Made available in DSpace on 2014-12-17T14:08:32Z (GMT). No. of bitstreams: 1 TommyAP_capa_ate_cap4.pdf: 809913 bytes, checksum: 0090aa039ef326f260cb40945133e6d1 (MD5) Previous issue date: 2009-04-27 / Petr?leo Brasileiro SA - PETROBRAS / The gas injection has become the most important IOR process in the United States. Furthermore, the year 2006 marks the first time the gas injection IOR production has surpassed that of steam injection. In Brazil, the installation of a petrochemical complex in the Northeast of Brazil (Bahia State) offers opportunities for the injection of gases in the fields located in the Rec?ncavo Basin. Field-scale gas injection applications have almost always been associated with design and operational difficulties. The mobility ratio, which controls the volumetric sweep, between the injected gas and displaced oil bank in gas processes, is typically unfavorable due to the relatively low viscosity of the injected gas. Furthermore, the difference between their densities results in severe gravity segregation of fluids in the reservoirs, consequently leading to poor control in the volumetric sweep. Nowadays, from the above applications of gas injection, the WAG process is most popular. However, in attempting to solve the mobility problems, the WAG process gives rise to other problems associated with increased water saturation in the reservoir including diminished gas injectivity and increased competition to the flow of oil. The low field performance of WAG floods with oil recoveries in the range of 5-10% is a clear indication of these problems. In order to find na effective alternative to WAG, the Gas Assisted Gravity Drainage (GAGD) was developed. This process is designed to take advantage of gravity force to allow vertical segregation between the injected CO2 and reservoir crude oil due to their density difference. This process consists of placing horizontal producers near the bottom of the pay zone and injecting g?s through existing vertical wells in field. Homogeneous models were used in this work which can be extrapolated to commercial application for fields located in the Northeast of Brazil. The simulations were performed in a CMG simulator, the STARS 2007.11, where some parameters and their interactions were analyzed. The results have shown that the CO2 injection in GAGD process increased significantly the rate and the final recovery of oil / A inje??o de g?s tem sido o m?todo de recupera??o mais utilizado nos Estados Unidos e o ano de 2006 marca a primeira vez em que a produ??o proveniente dos processos de inje??o de g?s superou os de inje??o de vapor. No Brasil, a instala??o do complexo petroqu?mico, no estado da Bahia, oferece oportunidades para inje??o de g?s na Bacia do Rec?ncavo. As aplica??es de inje??o de g?s em campo foram quase sempre associadas com dificuldades operacionais e de projetos. A raz?o de mobilidade, que controla a varredura volum?trica, entre o g?s injetado e o banco de ?leo deslocado, ? tipicamente desfavor?vel devido ? baixa viscosidade do g?s. Al?m de que a diferen?a entre as densidades conduz a segrega??o gravitacional severa dos fluidos no reservat?rio e consequentemente, levando a um pobre controle na varredura volum?trica. Atualmente, grande parte dos projetos de inje??o de g?s no mundo ? do tipo WAG. Entretanto, na tentativa de resolver os problemas de mobilidade, o processo WAG causa outros problemas como o aumento na satura??o de ?gua no reservat?rio, incluindo a diminui??o na injetividade do g?s e aumento da competi??o no fluxo do ?leo. O baixo desempenho na recupera??o de ?leo deste processo no campo, na ordem de 5 a 10%, ? uma clara indica??o destes problemas. A fim de encontrar uma alternativa eficaz para o WAG, o processo de drenagem gravitacional assistida por inje??o de g?s (GAGD) foi desenvolvido. O processo GAGD ? projetado para tomar vantagem da for?a gravitacional causando assim, a segrega??o vertical entre o CO2 injetado e a reserva de ?leo devido ? diferen?a de densidades. Este processo consiste na coloca??o de po?os produtores horizontais pr?ximos a parte inferior da zona de ?leo e inje??o de g?s atrav?s de po?os verticais existentes em campo. Modelos homog?neos foram utilizados neste trabalho os quais podem ser extrapolados para aplica??o comercial em campos localizados no nordeste brasileiro. As simula??es foram realizadas no simulador da CMG STARS 2007.11, sendo analisados alguns par?metros e suas intera??es. Os resultados mostraram que a inje??o de CO2 no processo GAGD aumentou significativamente a vaz?o e a recupera??o final de ?leo

