Mineralogical and Maturation Considerations of the Coqueiros Formation (Campos Basin, Brazil): Insights from Multi-Technique Analyses of Source Rocks
The Coqueiros Formation, a strategic stratigraphic unit within the Lagoa Feia Group (LFG) in the Campos Basin offshore Brazil, is known for its lacustrine carbonate deposits, which include both organic-rich shales and economically important “coquina” reservoirs. While coquina facies are widely recog...
Saved in:
| Main Authors: | , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-10-01
|
| Series: | Geosciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3263/14/11/286 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1846153460366442496 |
|---|---|
| author | Gabriel A. Barberes Flávia C. Marques Dalva A. L. Almeida Linus Pauling F. Peixoto Lenize F. Maia Antonio Carlos Sant’Ana Gustavo F. S. Andrade Celly M. S. Izumi Victor Salgado-Campos Thiago Feital Luiz Fernando C. de Oliveira Ana Luiza Albuquerque |
| author_facet | Gabriel A. Barberes Flávia C. Marques Dalva A. L. Almeida Linus Pauling F. Peixoto Lenize F. Maia Antonio Carlos Sant’Ana Gustavo F. S. Andrade Celly M. S. Izumi Victor Salgado-Campos Thiago Feital Luiz Fernando C. de Oliveira Ana Luiza Albuquerque |
| author_sort | Gabriel A. Barberes |
| collection | DOAJ |
| description | The Coqueiros Formation, a strategic stratigraphic unit within the Lagoa Feia Group (LFG) in the Campos Basin offshore Brazil, is known for its lacustrine carbonate deposits, which include both organic-rich shales and economically important “coquina” reservoirs. While coquina facies are widely recognized as reservoirs, the source-rock potential of the intercalated shales remains relatively underexplored. This study aims to characterize the mineralogy and thermal maturity of the Coqueiros Formation to assess its potential as a source rock, using a multi-technique approach integrating X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Raman spectroscopy analyses of shale samples from two wells: 3-BP-11-RJS and 6-DEV-18P-RJS. XRD analyses revealed a heterogeneous mineralogy dominated by carbonates (calcite and dolomite) and quartz, with significant contributions from clay minerals and trace minerals such as pyrite and barite. SEM imaging revealed a heterogeneous fabric with grain size, morphology, and porosity variations, reflecting a dynamic lacustrine depositional setting influenced by storm events and fluctuations in terrigenous input. The presence of authigenic minerals, as reported in other studies, such as saddle dolomite, mega-quartz, and various sulfides, provides evidence for hydrothermal alteration, likely related to Late Cretaceous magmatic activity in the Campos Basin. Raman spectroscopy yielded equivalent vitrinite reflectance (Ro%) values consistently exceeding 1.00, ranging from 1.03 to 1.40, indicating that the organic matter in the Coqueiros Formation shales has attained a high thermal maturity level, surpassing the oil window and reaching the condensate wet gas zone. The mineralogical and equivalent maturation data presented herein provide a valuable foundation for future studies, highlighting the complexity and heterogeneity of the Coqueiros Formation and its potential significance as a source rock within the Campos Basin petroleum system. |
| format | Article |
| id | doaj-art-b47c1ec3ea524ec2bc5f29bd3329bd53 |
| institution | Kabale University |
| issn | 2076-3263 |
| language | English |
| publishDate | 2024-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Geosciences |
| spelling | doaj-art-b47c1ec3ea524ec2bc5f29bd3329bd532024-11-26T18:05:37ZengMDPI AGGeosciences2076-32632024-10-01141128610.3390/geosciences14110286Mineralogical and Maturation Considerations of the Coqueiros Formation (Campos Basin, Brazil): Insights from Multi-Technique Analyses of Source RocksGabriel A. Barberes0Flávia C. Marques1Dalva A. L. Almeida2Linus Pauling F. Peixoto3Lenize F. Maia4Antonio Carlos Sant’Ana5Gustavo F. S. Andrade6Celly M. S. Izumi7Victor Salgado-Campos8Thiago Feital9Luiz Fernando C. de Oliveira10Ana Luiza Albuquerque11Departamento de Geologia e Geofísica, Universidade Federal Fluminense, Av. Gen. Milton Tavares de Souza s/nº—Gragoatá—Campus da Praia Vermelha, Niterói 24210-346, RJ, BrazilNúcleo de Espectroscopia e Estrutura Molecular, Centro de Estudos de Materiais, Departamento de Química, Universidade Federal de Juiz de Fora, R. José Lourenço Kelmer s/n, Martelos, Juiz de Fora 36036-900, MG, BrazilNúcleo de Espectroscopia e Estrutura Molecular, Centro de Estudos de Materiais, Departamento de Química, Universidade Federal de Juiz de Fora, R. José Lourenço Kelmer s/n, Martelos, Juiz de Fora 36036-900, MG, BrazilNúcleo de Espectroscopia e Estrutura Molecular, Centro de Estudos de Materiais, Departamento de Química, Universidade Federal de Juiz de Fora, R. José Lourenço Kelmer s/n, Martelos, Juiz de Fora 36036-900, MG, BrazilNúcleo de Espectroscopia e Estrutura Molecular, Centro de Estudos de Materiais, Departamento de Química, Universidade Federal de Juiz de Fora, R. José Lourenço Kelmer s/n, Martelos, Juiz de Fora 36036-900, MG, BrazilNúcleo de Espectroscopia e Estrutura Molecular, Centro de Estudos de Materiais, Departamento de Química, Universidade Federal de Juiz de Fora, R. José Lourenço Kelmer s/n, Martelos, Juiz de Fora 36036-900, MG, BrazilNúcleo de Espectroscopia e Estrutura Molecular, Centro de Estudos de Materiais, Departamento de Química, Universidade Federal de Juiz de Fora, R. José Lourenço Kelmer s/n, Martelos, Juiz de Fora 36036-900, MG, BrazilNúcleo de