Modeling the effects of natural fractures on the permeability of reservoir rocks

Detalhes bibliográficos
Autor(a) principal: Fabbri, Heber Agnelo Antonel
Data de Publicação: 2019
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Institucional da UNESP
Texto Completo: http://hdl.handle.net/11449/190698
Resumo: This work presents a numerical method based on Discrete Fracture Model (DFM) and the Finite Element Method (FEM), where the fractures are approximated by a reduced model. The flow along and across the fracture is described by a simplified set of equations considering both conductive fractures and barriers. The coupled hydromechanical model is composed of a linear poroelastic Biot medium and a nonlinear model based on damage mechanics for the fractures, which captures the nonlinear normal deformation and shear dilation according to the Barton-Bandis model. Both flow and geomechanical models are approximated using the finite element model. Fractures are explicitly represented by three-node standard finite elements with high aspect ratio (i.e. ratio between the largest and the smallest element dimensions) and appropriate constitutive laws. These interface high aspect ratio elements represent a regularization method which continuously approximate the discontinuous pressure and displacement fields on a narrow material band around the fracture. The complete mathematical formulation is presented together with the algorithm suggested for its numerical implementation. The efficiency of the proposed method is demonstrated through numerical examples, as well as the effects of fractures in the hydraulic properties of porous rocks and its dependency of the stress state.
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spelling Modeling the effects of natural fractures on the permeability of reservoir rocksModelagem do efeito de fraturas naturais na permeabilidade de rochas reservatórioFractured reservoirHydromechanical couplingBarton-Bandis modelInterface finite elements with high aspect ratioReservatórios fraturadosAclopamento hidromecânicoModel de Barton-BandisElementos finitos de interface com elevada razão de aspectoThis work presents a numerical method based on Discrete Fracture Model (DFM) and the Finite Element Method (FEM), where the fractures are approximated by a reduced model. The flow along and across the fracture is described by a simplified set of equations considering both conductive fractures and barriers. The coupled hydromechanical model is composed of a linear poroelastic Biot medium and a nonlinear model based on damage mechanics for the fractures, which captures the nonlinear normal deformation and shear dilation according to the Barton-Bandis model. Both flow and geomechanical models are approximated using the finite element model. Fractures are explicitly represented by three-node standard finite elements with high aspect ratio (i.e. ratio between the largest and the smallest element dimensions) and appropriate constitutive laws. These interface high aspect ratio elements represent a regularization method which continuously approximate the discontinuous pressure and displacement fields on a narrow material band around the fracture. The complete mathematical formulation is presented together with the algorithm suggested for its numerical implementation. The efficiency of the proposed method is demonstrated through numerical examples, as well as the effects of fractures in the hydraulic properties of porous rocks and its dependency of the stress state.Este trabalho apresenta um método numérico baseado no Modelo de Fratura Discreta (MFD) e no Método dos Elementos Finitos (MEF), onde as fraturas são aproximadas por um modelo reduzido. O fluxo ao longo e através da fratura é descrito por um conjunto simplificado de equações, considerando tanto fraturas condutoras quanto barreiras. O modelo hidromecânico acoplado é composto por um meio poroelástico linear e um modelo não linear para fraturas, baseado na mecânica do dano e que captura a deformação normal não linear e a dilatância ao cisalhamento de acordo com o modelo de Barton-Bandis. Os modelos de fluxo e geomecânico são aproximados usando o método dos elementos finitos. As fraturas são explicitamente representadas por elementos finitos triangulares de três nós com elevada razão de aspecto (isto é, a razão entre a maior e a menor dimensão do elemento) e leis constitutivas apropriadas. Esses elementos de elevada razão de aspecto representam um método de regularização que aproxima de forma contínua os campos de pressão e deslocamento descontínuos em uma estreita faixa material ao redor da fratura. A formulação matemática completa é apresentada juntamente com o algoritmo sugerido para sua implementação numérica. A eficiência do método proposto é demonstrada através de exemplos numéricos, bem como os efeitos de fraturas nas propriedades hidráulicas de rochas porosas e sua dependência do estado de tensão.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)001Universidade Estadual Paulista (Unesp)Manzoli, Osvaldo Luís [UNESP]Universidade Estadual Paulista (Unesp)Fabbri, Heber Agnelo Antonel2019-10-10T17:40:54Z2019-10-10T17:40:54Z2019-07-12info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/11449/19069800092587533004056080P8enginfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESP2024-06-28T19:31:02Zoai:repositorio.unesp.br:11449/190698Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T23:40:09.585846Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false
