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Akangbou, H. N. "Optimizing oil production in horizontal wells (water/oil cresting in horizontal wells)." Thesis, University of Salford, 2017. http://usir.salford.ac.uk/43678/.
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In recent years, the application of horizontal wells has been predominant in minimizing cresting scenarios due to significant reservoir exposure of its laterals. Cresting is known to occur in horizontal wells when the pressure drop supersedes the hydrostatic pressure existing between the phases in a typical reservoir. Cresting poses problems such as uneconomic oil production rates due to increasing volumes of effluent(s) (unwanted water and or gas) produced with oil over time as well as the overall recovery efficiency of oil reservoirs. Production optimization from crest-affected thick- and thin-oil rim homogeneous reservoirs were investigated experimentally by considering the effect of varying the inclined sections of a horizontal well at low angles of inclination (15o-30o), initial surface pressures (-4.351Psig), lateral length in reservoir (lr, = 0.305 m) and oil viscosity (50 cP) on oil recovery, oil produced and cumulative water produced during cresting. A strong bottom aquifer and considerable gas cap were modeled at constant bottom water injection rate of 41.68 cm3/s and at atmospheric pressure (14.7 Psi) respectively. An experimental proactive cresting control technique based on reservoir wettability, gravity segregation and effluent(s) breakthrough times were investigated for cresting control in thick- and thin-oil rim homogeneous reservoirs, using an electromagnetic valve installation. Numerical simulations were considered using Particle Image Velocimetry (PIV) to the determine the velocity of captured water cresting images and Computational Fluid Dynamics (CFD) to validate the oil withdrawal rate, Gas-Oil-Contact (GOC) and Water-Oil-Contact (WOC) by applying boundary conditions from the physical model. From results of varying the inclined section of the horizontal well, the Short radius wells with 30o angle of inclination and ratio of vertical displacement of the inclined section to reservoir height (Vd/Hr) of 0.079 resulted in 177.75 cm3 increment in oil recovered and reduction in cumulative water produced (258 cm3) at a production time of 300 s in thick-oil rim reservoirs while 250 cm3 increment in oil was observed with 356 cm3 reduction in cumulative water produced at a production time of 495 s in thick-oil rim reservoirs with Vd/Hr, 0.063. Further increment of 108.91 cm3 in oil produced and reduction in cumulative water produced (183.99 cm3), was observed when cresting was controlled proactively in thick-oil rim reservoirs. From varying the inclined section of the horizontal well, increment in oil produced of 163 cm3 and 134 cm3 cumulative reduction in produced water were observed at Vd/Hr equals 0.079 in thin-oil rim reservoirs at a simulation time of 210 s while a lower oil increment of 6.84 cm3 and cumulative water reduction of 10.98 cm3 were observed in thin-oil rim reservoirs when controlled proactively. The over predicted quantitative results as high as 75.06% using the CFD model compared with experimental data were due to two-dimensional (2D) model limitations in porous media as well as the corresponding grain sizes. To exemplify, for WOC the predicted results was about 28.56% compared to experimental data at 4.5 s. The average velocity profile from PIV analysis increased steadily from 0.113 to 2.08E-15 m/s from 10 to 90 s.
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Ozkan, Erdal. "Performance of horizontal wells /." Access abstract and link to full text, 1988. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/8825498.
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Nunsavathu, Upender Naik. "Productivity index of multilateral wells." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4702.
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Thesis (M.S.)--West Virginia University, 2006.Title from document title page. Document formatted into pages; contains xi, 106 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 104-106).
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Mishra, Nekkhil. "Investigation of hole cleaning parameters using computational fluid dynamics in horizontal and deviated wells." Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5111.
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Thesis (M.S.)--West Virginia University, 2007.Title from document title page. Document formatted into pages; contains x, 65 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 58-60).
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Kaparthi, Prashanth. "Kinematic synthesis of a well service machine." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=2244.
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Thesis (M.S.)--West Virginia University, 2001.Title from document title page. Document formatted into pages; contains viii, 64 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 63-64).
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Cheung, Lok Yee Geraldine. "Micromechanics of sand production in oil wells." Thesis, Imperial College London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.528300.
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Laderian, Asghar. "Prediction of temperature profile in oil wells." Thesis, University of Newcastle Upon Tyne, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315615.
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GOMES, DALILA DE SOUSA. "MULTIPHASE FLOW SIMULATOR FOR OIL PRODUCTION WELLS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2015. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=26315@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Sistemas de escoamento multifásico se formam ao longo de um poço de produção de petróleo. A análise do comportamento do escoamento através da coluna de produção é realizada com o apoio de ferramentas computacionais e é essencial para o projeto e operação de um sistema de produção de petróleo. Os simuladores comerciais disponíveis para esse tipo de análise exigem aquisição de licença, cujo custo é elevado, restringindo seu uso às grandes companhias petrolíferas e aos renomados institutos de pesquisa. Além disso, esses programas não permitem a visualização da metodologia utilizada para o tratamento do problema físico e para a solução numérica empregada, e nem a alteração de parâmetros internos, tornando seu uso restrito a certas classes de problemas. Apesar da grande demanda e utilidade desse tipo de software ainda há poucos trabalhos desenvolvidos nessa área. Esta pesquisa tem como objetivo apresentar o desenvolvimento de um simulador de escoamento multifásico simplificado e aberto, com aplicação na otimização da produção de óleo e gás. Dentre as aplicações do programa podemos citar a obtenção das curvas de gradiente de pressão e a otimização de gás-lift. Um estudo paramétrico foi conduzido, mostrando a influência de parâmetros como, por exemplo, o diâmetro da tubulação. Os resultados obtidos foram comparados com a literatura e são fisicamente coerentes. Sendo assim, o programa desenvolvido mostra-se promissor.
Multiphase flow systems are formed along an oil production well. The analysis of the flow behavior through the production column is performed with the aid of computational tools, and is very important to the design and optimization of the oil well production operation. In general, the commercial softwares available to analyze this process are very expensive, which restrict its use to some particular companies. In addition, the methodology used to analyze the physical problem, and the numerical solution are fixed and closed, which restrict its use to certain classes of problems, since it is not possible to change or improve the numerical solution. Despite the great demand and use of this kind of software, there are few researches in this area. This research aims to present the development of a simplified multiphase flow simulator open to public, with application to the optimization of oil and gas production wells. Among the applications are the plot of pressure-distribution curves and the optimization of gas-lift. A parametric study is performed, showing the influence of some governing parameters, such as tubing diameter, in the production flow rate. The results obtained were compared with pertinent literature and are physically reasonable, showing that the software developed is promising.
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ALCOFRA, ELISA LAGE MODESTO. "ANNULAR PRESSURE BUILD-UP IN OIL WELLS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=35522@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROO projeto de dimensionamento dos revestimentos na indústria de óleo e gás deve garantir a integridade do poço ao longo de todo o seu ciclo de vida, que pode ser de várias décadas. Um carregamento importante a ser considerado surge em consequência da produção, que movimenta os fluidos desde o reservatório até a superfície, aquecendo as partes mais rasas do poço. Este processo de aquecimento expande os fluidos de perfuração e completação que foram confinados nos anulares durante o processo de construção do poço. Esta mudança de volume do fluido é contida pela rigidez dos elementos que o mantém confinado e essa resistência à livre expansão do fluido provoca um aumento de pressão. Em alguns casos, a pressão pode tornar-se tão grande que pode levar o revestimento a colapsar, levando ao abandono de poços e a grandes perdas. Este fenômeno de aumento da pressão é conhecido na indústria do petróleo como anular pressure build-up (APB). O presente trabalho apresenta um modelo térmico para determinar o perfil de temperatura e pressão do fluido monofásico escoando em regime permanente na coluna de produção e a distribuição de temperatura ao longo de todos os elementos do poço. Como os revestimentos não são perfeitamente rígidos, um aumento de temperatura e pressão no poço acarreta na variação do volume do anular, os quais são avaliados de forma acoplada, pois a variação de volume de um anular influencia no outro, assim como os deslocamentos dos revestimentos. O estudo compara os resultados obtidos com um aplicativo comercial, apresentando boa concordância. Além disso, uma análise de sensibilidade é realizada para fornecer uma melhor compreensão do fenômeno.
