AUTHOR=He Junbo , Tang Jiren , Zhang Jing , Ling Yuanfei , Jin Dongxu 

TITLE=Experimental Determination on Shale Gas Loss During the Coring Process in Eastern Sichuan Basin

JOURNAL=Frontiers in Energy Research

VOLUME=Volume 8 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2020.00177

DOI=10.3389/fenrg.2020.00177

ISSN=2296-598X

ABSTRACT=Abstract: Shale gas loss by leakage directly affects the accurate measurement of shale gas content during drilling and coring. To accurately calculate shale gas loss, in combination with the actual situation of the shale coring, considering the influence factors of the main occurrence state of shale gas (free state and adsorption state), by means of treating the three stages of the shale well core removal, ground exposure, and water bath heating and desorption as a process of desorption that changes with confining pressure, an indoor shale gas loss simulation experiment method was independently designed to determine shale gas loss. Two groups of samples with large differences in physical properties in eastern Sichuan were selected for shale gas loss simulation experiment. We propose to use the error reduction rate of shale gas loss (the percentage of the difference between the shale gas loss obtained by simulation experiment method and that obtained by the improved USBM method and curve fitting method and the amount of gas loss of core injected) to verify the accuracy of simulation experiment method. The results show that compared with the improved USBM method, the average error reduction rate of cores were: 8.64%. Compared with the curve fitting method, the average error reduction rate of cores were 25.11%, which proved that shale gas loss simulation experiment method had higher accuracy.