{"title":"考虑层理取向的页岩产气过程中渗透率演化:孔隙弹性和气动力的相对贡献","authors":"Yufei Chen , Weimeng Chen , Qiangui Zhang , Xiangyu Fan , Changbao Jiang , Chuanyao Zhong , Pengfei Zhao","doi":"10.1016/j.jgsce.2025.205737","DOIUrl":null,"url":null,"abstract":"<div><div>Gas recovery and permeability evolution in shale reservoirs with various bedding orientations during the lifetime gas production are dynamically controlled by the coupling of poroelasticity and gas dynamics, however, the relative contributions of both effects to shale permeability still remain unclear. In this study, we experimentally and theoretically investigated the changes in shale permeability using shale samples with four separate bedding angles (0°, 30°, 60°, and 90°), under both constant effective stress and constant confining pressure conditions. Results show that an increase in bedding angle generally enhances the effect of poroelasticity on shale permeability but suppresses that of gas dynamics. Also, utilizing the effective stress coefficient <em>χ</em> would unify the permeability evolutions at relatively high pore pressures (approximately > 6 MPa). A theoretical permeability model was derived and it could reasonably match the permeability data. Most importantly, poroelasticity and gas dynamics contribute oppositely to the overall shale permeability evolution and an almost 25-percent contribution of gas dynamics would result in a permeability rebound. We further provided a new method to evaluate the deformation-induced reduction of gas dynamics effect on gas flow and this reduction increases with increasing pore pressure but decreasing bedding angle. Finally, we determined the critical pore pressure below which the gas flow behavior in shale reservoirs will transform from poroelasticity-to gas dynamics-dominated to enhance the apparent permeability. This parameter, approximately ranging from 6.5 to 9 MPa, increases in deep- but decreases in inclined-shale reservoirs. The present study aims to provide a theoretical support for the high-efficiency development and high-precision production prediction of shale gas.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"143 ","pages":"Article 205737"},"PeriodicalIF":5.5000,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Shale permeability evolution during lifetime gas production considering bedding orientation: Relative contributions of poroelasticity and gas dynamics\",\"authors\":\"Yufei Chen , Weimeng Chen , Qiangui Zhang , Xiangyu Fan , Changbao Jiang , Chuanyao Zhong , Pengfei Zhao\",\"doi\":\"10.1016/j.jgsce.2025.205737\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Gas recovery and permeability evolution in shale reservoirs with various bedding orientations during the lifetime gas production are dynamically controlled by the coupling of poroelasticity and gas dynamics, however, the relative contributions of both effects to shale permeability still remain unclear. In this study, we experimentally and theoretically investigated the changes in shale permeability using shale samples with four separate bedding angles (0°, 30°, 60°, and 90°), under both constant effective stress and constant confining pressure conditions. Results show that an increase in bedding angle generally enhances the effect of poroelasticity on shale permeability but suppresses that of gas dynamics. Also, utilizing the effective stress coefficient <em>χ</em> would unify the permeability evolutions at relatively high pore pressures (approximately > 6 MPa). A theoretical permeability model was derived and it could reasonably match the permeability data. Most importantly, poroelasticity and gas dynamics contribute oppositely to the overall shale permeability evolution and an almost 25-percent contribution of gas dynamics would result in a permeability rebound. We further provided a new method to evaluate the deformation-induced reduction of gas dynamics effect on gas flow and this reduction increases with increasing pore pressure but decreasing bedding angle. Finally, we determined the critical pore pressure below which the gas flow behavior in shale reservoirs will transform from poroelasticity-to gas dynamics-dominated to enhance the apparent permeability. This parameter, approximately ranging from 6.5 to 9 MPa, increases in deep- but decreases in inclined-shale reservoirs. The present study aims to provide a theoretical support for the high-efficiency development and high-precision production prediction of shale gas.</div></div>\",\"PeriodicalId\":100568,\"journal\":{\"name\":\"Gas Science and Engineering\",\"volume\":\"143 \",\"pages\":\"Article 205737\"},\"PeriodicalIF\":5.5000,\"publicationDate\":\"2025-07-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Gas Science and Engineering\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2949908925002018\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"0\",\"JCRName\":\"ENERGY & FUELS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Gas Science and Engineering","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2949908925002018","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"0","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
Shale permeability evolution during lifetime gas production considering bedding orientation: Relative contributions of poroelasticity and gas dynamics
Gas recovery and permeability evolution in shale reservoirs with various bedding orientations during the lifetime gas production are dynamically controlled by the coupling of poroelasticity and gas dynamics, however, the relative contributions of both effects to shale permeability still remain unclear. In this study, we experimentally and theoretically investigated the changes in shale permeability using shale samples with four separate bedding angles (0°, 30°, 60°, and 90°), under both constant effective stress and constant confining pressure conditions. Results show that an increase in bedding angle generally enhances the effect of poroelasticity on shale permeability but suppresses that of gas dynamics. Also, utilizing the effective stress coefficient χ would unify the permeability evolutions at relatively high pore pressures (approximately > 6 MPa). A theoretical permeability model was derived and it could reasonably match the permeability data. Most importantly, poroelasticity and gas dynamics contribute oppositely to the overall shale permeability evolution and an almost 25-percent contribution of gas dynamics would result in a permeability rebound. We further provided a new method to evaluate the deformation-induced reduction of gas dynamics effect on gas flow and this reduction increases with increasing pore pressure but decreasing bedding angle. Finally, we determined the critical pore pressure below which the gas flow behavior in shale reservoirs will transform from poroelasticity-to gas dynamics-dominated to enhance the apparent permeability. This parameter, approximately ranging from 6.5 to 9 MPa, increases in deep- but decreases in inclined-shale reservoirs. The present study aims to provide a theoretical support for the high-efficiency development and high-precision production prediction of shale gas.