Casing design projects must ensure well integrity throughout its life, which can be as long as several decades. An important load to be considered appears as a consequence of production. During production, the annuli became heated from the transfer of bottom hole temperature up the well by the produced fluids. With heat-up, the fluids trapped in the annulus began to thermally expand. The expansion induces a volume enlargement, which is restrained by the stiffness of the well structure. This resistance to fluid free expansion keep the fluid confined and can produce a substantial pressure increase. In some cases, pressure may become so great that it can collapse casing, leading to well abandonment and large losses. This pressure increase phenomenon is well-known in the oil industry as annular pressure build-up (APB). In the present study, a monophasic state-state thermal model was developed to determine the oil temperature profile in the tubing and the temperature profile in all structures of the well. As casings are not perfectly rigid, temperature and pressure increase in the well results in annular volume change. Because the well consists of a sequence of casing strings that define the well annuli, the modeling of casing strains should be based on a systematic approach that considers the interaction among the various strings. The study compares results to those obtained with a commercial computer application, presenting good agreement. Further, a sensitivity analysis is performed to provide a better understanding of the phenomenon.
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Gessel, Gregory M. "A New Method for Treating Wells in Reservoir Simulation." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1902.pdf.
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Liao, Tianlu. "Mechanistic modeling of intermittent gas lift /." Access abstract and link to full text, 1991. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9210710.
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Feitosa, Gilvan Soares. "Well test analysis for heterogenous reservoirs /." Access abstract and link to full text, 1993. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9330022.
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VARGES, PRISCILLA RIBEIRO. "PLUGGING OIL WELLS: AN INVESTIGATION OF EXCHANGE FLOWS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=31831@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Operações de posicionamento de tampão de cimento na indústria do petróleo representam um exemplo de escoamento dominado por efeitos gravitacionais. Essa situação é altamente instável visto que o cimento geralmente é mais denso que o fluido do poço e, como consequência, suas posições tendem a se inverterem. O presente estudo objetiva aprimorar a percepção dos mecanismos físicos associados às operações de tamponamento através da análise de escoamentos de inversão por gravidade. Com esta finalidade, executam-se experimentos de visualização com líquido mais denso posicionado sobre outro de menor densidade em tubo vertical. Ademais determina-se a velocidade da interface através do processamento e análise de imagens. A influência dos parâmetros governantes é averiguada sobre a velocidade de inversão e o regime de escoamento. A importância relativa entre as forças gravitacionais, viscosa, inercial e interfacial são avaliadas. A primeira etapa do estudo consiste na realização de experimentos com pares de fluidos newtonianos e imiscíveis com pequena diferença de densidade. Examinam-se dois regimes de escoamento, a saber gotas e slugs em queda. Os resultados experimentais demonstram que a velocidade terminal pode ser estimada por correlações empíricas de esferas rígidas em queda dentro de um tubo. A segunda etapa da pesquisa consiste na análise de escoamento de inversão por gravidade com fluido elasto viscoplástico tixotrópico sobre óleo newtoniano menos denso. Constatam-se três diferentes regimes de escoamento, denominados instável, quase-estável e estável (sem escoamento). O regime instável apresenta escoamento wavy core annular com o líquido mais denso no centro. No regime quase-estável há formação de plug flow após um tempo de retardo, que é função dos efeitos tixotrópicos e elásticos do material. Através da análise dos resultados experimentais é possível identificar, para um dado par de fluidos, a janela de operações no espaço de parâmetros governantes dentro da qual a velocidade de inversão é suficientemente baixa (ou nula) para assegurar o sucesso da operação de tamponamento.
Cement plug placement in oil industry operations represents an example of buoyancy-driven exchange flows. This situation is highly unstable since cement is usually denser than well fluid and, as a consequence, their positions tend to invert. The present study aims to improve the perception of the physical mechanisms associated to cement plug operations through the analysis of exchange flows. To this end, visualization experiments are performed with denser liquid positioned above a lower-density liquid in a vertical tube. In addition, the interface front speed is determined through image processing and analysis. The influence of the governing parameters is investigated on the speed of inversion and flow regime. The first stage of the study consists of conducting experiments with pairs of immiscible Newtonian liquids with small density difference. Two different flow regimes were examined, namely, falling drops and falling slugs. Experimental results demonstrate that the terminal velocity can be estimated by empirical correlations for falling rigid spheres within a tube. The second stage of the research consists of an exchange flow analysis considering an elastoviscoplastic thixotropic fluid above a less dense Newtonian oil. Three different flow regimes were observed, namely unstable, quasi-stable, and stable (no flow). The unstable regime is a wavy core-annular flow with the denser liquid in the core. In the quasi-stable regime a slow plug flow starts after a time delay, which is a function of material thixotropic and elastic effects. Through analysis of the experimental results it is possible to identify, for a given pair of fluids, the operational window in the governing parameter space within which the speed of inversion is sufficiently low (or zero) to ensure the cement plug operation success.
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Shmeleva, Mariia. "Geothermal Energy Production from Oil and Gas Wells." Thesis, KTH, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-245059.
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This Thesis presents an investigation of geothermal energy production and utilization for electricity generation on the petroleum fields. According to the global energy market in Russia, the leading position takes oil and gas industry. Experts say that most of large petroleum deposits are depleted and the water cut reaches up to 80-90%. To develop such fields and deposits is not economic attractive, that is why wells with high water cut, more than 95%, are turned into abandoned wells. The technology of obtaining geothermal energy from abandoned wells allows reusing already drilled deep wells to generate electricity in an environmentally friendly way. It is especially relevant in oilfields isolated from the grids. In this work the scheme of geothermal energy extraction and utilization is presented. Based on the knowledge of heat exchange in a well and foreign experience a mathematical model describing heat exchange between injected fluid and surrounding rocks in a double pipe was developed. Apart from that the main factors affecting the efficiency of geothermal heat extraction and electricity generation were thoroughly examined. Furthermore, the economic and ecological effect from electricity production by ORC was defined.Denna avhandling presenterar en undersökning av produktion av geotermisk energi och utnyttjande av elproduktion på petroleumsområdena. Enligt den globala energimarknaden i Ryssland tar ledande position olje- och gasindustrin. Experter säger att de flesta stora oljefyndigheter är utarmade och vattnets snitt når upp till 80-90%. Att utveckla sådana fält och insättningar är inte ekonomiskt attraktiva, det är därför brunnar med högvattenskärning, mer än 95%, förvandlas till övergivna brunnar. Tekniken för att erhålla geotermisk energi från övergivna brunnar möjliggör återanvändning av redan borrade djupa brunnar för att generera el på ett miljövänligt sätt. Det är särskilt relevant i oljefält isolerade från nätet. I detta arbete presenteras systemet för geotermisk energiutvinning och -utnyttjande. Baserat på kunskapen om värmeväxling i en brunn och utländsk erfarenhet utvecklades en matematisk modell som beskriver värmeväxling mellan injicerad vätska och omgivande stenar i ett dubbelrör. Bortsett från detta undersöktes de viktigaste faktorerna som påverkar effektiviteten av geotermisk utvinning och elproduktion. Vidare definierades den ekonomiska och ekologiska effekten av elproduktion av ORC.
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Araque-Martinez, Aura N. "Modeling the effects of geochemistry on well impairment." Thesis, Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3008267.
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Onur, Mustafa. "New well testing applications of the pressure derivative /." Access abstract and link to full text, 1989. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/8917500.
