Fracture toughness tests of shale outcrops: Effects of confining pressure

Autores
Antinao Fuentealba, Fabián Jorge; Blanco, Gonzalo; Bianchi, Leandro Noe; Otegui, Luis Jose; Bianchi, Gustavo Luis
Año de publicación
2023
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Brittle rock fracture is a core concept in oil and gas and other rock mechanics projects. However, the understanding of fracture behavior under mechanical well-bottom conditions remains insufficient. This article aims to analyze experimental results for the critical stress intensity factor (KIC) of outcrops from Vaca Muerta carbonate-rich shale rocks, tested under a range of crack depths and confining pressures (0–70 MPa). Fracture toughness (KIC) is determined in multi-notched 1.5″ plugs using a novel experimental set up, in which the crack-driving-force KI and the confinement pressure are both applied by hydraulic systems. Finite fracture-mechanics-based models are used to calculate KI. Our experimental results show that tests carried out at well-bottom pressures lead to apparent rock toughness doubling those for tests at atmospheric pressure. Stress analysis demonstrates that the size of the tensile stressed zone ahead of the crack tip tends to decrease as confining pressure increases. Additionally, compressive deviatoric stresses are developed ahead of the tensile zone, with their magnitude being dependent on the level of confinement. Moreover, triaxial stress states induced by confinement could lead to microcracking ahead of the crack tip. The mechanisms of crack closure and deviatoric stress-induced microcrack initiation are combined to assess a plausible mechanism for rock toughness enhancement under confined conditions. It is concluded that increasing triaxial pressure confinement allows to accurately model the mechanical response of shale rocks under reservoir conditions.
Fil: Antinao Fuentealba, Fabián Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina
Fil: Blanco, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina
Fil: Bianchi, Leandro Noe. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina
Fil: Otegui, Luis Jose. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina
Fil: Bianchi, Gustavo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina
Materia
FRACTURE TEST
MICROCRACKING
SHALE ROCKS
TOUGHENING MECHANISM
VACA MUERTA
Nivel de accesibilidad
acceso embargado
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/224399
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/224399
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Fracture toughness tests of shale outcrops: Effects of confining pressureAntinao Fuentealba, Fabián JorgeBlanco, GonzaloBianchi, Leandro NoeOtegui, Luis JoseBianchi, Gustavo LuisFRACTURE TESTMICROCRACKINGSHALE ROCKSTOUGHENING MECHANISMVACA MUERTAhttps://purl.org/becyt/ford/1.7https://purl.org/becyt/ford/1Brittle rock fracture is a core concept in oil and gas and other rock mechanics projects. However, the understanding of fracture behavior under mechanical well-bottom conditions remains insufficient. This article aims to analyze experimental results for the critical stress intensity factor (KIC) of outcrops from Vaca Muerta carbonate-rich shale rocks, tested under a range of crack depths and confining pressures (0–70 MPa). Fracture toughness (KIC) is determined in multi-notched 1.5″ plugs using a novel experimental set up, in which the crack-driving-force KI and the confinement pressure are both applied by hydraulic systems. Finite fracture-mechanics-based models are used to calculate KI. Our experimental results show that tests carried out at well-bottom pressures lead to apparent rock toughness doubling those for tests at atmospheric pressure. Stress analysis demonstrates that the size of the tensile stressed zone ahead of the crack tip tends to decrease as confining pressure increases. Additionally, compressive deviatoric stresses are developed ahead of the tensile zone, with their magnitude being dependent on the level of confinement. Moreover, triaxial stress states induced by confinement could lead to microcracking ahead of the crack tip. The mechanisms of crack closure and deviatoric stress-induced microcrack initiation are combined to assess a plausible mechanism for rock toughness enhancement under confined conditions. It is concluded that increasing triaxial pressure confinement allows to accurately model the mechanical response of shale rocks under reservoir conditions.Fil: Antinao Fuentealba, Fabián Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; ArgentinaFil: Blanco, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; ArgentinaFil: Bianchi, Leandro Noe. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Otegui, Luis Jose. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Bianchi, Gustavo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; ArgentinaElsevier2023-11info:eu-repo/date/embargoEnd/2024-05-22info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/224399Antinao Fuentealba, Fabián Jorge; Blanco, Gonzalo; Bianchi, Leandro Noe; Otegui, Luis Jose; Bianchi, Gustavo Luis; Fracture toughness tests of shale outcrops: Effects of confining pressure; Elsevier; Geoenergy Science and Engineering; 232; 11-2023; 1-262949-8910CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S2949891023010412info:eu-repo/semantics/altIdentifier/doi/10.1016/j.geoen.2023.212454info:eu-repo/semantics/embargoedAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T10:11:05Zoai:ri.conicet.gov.ar:11336/224399instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-03 10:11:06.056CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Fracture toughness tests of shale outcrops: Effects of confining pressure
title Fracture toughness tests of shale outcrops: Effects of confining pressure
spellingShingle Fracture toughness tests of shale outcrops: Effects of confining pressure
Antinao Fuentealba, Fabián Jorge
FRACTURE TEST
MICROCRACKING
