Mechanism and Influencing Factor Analysis of Near-Well Stimulation for Hot Dry Rock Reservoirs by Liquid CO Phase Transition Blasting: Applied to Matouying Uplift.

To improve the heat transfer efficiency of the hot dry rock (HDR) well group, a near-well stimulation method of liquid CO phase transition blasting (LCO-PB) is put forward, the fracturing characteristics and mechanism of samples induced by impact dynamic load are analyzed, the effects of hydraulic fracturing cracks, buried depth, shock wave amplitude, and blasting frequency on the reservoir stimulation are clarified, and feasible suggestions have been proposed for its on-site application. Results show that the dynamic load applied by LCO-PB can effectively increase the number and connectivity of cracks and enhance the complexity of damaged cracks. The existence of hydraulic fracturing cracks has a promoting effect on the generation and distribution because blasting stress wave can reflect and refract in the hydraulic fracturing cracks and torn apart the surrounding area.