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Serra, Kelsen Valente. "Well testing for solution gas drive reservoirs /." Access abstract and link to full text, 1988. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/8811978.
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Cook, Joshua R. "Development of a program to gather and process data from oil and gas fields." Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3727.
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Thesis (M.S.)--West Virginia University, 2004.Title from document title page. Document formatted into pages; contains ix, 80 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 33-34).
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Kahya, Ali Cenk. "Analyzing The Design Of Submersible Lifted Deviated Oil Wells." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12605742/index.pdf.
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Electrical Submersible Pumping (ESP) is a well known artificial lift technique in reservoirs having high-water cut and low gas-oil ratio. It is known as an effective and economical method of producing large volumes of fluid under different well conditions. ESP equipments are capable of producing in a range of 200 b/d to 60.000 b/d. A case study was done, by designing 10 deviated or horizontal wells selected from the Y-oilfield in Western Siberia. SubPUMP software developed by IHS Energy is used for designing the ESP systems of these wells. These 10 wells will be working with variable speed drives. After selecting the available equipment from the inventory, the best running frequencies are selected for these wells. Evaluations of the designs are made from the pump performance graphs of each well. The pumps should work within their optimum efficiency ranges. These ranges can be seen from the pump performance curves. If the designs made are not within these efficiency ranges, designs should be evaluated and selecting new equipment should be should be an option. Because working outside the optimum efficiency ranges will decrease the production, shorten the runlifes of the pumps and the production will not be stable.
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McGee, Bruce C. W. "Electrical heating of heavy oil reservoirs using horizontal wells." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq29074.pdf.
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CACHAY, LEONARDO RODIN SALAS. "PROPPANT FLOWBACK IN OIL WELLS STIMULATED BY HYDRAULIC FRACTURING." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=6513@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROUm dos principais objetivos da engenharia de petróleo é desenvolver e aplicar técnicas capazes de aumentar a produtividade de poços de petróleo, incluindo a estimulação da formação através de operações que aumentem a permeabilidade da rocha-reservatório e facilitem o escoamento do fluido. Dentre as técnicas de estimulação, a mais utilizada é o fraturamento hidráulico, a qual tem viabilizado a exploração em cerca de 40% dos poços produtores de petróleo em todo o mundo. Durante o fraturamento hidráulico, um material granular conhecido como material de sustentação ou propante, é injetado nas fraturas recém-criadas com o objetivo de mantê-las abertas e garantir-lhes condições de alta permeabilidade. A produção de material de sustentação (proppant flowback) é termo usado para descrever o refluxo do propante para o interior do poço, juntamente com o hidrocarboneto produzido. O controle do fluxo de propante representa um grave desafio para a indústria de petróleo, pois pode causar graves problemas operacionais e de segurança, relacionados com o desgaste dos equipamentos de produção, problemas econômicos associados ao custo de limpeza, paralisação das operações e intervenção no tratamento da fratura, problemas ambientais relacionados com a disposição de sólidos impregnados por hidrocarbonetos, etc. Neste contexto, a presente dissertação apresenta um estudo detalhado dos principais tipos de propante e de suas propriedades, bem como descreve os mecanismos que influem no refluxo do material de sustentação da fratura e analisa os principais modelos apresentados na literatura para previsão deste fenômeno. Uma retroanálise considerando os dados de campo em 22 poços da Petrobrás, localizados em Sergipe, permite uma comparação da eficiência entre quatro dos modelos, desenvolvidos com base em resultados de ensaios de laboratório, indicando suas vantagens e desvantagens para aplicação na prática da engenharia.
One of the main objectives of petroleum engineering is to develop and to apply techniques aiming the productivity increase of oil fields, including the stimulation of the rock through operations that increase the permeability of the oil reservoir and makes the flow of the fluid toward the well more efficient. Among the stimulation techniques, the most used is the hydraulic fracturing, carried out in about 40 percent of the producing oil wells around the world. During hydraulic fracturing, a granular material known as proppant, is injected into the just created fractures with the objective to keep them open and in order to guarantee the designed conditions of high permeability. Proppant flowback is the technical terminology employed to describe the flow of proppant from the fracture to the interior of the oil well, together with the produced hydrocarbon. An efficient and reliable control of this problem is still a major challenge to the oil industry, given the serious operational and security problems that it may cause, including costs of interrupted operations, cleaning measures, environmental contamination risks associated with the disposal of residues impregnated by oil, etc. In this context, the present thesis presents a detailed description on the main proppant materials and their engineering properties and available treatments, as well as on the physical mechanisms that control the flowback phenomenon. Several simple models published in the literature, that permit the forecast of proppant flowback in a fast and easy way, are also presented and discussed. Finally, a back-analysis considering the actual conditions in 22 Petrobras oil wells located in Sergipe was also carried out, what permitted a comparison among the results calculated according 4 prediction models, putting in evidence their advantages, shortcomings and adequacy as a design or control tool in the design and exploration of oil fields stimulated by hydraulic fracturing.
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MURGAS, JOSE FRANCISCO CONSUEGRA. "NUMERICAL MODELING OF LEAK OFF TEST IN OIL WELLS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=19630@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
Em operações de perfuração, é importante ter uma estimativa do gradiente de fratura de determinada formação, como o objetivo de poder estimar o máximo peso da lama necessária para a próxima seção da formação rochosa, antes de colocar o revestimento. Por esse motivo, são realizados ensaios de Leak-Off para determinar a máxima pressão que a nova seção do poço pode sustentar sem fraturar ou perder fluido, sendo realizados durante a fase de perfuração do poço, nas formações imediatamente abaixo de cada sapata de revestimento. A finalidade deste estudo é realizar a simulação numérica deste ensaio usando um programa comercial de elementos finitos para calcular a pressão de Leak-Off, considerando a taxa de bombeamento como um dado de entrada do problema e a pressão na parede do poço como uma resposta. O trabalho abordará dois cenários: uma formação rochosa permeável e uma formação rochosa impermeável constituída de rocha de sal. Deste modo, para um estudo de uma análise real de um ensaio de Leak-Off em rocha permeável e rocha impermeável, torna-se necessário a utilização de modelos que considerem poroelasticidade e fluência, respectivamente. Para a caracterização do comportamento da rocha de sal foi usada uma lei de fluência de duplo mecanismo de deformação, que considera apenas os mecanismos de fluência: planar e indefinido. Os modelos estudados foram bidimensionais e analisados sobre a hipótese de deformação plana. A hipótese, de que a pressão de Leak-Off é atingida quando a tensão tangencial efetiva é igual a zero (calculada graficamente), foi considerada. Finalmente, foram simulados alguns casos para verificar os possíveis efeitos da alteração da permeabilidade e influência do fluido de pressurização no cálculo da pressão de Leak-Off em rocha permeável.
In drilling operations, it is important to have an estimate of the fracture gradient of certain formation, in order to being able to estimate the maximum mud weight required for the next section of the rock formation, before casing is placed. For this reason, Leak-Off tests are conducted to determine the maximum pressure that the new section of the well can support without fracturing or losing fluid, being made during the drilling phase of the well in formations immediately below each casing shoe. The purpose this study is to perform the numerical simulation of this test using a commercial finite element program to calculate the Leak-Off pressure, considering the pumping rate as an input data of the problem and pressure at the borehole wall as the answer. The work will address two cases: a permeable rock formation and an impermeable rock formation composed of salt rock. Thus, for studying a real analysis of a Leak-Off test in permeable and impermeable rock, it becomes necessary to use models that consider poroelasticity and creep, respectively. For the characterization of salt rock it was used a creep law of dual mechanism of deformation, which considers only the dislocation creep mechanisms: planar and undefined. The two-dimensional models were studied and analyzed under the assumption of plane strain. The hypothesis that the Leak-Off pressure is reached when the effective tangential stress is zero (estimated graphically), was considered. Finally, some cases were simulated to check the possible effects of changing the permeability and the influence of pressurized fluid in the calculation of Leak-Off pressure in the permeable rock.
