Investigation into the Stimulation Effect of Energized Fracturing: An Experimental Study

ABSTRACT: This study systematically evaluates the impact of five energy storage media-N2, SC-CO2, fresh water, produced water, and flow back fluid-on fracture propagation and crude oil recovery through integrated experiments of energy storage, fracturing, and oil displacement. Utilizing tight Conglomerate core samples from Xinjiang Oilfield, the research employs CT scanning, nuclear magnetic resonance, and 3D fracture reconstruction technologies to quantitatively analyze fracture morphology, volume, fractal dimension, and breakdown pressure changes under different energy storage media and calculate the enhancement in recovery efficiency. The results indicate that gaseous energy storage media (SC-CO2, N2) outperform water-based media (produced water, flow back fluid, fresh water) due to their low viscosity and high diffusivity, significantly increasing fracture complexity and volume. Specifically, SC-CO2 energy storage results in a fracture volume 2.84 times that of direct fracturing, a reduction in breakdown pressure by 3.71 MPa, and an ultimate recovery efficiency improvement of 10.13%, reaching up to 36.67%. Among water-based media, produced water shows the best performance in multi-cycle energy storage, with a fracture volume increase of 37% and higher fractal dimensions. The study confirms that energy storage fracturing effectively enhances the complexity of the fracture network and the mobilization capability of crude oil by reducing effective stress and increasing pore pressure, providing significant insights for optimizing fracturing techniques in unconventional oil and gas reservoirs.