An innovative experimental equipment for liquid nitrogen fracturing

Due to the unique physical and chemical properties of liquid nitrogen (LN2), LN2 fracturing has been considered as a promising reservoir stimulation technique. In order to further investigate the feasibility of LN2 fracturing, a new device is designed to research the effect of LN2 fracturing under different conditions, such as different specimen sizes, temperatures, and confining pressures. The setup consists of three units: a high-pressure LN2 generating system, a true-triaxial loading and heating system, and a control and data acquisition system. Now, a series of experiments have been successfully carried out based on the setup. The results have proven the excellent fracturing effect of LN2 and the applications of this setup. The apparatus lays a foundation for the application of LN2 fracturing in both conventional and geothermal reservoirs.