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Fluid flow modeling of naturally fractured reservoirs remains a challenge because of the complex nature of fracture systems controlled by various chemical and physical phenomena. A discrete fracture network (DFN) model represents an approach to capturing the relationship of fractures in a fracture system. Topology represents the connectivity aspect of the fracture planes, which have a fundamental role in flow simulation in geomaterials involving fractures and the rock matrix. Therefore, one of the most-used methods to treat fractured reservoirs is the double porosity-double permeability model. This approach requires the shape factor calculation, a key parameter used to determine the effects of coupled fracture-matrix fluid flow on the mass transfer between different domains. This paper presents a numerical investigation that aimed to evaluate the impact of fracture topology on the shape factor and equivalent permeability through hydraulic connectivity (f). This study was based on numerical simulations of flow performed in discrete fracture network (DFN) models embedded in finite element meshes (FEM). Modeled cases represent four hypothetical examples of fractured media and three real scenarios extracted from a Brazilian pre-salt carbonate reservoir model. We have compared the results of the numerical simulations with data obtained using Oda’s analytical model and Oda’s correction approach, considering the hydraulic connectivity f. The simulations showed that the equivalent permeability and the shape factor are strongly influenced by the hydraulic connectivity (f) in synthetic scenarios for X and Y-node topological patterns, which showed the higher value for f (0.81) and more expressive values for upscaled permeability (kx-node = 0.1151 and ky-node = 0.1153) and shape factor (25.6 and 14.5), respectively. We have shown that the analytical methods are not efficient for estimating the equivalent permeability of the fractured medium, including when these methods were corrected using topological aspects.

ABSTRACT. This study aimed to elaborate a mathematical model to estimate the amount of residential solid waste (RSW) generated and thus, to propose an alternative methodology for calculating the waste collection tax (WCT) for the city of João Pessoa, in Northeast region of Brazil, based on the estimated amount of RSW generated rather than on the constructed area of the residence, as is the case for this city. The methodological procedures consisted of daily weighing of the RSW along with readings of water and electricity consumption in three multi-family buildings and two single-family houses in the city of João Pessoa. Results have shown that the RSW generation rate was 0.526 kg capita in houses (single-family residence). Results also indicated that water consumption was highly correlated with RSW generation and that it is possible to estimate the amount of RSW generated in a residence considering its population and water consumption. Based on this model, a new methodology for the WCT calculation was proposed: an alternative which relies on the estimated amount of RSW rather than on the constructed area.Keywords: RSW collection tax, case study in João Pessoa.Proposição do cálculo da taxa de coleta de resíduos, pela quantidade estimada de resíduos sólidos domiciliares: estudo de caso da cidade de João Pessoa, estado da Paraíba RESUMO. Este trabalho objetivou a elaboração de um modelo matemático para estimativa da quantidade gerada de resíduos sólidos domiciliares (RSD) e propor uma metodologia alternativa para o cálculo da taxa de coleta de resíduos (TCR) para a cidade de João Pessoa-PB, com base na quantidade estimada de resíduos e não na área construída da residência, como é o caso desta cidade. O procedimento metodológico consistiu em se pesar diariamente a quantidade de RSD, bem como efetuar a leitura do consumo de água e de eletricidade em três edifícios multifamiliares e duas residências unifamiliares na cidade de João Pessoa. Os resultados indicaram que a taxa de geração per capita de RSD foi de 0,526 kg hab em casas. Os resultados também mostraram que o consumo de água é fortemente correlacionado com a geração de RSD e que é possível estimar a massa de RSD, pela população e pelo consumo de água da edificação. Com base neste modelo, uma metodologia alternativa para o cálculo da TCR foi proposta, levando em conta a massa estimada de RSD e não a área construída da edificação.Palavras-chave: taxa de coleta de RSD, caso de João Pessoa.

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