Analysis of uneven density of oil-based drilling fluid caused by shale respiration Xiaoxiao Ni, Jian Li, Jianhua Wang, Haijun Yang, Rentong Liu, He Shi, Lili Yan, Shan Gao, Xiaofei Wang and Die Zhang E3S Web Conf., 560 (2024) 01021 Published online: 05 August 2024 DOI: 10.1051/e3sconf/202456001021