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Time-Dependent Effect of Seepage Force on Initiation of Hydraulic Fracture around a Vertical Wellbore
Fluid penetration into the rock during hydraulic fracturing has been an essential issue in studying the mechanism of fracture initiation, especially the seepage force caused by fluid penetration, which has an important effect on the fracture initiation mechanism around a wellbore. However, in previo...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10004142/ https://www.ncbi.nlm.nih.gov/pubmed/36903134 http://dx.doi.org/10.3390/ma16052012 |
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author | Rim, Hyonchol Chen, Youliang Tokgo, Jun Du, Xi Li, Yi Wang, Suran |
author_facet | Rim, Hyonchol Chen, Youliang Tokgo, Jun Du, Xi Li, Yi Wang, Suran |
author_sort | Rim, Hyonchol |
collection | PubMed |
description | Fluid penetration into the rock during hydraulic fracturing has been an essential issue in studying the mechanism of fracture initiation, especially the seepage force caused by fluid penetration, which has an important effect on the fracture initiation mechanism around a wellbore. However, in previous studies, the effect of seepage force under unsteady seepage on the fracture initiation mechanism was not considered. In this study, a new seepage model that can predict the variations of pore pressure and seepage force with time around a vertical wellbore for hydraulic fracturing was established by using the method of separation of variables and the Bessel function theory. Then, based on the proposed seepage model, a new circumferential stress calculation model considering the time-dependent effect of seepage force was established. The accuracy and applicability of the seepage model and the mechanical model were verified by comparison with numerical, analytical and experimental results. The time-dependent effect of seepage force on fracture initiation under unsteady seepage was analyzed and discussed. The results show that when the wellbore pressure is constant, the circumferential stress induced by seepage force increases over time, and the possibility of fracture initiation also increases. The higher the hydraulic conductivity, the lower the fluid viscosity and the shorter the time required for tensile failure during hydraulic fracturing. In particular, when the tensile strength of rock is lower, the fracture initiation may occur within the rock mass rather than on the wellbore wall. This study is promising to provide a theoretical basis and practical guidance for further research on fracture initiation in the future. |
format | Online Article Text |
id | pubmed-10004142 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-100041422023-03-11 Time-Dependent Effect of Seepage Force on Initiation of Hydraulic Fracture around a Vertical Wellbore Rim, Hyonchol Chen, Youliang Tokgo, Jun Du, Xi Li, Yi Wang, Suran Materials (Basel) Article Fluid penetration into the rock during hydraulic fracturing has been an essential issue in studying the mechanism of fracture initiation, especially the seepage force caused by fluid penetration, which has an important effect on the fracture initiation mechanism around a wellbore. However, in previous studies, the effect of seepage force under unsteady seepage on the fracture initiation mechanism was not considered. In this study, a new seepage model that can predict the variations of pore pressure and seepage force with time around a vertical wellbore for hydraulic fracturing was established by using the method of separation of variables and the Bessel function theory. Then, based on the proposed seepage model, a new circumferential stress calculation model considering the time-dependent effect of seepage force was established. The accuracy and applicability of the seepage model and the mechanical model were verified by comparison with numerical, analytical and experimental results. The time-dependent effect of seepage force on fracture initiation under unsteady seepage was analyzed and discussed. The results show that when the wellbore pressure is constant, the circumferential stress induced by seepage force increases over time, and the possibility of fracture initiation also increases. The higher the hydraulic conductivity, the lower the fluid viscosity and the shorter the time required for tensile failure during hydraulic fracturing. In particular, when the tensile strength of rock is lower, the fracture initiation may occur within the rock mass rather than on the wellbore wall. This study is promising to provide a theoretical basis and practical guidance for further research on fracture initiation in the future. MDPI 2023-02-28 /pmc/articles/PMC10004142/ /pubmed/36903134 http://dx.doi.org/10.3390/ma16052012 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Rim, Hyonchol Chen, Youliang Tokgo, Jun Du, Xi Li, Yi Wang, Suran Time-Dependent Effect of Seepage Force on Initiation of Hydraulic Fracture around a Vertical Wellbore |
title | Time-Dependent Effect of Seepage Force on Initiation of Hydraulic Fracture around a Vertical Wellbore |
title_full | Time-Dependent Effect of Seepage Force on Initiation of Hydraulic Fracture around a Vertical Wellbore |
title_fullStr | Time-Dependent Effect of Seepage Force on Initiation of Hydraulic Fracture around a Vertical Wellbore |
title_full_unstemmed | Time-Dependent Effect of Seepage Force on Initiation of Hydraulic Fracture around a Vertical Wellbore |
title_short | Time-Dependent Effect of Seepage Force on Initiation of Hydraulic Fracture around a Vertical Wellbore |
title_sort | time-dependent effect of seepage force on initiation of hydraulic fracture around a vertical wellbore |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10004142/ https://www.ncbi.nlm.nih.gov/pubmed/36903134 http://dx.doi.org/10.3390/ma16052012 |
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