Elastic-Plastic-Damaged Zones around a Deep Circular Wellbore under Non-Uniform Loading
Wellbores are largely constructed during coal mining, shale gas production, and geothermal exploration. Studying the shape and size of the disturbed zone in surrounding rock is of great significance for wellbore stability control. In this paper, a theoretical model for elastic-plastic-damage analysi...
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MDPI AG
2020-02-01
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| Series: | Symmetry |
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| Online Access: | https://www.mdpi.com/2073-8994/12/2/323 |
| _version_ | 1798034297557352448 |
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| author | Xiaoji Shang Zhizhen Zhang |
| author_facet | Xiaoji Shang Zhizhen Zhang |
| author_sort | Xiaoji Shang |
| collection | DOAJ |
| description | Wellbores are largely constructed during coal mining, shale gas production, and geothermal exploration. Studying the shape and size of the disturbed zone in surrounding rock is of great significance for wellbore stability control. In this paper, a theoretical model for elastic-plastic-damage analysis around a deep circular wellbore under non-uniform compression is proposed. Based on the elastoplastic softening constitutive model and Mohr-Coulomb strength criterion, the analytical expressions of stresses in the elastic, plastic and damaged zones around a circle wellbore are derived. Further, the boundary line equations among the three zones are obtained according to the conditions of stress continuity. Then, the influence rules of non-uniform in-situ stress and mechanical parameters on the stress distribution and plastic zone size in surrounding rock mass are analyzed. The plastic and the damaged zones are both approximately elliptical in shape. When the lateral stress coefficient of the in-situ stress field takes the value 1, the model degenerates into the Yuan Wenbo’s Solution. If the brittleness coefficient of the surrounding rock is 0, the model degenerates into the Kastner’s Equation. Finally, the results are compared with those under two special cases (in the elastoplastic softening rock under a uniform stress field, in the ideal elastoplastic rock under a non-uniform stress field) and a common approximation method (the perturbation method). |
| first_indexed | 2024-04-11T20:42:18Z |
| format | Article |
| id | doaj.art-1ce11399e79843b78077cb5a9d8455e0 |
| institution | Directory Open Access Journal |
| issn | 2073-8994 |
| language | English |
| last_indexed | 2024-04-11T20:42:18Z |
| publishDate | 2020-02-01 |
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| record_format | Article |
| series | Symmetry |
| spelling | doaj.art-1ce11399e79843b78077cb5a9d8455e02022-12-22T04:04:10ZengMDPI AGSymmetry2073-89942020-02-0112232310.3390/sym12020323sym12020323Elastic-Plastic-Damaged Zones around a Deep Circular Wellbore under Non-Uniform LoadingXiaoji Shang0Zhizhen Zhang1State Key Laboratory of Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaState Key Laboratory of Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, ChinaWellbores are largely constructed during coal mining, shale gas production, and geothermal exploration. Studying the shape and size of the disturbed zone in surrounding rock is of great significance for wellbore stability control. In this paper, a theoretical model for elastic-plastic-damage analysis around a deep circular wellbore under non-uniform compression is proposed. Based on the elastoplastic softening constitutive model and Mohr-Coulomb strength criterion, the analytical expressions of stresses in the elastic, plastic and damaged zones around a circle wellbore are derived. Further, the boundary line equations among the three zones are obtained according to the conditions of stress continuity. Then, the influence rules of non-uniform in-situ stress and mechanical parameters on the stress distribution and plastic zone size in surrounding rock mass are analyzed. The plastic and the damaged zones are both approximately elliptical in shape. When the lateral stress coefficient of the in-situ stress field takes the value 1, the model degenerates into the Yuan Wenbo’s Solution. If the brittleness coefficient of the surrounding rock is 0, the model degenerates into the Kastner’s Equation. Finally, the results are compared with those under two special cases (in the elastoplastic softening rock under a uniform stress field, in the ideal elastoplastic rock under a non-uniform stress field) and a common approximation method (the perturbation method).https://www.mdpi.com/2073-8994/12/2/323wellborenon-uniform loadingplastic zonedamaged zoneelastoplastic softening modelanalytical solutionmohr-coulomb |
| spellingShingle | Xiaoji Shang Zhizhen Zhang Elastic-Plastic-Damaged Zones around a Deep Circular Wellbore under Non-Uniform Loading Symmetry wellbore non-uniform loading plastic zone damaged zone elastoplastic softening model analytical solution mohr-coulomb |
| title | Elastic-Plastic-Damaged Zones around a Deep Circular Wellbore under Non-Uniform Loading |
| title_full | Elastic-Plastic-Damaged Zones around a Deep Circular Wellbore under Non-Uniform Loading |
| title_fullStr | Elastic-Plastic-Damaged Zones around a Deep Circular Wellbore under Non-Uniform Loading |
| title_full_unstemmed | Elastic-Plastic-Damaged Zones around a Deep Circular Wellbore under Non-Uniform Loading |
| title_short | Elastic-Plastic-Damaged Zones around a Deep Circular Wellbore under Non-Uniform Loading |
| title_sort | elastic plastic damaged zones around a deep circular wellbore under non uniform loading |
| topic | wellbore non-uniform loading plastic zone damaged zone elastoplastic softening model analytical solution mohr-coulomb |
| url | https://www.mdpi.com/2073-8994/12/2/323 |
| work_keys_str_mv | AT xiaojishang elasticplasticdamagedzonesaroundadeepcircularwellboreundernonuniformloading AT zhizhenzhang elasticplasticdamagedzonesaroundadeepcircularwellboreundernonuniformloading |