Made available in DSpace on 2014-12-17T14:08:38Z (GMT). No. of bitstreams: 1 Ernesto Vargas Bautista_DISSERT_01_59.pdf: 4396872 bytes, checksum: 70a69eb1e9973135d541fd7ce76f4ed9 (MD5) Previous issue date: 2010-02-26 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In Brazil and around the world, oil companies are looking for, and expected development of new technologies and processes that can increase the oil recovery factor in mature reservoirs, in a simple and inexpensive way. So, the latest research has developed a new process called Gas Assisted Gravity Drainage (GAGD) which was classified as a gas injection IOR. The process, which is undergoing pilot testing in the field, is being extensively studied through physical scale models and core-floods laboratory, due to high oil recoveries in relation to other gas injection IOR. This process consists of injecting gas at the top of a reservoir through horizontal or vertical injector wells and displacing the oil, taking advantage of natural gravity segregation of fluids, to a horizontal producer well placed at the bottom of the reservoir. To study this process it was modeled a homogeneous reservoir and a model of multi-component fluid with characteristics similar to light oil Brazilian fields through a compositional simulator, to optimize the operational parameters. The model of the process was simulated in GEM (CMG, 2009.10). The operational parameters studied were the gas injection rate, the type of gas injection, the location of the injector and production well. We also studied the presence of water drive in the process. The results showed that the maximum vertical spacing between the two wells, caused the maximum recovery of oil in GAGD. Also, it was found that the largest flow injection, it obtained the largest recovery factors. This parameter controls the speed of the front of the gas injected and determined if the gravitational force dominates or not the process in the recovery of oil. Natural gas had better performance than CO2 and that the presence of aquifer in the reservoir was less influential in the process. In economic analysis found that by injecting natural gas is obtained more economically beneficial than CO2 / No Brasil e no mundo, as empresas de petr?leo est?o ? procura, desenvolvimento e ? espera de novas tecnologias e processos que possam elevar o fator de recupera??o de ?leo em seus reservat?rios, com um equilibrado custo-benef?cio. Na procura de novas tecnologias foi desenvolvido o processo de drenagem gravitacional assistida por g?s (GAGD Gas Assisted Gravity Drainage) que foi classificado dentro dos m?todos de recupera??o avan?ada de ?leo. O processo GAGD, que se encontra em fase de teste piloto em campo, est? sendo muito estudado atrav?s de modelos f?sicos em escala de laborat?rio e em testemunhos, isto devido ?s altas recupera??es de ?leo em rela??o aos outros processos de inje??o de g?s. Este m?todo consiste em injetar g?s no topo de um reservat?rio atrav?s de po?os injetores verticais ou horizontais e deslocar o ?leo, aproveitando a segrega??o gravitacional natural dos fluidos, para um po?o produtor horizontal colocado na base do reservat?rio. Para estudar este processo foi idealizado um reservat?rio homog?neo e um modelo de fluido multicomponente com caracter?sticas parecidas aos campos de ?leo leve do Brasil para que, atrav?s de um simulador composicional, se analisem os par?metros operacionais. O processo foi simulado no programa comercial GEM da CMG (Computer Modelling Group). Os par?metros operacionais estudados foram a vaz?o de inje??o de g?s, o tipo de g?s injetado (g?s natural e CO2), a localiza??o do po?o injetor e do po?o produtor. Tamb?m foi estudada a presen?a de aq??fero no processo. Os resultados mostraram que o m?ximo espa?amento vertical entre os dois po?os, provocou a m?xima recupera??o de ?leo no GAGD. Tamb?m, verificou-se que a maiores vaz?es de inje??o, se obtiveram os maiores fatores de recupera??o. Este par?metro controlou a velocidade da frente do g?s injetado e determinou se a for?a gravitacional domina ou n?o sobre o processo na recupera??o de ?leo. O g?s natural teve melhor desempenho que o CO2 e que, a presen?a de aq??fero no reservat?rio influenciou pouco no processo. Na an?lise econ?mica verificou-se que a inje??o de g?s natural obteve o melhor beneficio econ?mico que com CO2

