CO 2 , N 2 , and CO 2 /N 2 mixed gas injection for enhanced shale gas recovery and CO 2 geological storage

In this work, using fractured shale cores, isothermal adsorption experiments and core flooding tests were conducted to investigate the performance of injecting different gases to enhance shale gas recovery and CO 2 geological storage efficiency under real reservoir conditions. The adsorption process of shale to different gases was in agreement with the extended-Langmuir model, and the adsorption capacity of CO 2 was the largest, followed by CH 4 , and that of N 2 was the smallest of the three pure gases. In addition, when the CO 2 concentration in the mixed gas exceeded 50