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Semkiv, Bogdan. "Problems of monitoring existing oil wells of Western Ukraine." Thesis, National Aviation University, 2021. https://er.nau.edu.ua/handle/NAU/50623.
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1. V.Pryhid. Ecological catastrophe: Boryslav has not laughed for a long time // Deutsche Welle. - 30.10.2017. – Lviv. https://p.dw.com/p/2mdS7.
2. Dryguluch P.G., Pukish A.V. Problems of urban areas during the development of oil and gas fields (on the example of the city of Boryslav)// Oil and gas industry of Ukraine. 2013. № 2.The territory of Ukraine has a large number of wells, as the history of hydrocarbon production dates back to XVI - XVII centuries. The western region of Ukraine is represented by several oil and gas regions: Lviv, Ivano-Frankivsk, Chernivtsi and Zakarpattia regions, which has a total of 91 deposits. Special attention in Western Ukraine should be paid to the Boryslav oil and gas field, which began to be developed in 1854. Since the oil was in layers at a depth of only tens, or sometimes about hundreds of meters, the production was conducted through primitive oil wells - pits. In those years in Borislav there were about 5 thousand such pits with a depth of 35-40 m. In 1870, oil production in Boryslav reached 10.6 thousand tons. There were about 800 small businesses, which employed almost 10 thousand workers [1]. Foreign firms from the USA, Canada, Belgium, France, Germany for the purpose of enrichment carried out exhaustive exploitation of deposits, respectively, without paying attention to labor protection, care of the environment and ignoring keeping records of wells in the documentation. Thus chaotically there were all new places of oil production and in a terrible state remained abandoned primitive wells.
Територія України має велику кількість свердловин, оскільки історія видобутку вуглеводнів сягає XVI - XVII століть. Західний регіон України представлений кількома нафтогазоносними регіонами: Львівською, Івано-Франківською, Чернівецькою та Закарпатською областями, що має загалом 91 родовище. Особливу увагу в Західній Україні слід приділити Бориславському нафтогазовому родовищу, яке почали розробляти в 1854 році. Оскільки нафта була шарами на глибині лише десятки, а іноді і близько сотні метрів, видобуток вівся через примітивні нафтові свердловини - ями. У ті роки в Бориславі було близько 5 тис. таких ям глибиною 35-40 м. У 1870 р. Видобуток нафти в Бориславі досяг 10,6 тис. тонн. Налічувалося близько 800 малих підприємств, на яких працювало майже 10 тис. робітників [1]. Іноземні фірми з США, Канади, Бельгії, Франції, Німеччини з метою збагачення проводили вичерпну експлуатацію родовищ, відповідно, не звертаючи уваги на охорону праці, догляд за навколишнім середовищем та ігноруючи ведення записів свердловин у документації. Таким чином хаотично з'явилися все нові місця видобутку нафти і в жахливому стані залишилися занедбані примітивні свердловини.
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Coskun, Eyup. "From oil wells to institution building an approach for fair oil distribution in Iraq." Thesis, Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion-image.exe/07Dec%5FCoskun.pdf.
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Thesis (M.A. in National Security Affairs)--Naval Postgraduate School, December 2007.Thesis Advisor(s): Looney, Robert. "December 2007." Description based on title screen as viewed on January 22, 2008. Includes bibliographical references (p. 81-88). Also available in print.
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King, Jeremy Scott. "Acoustical signal during hydraulic fracturing." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=565.
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Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains x, 82 p. : ill. (some col.) Vita. Includes abstract. Includes bibliographical references (p. 42).
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Torok, Joseph S. "Mathematical modeling and analysis of mechanisms associated with the propagation of hydraulically induced fractures in poro-elastic media /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487264603217279.
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Purnomo, Hadi. "Inflow performance relationship for gas condensate and volatile oil wells." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300786.
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Badescu, Adrian Constantin. "Reservoir characterization of the Miocene Starfak and Tiger Shoal fields, offshore Louisiana through integration of sequence stratigraphy, 3-D seismic, and well-log data." Access restricted to users with UT Austin EID, 2002. http://wwwlib.umi.com/cr/utexas/fullcit?p3108452.
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Campos, Wellington. "Mechanistic modeling of cuttings transport in directional wells /." Access abstract and link to full text, 1995. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9527819.
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Amin, Aram. "Well test analysis of infrequent flow behaviour of fractured wells in oil and gas reservoirs." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/24556.
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The purpose of hydraulic fracturing is to increase the contact area of the wellbore in the reservoir to maximise production rates. For modelling purposes, the induced fracture is assumed to be of infinite or finite conductivity. The modelled fracture tends to show either features of infinite conductivity with half slope or finite conductivity with quarter slope at early time. These flow behaviours are clear indications of a stimulated well. However, observations in some post-frac well tests report a single unit slope in early time, which indicates non-fractured well response. The objective of this study is to investigate the unusual flow behaviour associated with the testing of fractured wells following a proppant frac job and address reasons for this behaviour assuming the frac job has targeted the reservoir interval of interest. This infrequent behaviour is referred to briefly in a limited number of publications but with no clear explanation. Study suggests that the controlling factors are fracture length, fracture conductivity, non-Darcy flow in the case of gas wells and the damage caused by the fracture operation including choked fracture effect and less importantly fracture face skin. This study utilizes 3-D numerical black oil and compositional simulation in single and multi-layered reservoirs containing different fluid types. A range of factors are examined that may impact the introduced fracture flow behaviour based on actual fractured well flow features found in the literature. The main fracture and reservoir parameters investigated include: fracture half-length (xf), fracture conductivity (kfwf), fracture damage including fracture choke (Sfc) and fracture face skin (Sff), non-Darcy effect, formation permeability and many others. The study also examines fractured well behaviour in naturally fractured reservoirs and gas-condensate (lean and rich) reservoirs to investigate liquid drop out effect on the induced fracture flow behaviour. It is concluded that the investigated fracture behaviour is likely to be associated with damaged fractures of short lengths and low fracture conductivity values, which often result from poorly executed frac job on the well. Knowledge obtained from the study is applied to the analysis of well tests from actual fractured wells. Understanding the flow behaviour of fractured wells is crucial to operators and service companies in evaluating the effectiveness of stimulation work performed on the well.
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MESSER, BRUNO. "MULTILATERAL WELLS DESIGN IN OIL RESERVOIR THROUGH GENETIC ALGORITHMS OPTIMIZATION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2009. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=14734@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORUm dos fatores mais importantes para recuperação de óleo de reservatórios petrolíferos é a configuração dos poços. Atualmente, na indústria, esse processo é feito de forma manual onde um especialista gera algumas poucas opções de configurações e utiliza a de melhor resultado. Este trabalho se propõe a investigar um sistema de apoio à decisão para otimizar a configuração dos poços utilizando Algoritmos Genéticos e o simulador de reservatórios IMEX. Os parâmetros otimizados são: o número de poços produtores e injetores, a posição, a inclinação, a direção e o comprimento de cada poço, o número de laterais de cada poço e o ponto da junta, a inclinação relativa ao poço, a direção e o comprimento de cada lateral. Na busca pela configuração ótima dos poços, o objetivo da otimização é minimizar o investimento inicial, minimizar a produção de água e maximizar a produção de óleo buscando maximizar o VPL do empreendimento. A otimização é conduzida respeitando as restrições de projeto, dadas por um engenheiro, e restrições de simulação, dadas pelo próprio modelo de reservatório. O modelo proposto foi avaliado utilizando-se sete reservatórios. Cinco destes são sintéticos cujas configurações ótimas são conhecidas, um semi-sintético e um reservatório real. Foram conduzidos testes de convergência onde o modelo se mostrou capaz de localizar e otimizar as zonas produtoras, chegando à alternativa ótima até 80% das vezes. Nos últimos dois reservatórios os resultados indicam que o sistema consegue encontrar configurações de poços com altos valores de VPL, superiores a soluções propostas por especialistas e por outros sistemas de otimização, com ganhos de VPL de até 37% sobre a alternativa proposta por um especialista para o reservatório real.
