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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Desenvolvimento de sistemas a base de tensoativos para recupera??o avan?ada de petr?leo

Ribeiro Neto, Valdir Cotrim 31 August 2007 (has links)
Made available in DSpace on 2014-12-17T15:01:13Z (GMT). No. of bitstreams: 1 ValdirCRN.pdf: 131656 bytes, checksum: 4153e21d4042d68f4cdd2a9f2c14b5e9 (MD5) Previous issue date: 2007-08-31 / Petroleum is a complex combination of various classes of hydrocarbons, with paraffinic, naphtenic and aromatic compounds being those more commonly found in its composition. The recent changes in the world scenario, the large reserves of heavy oils and also the lack of new discoveries of large petroleum fields are indications that, in the near future, the oil recovery by conventional methods will be limited. In order to increase the efficiency of the extraction process, enhanced recovery methods are cited in applications where conventional techniques have proven to be little effective. The injection of surfactant solutions as an enhanced recovery method is advantageous in that surfactants are able to reduce the interfacial tensions between water and oil, thus augmenting the displacement efficiency and, as a consequence, increasing the recovery factor. This work aims to investigate the effects of some parameters that influence the surfactant behavior in solution, namely the type of surfactant, the critical micelle concentration (CMC) and the surface and interface tensions between fluids. Seawater solutions containing the surfactants PAN, PHN and PJN have been prepared for presenting lower interfacial tensions with petroleum and higher stability under increasing temperature and salinity. They were examined in an experimental apparatus designed to assess the recovery factor. Botucatu (Brazil) sandstone plug samples were submitted to assay steps comprising saturation with seawater and petroleum, conventional recovery with seawater and enhanced recovery with surfactant solutions. The plugs had porosity between 29.6 and 32.0%, with average effective permeability to water of 83 mD. The PJN surfactant, at a concentration 1000% above CMC in water, had a higher recovery factor, causing the original oil in place to be recovered by an extra 20.97%, after conventional recovery with seawater / O petr?leo ? uma combina??o complexa de v?rias s?ries de hidrocarbonetos, sendo as mais comumente encontradas as parafinicas, naft?nicas e arom?ticas. As recentes mudan?as no cen?rio mundial, as grandes reservas de ?leos pesados, bem como a escassez de descobertas de grandes campos de petr?leo, indicam que em um futuro pr?ximo a recupera??o de ?leo por m?todos convencionais ser? limitada. Para aumentar a efici?ncia do processo de extra??o, faz-se uso dos m?todos avan?ados de recupera??o para agir nos pontos onde o processo convencional mostrou-se pouco eficiente. A inje??o de solu??o de tensoativo, como um m?todo avan?ado de recupera??o mostra-se vantajosa, pois os tensoativos t?m a finalidade de reduzir as tens?es interfaciais entre a ?gua e o ?leo, ampliando a efici?ncia de deslocamento e, conseq?entemente, aumentando o fator de recupera??o. Este trabalho se prop?s a estudar os efeitos dos par?metros que influenciam as solu??es de tensoativos, como: tipo de tensoativo, concentra??o micelar cr?tica e tens?o superficial e interfacial entre os fluidos. As solu??es com ?gua do mar dos tensoativos PAN, PHN e PJN, por apresentarem menores tens?es interfaciais com o petr?leo e maior estabilidade com o aumento da temperatura e salinidade, foram estudadas em um aparato experimental para avalia??o do fator de recupera??o. Os testemunhos de arenito Botucatu foram submetidos a etapas de satura??o com ?gua do mar e petr?leo, recupera??o convencional com ?gua do mar e recupera??o avan?ada com solu??es de tensoativos. Os testemunhos apresentaram porosidade entre 29,6 e 32,0%, com permeabilidade m?dia efetiva ? ?gua de 83 mD. O tensoativo PJN, com concentra??o de 1000% acima da CMC apresentou maior fator de recupera??o, aumentando em 20,97% a recupera??o do ?leo original in place ap?s a recupera??o convencional com ?gua do mar
2

Remo??o de ?leo da ?gua de produ??o por flota??o em coluna utilizando tensoativos de origem vegetal

