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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Estudo do comportamento de solos contaminados com óleo de isolamento de transformadores. / Study of behavior of soils contaminated with transformers insulate oil.

Lauro Massao Wada 06 February 2012 (has links)
Com a finalidade de estudar o comportamento de fluidos aquosos não miscíveis em água no solo, foram executados ensaios de laboratório, a construção de um modelo físico e a comparação dos dados com a simulação numérica com o programa HSSM. Os ensaios de laboratório tiveram a finalidade de obter os parâmetros do solo utilizado no modelo físico e numérico. Foram obtidas curvas de retenção do solo com concentrações de 2, 5, 10 e 15% de óleo e somente com água, para comparar o comportamento das curvas. Para o modelo físico, foi construído um tanque experimental para simular o derramamento de óleo no solo e, assim, obter uma pluma de contaminação de óleo de maneira controlada. Foram executados três ensaios com o tanque experimental, primeiro com o solo na umidade higroscópica, o segundo com um nível dágua definido, e o terceiro com o solo úmido, mas sem um nível dágua. Destes ensaios no tanque, foram coletadas amostras para a análise em laboratório das concentrações de óleo de cada parte do tanque. A partir dos resultados das curvas características foi possível observar que o óleo influencia principalmente na umidade residual. E a análise das amostras coletadas do tanque experimental indica que a concentração de óleo na pluma estava constante, com concentração de 2% de óleo. Juntando os dados colhidos dos ensaios de laboratório e do tanque experimental, foram executadas simulações da evolução da pluma de contaminação de NAPL para os três casos simulados no tanque experimental. A simulação numérica foi coerente com o modelo físico, mas foi observado que subestima a velocidade de expansão da pluma, principalmente quando o solo está com a umidade baixa. / In order to study the behavior of non-aqueous phased liquids in the soil, laboratory tests were performed, and the construction of a physical model and comparison of data obtained with the numerical simulation with the program HSSM. Laboratory tests are designed to obtain the soil parameters used in the physical and numerical model. Retention curves of soil with concentrations of 2, 5, 10 and 15% of oil and water only were obtained to compare the curves. For the physical model, an experimental tank was built to simulate the oil spill on the ground and have a contamination plume of oil with controlled conditions. Were performed three experiments with the tank, first with the hygroscopic soil moisture, the second with a defined water table, and the third with natural soil moisture, but without a water table. From these tests in the tank, samples were collected for laboratory analysis of concentrations of each part of the oil tank. From the results of the retention curves it was observed that the major oil influence was on residual moisture. And the analysis of samples collected from the experimental tank indicates that the oil concentration in the plume was constant at the concentration of 2% of oil. Combining the data collected in laboratory testing and experimental tank, numerical simulations were performed of the evolution of NAPL contamination plume for the three cases simulated in the experimental tank. The numerical simulation was consistent with the physical model, but it was observed that underestimates the rate of expansion of the contamination plume, especially when the moisture of soil is low.
32

Förslag till modell av kemikaliespridning i mark anpassad för användning vid räddningsinsats - Kemspill Mark 4.0