One of the most important factors for recovering oil from oil reservoirs is the wells configuration. Now a days, on the industry, this process is conduced manually, where a specialist generates a few configuration options and uses the best one with best results. This work proposes to investigate a decision support system to optimize the wells’ configuration using Genetic Algorithms and the reservoir simulator IMEX. The optimized parameters include: the number of producers and injectors wells, the position, the inclination, the direction and the length of each well, the number of laterals for each well and the junction point, the inclination relative to the well and the length of each lateral. On the search of the optimal configuration of wells, the objective of the optimization is to minimize the initial investment, minimize the water production and maximize the oil production towards the maximization of the venture`s NPV. The optimization is conduced respecting the project`s restrictions, stated by an engineer, and the simulation`s restrictions, imposed by the reservoir model. The optimization model proposed was evaluated using seven reservoirs. Five of them are synthetic which the optimum well`s configuration are known, one semi-synthetic and one real reservoir. Convergence tests were conducted where the model confirmed to be able to locate and optimize the production zones, achieving the optimum alternative 80% of the times. On the last two reservoirs the results indicate that the system was able to achieve well configurations with high values of NPV, superiors from solutions given by specialists and by other optimization systems, with NPV´s increase reaching 37% over the specialist`s purposed alternative for the real reservoir case.
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BELCHIOR, INGRID MILENA REYES MARTINEZ. "NUMERICAL MODELING OF ROCK CUTTING PROCESS FOR DRILLING OIL WELLS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2012. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=20363@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
O mecanismo de corte em rocha é determinante na eficiência do processo de perfuração de poços de petróleo. Este mecanismo tem sido estudado através de ensaios de corte com um único cortador. Neste trabalho foram desenvolvidos modelos com o método dos elementos finitos para simular o processo de corte em rocha realizado por um cortador único. Este trabalho está vinculado ao Projeto de Modelagem de Perfuração de Evaporitos sob Altas Pressões desenvolvido pela Baker-Hughes e o Grupo de Tecnologia em Engenharia de Petróleo (GTEP) da PUC-Rio. As simulações numéricas foram feitas utilizando-se o programa ABAQUS. O modelo constitutivo de Drucker-Prager foi descrito e usado para modelar o comportamento da rocha. O modelo de dano isotrópico foi usado para modelar a erosão do material produzida na interação rocha-cortador. Os resultados das simulações com modelos bidimensionais e tridimensionais permitiram analisar a influência da variação da profundidade de corte e da pressão de confinamento na energia específica necessária para realizar o corte em rocha. Observou-se que, até certo limite, quanto mais profundo estiver o cortador menor energia específica será necessária para o corte. A análise da influência da pressão de confinamento mostrou que o corte de rocha em condições atmosféricas fornece valores de energia específica muito próximos à resistência à compressão não confinada da rocha, enquanto que a aplicação de pressão confinante causa incrementos da energia específica.
The understanding of rock cutting mechanism is critical to the efficiency of borehole drilling process. This mechanism is studied through single cutter tests. In this work were developed models with the Finite Element Method to simulate the rock cutting process by a single cutter. This work is connected to the project Modeling of Evaporite Drilling Under High Pressure, sponsored by Baker Hughes in partnership with the Group of Technology and Petroleum Engineering (GTEP) of the Pontifical Catholic University of Rio de Janeiro. The numerical simulations were performed using the program ABAQUS. The Drucker- Prager constitutive relationship was used to model the rock behavior. Also, an isotropic model of damage was described and employed for modeling the erosion mechanism that represents the rock-cutter interaction. Two and three-dimensional simulations allowed the analysis of the influence of the variation of cutting depth and confining pressure on the mechanical specific energy required to cut the rock. To certain depth limit, it was observed that for larger depths of cut, less specific energy is required to cut the rock. The analysis of experiments under confining pressure showed that cutting process under atmospheric conditions produced specific energy close to the unconfined compressive strength of rock, while the application of confining pressure showed a remarkable increase in specific energy required for cutting.
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ESTEU, BRUNO ROMANELLI MENECHINI. "CLUSTERING VIBRATION DATA FROM OIL WELLS THROUGH UNSUPERVISED NEURAL NETWORK." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=25049@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
A perfuração de poços de petróleo em águas profundas tem como objetivo atingir o melhor ponto de extração de óleo e gás natural presentes em reservatórios a alguns milhares de metros no fundo do mar. Um melhor entendimento da dinâmica de perfuração através da análise de parâmetros operacionais em tempo real é importante para otimizar os processos de perfuração e reduzir seus tempos de operação. Com esse objetivo, operadoras de petróleo têm realizado grandes investimentos no desenvolvimento de ferramentas de medição e transmissão de parâmetros durante a perfuração, tais como, entre outros, o peso sobre broca, rotação da coluna e vazão do fluido de perfuração. Dentre as vantagens em se monitorar estes dados em tempo real, destaca-se a otimização de parâmetros operacionais buscando obter uma taxa de penetração satisfatória com o menor gasto de energia possível. Em uma perfuração rotativa, essa energia é muitas vezes parcialmente dissipada devido à vibração da coluna causada pela interação entre broca e formação. Nesta dissertação, com o objetivo de extrair características comuns que pudessem vir a ajudar na otimização da atividade de perfuração, foi utilizada uma técnica de redes neurais não supervisionadas para análise de uma extensa base de dados levantados ao longo de campanhas de perfuração de poços em um mesmo campo de petróleo. Os dados de campo analisados foram obtidos ao longo de perfurações de poços verticais, exclusivamente empregando brocas tipo PDC e exibindo elevados níveis de vibração torcional. O estudo realizado a partir de registros de parâmetros de perfuração, características dos poços e respostas de vibração obtidas em tempo real por ferramentas de poço, e empregando o código de mineração de dados WEKA e a plataforma computacional de análise TIBCO Spotfire, permitiu a determinação de uma curva de desgaste de broca e a influência das ferramentas de navegação no nível de severidade de vibração ao longo da perfuração.
Drilling oil wells in deep waters aims to achieve the best point of extraction of oil and natural gas reservoirs present in a few thousand meters in the seabed. A better understanding of the drilling dynamics through the analysis of real time operation parameters is important to optimize drilling process and reduce operation time. For this purpose petroleum operator companies have been made great investments in developing tools that measure and transmit parameters during drilling operation, such as the weight on bit, pipes rotation per minute and drilling fluid flow. Among the advantages to monitor this real time data there is the operational parameters optimization looking for the least expenditure of energy as possible. In a rotary drilling operation this energy is often lost partially due to column vibration caused by the interaction between bit and formation.In this master s thesis in order to extract common features that could help on the drilling operation optimization a technique using unsupervised neural networks for analyze an extensive database which was built over drilling campaigns in a big oil field . The field data analyzed were obtained during drilling vertical wells exclusively employing PDC bits and presented high levels of torcional vibration. The study was made from drilling parameters records, wells characteristics and vibration responses obtained in real time by downhole tools. Employing the WEKA data mining code and the computing analysis platform TIBCO potfire it was possible determine a bit wear curve and the real influence of navigation tools on the severity levels of vibration during drilling operations.
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Ogbonna, Nneoma. "Decoupled overlapping grids for modelling transient behaviour of oil wells." Thesis, Heriot-Watt University, 2010. http://hdl.handle.net/10399/2401.
