Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-09-05T19:25:26Z No. of bitstreams: 1 LeonardoAsforaDeOliveira_DISSERT.pdf: 3243516 bytes, checksum: fb2dc43eeb22b49aabf1764ae000b894 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-09-13T23:26:22Z (GMT) No. of bitstreams: 1 LeonardoAsforaDeOliveira_DISSERT.pdf: 3243516 bytes, checksum: fb2dc43eeb22b49aabf1764ae000b894 (MD5) / Made available in DSpace on 2017-09-13T23:26:22Z (GMT). No. of bitstreams: 1 LeonardoAsforaDeOliveira_DISSERT.pdf: 3243516 bytes, checksum: fb2dc43eeb22b49aabf1764ae000b894 (MD5) Previous issue date: 2017-06-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Quando o reservat?rio n?o possui energia suficiente para elevar os fluidos ? superf?cie ou quando a vaz?o de surg?ncia n?o ? economicamente vi?vel, faz-se necess?rio a instala??o de m?todos de eleva??o artificial. Nestes est?o inclusos aqueles denominados de bombeados, que se valem da instala??o de uma bomba de subsuperf?cie no fundo do po?o. Devido ao princ?pio de funcionamento destas bombas, elas apresentam redu??o de performance quando succionam g?s livre advindo do reservat?rio. Isso justifica a completa??o destes po?os sem a utiliza??o de packer e com separadores de g?s na suc??o das bombas, de forma a redirecionar parte do g?s livre para o espa?o anular. O g?s separado ? ent?o transferido ? linha de surg?ncia atrav?s de uma v?lvula de reten??o, que permite sua passagem sempre que a press?o de revestimento for maior do que a da linha. No entanto, em muitos casos a press?o de linha ? alta, fazendo com que o g?s seja aprisionado no anular, elevando a press?o de revestimento e reduzindo a submerg?ncia destas bombas. Nos casos mais cr?ticos, quando o reservat?rio j? encontra-se depletado, a press?o de revestimento compreende parcelas significativas da press?o de fluxo de fundo, de forma que o n?vel de l?quido pode atingir a suc??o das bombas, tornando a produ??o inst?vel ou, muitas vezes, inviabilizando-a. Este trabalho, portanto, se prop?e a estudar uma poss?vel solu??o para este problema, advinda de uma colabora??o entre Petrobras e UFRN: a instala??o de ejetores na linha de surg?ncia. Ejetores s?o equipamentos que se utilizam da energia de um fluido, denominado de fluido motriz, para aspirar ou succionar outro, denominado de secund?rio. Nesta aplica??o, a pr?pria produ??o do po?o de petr?leo seria utilizada para aspirar o g?s do anular. Ao longo do texto, ? desenvolvida uma modelagem matem?tica simplificada para fins de an?lise de performance e dimensionamento destes ejetores, onde foram utilizados os princ?pios da conserva??o de massa, momento e energia em cada se??o do ejetor. Este modelo foi verificado e ajustado atrav?s da fluidodin?mica computacional utilizando o software CFX da empresa ANSYS, vers?o 16.0. Por fim, a influ?ncia de um ejetor na linha de surg?ncia de um po?o que opera por Bombeio Centr?fugo Submerso ? analisada atrav?s de an?lise nodal, onde foi poss?vel demonstrar que sua instala??o permite um aumento da vaz?o de produ??o do po?o quando este ? equipado com variador de frequ?ncia, mantendo inalterada a submerg?ncia. / When the reservoir doesn?t have enough energy to raise the fluids to the surface or when its natural flow rate isn?t economically viable, artificial lift methods are required. Among these there are those that are called pumping methods, which rely on bottomhole pumps. Because of their working principle, the performance of these pumps decrease when free gas is ingested. Therefore, sometimes gas separators are installed upstream of the pump in order to redirect some of the gas to the annulus, and the completion is made without a packer. The annulus and the production line are connected via a check valve, allowing gas flow from the annulus to the production line whenever the casing pressure is higher than the wellhead pressure. However, in some cases the wellhead pressure is high enough, causing the gas to get trapped in the annulus, increasing casing pressure and therefore reducing pumps? submergence. In the worst case scenario, when the reservoir is depleted, the casing pressure comprises significant part of the bottomhole pressure. When this is the case, the fluid level become very close to the suction ports, provoking flow instabilities or, in some cases, making it unfeasible. This dissertation intends to study one possible solution to this problem, which came about as part of a partnership between Petrobras and UFRN, which is the installation of an ejector in the production line. Ejectors are devices that utilizes the energy of a motive fluid in order to suck a secondary one. In this particularly application, the well?s own production is used to suck the separated gas from the annulus. Throughout the text, a simplified mathematical model is developed in order to conduct performance analysis and design by using the basic principles of conservation of mass, momentum and energy for control volumes. This model was verified with the aids of computational fluid dynamics, where the software CFX from ANSYS version 16.0 was utilized. Finally, ejector?s influence on an well equipped with an Electrical Submersible Pump is discussed utilizing nodal analysis, where it was shown that it?s possible to increase flow rate when a Variable Speed Drive (VSD) is available, maintaining the same submergence.