Alsterhag, Elin January 2005 (has links)
<p>After emergencies involving chemical spills it is of great importance that correct measures are taken with short notice, both for the security of people and in order to minimize future environmental consequences. The RIB-unit at the Swedish Rescue Services Agency initiated this study, the aim of which is to propose changes to the existing chemical transport calculation tool: Chemical Spill 3.4, included in RIB - Integrated Decision Support for Civil Protection, so that it can be used for decision support as well as in preventive work. A rough estimation of chemical transport in the subsurface is considered being of great importance when making decisions during emergency response operations.</p><p>The proposition presented in this report is a non site specific chemical transport model which is designed to give a rough estimation of NAPL flow in homogenous isotropic soil shortly after an instantaneous release. The model can be used at two levels; both in situations without access to information on subsurface properties, and with more accuracy in situations with knowledge of the included parameters. For that reason the user can choose among predefined alternatives or assign the parameters a numeric value to increase the quality of the model output. The predefined alternatives are represented by default values for different parameters in the model.</p><p>Suggested model output are vertical and horizontal transport of NAPL phase, horizontal transport of dissolved chemical in the aqueous phase, as well as the amounts of spill that are evaporated and entrapped in the soil, all at the time specified by the user. Moreover the maximum transport of the chemical phase and time to groundwater pollution are given. To make the uncertainty of the model clear for the user the results are given as the most likely value together with the smallest and largest values that can be expected.</p><p>Equations presented in this report describe a selection of subsurface processes which occur after a release of chemicals. The selection is made with the aim to reach satisfying result when the model is used within its domain without making the model complicated for the user. Therefore simplifying assumptions have been made in the descriptions of some processes while some other processes are neglected. Simplifications have been based on recognized references or on theoretical arguments, but the overall performance of the model as well as some of the default input parameters need to be further tested and validated before the new version of the model can be included in RIB. However, compared with the existing version Chemical Spill 3.4 several changes have been suggested; including additional processes, development of default values and making model uncertainty clear to the user. These changes are thought to significantly improve the existing model.</p> / <p>Vid olyckor med kemikalieutsläpp är det av stor vikt att rätt åtgärder snabbt vidtas, både för människors säkerhet och för att minimera framtida miljökonsekvenser. Räddningsverkets RIB-enhet initierade den här studien vars mål är att ge förslag på modellteknisk förbättring av det befintliga beräkningsprogrammet Kemspill Mark 3.4, som ingår i programpaketet RIB - Integrerat beslutsstöd för skydd mot olyckor, så att det i framtiden kan användas som beslutsstöd vid räddningsinsats efter kemikalieutsläpp samt vid förebyggande planeringsarbete. En grov vägledning om kemikaliens spridning anses vara av stor betydelse för att räddningstjänsten ska kunna fatta rätt beslut vid en insats.</p><p>Förslaget som presenteras i denna rapport är en icke platsspecifik spridningsmodell anpassad för vätskor med begränsad löslighet i vatten och ger en grov uppskattning av spridning i homogen och isotrop mark inom några timmar efter ett momentant utsläpp.</p><p>Modellen ska kunna användas på två nivåer; för att ge en mycket grov uppskattning av spridningen även utan tillgång på uppgifter om markegenskaper, samt med större noggrannhet då informationen finns. Med anledning av detta kommer användaren ges möjlighet att välja bland fördefinierade alternativ eller att ange indata numeriskt för att öka noggrannheten. De fördefinierade valen representeras av typvärden för olika parametrar i modellen.</p><p>Den nya modellen i förslaget ger vid angiven tid vertikal och horisontell spridning av fri kemikaliefas, horisontell spridning av löst förorening i vattenfas samt hur stor andel av utsläppet som hålls kvar i marken respektive har avdunstat från spillytan. Dessutom anges kemikaliefasens maximala spridning och hur lång tid det tar för utsläppet att nå grundvattnet. För att tydliggöra modellens osäkerhet för användaren ges utdata som det mest sannolika värdet tillsammans med det största och minsta värdet som är sannolikt.</p><p>Ekvationerna som presenteras i rapporten beskriver ett urval av de processer som sker i marken vid ett kemikalieutsläpp. Urvalet har gjorts med utgångspunkt att uppnå tillfredställande resultat inom modellens domän utan att komplicera för användaren och därmed har förenklande antaganden gjorts för att beskriva vissa förlopp medan andra försummats helt. Förenklingarna har grundats på vedertagna referenser eller på teoretiskt resonemang. Validering av modellresultat samt vissa typvärdens intervall krävs före inkludering i RIB. Jämfört med det befintliga Kemspill Mark 3.4 har dock stora förändringar föreslagits; fler processer inkluderas, typvärden utvecklas och modellens osäkerhet görs tydlig för användaren. Förändringar tros medföra en signifikant förbättring av modellen.</p>
33

Undersökningsmetodik för klorerade lösningsmedel i marken / Chlorinated solvents in soil and groundwater : Investigation methodology and analysis of completed investigations

Walger, Ellen January 2006 (has links)
Chlorinated solvent are volatile organic substances that can be harmful for humans and for the environment. Examples of common chlorinated solvents are perchloroethene, PCE, and trichloroethene, TCE. Chlorinated solvents appear as contaminants in soils primarily where they have been used as washing fluids in dry-cleaning facilities or as degreasers in metal industries. Chlorinated solvents are DNAPLs (dense non-aqueous phase liquids), which means that they are not easily dissolved in water and that they sink to the bottom of the aquifer. Adsorption to soils is low so chlorinated solvents are mobile in soils. Chlorinated solvents can be harmful at low concentrations. Complete degradation can only occur under specific conditions. Because of the properties of these substances, investigation and analysis methodology are extra important for determining transport and risks in a contaminated area. In this work, investigation and analysis methods for chlorinated solvents are described. Planning, fieldwork, modeling and risk analysis are described. Projects concerning chlorinated solvents completed by Golder Associates AB have been compiled and analysed. Based on the compilation, conclusions have been drawn and statistics have been calculated. Investigations of the relation between concentrations in different media have been made as well as investigations of the relation between degradation products at different distances from the source and at different times after release. The data from the environmental investigations have been compared with theoretical literature values and modelling results. The results show that there is a large natural variation in the data and that the differences between different areas are quite large. The results confirm the theory that the percentage of degradation products increases with distance from the source and with time from release. In addition, solvents with a higher degree of chlorination seams to appear to a greater extent in the soil and the more volatile substances seams to appear to a greater extent in the soil air. / Klorerade lösningsmedel är flyktiga klorerade organiska ämnen som kan vara skadliga för människor och miljön. Exempel på vanliga klorerade lösningsmedel är perkloreten, PCE och trikloreten, TCE. Klorerade lösningsmedel förekommer som markföroreningar främst efter användning som tvättvätska i kemtvättar och som avfettningsmedel i metallindustrin. Klorerade lösningsmedel är DNAPLs (dense non-aqueous phase liquids), det innebär att de är svårlösliga i vatten och att de sjunker och lägger sig på botten av akviferen. Fastläggningen i jorden är liten hos klorerade lösningsmedel som därmed är rörliga i marken. De är farliga redan vid små koncentrationer och fullständig nedbrytning sker endast under vissa förutsättningar. Ämnenas egenskaper gör att undersöknings- och analysmetodiken är viktig för att riktigt kunna bestämma deras utbredning och risk på ett förorenat område. I detta arbete beskrivs undersöknings- och analysmetodiken för områden förorenade med klorerade lösningsmedel. Upplägg, fältarbete, modellering och riskbedömning beskrivs. Projekt som handlar om klorerade lösningsmedel utförda av Golder Associates AB har sammanställts. Sammanställningen har analyserats och utifrån den har olika slutsatser dragits och statistik beräknats. Bland annat har samband mellan halter i olika medier samt samband mellan halter av nedbrytningsprodukter på olika avstånd från källan respektive efter olika lång tid från läckage har undersökts. Data från miljöundersökningarna har även jämförts med teoretiska litteraturvärden samt modelleringsresultat. Resultatet visar att den naturliga spridningen av data är stor samt att resultaten skiljer sig åt mellan olika områden. Resultaten bekräftar teorierna att halten nedbrytningsprodukter ökar med avståndet från källan och med tiden samt att ämnen med högre kloreringsgrad finns i större utsträckning i jorden och att flyktigare ämnen finns i större utsträckning i porluften.
34