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This research presents a new method, the decoupled overlapping grids method, for the numerical modelling of transient pressure and rate properties of oil wells. The method is implemented in two stages: a global stage solved in the entire domain with a point or line source well approximation, and a local (post-process) stage solved in the near-well region with the well modelled explicitly and boundary data interpolated from the global stage results. We have carried out simulation studies in two- and three- dimensions to investigate the accuracy of the method. For homogeneous case studies in 2D, we have demonstrated the convergence rate of the maximum error in the quantities of interest of the global and local stage computations by numerical and theoretical means. We also proposed a guideline for the selection of the relative mesh sizes of the local and global simulations based on error trends. Comparison to other methods in the literature showed better performance of the decoupled overlapping grids method in all cases. We carried out further investigations for heterogeneous case studies in 2D and partially-penetrating wells in 3D which show that the error trends observed for the 2D homogeneous case deteriorate only slightly, and that a high level of accuracy is achieved. Overall the results in this thesis demonstrate the potential of the method of decoupled overlapping grids to accurately model transient wellbore properties for arbitrary well con gurations and reservoir heterogeneity, and the gain in computational e ciency achieved from the method.
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Valencia, Karen Joy Petroleum Engineering Faculty of Engineering UNSW. "Optimising hydraulic fracture treatments in reservoirs under complex conditions." Awarded by:University of New South Wales. School of Petroleum Engineering, 2005. http://handle.unsw.edu.au/1959.4/23318.
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Growing global energy demand has prompted the exploitation of non-conventional resources such as Coal Bed Methane (CBM) and conventional resources such as gas-condensate reservoirs. Exploitation of these resources primarily depends on stimulation by hydraulic fracturing. Traditional hydraulic fracturing practices, however, are in many ways inadequate in addressing difficulties associated with these non-conventional and conventional resources. For example, complex in-situ stress distribution, large material property contrasts and unique production mechanism complicate the implementation of hydraulic fracture treatments in CBM and gas-condensate reservoirs respectively. An integrated approach to optimise hydraulic fracture treatments in reservoirs under complex conditions is developed in this thesis. The optimisation methodology integrates a fracture geometry model which predicts fracture geometry for a given set of treatment parameters, a production model which estimates reservoir productivity after stimulation and an economic model which calculates net present value. A stochastic optimisation algorithm combining features of evolutionary computations is used to search for the optimum design. Numerical techniques such as finite element analysis, iterative semi-analytical methods and evolutionary computation are also used. The following are the major contributions of this thesis: 1. A three-dimensional hydraulic fracture geometry model which accounts for poroelastic effects, in-situ stress and rock material properties, has been developed to provide a more realistic description of the hydraulic fracture geometry. This served as a tool to visualise hydraulic fracture propagation for a given in-situ stress distribution, rock material properties and treatment parameters. Furthermore, by accounting for poroelastic effects, it is possible to identify the causes of exceptionally high treatment pressures. 2. An innovative production model was formulated in this thesis to quantify the well deliverability due to hydraulic fracturing. The production model has been used for a range of production scenarios for CBM and gas-condensate reservoirs such as: multiple wells at arbitrary locations and various well types (stimulated and unstimulated wells). 3. The optimisation methodology presented in this work provides a platform for operators to assess risks and gains associated with different field development scenarios. The added feature of sub-optimal NPV contouring provided flexibility to calibrate the treatment design in real-time. The strength of the optimisation methodology lies in the flexibility to: (1) impose design constraints, (2) optimise multiple variables and (3) simulate multiple objectives.
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Echavarria, Erika. "Acoustic properties of a 2-D fracture during formation." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=1143.
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Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains xiii, 132 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 98).
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Sagar, Rajiv K. "Reservoir description by integration of well test data and spatial statistics /." Access abstract and link to full text, 1993. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9416603.
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Camacho-Velázquez, Rodolfo Gabriel. "Well performance under solution gas drive /." Access abstract and link to full text, 1987. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/8720613.
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Climent, Pera Natalia. "A coupled CFD-DEM model for sand production in oil wells." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/403981.
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During the oil recovery a hole is drilled, the sandstone is left unsupported next to the cavity and disloged sand grains can enter the oil recovery system. This process is called sand production and several problems may arise due to that process, as clogging up of the well or damage to the well equipment. The study of sand production process is of paramout importance for safe and economical hydrocarbon production.
The majority of numerical models to predict sand production that have been used to date are continuum-based. However, a continuum approach cannot easily capture important features of the sanding problem, such as erosion, and it requires the formulation recognized as a difficult task because of the large number of interactions and non-lineaities intrinsic to the problem.
On the other hand, discrete-element based approaches allow a simpler formulation of the problem and a better understanding of some of its features. Discrete Element Methods (DEM) describe more naturally the disaggregation and erosion of sand particles and the fluid-solid interaction.
In this research rock behavior has been epresented in DEM using the parallel-bond model (PBM) because it mimics the effect of cement between particles. The study has involved the calibration of the DEM rock model agains real data. Moreover, limitations of the DEM model have been explored and sensitivity analyses examining the effects of the local damping have been performed.
The main aim of this research is to improve the understanding of sand production based on a Computational Fluid Dynamics (CFD) -DEM coupling model. CFD-DEM is frequently used for process and chemical engineering problems (Zhu et al., 2007). To simulate the interaction of the particles with the fluid, the solid DEM model is coupled with a fluid model (CFD). A validation of the CFD-DEM model has been carried out in this thesis by performing single particle simulations and analyses of ermeability tests.
Simulations of sand production using a omogeneous sandstone analogue and, finally, the simulation of sand production under realistic conditions are presented.En este estudio se ha representado el comportamiento de la roca en DEM utilizando el modelo de enlace paralelo (parallel-bond model - PBM) porque simulat el efecto del cemento entre partículas. El estudio ha implicado la calibración del model en DEM de la roca en comparación don datos reales. Además, las limitaciones del modelo en DEM se ha exploradoy se han llevado a cabo análisis de sensibilidad para examinar los efectos del parámetro de amortiguación (local damping). El principal objetivo de este estudio es mejorar la comprensión de la producción de arena basado en un modelo de acoplamiento con Dinámica de Fluidos Computacional (Computational Fluid Dynamics - CFD) CFD-DEM. El CFD-DEM se usa frecuentemente para problemas de procesos y de ingeniería química. Para simular la interacción de las partículas con el fluido, el modelo sólido DEM es acoplado con el modelo de fluido (CFD). En esta tesis se ha llevado a cabo una validación del modelo CFD-DEM realizando simulaciones con una sola partícula y con análisis de tests de permeabilidad. Se han presentado simulaciones de producción de arena utilizando un modelo análogo a una arenisca homogénea, y finalmente se han presentado simulaciones de producción de arena bajo condiciones realistas. Durante el proceso de extracción de petróleo se perfora un agujero y la arenisca queda sin apoyo junto a la vacidad y los granos de arena sueltos pueden entrar en el sistema de extracción del petróleo. Este proceso se llama producción de arena y pueden producirse varios problemas debido a este proceso, como obstruir el pozo o dañar el equipo instalado en el pozo. El estudio del proceso de producción de arena es de primordial importancia para una producción de hidrocarburo segura y rentable. La mayoría de los modelos numéricos para predecir la producción de arena que se han estado usando hasta el momento están basados en medio continuo. No obstante, un método continuo no puede captar fácilmente algunas características importantes del problema de la producción de arena, como es la erosión, y requiere una formulación que se reconoce como una tarea difícil debido al gran número de interacciones y no-linearidades intrínsecas al problema. Por otro lado, los métodos basados en elementos discretos permiten una formulación más simple del problema y un entendimiento mejor de algunas de sus características. Los Métodos de Elementos Discretos (Discrete Element Methods - DEM) describen de una forma más natural la desagregación y la erosión de partículas de arena y de la interacción sólido-fluido.
