Global ETD Search

111	Pressure Normalization of Production Rates Improves Forecasting Results Lacayo Ortiz, Juan Manuel 16 December 2013 (has links) New decline curve models have been developed to overcome the boundary-dominated flow assumption of the basic Arps’ models, which restricts their application in ultra-low permeability reservoirs exhibiting long-duration transient flow regimes. However, these new decline curve analysis (DCA) methods are still based only on production rate data, relying on the assumption of stable flowing pressure. Since this stabilized state is not reached rapidly in most cases, the applicability of these methods and the reliability of their solutions may be compromised. In addition, production performance predictions cannot be disassociated from the existing operation constraints under which production history was developed. On the other hand, DCA is often carried out without a proper identification of flow regimes. The arbitrary application of DCA models regardless of existing flow regimes may produce unrealistic production forecasts, because these models have been designed assuming specific flow regimes. The main purpose of this study was to evaluate the possible benefits provided by including flowing pressures in production decline analysis. As a result, it have been demonstrated that decline curve analysis based on pressure-normalized rates can be used as a reliable production forecasting technique suited to interpret unconventional wells in specific situations such as unstable operating conditions, limited availability of production data (short production history) and high-pressure, rate-restricted wells. In addition, pressure-normalized DCA techniques proved to have the special ability of dissociating the estimation of future production performance from the existing operation constraints under which production history was developed. On the other hand, it was also observed than more consistent and representative flow regime interpretations may be obtained as diagnostic plots are improved by including MBT, pseudovariables (for gas wells) and pressure-normalized rates. This means that misinterpretations may occur if diagnostic plots are not applied correctly. In general, an improved forecasting ability implies greater accuracy in the production performance forecasts and more reliable reserve estimations. The petroleum industry may become more confident in reserves estimates, which are the basis for the design of development plans, investment decisions, and valuation of companies’ assets. Flow regime identification boundary-dominated flow boundary dominated flow transient flow regime unconventional reservoirs rate transient analysis shale gas shale oil production forecasting reserves estimation hindcasting hindcasts low permeability tight sands high pressure rate controlled unstable flowing conditions.
112	Da revolução do gás não convencional nos EUA tendo como substrato uma interferência governamental persistente no estímulo a atividade econômica e no fomento as inovações tecnológicas afetas ao setor Valle, Arthur 13 January 2014 (has links) Submitted by ARTHUR VALLE (arthurvalle.f@gmail.com) on 2014-02-25T15:54:39Z No. of bitstreams: 1 ARTIGO SHALE FINAL (atual FGV-OS).pdf: 455344 bytes, checksum: 3be4fa41a18545524133c57cfb9e5de6 (MD5) / Rejected by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br), reason: Prezado aluno, Substituir a folha de alterações nº 2 pela folha de aprovação com assinatura dos membros da banca e submeter novamente. ÁUREA SRA on 2014-02-26T13:41:40Z (GMT) / Submitted by ARTHUR VALLE (arthurvalle.f@gmail.com) on 2014-03-08T14:26:34Z No. of bitstreams: 1 ARTIGO SHALE FINAL (ENTREGUE - FGV).pdf: 600365 bytes, checksum: 3a72197ea83d5df9f9e396366e535e1e (MD5) / Approved for entry into archive by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br) on 2014-04-04T17:04:35Z (GMT) No. of bitstreams: 1 ARTIGO SHALE FINAL (ENTREGUE - FGV).pdf: 600365 bytes, checksum: 3a72197ea83d5df9f9e396366e535e1e (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2014-04-09T13:43:33Z (GMT) No. of bitstreams: 1 ARTIGO SHALE FINAL (ENTREGUE - FGV).pdf: 600365 bytes, checksum: 3a72197ea83d5df9f9e396366e535e1e (MD5) / Made available in DSpace on 2014-04-09T14:52:02Z (GMT). No. of bitstreams: 1 ARTIGO SHALE FINAL (ENTREGUE - FGV).pdf: 600365 bytes, checksum: 3a72197ea83d5df9f9e396366e535e1e (MD5) Previous issue date: 2014-01-13 / O presente estudo versa sobre os fatores tecnológicos e ambientais que vêm resultando no crescimento da produção de gás natural não convencional nos EUA. Os objetos de analise principais serão as políticas públicas, assim como a dinâmica entre os atores sociais e o ambiente propício que fora criado para que houvesse o adensamento do fomento e do estímulo às inovações tecnológicas sucedidas no setor. / The present study deals with the technological and environmental factors that have resulted in increased of production of unconventional natural gas in the U.S.. The objects of analysis will be the public policies, as well as the dynamics between social actors and enabling environment which was created to promote and the encourage the successful technological innovations in the industry. Gás de Xisto Gás Não Convencional Fraturamento Hidráulico Perfuração horizontal Revolução do gás Mapeamento microssísmico Inovação Políticas públicas Shale gas Unconventional gas Hydraulic Fracturing Horizontal Drilling Gas Revolution Microssísmic mapping Innovation Public policy Administração de empresas Gás de xisto Fraturamento hidráulico Inovações tecnológicas Políticas públicas