Mass Transfer to/from Distributed Sinks/Sources in Porous Media

Zhao, Weishu January 2006 (has links)
This research addresses a number of fundamental issues concerning convective mass transfer across fluid-fluid interfaces in porous media. Mass transfer to/from distributed sinks/sources is considered for i) the slow dissolution of liquid filaments of a wetting non-aqueous phase liquid (NAPL) held in the corners of angular pores or throats and ii) the fate of gas bubbles generated during the flow of a supersaturated aqueous phase in porous media. 1. Effects of the stability of NAPL films on wetting NAPL dissolution Wettability profoundly affects the distribution of residual NAPL contaminants in natural soils. Under conditions of preferential NAPL wettability, NAPL is retained within small pores and in the form of thick films (liquid filaments) along the corners and crevices of the pore walls. NAPL films in pore corners provide capillary continuity between NAPL-filled pores, dramatically influencing the behaviour of NAPL dissolution to the flowing aqueous phase by convection and diffusion. A pore network model is developed to explore the dissolution behaviour of wetting NAPL in porous media. The effects of initial NAPL distribution and NAPL film stability on dissolution behaviour are studied using the simulator. NAPL phase loses continuity and splits into disconnected clusters of NAPL-filled pores due to rupture of NAPL films. Quasi-state drainage and fingering of the aqueous phase into NAPL-filled pores is treated as an invasion percolation process and a stepwise procedure is adopted for the solution of flow and solute concentration fields. NAPL film stability is shown to critically affect the rate of mass transfer as such that stable NAPL films provide for more rapid dissolution. The network simulator reproduces the essential physics of wetting NAPL dissolution in porous media and explains the concentration-tailing behaviour observed in experiments, suggesting also new possibilities for experimental investigation. 2. Convective Mass Transfer across Fluid Interfaces in Straight Angular Pores Steady convective mass transfer to or from fluid interfaces in pores of angular cross-section is theoretically investigated. The model incorporates the essential physics of capillarity and solute mass transfer by convection and diffusion in corner fluid filaments. The geometry of the corner filaments, characterized by the fluid-fluid contact angle, the corner half-angle and the interface meniscus curvature, is accounted for. Boundary conditions of zero surface shear (‘perfect-slip’) and infinite surface shear (‘no-slip’) at the fluid-fluid interface are considered. The governing equations for laminar flow within the corner filament and convective diffusion to or from the fluid-fluid interface are solved using finite-element methods. Flow computations are verified by comparing the dimensionless resistance factor and hydraulic conductance of corner filaments against recent numerical solutions by Patzek and Kristensen [2001]. Novel results are obtained for the average effluent concentration as a function of flow geometry and pore-scale Peclet number. These results are correlated to a characteristic corner length and local pore-scale Peclet number using empirical equations appropriate for implementation in pore network models. Finally, a previously published “2D-slit” approximation to the problem at hand is checked and found to be in considerable error. 3. Bubble evolution driven by solute diffusion during the process of supersaturated carbonated water flooding In situ bubble growth in porous media is simulated using a pore network model that idealizes the pore space as a lattice of cubic chambers connected by square tubes. Evolution of the gas phase from nucleation sites is driven by the solute mass transfer from the flowing supersaturated water solution to the bubble clusters. Effects of viscous aqueous phase flow and convective diffusion in pore corners are explicitly accounted for. Growth of bubble clusters is characterised by a pattern of quasi-static drainage and fingering in the gas phase, an invasion percolation process controlled by capillary and gravitational forces. A stepwise solution procedure is followed to determine the aqueous flow field and the solute concentration field in the model by solving the conservation equations. Mobilization of bubbles driven by buoyancy forces is also studied. Results of bubble growth pattern, relative permeability and macroscopic mass transfer coefficient are obtained under different gas saturations and aqueous flow conditions.
35