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El, Kamkhi M. "Investigation into descaling of production tubing in oil and gas wells." Thesis, University of Salford, 2011. http://usir.salford.ac.uk/26650/.
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One of the most common production problems in oil and gas fields is scale deposition within oil and gas wellbores. Scale formation in surface and subsurface oil and gas production equipment has been recognised to be a major operational problem. The effect of scale formation is a reduction in the well productivity and the damage to safety valves and gas-lift mandrels. This investigation proposes a new and novel technique to address the problem and lay the foundations for a methodology for descaling in-situ production tubing. This problem currently requires either aggressive chemicals or extraction and replacement tubing both of which are very expensive. The overall aim of this investigation is to study the fundamentals of the decaling process using flat fan sprays at high water pressure ( < 6 MPa ) and high impact force (< 0.657MPa). The spray was characterised quantitatively and qualitatively under ambient conditions utilising single flat fan atomiser or a combination of two or three atomisers with an overlapping configurations. The volume (or mass) flux (VLf) was measured using a patternator which was designed during this investigation. Liquid volume (or mass) flux was found to be symmetrical at different downstream distances (25, 50 and 75 mm). Impact force (IF) was also experimentally measured at different downstream distances (25, 50 and 75 mm) and at various water supply pressure of 3.7, 4.8 and 6 MPa for the corresponding sprays. The result showed that impact force can lie between 0.146 to 0.657MPa Sprays were also characterised using Phase-Doppler Anemometry (PDA). The range of velocity (U) was found to be between 62.48 to 81.85 m/s at 25 mm downstream distance whilst at 50 mm downstream, it was in the range of 55.96 to 73.13 m/s and at 75 mm was between 48.89 to 66.98 m/s. However, the Sauter mean drop size diameter (D^ at 25 downstream distances was found to be in the range of 62.45 um to 75.80 urn and at 50 mm downstream the drop size was between 67.30 jam to 81.43 urn whereas at 75 mm it was 73.56um to 86.42 um. Also, from the results, the liquid volume flux (ULf) obtained using PDA was measured to be between 0.063 and 1.2 (cm3/s)/cm2 at 25 mm downstream and 0.016 to 0.250 (cm3/s)/cm2 at 50 mm and 0.010 to 0.120 (cm3/s)/cm2 at 75 mm downstream distance. Comparing these results with those found via patternator mesurements showed in some instanous, that there is significant (i.e up to 90%) difference between each values which were obtained by the PDA, measured at the centre of the sprays. This was mainley to lack of caputuring the certain drop sizes by PDA and also the design geometry of the patternator together with the nature of flat shape of the spray being not truly flat. Simulated laboratory scale removal rig was subsequently designed and built to demonstrate the effects of using overlapping flat sprays atomisers to remove scales that normally found in oil and gas. Four scale samples (candle wax, soft oil wax, soft gas and oil hard) were tested. The quantity of scale removed using soft candle wax was (53 cm3) at 30 degree atomiser angle to the vertical axis. The scales samples which were obtained from both oil and gas fields were also tested as follows: - a total of 11.688 cm3 of soft scale was removed using three high pressure and high impact atomisers whilst the volume of the scale removed from the oil wax was within 13.750 cm3 for the hard oil scale was found to be approximately 0.989 cm3 . The structures of the flat sprays were also mathematically analysed using the Computational Fluid Dynamics (CFD) package which allowed validating the PDA data. The velocity of the drops compared well with those obtained from PDA. The liquid volume flux, however, was found, generally, between 26% < ULf < 90% compared with those of PDA data.
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BOTELHO, FABRICIO VIEIRA CUNHA. "NUMERICAL ANALYSIS OF MECHANICAL BEHAVIOR OF THE SALT IN OIL WELLS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=12391@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
A presença de estruturas salinas ao redor do mundo em águas profundas do golfo do México, do Brasil, de Angola, do norte e do oeste da África forma condições favoráveis para o aprisionamento dos hidrocarbonetos e aumenta a probabilidade de sucesso na prospecção de óleo e gás. Na Bacia de Santos, por exemplo, foram divulgadas recentemente novas descobertas de óleo abaixo de uma espessa camada salina. Por outro lado, muitos problemas operacionais, como o aprisionamento de coluna de perfuração e o colapso do poço, têm sido registrados pela indústria do petróleo quando se está perfurando através de espessas camadas de sal. Estes contratempos criam grandes desafios e geram oportunidade de evolução da Indústria do Petróleo. Desta forma, esta dissertação propõe um estudo do comportamento mecânico do sal em poços de petróleo. Analisaram-se os deslocamentos, deformações e tensões na parede do poço e em sua vizinhança para diversos pesos de fluido de perfuração com a utilização do método dos elementos finit os. Foram realizadas modelagens computacionais mediante o uso de um programa comercial de elementos finitos: o Abaqus. Através de análises de deformação plana e análises axissimétricas, estas simulações numéricas puderam prever o comportamento elástico e, principalmente, o de fluência (creep) do sal. Sendo assim, como contribuição técnica, este estudo auxilia o controle e o monitoramento do fechamento de poços de petróleo em estratos salinos, evitando deste modo, diversos problemas causados pelo comportamento de fluência do sal, como o colapso do poço. Com isso, é fundamental a inclusão das análises das seções salinas nos projetos de perfuração de poços de petróleo. No que diz respeito ao quesito econômico, a principal contribuição deste trabalho é a redução do tempo de intervenções do poço provocadas por problemas ocorridos em camadas de sal e, conseqüentemente, a redução do tempo necessário para perfuração do poço e a diminuição do tempo de aluguel da sonda.
The presence of saline structures around the world, in deepwater like the ones of the Mexican Gulf, Brazil, Angola, North and West Africa, provides favorable conditions for hydrocarbons imprisonment. It increases the probability of success in oil and gas exploration. In the Santos Basin, for example, it was recently noticed that a light crude oil located below a thick salt layer was discovered. On the other hand many operational problems in salt drilling like the imprisonment of the drillstring and closing of the well have been registered in the industry. These types of problems create big challenges in the oil industry and at the same time opportunities for the evolution of the drilling technology. This work proposes the study of the mechanical behavior of salt in oil wells. Dislocations, strains and stresses were analyzed in the face of the wellbore and into the salt formation by finite element analysis. Several finite element analyses were developed to represent the possible scenarios in salt drilling using a program denominated Abaqus. These numerical simulations were analyzed through plane strain and axisymmetric techniques, could predict elastic and specially creep behavior. As a technical contribution, this study helps to avoid wellbore closure and casing collapse of salt sections, adding to the wellbore and drilling project an accurate salt section analysis and preventing workover operations due to salt mass deformation. Finally the economical contribution of this study is the reduction of workover time and of expenses in salt sections drilling. By reducing workover time, there is a notorious decrease in rig time use.
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URIBE, JUAN DAVID VELILLA. "OIL WELLS STABILITY IN FRACTURED MEDIA USING THE DISCRETE ELEMENT METHOD." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2013. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=22127@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
A estabilidade de poços de petróleo é convencionalmente analisada empregando soluções analíticas que não são adequadas para modelagem de meios fraturados, devido a suposições de meio continuo. Esta dissertação tem como objetivo principal desenvolver uma metodologia computacional para geração de janela operacional utilizando uma solução numérica, adequada para meios fraturados. No trabalho foi escolhido o software UDEC (Universal Distinct Element Code), que é baseado no método dos elementos discretos (MED). Este método considera o maciço rochoso como a união de blocos de rocha intactos, unidos pelas fraturas e cujo comportamento físico para cada elemento pode ser analisado individualmente. A modelagem computacional no UDEC foi realizada mediante uma analise hidromecânica acoplada. Esta modelagem permitiu avaliar a influencia de alguns mecanismos que governam a estabilidade de poços, como: as tensões in situ, a poropressão e a orientação, espaçamento e persistência das famílias de fraturas. Os resultados numéricos mostram o efeito das fraturas na orientação e magnitude das tensões, além da magnitude da poropressão resultando em cálculos dos limites de colapso inferior e fratura superior da rocha mais realistas.
