Validating the application of cyclic hydraulic pressure pulses to reduce breakdown pressure in granite.

As the geoenergy sector moves toward more sustainable practices, an emerging field of research is the proposed utilization of cyclic hydraulic pressure pulses to safely and efficiently enhance productivity. We demonstrate how cyclic hydraulic pressure pulses can reduce hydraulic breakdown pressure in granite using newly developed experimental equipment, which applies pulsed square waves of fluid pressure to large bench-top samples, monitored with dynamic high-resolution fiber optic strain sensors. Our results show a significant reduction in breakdown pressure can be achieved by cyclic pulsed pumping, and we explore the role of mean pressure and cyclic amplitude.