Continuum Approach to Two- and Three-Phase Flow during Gas-Supersaturated Water Injection in Porous Media

Enouy, Robert 09 December 2010 (has links)
Degassing and in situ formation of a mobile gas phase takes place when an aqueous phase equilibrated with a gas at a pressure higher than the subsurface pressure is injected in water-saturated porous media. This process, which has been termed supersaturated water injection (SWI), is a novel and hitherto unexplored means of introducing a gas phase into the subsurface. Herein is a first macroscopic account of the SWI process on the basis of continuum scale simulations and column experiments with CO2 as the dissolved gas. A published empirical mass transfer correlation (Nambi and Powers, Water Resour Res, 2003) is found to adequately describe the non-equilibrium transfer of CO2 between the aqueous and gas phases. Remarkably, the dynamics of gas-water two-phase flow, observed in a series of SWI experiments in homogeneous columns packed with silica sand or glass beads, are accurately predicted by traditional two-phase flow theory which allows the corresponding gas phase relative permeability to be determined. A key consequence of the finding, that the displacement of the aqueous phase by gas is compact at the macroscopic scale, is consistent with pore scale simulations of repeated mobilization, fragmentation and coalescence of large gas clusters (i.e., large ganglion dynamics) driven entirely by mass transfer. The significance of this finding for the efficient delivery of a gas phase below the water table in relation to the alternative process of in-situ air sparging and the potential advantages of SWI are discussed. SWI has been shown to mobilize a previously immobile oil phase in the subsurface of 3-phase systems (oil, water and gas). A macroscopic account of the SWI process is given on the basis of continuum-scale simulations and column experiments using CO2 as the dissolved gas and kerosene as the trapped oil phase. Experimental observations show that the presence of oil ganglia in the subsurface alters gas phase mobility from 2-phase predictions. A corresponding 3-phase gas relative permeability function is determined, whereas a published 3-phase relative permeability correlation (Stone, Journal of Cana Petro Tech, 1973) is found to be inadequate for describing oil phase flow during SWI. A function to predict oil phase relative permeability is developed for use during SWI at high aqueous phase saturations with a disconnected oil phase and quasi-disconnected gas phase. Remarkably, the dynamics of gas-water-oil 3-phase flow, observed in a series of SWI experiments in homogeneous columns packed with silica sand or glass beads, are accurately predicted by traditional continuum-scale flow theory. The developed relative permeability function is compared to Stone’s Method and shown to approximate it in all regions while accurately describing oil flow during SWI. A published validation of Stone’s Method (Fayers and Matthews, Soc of Petro Eng Journal, 1984) is cited to validate this approximation of Stone’s Method.
36

Förslag till modell av kemikaliespridning i mark anpassad för användning vid räddningsinsats - Kemspill Mark 4.0