113	Ozone Pollution of Shale Gas Activities in North Texas Ahmadi, Mahdi 05 1900 (has links) The effect of shale gas activities on ground-level ozone pollution in the Dallas-Fort Worth area is studied in detail here. Ozone is a highly reactive species with harmful effects on human and environment. Shale gas development, or fracking, involves activities such as hydraulic fracturing, drilling, fluid mixing, and trucks idling that are sources of nitrogen oxides (NOX) and volatile organic compounds (VOC), two of the most important precursors of ozone. In this study two independent approaches have been applied in evaluating the influences on ozone concentrations. In the first approach, the influence of meteorology were removed from ozone time series through the application of Kolmogorov-Zurbenko low-pass filter, logarithmic transformation, and subsequent multi-linear regression. Ozone measurement data were acquired from Texas Commission on Environmental Quality (TCEQ) monitoring stations for 14 years. The comparison between ozone trends in non-shale gas region and shale gas region shows increasing ozone trends at the monitoring stations in close proximity to the Barnett Shale activities. In the second approach, the CAMx photochemical model was used to assess the sensitivity of ozone to the NOX and VOC sources associated with shale oil and gas activities. Brute force method was applied on Barnett Shale and Haynesville Shale emission sources to generate four hypothetical scenarios. Ozone sensitivity analysis was performed for a future year of 2018 and it was based on the photochemical simulation that TCEQ had developed for demonstrating ozone attainment under the State Implementation Plan (SIP). Results showed various level of ozone impact at different locations within the DFW region attributed to area and point sources of emissions in the shale region. Maximum ozone impact due to shale gas activities is expected to be in the order of several parts per billion, while lower impacts on design values were predicted. The results from the photochemical modeling can be used for health impact assessment and air quality management purposes. Both studies in this research show that the impact of shale gas development on local and regional level of ozone is significant, and therefore, it should be considered in the implementation of effective air quality strategies. shale gas fracking ozone air pollution photochemical simulation statistical analysis Texas Barnett Shale atmospheric sciences mechanical engineering environmental sciences Ozone.
114	Study of organic matter decomposition under geological conditions from replica exchange molecular dynamics simulations / Etude de la décomposition de matière organique dans des conditions géologiques par simulations numériques de replica exchange molecular dynamics Atmani, Léa 15 May 2017 (has links) Pétrole et gaz proviennent de la décomposition de la matière organique dans la croûte terrestre. En s’enfouissant, les résidus organiques se décomposent en un solide poreux et carboné, appelé kérogène et en un fluide composé d’hydrocarbures et de petites molécules telles que de l’eau. Le processus de formation du kérogène n’est pas totalement élucidé et une modélisation aiderait à une meilleure compréhension à la fois de sa structure et de sa composition et serait utile à l’industrie pétrolière.Dans le présent travail, nous adoptons une approche thermodynamique ayant pour but, à l’aide de simulations numériques, de d’étudier la décomposition de précurseurs de kérogène d’un type donné –ici le type III- dans les conditions d’un réservoir géologique. La méthode dite de Replica Exchange Molecular Dynamics (REMD) est appliquée pour étudier la décomposition de cristaux de cellulose et de lignine. Le potentiel d’interaction ReaxFF et le code LAMMPS sont utilisés. La REMD est une façon de surmonter de larges barrières d’énergie libre, en améliorant l’échantillonnage de configurations d’une dynamique moléculaire conventionnelle à température constante, en utilisant des états générés à températures supérieures.En fin de simulation, les systèmes ont atteint un état d’équilibre entre deux phases : une phase riche en carbone, composée d’amas de macromolécules, que nous appelons « solide » et d’une phase riche en oxygène et en hydrogène, composée de petites molécules, que nous dénommons « fluide ». L’évolution des parties solides de nos systèmes coïncide avec celle d’échantillons naturels