Evaluation methods and engineering applications of in-situ stress in deep, strong heterogeneity terrestrial shale oil and gas reservoirs: a case study of jurassic shales in the Yingshan-Pingchang area, northeast Sichuan - Yin, Shujun; Zhang, Jianliang; Deng, Hucheng; Qin, Hao; Xia, Wenhao; Du, Yu; Gong, Ming; Huang, Tao; Li, Chang (Frontiers in Earth Science, 2025)