Alsterhag, Elin January 2005 (has links)
After emergencies involving chemical spills it is of great importance that correct measures are taken with short notice, both for the security of people and in order to minimize future environmental consequences. The RIB-unit at the Swedish Rescue Services Agency initiated this study, the aim of which is to propose changes to the existing chemical transport calculation tool: Chemical Spill 3.4, included in RIB - Integrated Decision Support for Civil Protection, so that it can be used for decision support as well as in preventive work. A rough estimation of chemical transport in the subsurface is considered being of great importance when making decisions during emergency response operations. The proposition presented in this report is a non site specific chemical transport model which is designed to give a rough estimation of NAPL flow in homogenous isotropic soil shortly after an instantaneous release. The model can be used at two levels; both in situations without access to information on subsurface properties, and with more accuracy in situations with knowledge of the included parameters. For that reason the user can choose among predefined alternatives or assign the parameters a numeric value to increase the quality of the model output. The predefined alternatives are represented by default values for different parameters in the model. Suggested model output are vertical and horizontal transport of NAPL phase, horizontal transport of dissolved chemical in the aqueous phase, as well as the amounts of spill that are evaporated and entrapped in the soil, all at the time specified by the user. Moreover the maximum transport of the chemical phase and time to groundwater pollution are given. To make the uncertainty of the model clear for the user the results are given as the most likely value together with the smallest and largest values that can be expected. Equations presented in this report describe a selection of subsurface processes which occur after a release of chemicals. The selection is made with the aim to reach satisfying result when the model is used within its domain without making the model complicated for the user. Therefore simplifying assumptions have been made in the descriptions of some processes while some other processes are neglected. Simplifications have been based on recognized references or on theoretical arguments, but the overall performance of the model as well as some of the default input parameters need to be further tested and validated before the new version of the model can be included in RIB. However, compared with the existing version Chemical Spill 3.4 several changes have been suggested; including additional processes, development of default values and making model uncertainty clear to the user. These changes are thought to significantly improve the existing model. / Vid olyckor med kemikalieutsläpp är det av stor vikt att rätt åtgärder snabbt vidtas, både för människors säkerhet och för att minimera framtida miljökonsekvenser. Räddningsverkets RIB-enhet initierade den här studien vars mål är att ge förslag på modellteknisk förbättring av det befintliga beräkningsprogrammet Kemspill Mark 3.4, som ingår i programpaketet RIB - Integrerat beslutsstöd för skydd mot olyckor, så att det i framtiden kan användas som beslutsstöd vid räddningsinsats efter kemikalieutsläpp samt vid förebyggande planeringsarbete. En grov vägledning om kemikaliens spridning anses vara av stor betydelse för att räddningstjänsten ska kunna fatta rätt beslut vid en insats. Förslaget som presenteras i denna rapport är en icke platsspecifik spridningsmodell anpassad för vätskor med begränsad löslighet i vatten och ger en grov uppskattning av spridning i homogen och isotrop mark inom några timmar efter ett momentant utsläpp. Modellen ska kunna användas på två nivåer; för att ge en mycket grov uppskattning av spridningen även utan tillgång på uppgifter om markegenskaper, samt med större noggrannhet då informationen finns. Med anledning av detta kommer användaren ges möjlighet att välja bland fördefinierade alternativ eller att ange indata numeriskt för att öka noggrannheten. De fördefinierade valen representeras av typvärden för olika parametrar i modellen. Den nya modellen i förslaget ger vid angiven tid vertikal och horisontell spridning av fri kemikaliefas, horisontell spridning av löst förorening i vattenfas samt hur stor andel av utsläppet som hålls kvar i marken respektive har avdunstat från spillytan. Dessutom anges kemikaliefasens maximala spridning och hur lång tid det tar för utsläppet att nå grundvattnet. För att tydliggöra modellens osäkerhet för användaren ges utdata som det mest sannolika värdet tillsammans med det största och minsta värdet som är sannolikt. Ekvationerna som presenteras i rapporten beskriver ett urval av de processer som sker i marken vid ett kemikalieutsläpp. Urvalet har gjorts med utgångspunkt att uppnå tillfredställande resultat inom modellens domän utan att komplicera för användaren och därmed har förenklande antaganden gjorts för att beskriva vissa förlopp medan andra försummats helt. Förenklingarna har grundats på vedertagna referenser eller på teoretiskt resonemang. Validering av modellresultat samt vissa typvärdens intervall krävs före inkludering i RIB. Jämfört med det befintliga Kemspill Mark 3.4 har dock stora förändringar föreslagits; fler processer inkluderas, typvärden utvecklas och modellens osäkerhet görs tydlig för användaren. Förändringar tros medföra en signifikant förbättring av modellen.
37

Continuum Approach to Two- and Three-Phase Flow during Gas-Supersaturated Water Injection in Porous Media

Enouy, Robert 09 December 2010 (has links)
Degassing and in situ formation of a mobile gas phase takes place when an aqueous phase equilibrated with a gas at a pressure higher than the subsurface pressure is injected in water-saturated porous media. This process, which has been termed supersaturated water injection (SWI), is a novel and hitherto unexplored means of introducing a gas phase into the subsurface. Herein is a first macroscopic account of the SWI process on the basis of continuum scale simulations and column experiments with CO2 as the dissolved gas. A published empirical mass transfer correlation (Nambi and Powers, Water Resour Res, 2003) is found to adequately describe the non-equilibrium transfer of CO2 between the aqueous and gas phases. Remarkably, the dynamics of gas-water two-phase flow, observed in a series of SWI experiments in homogeneous columns packed with silica sand or glass beads, are accurately predicted by traditional two-phase flow theory which allows the corresponding gas phase relative permeability to be determined. A key consequence of the finding, that the displacement of the aqueous phase by gas is compact at the macroscopic scale, is consistent with pore scale simulations of repeated mobilization, fragmentation and coalescence of large gas clusters (i.e., large ganglion dynamics) driven entirely by mass transfer. The significance of this finding for the efficient delivery of a gas phase below the water table in relation to the alternative process of in-situ air sparging and the potential advantages of SWI are discussed. SWI has been shown to mobilize a previously immobile oil phase in the subsurface of 3-phase systems (oil, water and gas). A macroscopic account of the SWI process is given on the basis of continuum-scale simulations and column experiments using CO2 as the dissolved gas and kerosene as the trapped oil phase. Experimental observations show that the presence of oil ganglia in the subsurface alters gas phase mobility from 2-phase predictions. A corresponding 3-phase gas relative permeability function is determined, whereas a published 3-phase relative permeability correlation (Stone, Journal of Cana Petro Tech, 1973) is found to be inadequate for describing oil phase flow during SWI. A function to predict oil phase relative permeability is developed for use during SWI at high aqueous phase saturations with a disconnected oil phase and quasi-disconnected gas phase. Remarkably, the dynamics of gas-water-oil 3-phase flow, observed in a series of SWI experiments in homogeneous columns packed with silica sand or glass beads, are accurately predicted by traditional continuum-scale flow theory. The developed relative permeability function is compared to Stone’s Method and shown to approximate it in all regions while accurately describing oil flow during SWI. A published validation of Stone’s Method (Fayers and Matthews, Soc of Petro Eng Journal, 1984) is cited to validate this approximation of Stone’s Method.
38