dc.title.none.fl_str_mv Modeling the effects of natural fractures on the permeability of reservoir rocks
Modelagem do efeito de fraturas naturais na permeabilidade de rochas reservatório
title Modeling the effects of natural fractures on the permeability of reservoir rocks
spellingShingle Modeling the effects of natural fractures on the permeability of reservoir rocks
Fabbri, Heber Agnelo Antonel
Fractured reservoir
Hydromechanical coupling
Barton-Bandis model
Interface finite elements with high aspect ratio
Reservatórios fraturados
Aclopamento hidromecânico
Model de Barton-Bandis
Elementos finitos de interface com elevada razão de aspecto
title_short Modeling the effects of natural fractures on the permeability of reservoir rocks
title_full Modeling the effects of natural fractures on the permeability of reservoir rocks
title_fullStr Modeling the effects of natural fractures on the permeability of reservoir rocks
title_full_unstemmed Modeling the effects of natural fractures on the permeability of reservoir rocks
title_sort Modeling the effects of natural fractures on the permeability of reservoir rocks
author Fabbri, Heber Agnelo Antonel
author_facet Fabbri, Heber Agnelo Antonel
author_role author
dc.contributor.none.fl_str_mv Manzoli, Osvaldo Luís [UNESP]
Universidade Estadual Paulista (Unesp)
dc.contributor.author.fl_str_mv Fabbri, Heber Agnelo Antonel
dc.subject.por.fl_str_mv Fractured reservoir
Hydromechanical coupling
Barton-Bandis model
Interface finite elements with high aspect ratio
Reservatórios fraturados
Aclopamento hidromecânico
Model de Barton-Bandis
Elementos finitos de interface com elevada razão de aspecto
topic Fractured reservoir
Hydromechanical coupling
Barton-Bandis model
Interface finite elements with high aspect ratio
Reservatórios fraturados
Aclopamento hidromecânico
Model de Barton-Bandis
Elementos finitos de interface com elevada razão de aspecto
description This work presents a numerical method based on Discrete Fracture Model (DFM) and the Finite Element Method (FEM), where the fractures are approximated by a reduced model. The flow along and across the fracture is described by a simplified set of equations considering both conductive fractures and barriers. The coupled hydromechanical model is composed of a linear poroelastic Biot medium and a nonlinear model based on damage mechanics for the fractures, which captures the nonlinear normal deformation and shear dilation according to the Barton-Bandis model. Both flow and geomechanical models are approximated using the finite element model. Fractures are explicitly represented by three-node standard finite elements with high aspect ratio (i.e. ratio between the largest and the smallest element dimensions) and appropriate constitutive laws. These interface high aspect ratio elements represent a regularization method which continuously approximate the discontinuous pressure and displacement fields on a narrow material band around the fracture. The complete mathematical formulation is presented together with the algorithm suggested for its numerical implementation. The efficiency of the proposed method is demonstrated through numerical examples, as well as the effects of fractures in the hydraulic properties of porous rocks and its dependency of the stress state.
publishDate 2019
dc.date.none.fl_str_mv 2019-10-10T17:40:54Z
2019-10-10T17:40:54Z
2019-07-12
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/masterThesis
format masterThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/11449/190698
000925875
33004056080P8
url http://hdl.handle.net/11449/190698
identifier_str_mv 000925875
33004056080P8
dc.language.iso.fl_str_mv eng
language eng
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universidade Estadual Paulista (Unesp)
publisher.none.fl_str_mv Universidade Estadual Paulista (Unesp)
dc.source.none.fl_str_mv reponame:Repositório Institucional da UNESP
instname:Universidade Estadual Paulista (UNESP)
instacron:UNESP
instname_str Universidade Estadual Paulista (UNESP)
instacron_str UNESP
institution UNESP
reponame_str Repositório Institucional da UNESP
collection Repositório Institucional da UNESP
repository.name.fl_str_mv Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)
repository.mail.fl_str_mv
_version_ 1808129541073272832

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