de kérogènes de type III. / In deep underground, organic residues decompose into a carbonaceous porous solid, called kerogen and a fluid usually composed of hydrocarbons and other small molecules such as water, carbon monoxide. The formation process of the kerogen remains poorly understood. Modeling its geological maturation could widen the understanding of both structure and composition of kerogen, and could be useful to oil and gas industry.In this work we adopt a purely thermodynamic approach in which we aim, through molecular simulations, at determining the thermodynamic equilibrium corresponding to the decomposition of given organic precursors of a specific type of kerogen –namely type III- under reservoir conditions. Starting from cellulose and lignin crystal structures we use replica exchange molecular dynamics (REMD) simulations, using the reactive force field ReaxFF and the open-source code LAMMPS. The REMD method is a way ofovercoming large free energy barriers, by enhancing the configurational sampling of a conventional constant temperature MD using states from higher temperatures.At the end of the simulations, we have reached for both systems, a stage where they can clearly be cast into two phases: a carbon-rich phase made of large molecular clusters that we call here the "solid" phase, and a oxygen and hydrogen rich phase made of small molecules that we call "fluid" phase.The evolution of solid parts for both systems and the natural evolution of a type III kerogen clearly match. Evolution of our systems follows the one of natural samples, as well as the one of a type III kerogen submitted to an experimental confined pyrolysis. Kérogène Remd Simulations Gaz Pétrole Gaz de schistes Matière organique Lammps ReaxFF Cellulose Lignine Van Krevelen Hydrocarbures Simulations Numériques Carbone Potentiel réactif Carbone amorphe Thermodynamique Géologie Roche mère Maturation Dynamique Moléculaire Pyrolyse Kerogen Remd Replica Exchange Molecular Dynamics Gas Shale Gas Oil Organic Matter Lammps ReaxFF Cellulose Lignin Van Krevelen Pyrolysis Hydrocarbons Numerical simulations Carbon Reactive Potential Amorphous Carbon Thermodynamics Petroleum Geology Source rocks Maturation Molecular Dynamics 530
115	Processes for Light Alkane Cracking to Olefins Peter Oladipupo (8669685) 12 October 2021 (has links) <p>The present work is focused on the synthesis of small-scale (modular processes) to produce olefins from light alkane resources in shale gas.</p> <p>Olefins, which are widely used to produce important chemicals and everyday consumer products, can be produced from light alkanes - ethane, propane, butanes etc. Shale gas is comprised of light alkanes in significant proportion; and is available in abundance. Meanwhile, shale gas wells are small sized in nature and are distributed over many different areas or regions. In this regard, using shale gas as raw material for olefin production would require expensive transportation infrastructure to move the gas from the wells or local gas gathering stations to large central processing facilities. This is because existing technologies for natural gas conversions are particularly suited for large-scale processing. One possible way to take advantage of the abundance of shale resource for olefins production is to place small-sized or modular processing plants at the well sites or local gas gathering stations.</p> <p>In this work, new process concepts are synthesized and studied towards developing simple technologies for on-site and modular processing of light alkane resources in shale gas for olefin production. Replacing steam with methane as diluent in conventional thermal cracking processes is proposed to eliminate front-end separation of methane from the shale gas processing scheme. Results from modeling studies showed that this is a promising approach. To eliminate the huge firebox volume associated with thermal cracking furnaces and allow for a compact cracking reactor system, the use of electricity to supply heat to the cracking reactor is considered. Synthesis efforts led to the development of two electrically powered reactor configurations that have improved energy efficiency and reduced carbon footprints over and compare to conventional thermal cracking furnace configurations.</p> <p>The ideas and results in the present work are radical in nature and could lead to a transformation in the utilization of light alkanes, natural gas and shale resources for the commercial production of fuels and chemicals.</p> Chemical Engineering Design Light Alkane Cracking Olefin Production Thermal Cracking Electrical Reactor Shale Gas Processing Natural Gas Processing Alkane Dehydrogenation Methane Ethane Cracking Methane as a Diluent Electrical Dehydrogenation Electrified Cracking Process Process Intensification Modularization Modular Process Small-Scale Chemical Process Light Gas Pyrolysis Alkane Pyrolysis Ethane Pyrolysis Ethane Cracking Ethane Dehydrogenation Ethylene Production

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