Adaptação de um edômetro com controle de sucção para a determinação da curva característica de solos contaminados por óleo diesel / Adaptation of an edometer with suction control for the determination of the retention curve of soil contaminated by diesel oil

Taytelbaum, Leandro Bergmann January 2008 (has links)
A presença de compostos orgânicos no solo proporciona o desenvolvimento de uma fase adicional nos poros, imiscível com a fase aquosa e gasosa pré-existentes. A característica de imiscibilidade destes compostos, denominados de fase livre não aquosa (“nonaqueos phase liquid” – NAPL), torna a avaliação de um solo contaminado por tais substâncias bastante complexa. Dentre as substâncias pertencentes a este grupo NAPL, destacam-se os produtos derivados do petróleo. As propriedades mais importantes na avaliação de um solo contaminado por NAPL são suas relações constitutivas. Uma destas propriedades relaciona a sucção dos fluídos com suas respectivas saturações, enquanto que a outra relaciona a condutividade relativa dos fluidos com a saturação de cada um destes fluidos. A partir da curva de retenção de um solo contaminado, é possível quantificar de forma indireta a relação condutividade relativa-saturação. Todavia, a obtenção desta curva de retenção para um solo contaminado por NAPL é bastante complexa e está em desenvolvimento, exigindo cuidados na sua determinação. Para isso, assume-se que no interior de um poro contendo água, óleo e ar, o contaminante estará preferencialmente localizado entre a água e o ar. Isto é determinante ao admitir-se que a saturação da água Sw é uma função da sucção mátrica desenvolvida entre a água e o óleo e a saturação total dos líquidos St, (soma da saturação da água e do óleo) é dependente da sucção mátrica gerada entre o óleo e o ar. Esta hipótese possibilita a obtenção das curvas de retenção para sistemas trifásicos ar-NAPL-água a partir dos sistemas bifásicos NAPL-água e ar-NAPL. Assim sendo, o objetivo deste trabalho é desenvolver, a partir de um oedômetro com controle de sucção, um equipamento, denominado de célula multifásica, que permita o controle independente das pressões do ar, do NAPL e da água. Especificamente, este equipamento permitirá a determinação das curvas de retenção para sistemas bi e trifásicos. Para atingir esta meta, foi necessário transformar uma pedra porosa cerâmica comum em uma pedra porosa hidrofóbica (repelente à água), através de um tratamento químico da pedra porosa convencional em uma solução contendo uma substância comercialmente conhecida como Glassclad 18. Este novo equipamento permite o monitoramento da variação do volume de água e de óleo no interior de uma amostra de solo para diversas pressões capilares. Ensaios preliminares foram realizados em uma mistura composta de 70% de um solo arenoso e 30% de um solo argilo-arenoso, sendo o primeiro coletado no estado do Rio Grande do Sul enquanto que o segundo em Santa Catarina. Ambos os solos possuem propriedades físicas bem conhecidas. / The presence of organic compounds in the soil provides the development of an additional phase in the pore space, immiscible with the preexisting water and gaseous phases. This characteristic of immiscibility of such substances, called nonaqueos phase liquids – NAPL’s, turns the evaluation of a soil contaminated by these substances sufficiently complex. Among the substances pertaining to this group, called NAPL, the petroleum products are distinguished. The most important properties in the evaluation of a soil contaminated by NAPL are their constitutive relationships. One of these properties relates the pressure of the fluids with their respective saturations, while the other one relates the relative permeability of the fluids with the saturation of each one of these fluids. From the pressure-saturation constitutive relationship of a contaminated soil, it is possible to quantify indirectly the relative permeability-saturation relationship. However, the evaluation of the pressure-saturation relationship for a soil contaminated by NAPL is sufficiently complex and is in development, demanding considerable care in its determination. For this, it is assumed that, in the interior of a pore contaning water, oil and air, the organic liquid will be preferentially located between the water and air. That is imperative when assuming that water saturation of Sw is a function of the suction developed between the oil-water interface and the total liquid saturation St (sum of water saturation and oil saturation) is dependent of the suction generated between the airoil interfaces. This hypothesis makes possible the evaluation of the pressure-saturation relationship for the three-phase system air-NAPL-water from the two-phase systems NAPLwater and air-oil. Thus, the objective of this work is to develop, from the edometer with pressure control, another equipment, called the multiphase cell, that allows the independent control of the air, NAPL and water pressures. Specifically, this equipment will allow the determination of the pressure-saturation relationship for bi- and three-phase systems. To reach this goal, it was necessary to transform a standard ceramic porous stone in a hidrophobic porous stone (repellent to water), through a chemical treatment of the standard porous stone in a solution containing a substance commercially known as Glassclad 18. This new equipment allows the control of the volume changes of water and oil within a soil sample for different suction. Preliminary tests have been carried out with a mixture composed by 70% of sand and 30% of silt; the first material were collected in the state of the Rio Grande do Sul (Brazil) and the second in the state of Santa Catarina. Both materials have their physical properties well known.
39

