SPH numerical simulation of SC-CO2 directional fracturing and emulsion explosives for rock breaking

Abstract

SC-CO2 (Supercritical carbon dioxide) directional fracturing is a promising alternative to explosive blasting in complex environments. This study aims to establish an equivalent method for directional fracturing using traditional explosives, promoting broader adoption of this technology. We conduct a comparative experiment analyzing explosive and SC-CO2 rock breaking, developing the SPH (Smoothed Particle Hydrodynamics) numerical model that includes characteristics of the rock-breaking area and dynamic effects of SC-CO2 and explosives. Additionally, we investigate the influence of the directional fracturing device on the energy release coefficient. Proposing a numerical simulation method for SC-CO2 directional fracturing based on equivalence to No.2 rock emulsion explosive, we use the SPH particle algorithm to enhance visualization of the rock-breaking area. Our findings show that the explosive method yields a larger rock-breaking volume than SC-CO2. Under identical explosive charges, the directional cracker model inhibits explosive energy release, with energy decreasing as distance increases. Calculating an inhibition coefficient of 0.45 for the cracker model in terms of explosive granite, the rock-breaking volume index is 0.48, with an average value of 0.465. In mudstone sites, a similar trend is observed with an average energy release inhibition coefficient of 0.44.