Assessment of continuous and alternating CO2 injection under Brazilian-pre-salt-like conditions R. O. Lima, A. de L. Cunha, J. A. O. Santos, A. J. V. Garcia, J. P. L. dos Santos Journal of Petroleum Exploration and Production Technology, 2020 Carbonate rocks have become very important in Brazil with pre-salt reservoir discoveries in Santos and Campos Basins. Since then, great efforts in research and technology have been made to characterize and develop these reservoirs. In this sense, outcrop analogue studies have become a powerful tool for helping the recognition of geological heterogeneities responsible for controlling the fluid flow in hydrocarbon reservoirs. Besides that, pre-salt oil recovery is associated with high carbon dioxide (CO2) production, and due environmental issues, it is required a sustainable destination for this contaminant. CO2injection in the reservoir, either pure or mixed to the produced gas stream, could be a good manner to deal with this undesirable component and increase the oil recovery. This work uses outcrop analogue characterization to understand how carbonate reservoir characteristics impact the selection of the best recovery strategy under Brazilian-pre-salt-like conditions. Numerical simulation models were run using the flow simulator TEMPEST MORE (version 7.1) with isothermal compositional modeling. The oil recovery process was modeled by continuous and alternating injection of CO2and water. The recovered oil fractions for the simulation case with water alternating CO2injection were higher than with the use of continuous injection of CO2or water.
Modeling and simulation of the desulfurization of a sour gas streams by adsorption: Influence of the isotherm model Santos dos, Lima de, Lobato de, Caetano Moraes, Severo Baptista, et al. Chemical Industry and Chemical Engineering Quarterly, 2019 The presence of elemental sulfur (S8) in natural gas streams has caused several problems at the delivery points, one of the most recurrent being the deposit of "yellow powder" in the pilots of pressure control valves. The presence of H2S in the natural gas stream may serve as the source for the S8 and/or increase the solubility thereof in the gas. Studies have shown that adsorption control mechanisms are more attractive for use in pipelines to control S8 deposition. In this study, computational simulations were performed in the software COMSOL Multiphysics, using the computational fluid dynamics (CFD) technique and 13X zeolite as adsorbent. The isotherm models of Langmuir, BET, Freundlich, Toth and Sips were tested in the modeling and simulation and the results obtained showed that the isotherm models presented the following decreasing order of precision in relation to the experimental results: Sips = = Freundlich > Toth > Langmuir > BET. In addition, it was possible to verify that the variation of the coefficient of axial dispersion significantly influences the size of the mass transfer zone.
An evaluation of the application of indirect methods of pore pressure gradient prediction in well projects of the Sergipe-Alagoas Basin Mariana Do Nascimento Silva, João Paulo Lobo dos Santos, Rafael De Castro Oliveira, Itson Santos de Souza, Acto De Lima Cunha Geologia USP Serie Cientifica, 2018 No cenário petrolífero atual, a exploração de petróleo em camadas com grandes profundidades é cada vez mais frequente. Com isso, um estudo mais completo das geopressões se faz necessário, visto que essas são as responsáveis pela manutenção da estabilidade do poço. Na previsão de geopressões são utilizados, geralmente, métodos indiretos, que consistem em correlações empíricas que foram calibradas para uma determinada área. Este trabalho teve como principal objetivo fazer uma análise comparativa e técnica das pressões de poros preditas na Bacia Sergipe-Alagoas, utilizando correlações empíricas calibradas para o Golfo do México. No cálculo dos gradientes de pressão de poros foram utilizados dados de dois poços, X e Y, fornecidos pela empresa Z. Os resultados obtidos através dos métodos indiretos foram comparados com os dados de testes de formação realizados nos poços durante a perfuração. Os resultados obtidos mostraram que, para o poço X, os valores preditos foram conclusivos e coerentes, pois os erros relativos médios dos gradientes de pressão de poros oscilaram entre 2,52 e 11,38%, sendo esses valores próximos dos dados medidos nos testes de formação. Já para o poço Y, os resultados preditos foram representativos apenas no intervalo em que o gradiente de poros medido no teste de formação apresentou valor normal.