Silva, Paula Katherine Leonez da 29 February 2008 (has links)
Made available in DSpace on 2014-12-17T15:01:13Z (GMT). No. of bitstreams: 1 PaulaKLS.pdf: 655947 bytes, checksum: 42dfa97fce97ed099a5660c9d396a0eb (MD5) Previous issue date: 2008-02-29 / In the petroleum industry, water is always present in the reservoir formation together with petroleum and natural gas and this fact provokes the production of water with petroleum, resulting in a great environmental impact. Several methods can be applied for treatment of oily waters, such as: gravitational vases, granulated media filtration systems, flotation process, centrifugation process and the use of hydrocyclones, which can also be used in a combined way. However, the flotation process has showed a great efficiency as compared with other methods, because these methods do not remove great part of the emulsified oil. In this work was investigated the use of surfactants derived from vegetable oils, OSS and OGS, as collectors, using the flotation process in a glass column with a porous plate filter in its base for the input of the gaseous steam. For this purpose, oil/water emulsions were prepared using mechanical stirring, with concentrations around 300 ppm. The air flow rate was set at 700 cm3/min and the porous plate filter used for the generation of the air bubbles has pore size varying from 16 to 40 Pm. The column operated at constant volume (1500mL). A new methodology has been developed to collect the samples, where, instead of collecting the water phase, it was collected the oil phase removed by the process in the top of the flotation column. It has been observed that it is necessary to find an optimum surfactant concentration to achieve enhanced removal efficiency. Being for OSS 1.275 mmol/L and for OGS 0.840 mmol/L, with removal efficiencies of 93% and 99%, respectively, using synthetic solutions. For the produced water, the removal in these concentrations was 75% for OSS and 65% for OGS. It is possible to remove oil from water in a flotation process using surfactants of high HLB, fact that is against the own definition of HLB (Hydrophile-Lipophile Balance). The interfacial tension is an important factor in the oil removal process using a flotation process, because it has direct interference in the coalescence of the oil drops. The spreading of the oil of the air bubble should be considered in the process, and for the optimum surfactant concentrations it reached a maximum value. The removal kinetics for the flotation process using surfactants in the optimum concentration has been adjusted according to a first order model, for synthetic water as for the produced water. / Na ind?stria petrol?fera, a ?gua est? associada ao petr?leo e ao g?s natural, formando a ?gua de produ??o e gerando um grande impacto ambiental. Existem diversos m?todos de tratamento para as ?guas oleosas, tais como: vasos gravitacionais, sistemas de filtra??o em meio granular, flota??o, centrifuga??o e utiliza??o de hidrociclones, podendo ser utilizados de forma combinada. Entretanto, a flota??o tem mostrado maior efici?ncia com rela??o aos outros m?todos, pois eles n?o conseguem remover grande parte do ?leo emulsionado. O presente trabalho estuda a utiliza??o de tensoativos de origem vegetal, OSS (?leo de Soja Saponificado) e OGS (?leo de Girassol Saponificado), como coletores, atrav?s da flota??o em uma coluna com aera??o da suspens?o atrav?s de uma placa porosa. Para este fim, foram preparadas emuls?es ?leo/?gua por agita??o mec?nica, com concentra??es m?dias de 300 ppm. A vaz?o de ar utilizada foi de 700 cm3/min e o filtro de placa porosa utilizado para a gera??o das bolhas de ar foi de porosidade de (16-40) Pm. A coluna trabalhou a um volume constante de 1500mL. Desenvolveu-se uma nova metodologia para coletar as amostras, onde, ao inv?s de coletar a ?gua, coletou-se o ?leo removido na parte superior da c?lula de flota??o. Observou-se que ? necess?rio encontrar uma concentra??o ?tima de tensoativo para que haja uma maior efici?ncia de remo??o. S?o elas 1,275 mmol/L para o OSS e 0,840 mmol/L para o OGS, com efici?ncias de remo??o de 93 % e 99 %, respectivamente, em ?guas sint?ticas. Para a ?gua de produ??o, a remo??o nestas concentra??es foi de 75% para o OSS e 65% para o OGS. ? poss?vel remover ?leo de ?gua em um processo de flota??o utilizando tensoativos de BHL alto, fato que contraria a pr?pria defini??o de BHL (Balan?o Hidrof?lico-Lipof?lico). A tens?o interfacial ? um fator importante no processo de remo??o do ?leo na flota??o, pois interfere diretamente na coalesc?ncia das gotas de ?leo. O espalhamento do ?leo da bolha de ar deve ser considerado no processo, e para as concentra??es ?timas de tensoativo atingiu um valor m?ximo. A cin?tica da remo??o se ajustou para o modelo de primeira ordem na flota??o utilizando tensoativos na concentra??o ?tima, tanto para ?gua sint?tica como para a ?gua de produ??o.

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