Banca de QUALIFICAÇÃO: JOAO VICTOR FREIRE PEREIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : JOAO VICTOR FREIRE PEREIRA
DATE: 15/09/2021
TIME: 14:30
LOCAL: videoconferência
TITLE:

Building a 3D Digital Outcrop Model incorporating stratigraphy, petrophysics and stochastic fracture networks: Application in the Cristal Cave (São Francisco Craton, NE/Brazil)

KEY WORDS:

Digital Outcrop Model; Discrete Fracture Network; fractures; karst

PAGES: 25
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

Carbonate rocks are relevant hydrocarbon reservoirs and represent a large portion of the world oil production. The multiple combinations of primary and secondary porosities (fractures and karstic features included) make the exploration of this type of reservoir a challenging task. Different scenarios of primary and secondary porosity can be used to generate computational models, which are the main tools for fluid flow simulations. The Discrete Fracture Networks (DFN) are a good example of models applied in those simulations. However, the DFNs are strictly focused in the fractures and do not incorporate karstic features even in the case of fracture enlargement due to dissolution processes. The present research aims to develop a 3D Digital Outcrop Model, that combines deterministic (stratigraphy and petrophysics) and stochastic (fracture networks with dissolution enlargement) elements. Photogrammetric data from the Access 1 of the Cristal Cave, São Francisco Craton, was interpreted to generate strata, karstic bodies and fracture networks. The statistical parameters of distribution and persistence (P21) were estimated from the fracture traces mapped in the walls and ceiling of the cave model. In sequence, these parameters supported a stochastic DFN generation, which is statistically equivalent to the real fracture network present in the volume containing the cave. The fracture enlargement by dissolution processes will be implemented through scale laws relating aperture and fracture length. The layers were mapped following horizontal discontinuities, as a mean to incorporate vertical variations in fracture density, guided by the fracture stratigraphy concept. The 3D digital model is then composed by layers containing karstic-enlarged fractures. Porosity and permeability variations might be added in the future. The final product will be a 3D digital model that integrates stratigraphy, petrophysics and a fracture network statistically equivalent to the real one. Different fracture karstification stages will be investigated, resulting in different static models that might be useful for fluid flow simulations.

BANKING MEMBERS:
Interno - 350640 - FRANCISCO HILARIO REGO BEZERRA
Externo à Instituição - RENATO RAMOS DA SILVA DANTAS - UFRN
Externo à Instituição - VINCENZO LA BRUNA - UFRN
Presidente - 349684 - WALTER EUGENIO DE MEDEIROS