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-04T22:04:54Z No. of bitstreams: 1 ErnestoVargasBautista_TESE.pdf: 4056194 bytes, checksum: 4254be419758b8c4d81ac80a522fc9b3 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-07T21:31:17Z (GMT) No. of bitstreams: 1 ErnestoVargasBautista_TESE.pdf: 4056194 bytes, checksum: 4254be419758b8c4d81ac80a522fc9b3 (MD5) / Made available in DSpace on 2016-01-07T21:31:17Z (GMT). No. of bitstreams: 1 ErnestoVargasBautista_TESE.pdf: 4056194 bytes, checksum: 4254be419758b8c4d81ac80a522fc9b3 (MD5) Previous issue date: 2014-11-13 / A distribui??o e mobiliza??o ou n?o dos fluidos num meio poroso dependem das for?as capilar, viscosa e gravitacional. Em campo, os processos de recupera??o avan?ada de ?leo envolvem a import?ncia e a altera??o destas for?as para incrementar o fator de recupera??o de ?leo. No caso do processo de drenagem gravitacional assistida por g?s (GAGD ? GasAssisted Gravity Drainage) ? importante entender a f?sica e mecanismos que mobilizam o ?leo atrav?s da intera??o destas for?as. Para isso, v?rios autores desenvolveram modelos f?sicos em escala de laborat?rio e testemunhos do GAGD para estudar o desempenho destas for?as atrav?s de grupos adimensionais. Estes modelos apresentaram resultados conclusivos. Por?m, modelos de simula??o num?rica foram pouco usados. O objetivo deste trabalho ? estudar a inter-rela??o das for?as capilar, viscosa e gravitacional no GAGD e suas influ?ncias no fator de recupera??o de ?leo atrav?s de um modelo de simula??o num?rica 2D. Para analisar cada uma dessas for?as, foram usados os grupos adimensionais reportados na literatura, N?mero Capilar (Nc), N?mero de Bond (Nb) e N?mero Gravitacional (Ng). Uma compara??o dos resultados obtidos neste trabalho tamb?m foi realizada com os resultados da literatura. Os resultados mostraram que antes da erup??o do g?s injetado, quanto menor ? o Nc e Nb, maior ? a recupera??o de ?leo, e ap?s da erup??o, quanto menor ? o Ng, maior ? a recupera??o de ?leo no GAGD. Uma boa rela??o foi encontrada entre os resultados deste trabalho e os resultados publicados na literatura / The distribution and mobilization of fluid in a porous medium depend on the capillary, gravity, and viscous forces. In oil field, the processes of enhanced oil recovery involve change and importance of these forces to increase the oil recovery factor. In the case of gas assisted gravity drainage (GAGD) process is important to understand the physical mechanisms to mobilize oil through the interaction of these forces. For this reason, several authors have developed physical models in laboratory and core floods of GAGD to study the performance of these forces through dimensionless groups. These models showed conclusive results. However, numerical simulation models have not been used for this type of study. Therefore, the objective of this work is to study the performance of capillary, viscous and gravity forces on GAGD process and its influence on the oil recovery factor through a 2D numerical simulation model. To analyze the interplay of these forces, dimensionless groups reported in the literature have been used such as Capillary Number (Nc), Bond number (Nb) and Gravity Number (Ng). This was done to determine the effectiveness of each force related to the other one. A comparison of the results obtained from the numerical simulation was also carried out with the results reported in the literature. The results showed that before breakthrough time, the lower is the injection flow rate, oil recovery is increased by capillary force, and after breakthrough time, the higher is the injection flow rate, oil recovery is increased by gravity force. A good relationship was found between the results obtained in this research with those published in the literature. The simulation results indicated that before the gas breakthrough, higher oil recoveries were obtained at lower Nc and Nb and, after the gas breakthrough, higher oil recoveries were obtained at lower Ng. The numerical models are consistent with the reported results in the literature