain measurement system were applied to the shale samples. The most evident experimental results showed that a large number of cell-shaped multiple cracks developed after the ESWs fracturing process. In addition, interior crack morphology and fluorescent tracing proved the evidence of penetration cracks. These cracks contributed to a great reduction of fracture pressure in fracturing test, which laid a scientific foundation for ESWs technique to be a promising method of well stimulation in those low permeability reservoir and further optimized into a new plugging relief and injection gain technology.