Experimental investigation of the fracture initiation and propagation for sandstone hydraulic fracturing under the effect of evenly distributed pore pressure

Abstract Pore pressure is disregarded in traditional laboratory rock hydraulic fracturing experiments, and the effect of pore not clear. An integrated experiment for seepage hydrofracturing was established used to perform sandstone experiments under an initial evenly distributed pressure. The experimental results show that there a positive correlation between breakdown at initiation stage. data fitting follow linear growth trend. As increases, acoustic emission energy moment borehole wall correspondingly increases. After fracturing, reduced magnitude pumping also indicating rupture range positively correlated with During propagation, propagation opening fracture increase as increases within same time. gradient generated on both sides mineral particles. When tensile stress or shear induced by reaches ultimate strength particle bonding surface, surface breaks opens. This process more similar actual oil gas reservoirs. These provide comprehensive theoretical basis resolving technical problems unconventional resource exploitation.