The stability of oil wells is conventionally analyzed using analytical solutions that are often not suitable for modeling fractured media due to assumptions of continuous medium. This work has as main objective to develop a computational method for generating mud window using a numerical solution, suitable for fractured media. The software chosen for this work was the UDEC (Universal Distinct Element Code), which is based on discrete element method (DEM). This method considers the rock mass as the union of blocks of intact rock jointed by fractures, and whose physical behavior for each element can be analyzed individually. Computational modeling in UDEC was carried out in a coupled hydromechanical analysis. This modeling allowed to evaluate the influences of some of the mechanisms that govern the stability of wells, as in situ stresses, pore pressure and orientation, spacing and persistence of families of fractures. Numerical results show the effect of fracture orientation and magnitude of the stresses, besides the magnitude of the pore pressure resulting in more realistic calculations of lower collapse and upper fracture of the rock mass.
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OLIVEIRA, PAULO GUILHERME OLIVEIRA DE. "RELIABILITY STUDY OF SUBSURFACE SAFETY VALVE CONTROL SYSTEM IN OIL WELLS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2016. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=27632@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROOs desafios na construção de poços de petróleo vêm aumentando ao longo do tempo, seja pelo aumento das dificuldades técnicas devido à maior complexidade das áreas a serem desenvolvidas, sejam pelas melhorias nas regras dos órgãos reguladores visando aumentar a segurança. Existem dois pilares que devem nortear um projeto de um poço de petróleo: segurança e produtividade. O equipamento denominado dispositivo de segurança de sub-superfície e seu sistema de controle podem ser considerados importantes para os dois, pois caso o sistema falhe, obtendo-se um fechamento prematuro do poço, afetará diretamente a produção. Por outro lado, caso a falha ocorra em uma tentativa de fechamento, poderá influenciar nas consequências de um desastre, o que afetaria tanto pessoas como o meio ambiente. O objetivo deste estudo e comparar a confiabilidade de alguns modelos de sistemas de controle do dispositivo de segurança de sub-superfície, levando em consideração as disposições dos equipamentos ao longo do sistema e suas respectivas taxas de falha. Além disso, a maioria dos estudos de confiabilidade realizados nesta área tem como foco principal a segurança, porém este estudo visa obter um foco de eficiência de produção, e as análises serão baseadas em comparações entre algumas configurações disponíveis do sistema, entre componentes em série e em paralelo, utilizando o modelo de análise de confiabilidade markoviano.
The challenges in well construction have been increasing over time, sometimes by increasing the technical difficulties due to the greater complexity of the areas to be developed, sometimes by the improvements in the rules of regulatory agencies to increase security. There are two pillars that should guide the project of a petroleum well: safety and productivity. The equipment called Subsurface Safety Valve and its control system can be considered important for both pillars, because if the system fails resulting in a premature well closure, it will directly affect the production. On the other hand, if the failure occurs in an attempt to closing it, may influence the consequence of a disaster, which would affect both people and the environment. The objective of this study is to compare the reliability of some control systems models taking into account the equipment positions throughout the system and their failure rates. Furthermore, most reliable studies conducted in this area has mainly focused on safety, but this study has a focus on production efficiency, and the analysis will be based on comparisons between some configurations available for subsurface safety valves control system, including serial and parallel components, using the model of Markov reliability analysis.
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Yusuf, Ahmed A. "The study of down-hole hydro-cyclone efficiency in oil wells using computational fluid dynamics." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4886.
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Thesis (M.S.)--West Virginia University, 2006.Title from document title page. Document formatted into pages; contains ix, 64 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 63-64).
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Khajotia, Burzin. "Cased based reasoning Taylor series model to predict corrosion rate in oil and gas wells and pipelines /." Ohio : Ohio University, 2007. http://www.ohiolink.edu/etd/view.cgi?ohiou1173828758.
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Hatzignatiou, Dimitrios Georgios. "Advances in well testing for solution-gas-drive reservoirs /." Access abstract and link to full text, 1990. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9033497.
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Peres, Alvaro Marcello Marco. "Analysis of slug and drillstem tests /." Access abstract and link to full text, 1989. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9004161.
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Chen, Guizhong. "A study of wellbore stability in shales including poroelastic, chemical, and thermal effects." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3025005.
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Zhang, Xutuan. "Quantitative risk assessment in drill casing design for oil and gas wells." Thesis, University of Wolverhampton, 2004. http://hdl.handle.net/2436/89102.
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FERNANDES, ANDRE ALONSO. "MODELING AND NONLINEAR CONTROL EVALUATION FOR MANAGED PRESSURE DRILLING OF OIL WELLS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2015. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=25706@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROPara acesso aos reservatórios portadores de hidrocarbonetos é necessária a perfuração de poços de petróleo. Entre as várias funções do fluido de perfuração podem se destacar o transporte do cascalho gerado pela broca, a função de primeira barreira para inibição de influxo das formações expostas no poço e a manutenção da pressão do poço dentre os limites de resistência das formações atravessadas (janela operacional). Alguns novos campos petrolíferos, bem como campos depletados sofrem restrições operacionais devido a pequenas janelas operacionais. A variação da pressão no poço aberto devido a perdas por atrito no anular, em alguns casos é maior do que a janela operacional, impedindo a perfuração do poço. Managed Pressure Drilling (MPD) é uma tecnologia alternativa à perfuração convencional. O anular do poço é vedado, possibilitando a retenção de pressão no anular. O ajuste da pressão no anular do poço possibilita compensar a variação da perda de atrito e perfurar poços com janelas operacionais estreitas. Para manutenção da pressão da zona objetivo dentro da janela operacional é necessário o controle adequado da pressão na superfície. A definição do valor de pressão necessário é obtida através do conhecimento do comportamento da dinâmica do fluido de perfuração no poço. Este trabalho desenvolveu um modelo de um sistema de poço de petróleo com MPD, levando em conta os efeitos estáticos e dinâmicos envolvidos na perfuração MPD. Sobre o modelo desenvolvido foram propostas e aplicadas diferentes técnicas de controle linear e não-linear para avaliação do desempenho dos controladores e identificação de pontos-chave na aplicação da técnica MPD. Os controles nãolineares propostos foram bem sucedidos em compensar os efeitos altamente nãolineares do sistema, melhorando sua resposta em tarefas típicas.
For access of hydrocarbon reservoirs, drilling oil wells is required.. Among the various functions the drilling fluid may provide are cutting transportation generated by the bit, a barrier function for inhibiting influx of exposed formations in the well and maintaining well pressure within the resistance limits of the formations exposed (operational window). Some new oil fields as well as some depleted fields are experiencing severe operational restrictions due to small operational windows. The open hole pressure variation due to friction losses on the annular in some cases is greater than the operational window, inhibiting the perforation of the well. Managed Pressure Drilling (MPD) is an alternative technology to conventional drilling. The annular of the well is sealed while pressure is contained within it. By adjusting annular pressure it is possible to compensate for friction loss variation on the annular and drill well sections with close operational windows. For the proper pressure maintenance on the target zone within the operating window, it is required adequate pressure control on the surface. The definition of the necessary pressure value is obtained through knowledge of the dynamic behavior of the drilling fluid in the well. This work has developed a model of an oil well system with MPD, taking into account the static and dynamic effects involved in MPD. To the developed model different linear and non-linear control techniques were proposed and applied for evaluating the performance of controllers and identifying key points in implementing the MPD technique. The proposed non-linear control techniques were able to compensate for the highly non-linear nature of the system, improving its response during typical tasks.