The petroleum industry faces problems in transportation of crude petroleum be- cause of the deposition of paraffins, hydrates and asphaltenes on the insides of the pipeline. These are conventionally removed using either chemical inhibitors or mechani- cal devices, called pigs, which travel through the pipeline and mechanically scrape away the deposits. These pigs are propelled by the pipeline product itself and hence travel at the same velocity as the product. Research has indicated that cleaning would be better if the pigs are traveling at a relatively constant velocity of around 70% of the product velocity. This research utilizes the concept of regulating the bypass flow velocity in order to maintain the pig velocity. The bypass flow is regulated by the control unit based on the feedback from the turbine flowmeter, which monitors the bypass flow. A motorized butterfly valve is used for actually controlling the bypass flow. In addition to cleaning, the proposed pig utilizes on-board electronics like accelerom- eter and pressure transducers to store the data gathered during the pig run. This data can then be analyzed and the condition of the pipeline predicted. Thus, this research addresses the problem of designing a pig to maintain a constant velocity in order to achieve better cleaning. It also helps gather elementary data that can be used to predict the internal conditions in the pipe.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-03T23:57:10Z No. of bitstreams: 1 RalysonRayalaGoncalvesDeOliveira_DISSERT.pdf: 3856655 bytes, checksum: 34ff8ff848067ea45bdaca75cd3e6f56 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-07T22:09:14Z (GMT) No. of bitstreams: 1 RalysonRayalaGoncalvesDeOliveira_DISSERT.pdf: 3856655 bytes, checksum: 34ff8ff848067ea45bdaca75cd3e6f56 (MD5) / Made available in DSpace on 2016-06-07T22:09:14Z (GMT). No. of bitstreams: 1 RalysonRayalaGoncalvesDeOliveira_DISSERT.pdf: 3856655 bytes, checksum: 34ff8ff848067ea45bdaca75cd3e6f56 (MD5) Previous issue date: 2015-11-20 / Na ind?stria do petr?leo s?o comumente empregados oleodutos e gasodutos para executar o transporte dos fluidos de produ??o a grandes distancias. As manuten??es desses dutos passam pela an?lise de diversas ferramentas, dentre as mais empregadas atualmente destaca-se as c?lulas de inspe??o de duto, popularmente conhecida como PIG. Dentre as variantes existentes no mercado, o chamado PIG instrumentado possui relev?ncia significativa, visto que atrav?s dos in?meros sensores existentes nele, o equipamento pode detectar falhas ou potenciais de falha ao longo da linha inspecionada. Apesar de sua versatilidade, o PIG instrumentado sofre com varia??es de velocidade, o que prejudica a leitura dos sensores embutidos nele. Como o PIG desloca-se em fun??o da velocidade do fluido de produ??o, uma forma de controlar a velocidade dele ? controlar a vaz?o deste fluido, atrav?s do controle da press?o, reduzindo a velocidade de escoamento do fluxo produzido, resultando na redu??o da produ??o total do fluido nos pr?prios dutos ou com o emprego de um elemento restritivo (v?lvula) instalado nele. A caracter?stica da raz?o vaz?o/perda de press?o de elementos restritivos do tipo orif?cio ? normalmente deduzida da equa??o ideal de energia (equa??o de Bernoulli) e, em seguida, corrigida para as perdas, normalmente por meio de testes experimentais. Assim, com o objetivo de controlar a vaz?o de um fluido que passa pelo PIG, foi desenvolvido uma v?lvula com obturador acionado por meio de solen?ide. Esta configura??o permite uma maior facilidade de controle e estabiliza??o do ajuste de vaz?o, com consequente resposta na quedas de press?o entre ? montante e ? jusante da restri??o. Para defini??o de coeficientes de vaz?o, foi montada uma bancada para realiza??o de ensaios, composta por um duto de quatro polegadas de di?metro interno, uma conjunto de obturadores dispostos em arranjo em uma placa e medidores de press?o para verifica??o de quedas de press?o no ensaio. A linha foi pressurizada e com base nas coletas de queda de press?o foi poss?vel tra?ar uma curva que caracterize o coeficiente de vaz?o do prot?tipo da v?lvula de controle e simular em bancada o funcionamento dela, resultando em redu??es de velocidade do PIG em aproximadamente 68%. / In the Oil industry, oil and gas pipelines are commonly utilized to perform the transportation of production fluids to longer distances. The maintenance of the pipelines passes through the analysis of several tools, in which the most currently used are the pipelines inspection cells, popularly knowing as PIG. Among the variants existing in the market, the instrumented PIG has a significant relevance; acknowledging that through the numerous sensors existing in the equipment, it can detect faults or potential failure along the inspected line. Despite its versatility, the instrumented PIG suffers from speed variations, impairing the reading of sensors embedded in it. Considering that PIG moves depending on the speed of the production fluid, a way to control his speed is to control the flow of the fluid through the pressure control, reducing the flow rate of the produced flow, resulting in reduction of overall production the fluid in the ducts own or with the use of a restrictive element (valve) installed on it. The characteristic of the flow rate/pressure drop from restrictive elements of the orifice plate is deducted usually from the ideal energy equation (Bernoulli?s equation) and later, the losses are corrected normally through experimental tests. Thus, with the objective of controlling the fluids flow passing through the PIG, a valve shutter actuated by solenoid has been developed. This configuration allows an ease control and stabilization of the flow adjustment, with a consequent response in the pressure drops between upstream and downstream of the restriction. It was assembled a test bench for better definition of flow coefficients; composed by a duct with intern diameter of four inches, one set of shutters arranged in a plate and pressure gauges for checking the pressure drop in the test. The line was pressurized and based on the pressure drop it was possible to draw a curve able to characterize the flow coefficient of the control valve prototype and simulate in mockup the functioning, resulting in PIG speed reduction of approximately 68%.