SHALE ROCKS
TOUGHENING MECHANISM
VACA MUERTA
title_short Fracture toughness tests of shale outcrops: Effects of confining pressure
title_full Fracture toughness tests of shale outcrops: Effects of confining pressure
title_fullStr Fracture toughness tests of shale outcrops: Effects of confining pressure
title_full_unstemmed Fracture toughness tests of shale outcrops: Effects of confining pressure
title_sort Fracture toughness tests of shale outcrops: Effects of confining pressure
dc.creator.none.fl_str_mv Antinao Fuentealba, Fabián Jorge
Blanco, Gonzalo
Bianchi, Leandro Noe
Otegui, Luis Jose
Bianchi, Gustavo Luis
author Antinao Fuentealba, Fabián Jorge
author_facet Antinao Fuentealba, Fabián Jorge
Blanco, Gonzalo
Bianchi, Leandro Noe
Otegui, Luis Jose
Bianchi, Gustavo Luis
author_role author
author2 Blanco, Gonzalo
Bianchi, Leandro Noe
Otegui, Luis Jose
Bianchi, Gustavo Luis
author2_role author
author
author
author
dc.subject.none.fl_str_mv FRACTURE TEST
MICROCRACKING
SHALE ROCKS
TOUGHENING MECHANISM
VACA MUERTA
topic FRACTURE TEST
MICROCRACKING
SHALE ROCKS
TOUGHENING MECHANISM
VACA MUERTA
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.7
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Brittle rock fracture is a core concept in oil and gas and other rock mechanics projects. However, the understanding of fracture behavior under mechanical well-bottom conditions remains insufficient. This article aims to analyze experimental results for the critical stress intensity factor (KIC) of outcrops from Vaca Muerta carbonate-rich shale rocks, tested under a range of crack depths and confining pressures (0–70 MPa). Fracture toughness (KIC) is determined in multi-notched 1.5″ plugs using a novel experimental set up, in which the crack-driving-force KI and the confinement pressure are both applied by hydraulic systems. Finite fracture-mechanics-based models are used to calculate KI. Our experimental results show that tests carried out at well-bottom pressures lead to apparent rock toughness doubling those for tests at atmospheric pressure. Stress analysis demonstrates that the size of the tensile stressed zone ahead of the crack tip tends to decrease as confining pressure increases. Additionally, compressive deviatoric stresses are developed ahead of the tensile zone, with their magnitude being dependent on the level of confinement. Moreover, triaxial stress states induced by confinement could lead to microcracking ahead of the crack tip. The mechanisms of crack closure and deviatoric stress-induced microcrack initiation are combined to assess a plausible mechanism for rock toughness enhancement under confined conditions. It is concluded that increasing triaxial pressure confinement allows to accurately model the mechanical response of shale rocks under reservoir conditions.
Fil: Antinao Fuentealba, Fabián Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina
Fil: Blanco, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina
Fil: Bianchi, Leandro Noe. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina
Fil: Otegui, Luis Jose. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina
Fil: Bianchi, Gustavo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina
description Brittle rock fracture is a core concept in oil and gas and other rock mechanics projects. However, the understanding of fracture behavior under mechanical well-bottom conditions remains insufficient. This article aims to analyze experimental results for the critical stress intensity factor (KIC) of outcrops from Vaca Muerta carbonate-rich shale rocks, tested under a range of crack depths and confining pressures (0–70 MPa). Fracture toughness (KIC) is determined in multi-notched 1.5″ plugs using a novel experimental set up, in which the crack-driving-force KI and the confinement pressure are both applied by hydraulic systems. Finite fracture-mechanics-based models are used to calculate KI. Our experimental results show that tests carried out at well-bottom pressures lead to apparent rock toughness doubling those for tests at atmospheric pressure. Stress analysis demonstrates that the size of the tensile stressed zone ahead of the crack tip tends to decrease as confining pressure increases. Additionally, compressive deviatoric stresses are developed ahead of the tensile zone, with their magnitude being dependent on the level of confinement. Moreover, triaxial stress states induced by confinement could lead to microcracking ahead of the crack tip. The mechanisms of crack closure and deviatoric stress-induced microcrack initiation are combined to assess a plausible mechanism for rock toughness enhancement under confined conditions. It is concluded that increasing triaxial pressure confinement allows to accurately model the mechanical response of shale rocks under reservoir conditions.
publishDate 2023
dc.date.none.fl_str_mv 2023-11
info:eu-repo/date/embargoEnd/2024-05-22
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/224399
Antinao Fuentealba, Fabián Jorge; Blanco, Gonzalo; Bianchi, Leandro Noe; Otegui, Luis Jose; Bianchi, Gustavo Luis; Fracture toughness tests of shale outcrops: Effects of confining pressure; Elsevier; Geoenergy Science and Engineering; 232; 11-2023; 1-26
2949-8910
CONICET Digital
CONICET
url http://hdl.handle.net/11336/224399
identifier_str_mv Antinao Fuentealba, Fabián Jorge; Blanco, Gonzalo; Bianchi, Leandro Noe; Otegui, Luis Jose; Bianchi, Gustavo Luis; Fracture toughness tests of shale outcrops: Effects of confining pressure; Elsevier; Geoenergy Science and Engineering; 232; 11-2023; 1-26
2949-8910
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S2949891023010412
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.geoen.2023.212454
dc.rights.none.fl_str_mv info:eu-repo/semantics/embargoedAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv embargoedAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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