With the growing demand of clean energy

much attention has been paid to the supercritical CO2 strengthened shale gas development technology. This paper aims to investigate the effect of supercritical CO2 on the mechanical properties of the shale. Supercritical CO2 immersion experiments were carried out on the Silurian shale from Sichuan Basin Longmaxi for different durations. Besides

indirect tension tests (i.e.

Brazilian disc tests) and triaxial compression tests were conducted to obtain the variation regularities of the strength and deformation of shale before and after immersion. Combing with the results of XRD

porosity and SEM tests

the effect of supercritical CO2 on the mechanical properties of shale was preliminarily discussed. The results showed that after supercritical CO2 immersion

the tensile strength

triaxial compressive strength

and elastic modulus (Young’s Modulus) of the shale all decreased at various degrees. However

the amount of shale strength loss increased with increasing the immersion time. Meanwhile

XRD

porosity tests and SEM results indicated that supercritical CO2 degraded mechanical properties of shale by changing the structure of mineral constituent

reducing the degree of cementation

and changing the particle framework and pore structure.