Adaptação de um edômetro com controle de sucção para a determinação da curva característica de solos contaminados por óleo diesel / Adaptation of an edometer with suction control for the determination of the retention curve of soil contaminated by diesel oil

Taytelbaum, Leandro Bergmann January 2008 (has links)
A presença de compostos orgânicos no solo proporciona o desenvolvimento de uma fase adicional nos poros, imiscível com a fase aquosa e gasosa pré-existentes. A característica de imiscibilidade destes compostos, denominados de fase livre não aquosa (“nonaqueos phase liquid” – NAPL), torna a avaliação de um solo contaminado por tais substâncias bastante complexa. Dentre as substâncias pertencentes a este grupo NAPL, destacam-se os produtos derivados do petróleo. As propriedades mais importantes na avaliação de um solo contaminado por NAPL são suas relações constitutivas. Uma destas propriedades relaciona a sucção dos fluídos com suas respectivas saturações, enquanto que a outra relaciona a condutividade relativa dos fluidos com a saturação de cada um destes fluidos. A partir da curva de retenção de um solo contaminado, é possível quantificar de forma indireta a relação condutividade relativa-saturação. Todavia, a obtenção desta curva de retenção para um solo contaminado por NAPL é bastante complexa e está em desenvolvimento, exigindo cuidados na sua determinação. Para isso, assume-se que no interior de um poro contendo água, óleo e ar, o contaminante estará preferencialmente localizado entre a água e o ar. Isto é determinante ao admitir-se que a saturação da água Sw é uma função da sucção mátrica desenvolvida entre a água e o óleo e a saturação total dos líquidos St, (soma da saturação da água e do óleo) é dependente da sucção mátrica gerada entre o óleo e o ar. Esta hipótese possibilita a obtenção das curvas de retenção para sistemas trifásicos ar-NAPL-água a partir dos sistemas bifásicos NAPL-água e ar-NAPL. Assim sendo, o objetivo deste trabalho é desenvolver, a partir de um oedômetro com controle de sucção, um equipamento, denominado de célula multifásica, que permita o controle independente das pressões do ar, do NAPL e da água. Especificamente, este equipamento permitirá a determinação das curvas de retenção para sistemas bi e trifásicos. Para atingir esta meta, foi necessário transformar uma pedra porosa cerâmica comum em uma pedra porosa hidrofóbica (repelente à água), através de um tratamento químico da pedra porosa convencional em uma solução contendo uma substância comercialmente conhecida como Glassclad 18. Este novo equipamento permite o monitoramento da variação do volume de água e de óleo no interior de uma amostra de solo para diversas pressões capilares. Ensaios preliminares foram realizados em uma mistura composta de 70% de um solo arenoso e 30% de um solo argilo-arenoso, sendo o primeiro coletado no estado do Rio Grande do Sul enquanto que o segundo em Santa Catarina. Ambos os solos possuem propriedades físicas bem conhecidas. / The presence of organic compounds in the soil provides the development of an additional phase in the pore space, immiscible with the preexisting water and gaseous phases. This characteristic of immiscibility of such substances, called nonaqueos phase liquids – NAPL’s, turns the evaluation of a soil contaminated by these substances sufficiently complex. Among the substances pertaining to this group, called NAPL, the petroleum products are distinguished. The most important properties in the evaluation of a soil contaminated by NAPL are their constitutive relationships. One of these properties relates the pressure of the fluids with their respective saturations, while the other one relates the relative permeability of the fluids with the saturation of each one of these fluids. From the pressure-saturation constitutive relationship of a contaminated soil, it is possible to quantify indirectly the relative permeability-saturation relationship. However, the evaluation of the pressure-saturation relationship for a soil contaminated by NAPL is sufficiently complex and is in development, demanding considerable care in its determination. For this, it is assumed that, in the interior of a pore contaning water, oil and air, the organic liquid will be preferentially located between the water and air. That is imperative when assuming that water saturation of Sw is a function of the suction developed between the oil-water interface and the total liquid saturation St (sum of water saturation and oil saturation) is dependent of the suction generated between the airoil interfaces. This hypothesis makes possible the evaluation of the pressure-saturation relationship for the three-phase system air-NAPL-water from the two-phase systems NAPLwater and air-oil. Thus, the objective of this work is to develop, from the edometer with pressure control, another equipment, called the multiphase cell, that allows the independent control of the air, NAPL and water pressures. Specifically, this equipment will allow the determination of the pressure-saturation relationship for bi- and three-phase systems. To reach this goal, it was necessary to transform a standard ceramic porous stone in a hidrophobic porous stone (repellent to water), through a chemical treatment of the standard porous stone in a solution containing a substance commercially known as Glassclad 18. This new equipment allows the control of the volume changes of water and oil within a soil sample for different suction. Preliminary tests have been carried out with a mixture composed by 70% of sand and 30% of silt; the first material were collected in the state of the Rio Grande do Sul (Brazil) and the second in the state of Santa Catarina. Both materials have their physical properties well known.
40