Espectroscopia e Estrutura Molecular, Centro de Estudos de Materiais, Departamento de Química, Universidade Federal de Juiz de Fora, R. José Lourenço Kelmer s/n, Martelos, Juiz de Fora 36036-900, MG, BrazilDepartamento de Geologia e Geofísica, Universidade Federal Fluminense, Av. Gen. Milton Tavares de Souza s/nº—Gragoatá—Campus da Praia Vermelha, Niterói 24210-346, RJ, BrazilOPTIMATECH Ltd.a., Rio de Janeiro 22410-905, RJ, BrazilNúcleo de Espectroscopia e Estrutura Molecular, Centro de Estudos de Materiais, Departamento de Química, Universidade Federal de Juiz de Fora, R. José Lourenço Kelmer s/n, Martelos, Juiz de Fora 36036-900, MG, BrazilDepartamento de Geologia e Geofísica, Universidade Federal Fluminense, Av. Gen. Milton Tavares de Souza s/nº—Gragoatá—Campus da Praia Vermelha, Niterói 24210-346, RJ, BrazilThe Coqueiros Formation, a strategic stratigraphic unit within the Lagoa Feia Group (LFG) in the Campos Basin offshore Brazil, is known for its lacustrine carbonate deposits, which include both organic-rich shales and economically important “coquina” reservoirs. While coquina facies are widely recognized as reservoirs, the source-rock potential of the intercalated shales remains relatively underexplored. This study aims to characterize the mineralogy and thermal maturity of the Coqueiros Formation to assess its potential as a source rock, using a multi-technique approach integrating X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Raman spectroscopy analyses of shale samples from two wells: 3-BP-11-RJS and 6-DEV-18P-RJS. XRD analyses revealed a heterogeneous mineralogy dominated by carbonates (calcite and dolomite) and quartz, with significant contributions from clay minerals and trace minerals such as pyrite and barite. SEM imaging revealed a heterogeneous fabric with grain size, morphology, and porosity variations, reflecting a dynamic lacustrine depositional setting influenced by storm events and fluctuations in terrigenous input. The presence of authigenic minerals, as reported in other studies, such as saddle dolomite, mega-quartz, and various sulfides, provides evidence for hydrothermal alteration, likely related to Late Cretaceous magmatic activity in the Campos Basin. Raman spectroscopy yielded equivalent vitrinite reflectance (Ro%) values consistently exceeding 1.00, ranging from 1.03 to 1.40, indicating that the organic matter in the Coqueiros Formation shales has attained a high thermal maturity level, surpassing the oil window and reaching the condensate wet gas zone. The mineralogical and equivalent maturation data presented herein provide a valuable foundation for future studies, highlighting the complexity and heterogeneity of the Coqueiros Formation and its potential significance as a source rock within the Campos Basin petroleum system.https://www.mdpi.com/2076-3263/14/11/286Campos BasinCoqueiros Formationsource rockXRDRaman spectroscopySEM |
| spellingShingle | Gabriel A. Barberes Flávia C. Marques Dalva A. L. Almeida Linus Pauling F. Peixoto Lenize F. Maia Antonio Carlos Sant’Ana Gustavo F. S. Andrade Celly M. S. Izumi Victor Salgado-Campos Thiago Feital Luiz Fernando C. de Oliveira Ana Luiza Albuquerque Mineralogical and Maturation Considerations of the Coqueiros Formation (Campos Basin, Brazil): Insights from Multi-Technique Analyses of Source Rocks Geosciences Campos Basin Coqueiros Formation source rock XRD Raman spectroscopy SEM |
| title | Mineralogical and Maturation Considerations of the Coqueiros Formation (Campos Basin, Brazil): Insights from Multi-Technique Analyses of Source Rocks |
| title_full | Mineralogical and Maturation Considerations of the Coqueiros Formation (Campos Basin, Brazil): Insights from Multi-Technique Analyses of Source Rocks |
| title_fullStr | Mineralogical and Maturation Considerations of the Coqueiros Formation (Campos Basin, Brazil): Insights from Multi-Technique Analyses of Source Rocks |
| title_full_unstemmed | Mineralogical and Maturation Considerations of the Coqueiros Formation (Campos Basin, Brazil): Insights from Multi-Technique Analyses of Source Rocks |
| title_short | Mineralogical and Maturation Considerations of the Coqueiros Formation (Campos Basin, Brazil): Insights from Multi-Technique Analyses of Source Rocks |
| title_sort | mineralogical and maturation considerations of the coqueiros formation campos basin brazil insights from multi technique analyses of source rocks |
| topic | Campos Basin Coqueiros Formation source rock XRD Raman spectroscopy SEM |
| url | https://www.mdpi.com/2076-3263/14/11/286 |
| work_keys_str_mv | AT gabrielabarberes mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks AT flaviacmarques mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks AT dalvaalalmeida mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks AT linuspaulingfpeixoto mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks AT lenizefmaia mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks AT antoniocarlossantana mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks AT gustavofsandrade mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks AT cellymsizumi mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks AT victorsalgadocampos mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks AT thiagofeital mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks AT luizfernandocdeoliveira mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks AT analuizaalbuquerque mineralogicalandmaturationconsiderationsofthecoqueirosformationcamposbasinbrazilinsightsfrommultitechniqueanalysesofsourcerocks |