Numerical Investigation on Mesoscale Evolution of Hydraulic Fractures in Hydrate-Bearing Sediments
Hydraulic fracturing is widely recognized as a potential stimulation technology for the development of challenging natural gas hydrate. However, the fracturing behavior of non-diagenetic hydrate reservoirs has peculiar characteristics that are different from those of conventional oil and gas reservo...
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MDPI AG
2023-11-01
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| Online Access: | https://www.mdpi.com/1996-1073/16/22/7502 |
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| author | Xiaowei Liang Hui Zhao Yongchao Dang Qihong Lei Shaoping Wang Xiaorui Wang Huiqiang Chai Jianbo Jia Yafei Wang |
| author_facet | Xiaowei Liang Hui Zhao Yongchao Dang Qihong Lei Shaoping Wang Xiaorui Wang Huiqiang Chai Jianbo Jia Yafei Wang |
| author_sort | Xiaowei Liang |
| collection | DOAJ |
| description | Hydraulic fracturing is widely recognized as a potential stimulation technology for the development of challenging natural gas hydrate. However, the fracturing behavior of non-diagenetic hydrate reservoirs has peculiar characteristics that are different from those of conventional oil and gas reservoirs. Herein, a fully coupled fluid-mechanical model for simulating hydraulic fracturing in hydrate-bearing sediments (HBS) was established based on the discrete element method, and the influence of hydrate saturation, in situ stress, and injection rate on the meso-fracture evolution was investigated. The results indicate that with the increase in hydrate saturation, the fracture morphology transitions from bi-wing to multi-branch, thereby enhancing fracture complexity. Both tensile and shear failure modes exist, and the tensile failure between the weakly cemented sediment particles is dominant. The tensile strength of HBS is an exponential function of hydrate saturation, with the breakdown pressure being governed by hydrate saturation and in situ stress, with the form being consistent with the classical Kirsch equation. Additionally, lower in situ stress and higher injection rates are conducive to the generation of microcracks, whereas an excessive injection rate reduces the fracture length. These findings contribute to understanding the meso-evolution mechanism of hydraulic fractures and guide the design of on-site hydraulic fracturing plans of natural gas hydrate reservoirs. |
| first_indexed | 2024-03-09T16:51:30Z |
| format | Article |
| id | doaj.art-24a9950b9c97458288dd1e6923f410a4 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-09T16:51:30Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-24a9950b9c97458288dd1e6923f410a42023-11-24T14:40:01ZengMDPI AGEnergies1996-10732023-11-011622750210.3390/en16227502Numerical Investigation on Mesoscale Evolution of Hydraulic Fractures in Hydrate-Bearing SedimentsXiaowei Liang0Hui Zhao1Yongchao Dang2Qihong Lei3Shaoping Wang4Xiaorui Wang5Huiqiang Chai6Jianbo Jia7Yafei Wang8Shale Oil Development Branch, PetroChina Changqing Oilfield Company, Qingyang 745000, ChinaShale Oil Development Branch, PetroChina Changqing Oilfield Company, Qingyang 745000, ChinaShale Oil Development Branch, PetroChina Changqing Oilfield Company, Qingyang 745000, ChinaExploration and Development Research Institute, PetroChina Changqing Oilfield Company, Xi’an 710016, ChinaDigital and Intelligentization Division, PetroChina Changqing Oilfield Company, Xi’an 710016, ChinaShale Oil Development Branch, PetroChina Changqing Oilfield Company, Qingyang 745000, ChinaShale Oil Development Branch, PetroChina Changqing Oilfield Company, Qingyang 745000, ChinaShale Oil Development Branch, PetroChina Changqing Oilfield Company, Qingyang 745000, ChinaCollege of Construction Engineering, Jilin University, Changchun 130026, ChinaHydraulic fracturing is widely recognized as a potential stimulation technology for the development of challenging natural gas hydrate. However, the fracturing behavior of non-diagenetic hydrate reservoirs has peculiar characteristics that are different from those of conventional oil and gas reservoirs. Herein, a fully coupled fluid-mechanical model for simulating hydraulic fracturing in hydrate-bearing sediments (HBS) was established based on the discrete element method, and the influence of hydrate saturation, in situ stress, and injection rate on the meso-fracture evolution was investigated. The results indicate that with the increase in hydrate saturation, the fracture morphology transitions from bi-wing to multi-branch, thereby enhancing fracture complexity. Both tensile and shear failure modes exist, and the tensile failure between the weakly cemented sediment particles is dominant. The tensile strength of HBS is an exponential function of hydrate saturation, with the breakdown pressure being governed by hydrate saturation and in situ stress, with the form being consistent with the classical Kirsch equation. Additionally, lower in situ stress and higher injection rates are conducive to the generation of microcracks, whereas an excessive injection rate reduces the fracture length. These findings contribute to understanding the meso-evolution mechanism of hydraulic fractures and guide the design of on-site hydraulic fracturing plans of natural gas hydrate reservoirs.https://www.mdpi.com/1996-1073/16/22/7502natural gas hydratehydraulic fracturinghydrate-bearing sedimentsfluid and mechanical couplingdiscrete element method |
| spellingShingle | Xiaowei Liang Hui Zhao Yongchao Dang Qihong Lei Shaoping Wang Xiaorui Wang Huiqiang Chai Jianbo Jia Yafei Wang Numerical Investigation on Mesoscale Evolution of Hydraulic Fractures in Hydrate-Bearing Sediments Energies natural gas hydrate hydraulic fracturing hydrate-bearing sediments fluid and mechanical coupling discrete element method |
| title | Numerical Investigation on Mesoscale Evolution of Hydraulic Fractures in Hydrate-Bearing Sediments |
| title_full | Numerical Investigation on Mesoscale Evolution of Hydraulic Fractures in Hydrate-Bearing Sediments |
| title_fullStr | Numerical Investigation on Mesoscale Evolution of Hydraulic Fractures in Hydrate-Bearing Sediments |
| title_full_unstemmed | Numerical Investigation on Mesoscale Evolution of Hydraulic Fractures in Hydrate-Bearing Sediments |
| title_short | Numerical Investigation on Mesoscale Evolution of Hydraulic Fractures in Hydrate-Bearing Sediments |
| title_sort | numerical investigation on mesoscale evolution of hydraulic fractures in hydrate bearing sediments |
| topic | natural gas hydrate hydraulic fracturing hydrate-bearing sediments fluid and mechanical coupling discrete element method |
| url | https://www.mdpi.com/1996-1073/16/22/7502 |
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