Wellbore stability research based on transversely isotropic strength criteria in shale formation
Borehole instability is a significant concern when drilling inclined wells through bedding layers. Traditional drilling techniques have encountered various challenges due to shale’s tendency to shear and slide along faults, joints, and weak planes. This study explores the mechanisms behind borehole...
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| Language: | English |
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Elsevier
2024-12-01
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| Series: | Soils and Foundations |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0038080624001197 |
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| author | Xiangsen Gao Min Wang Xian Shi Peng Dai Mingming Zhang |
| author_facet | Xiangsen Gao Min Wang Xian Shi Peng Dai Mingming Zhang |
| author_sort | Xiangsen Gao |
| collection | DOAJ |
| description | Borehole instability is a significant concern when drilling inclined wells through bedding layers. Traditional drilling techniques have encountered various challenges due to shale’s tendency to shear and slide along faults, joints, and weak planes. This study explores the mechanisms behind borehole instability in layered shale formations by conducting triaxial compression experiments on shale samples with varying bedding angles. It examines the anisotropic nature of shale properties and how strength varies with bedding angle. By integrating anisotropic strength criteria and transversely isotropic stress models around wells, the study develops a predictive model for borehole instability in layered shale formations and assesses the impact of different anisotropic strength criteria on predicting collapse pressures. The results show that shale’s elastic modulus and Poisson’s ratio have an inverse relationship with the increasing bedding angle. Besides, the patchy plane of weakness model, characterized by the parameter η, accurately predicts strength during inherent shear failure, sliding along bedding planes, and mixed failure. In contrast, the single plane of weakness model yields the highest collapse pressure predictions, while the Mohr-Coulomb criterion provides the lowest. The patchy plane of weakness model offers intermediate and more realistic pressure predictions. Moreover, while the type of in-situ stress does not affect the magnitude of collapse pressure, it influences the distribution characteristics of the collapse pressure cloud map. These findings, which account for shale anisotropy in minimum mud pressure analysis, have the potential to enhance drilling efficiency in practical applications. |
| format | Article |
| id | doaj-art-47e20709c38742e190038b2837112cdf |
| institution | DOAJ |
| issn | 2524-1788 |
| language | English |
| publishDate | 2024-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Soils and Foundations |
| spelling | doaj-art-47e20709c38742e190038b2837112cdf2025-08-20T02:49:08ZengElsevierSoils and Foundations2524-17882024-12-0164610154110.1016/j.sandf.2024.101541Wellbore stability research based on transversely isotropic strength criteria in shale formationXiangsen Gao0Min Wang1Xian Shi2Peng Dai3Mingming Zhang4School of Geoscience, China University of Petroleum, Qingdao 266580, China; Shandong Provincial Key Laboratory of Deep Oil & Gas, Qingdao 266580, China; Shandong Institute of Petroleum and Chemical Technology, Dongying 257061, ChinaSchool of Geoscience, China University of Petroleum, Qingdao 266580, China; Shandong Provincial Key Laboratory of Deep Oil & Gas, Qingdao 266580, China; Corresponding author at: School of Geoscience, China University of Petroleum, Qingdao 266580, China.School of Petroleum Engineering, China University of Petroleum, Qingdao 266580, ChinaSchool of Geoscience, China University of Petroleum, Qingdao 266580, China; Institute of Geophysical and Geochemical Exploration, Chinese Academy of Geological Science, Tianjin 300000, ChinaSinopec Research Institute of Petroleum Engineering Co. Ltd, China Petroleum & Chemical Corporation, Beijing 100101, ChinaBorehole instability is a significant concern when drilling inclined wells through bedding layers. Traditional drilling techniques have encountered various challenges due to shale’s tendency to shear and slide along faults, joints, and weak planes. This study explores the mechanisms behind borehole instability in layered shale formations by conducting triaxial compression experiments on shale samples with varying bedding angles. It examines the anisotropic nature of shale properties and how strength varies with bedding angle. By integrating anisotropic strength criteria and transversely isotropic stress models around wells, the study develops a predictive model for borehole instability in layered shale formations and assesses the impact of different anisotropic strength criteria on predicting collapse pressures. The results show that shale’s elastic modulus and Poisson’s ratio have an inverse relationship with the increasing bedding angle. Besides, the patchy plane of weakness model, characterized by the parameter η, accurately predicts strength during inherent shear failure, sliding along bedding planes, and mixed failure. In contrast, the single plane of weakness model yields the highest collapse pressure predictions, while the Mohr-Coulomb criterion provides the lowest. The patchy plane of weakness model offers intermediate and more realistic pressure predictions. Moreover, while the type of in-situ stress does not affect the magnitude of collapse pressure, it influences the distribution characteristics of the collapse pressure cloud map. These findings, which account for shale anisotropy in minimum mud pressure analysis, have the potential to enhance drilling efficiency in practical applications.http://www.sciencedirect.com/science/article/pii/S0038080624001197Collapse PressureWellbore StabilityLayered RockAnisotropicStrength criteria |
| spellingShingle | Xiangsen Gao Min Wang Xian Shi Peng Dai Mingming Zhang Wellbore stability research based on transversely isotropic strength criteria in shale formation Soils and Foundations Collapse Pressure Wellbore Stability Layered Rock Anisotropic Strength criteria |
| title | Wellbore stability research based on transversely isotropic strength criteria in shale formation |
| title_full | Wellbore stability research based on transversely isotropic strength criteria in shale formation |
| title_fullStr | Wellbore stability research based on transversely isotropic strength criteria in shale formation |
| title_full_unstemmed | Wellbore stability research based on transversely isotropic strength criteria in shale formation |
| title_short | Wellbore stability research based on transversely isotropic strength criteria in shale formation |
| title_sort | wellbore stability research based on transversely isotropic strength criteria in shale formation |
| topic | Collapse Pressure Wellbore Stability Layered Rock Anisotropic Strength criteria |
| url | http://www.sciencedirect.com/science/article/pii/S0038080624001197 |
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