Adaptação de um edômetro com controle de sucção para a determinação da curva característica de solos contaminados por óleo diesel / Adaptation of an edometer with suction control for the determination of the retention curve of soil contaminated by diesel oil

Taytelbaum, Leandro Bergmann January 2008 (has links)
A presença de compostos orgânicos no solo proporciona o desenvolvimento de uma fase adicional nos poros, imiscível com a fase aquosa e gasosa pré-existentes. A característica de imiscibilidade destes compostos, denominados de fase livre não aquosa (“nonaqueos phase liquid” – NAPL), torna a avaliação de um solo contaminado por tais substâncias bastante complexa. Dentre as substâncias pertencentes a este grupo NAPL, destacam-se os produtos derivados do petróleo. As propriedades mais importantes na avaliação de um solo contaminado por NAPL são suas relações constitutivas. Uma destas propriedades relaciona a sucção dos fluídos com suas respectivas saturações, enquanto que a outra relaciona a condutividade relativa dos fluidos com a saturação de cada um destes fluidos. A partir da curva de retenção de um solo contaminado, é possível quantificar de forma indireta a relação condutividade relativa-saturação. Todavia, a obtenção desta curva de retenção para um solo contaminado por NAPL é bastante complexa e está em desenvolvimento, exigindo cuidados na sua determinação. Para isso, assume-se que no interior de um poro contendo água, óleo e ar, o contaminante estará preferencialmente localizado entre a água e o ar. Isto é determinante ao admitir-se que a saturação da água Sw é uma função da sucção mátrica desenvolvida entre a água e o óleo e a saturação total dos líquidos St, (soma da saturação da água e do óleo) é dependente da sucção mátrica gerada entre o óleo e o ar. Esta hipótese possibilita a obtenção das curvas de retenção para sistemas trifásicos ar-NAPL-água a partir dos sistemas bifásicos NAPL-água e ar-NAPL. Assim sendo, o objetivo deste trabalho é desenvolver, a partir de um oedômetro com controle de sucção, um equipamento, denominado de célula multifásica, que permita o controle independente das pressões do ar, do NAPL e da água. Especificamente, este equipamento permitirá a determinação das curvas de retenção para sistemas bi e trifásicos. Para atingir esta meta, foi necessário transformar uma pedra porosa cerâmica comum em uma pedra porosa hidrofóbica (repelente à água), através de um tratamento químico da pedra porosa convencional em uma solução contendo uma substância comercialmente conhecida como Glassclad 18. Este novo equipamento permite o monitoramento da variação do volume de água e de óleo no interior de uma amostra de solo para diversas pressões capilares. Ensaios preliminares foram realizados em uma mistura composta de 70% de um solo arenoso e 30% de um solo argilo-arenoso, sendo o primeiro coletado no estado do Rio Grande do Sul enquanto que o segundo em Santa Catarina. Ambos os solos possuem propriedades físicas bem conhecidas. / The presence of organic compounds in the soil provides the development of an additional phase in the pore space, immiscible with the preexisting water and gaseous phases. This characteristic of immiscibility of such substances, called nonaqueos phase liquids – NAPL’s, turns the evaluation of a soil contaminated by these substances sufficiently complex. Among the substances pertaining to this group, called NAPL, the petroleum products are distinguished. The most important properties in the evaluation of a soil contaminated by NAPL are their constitutive relationships. One of these properties relates the pressure of the fluids with their respective saturations, while the other one relates the relative permeability of the fluids with the saturation of each one of these fluids. From the pressure-saturation constitutive relationship of a contaminated soil, it is possible to quantify indirectly the relative permeability-saturation relationship. However, the evaluation of the pressure-saturation relationship for a soil contaminated by NAPL is sufficiently complex and is in development, demanding considerable care in its determination. For this, it is assumed that, in the interior of a pore contaning water, oil and air, the organic liquid will be preferentially located between the water and air. That is imperative when assuming that water saturation of Sw is a function of the suction developed between the oil-water interface and the total liquid saturation St (sum of water saturation and oil saturation) is dependent of the suction generated between the airoil interfaces. This hypothesis makes possible the evaluation of the pressure-saturation relationship for the three-phase system air-NAPL-water from the two-phase systems NAPLwater and air-oil. Thus, the objective of this work is to develop, from the edometer with pressure control, another equipment, called the multiphase cell, that allows the independent control of the air, NAPL and water pressures. Specifically, this equipment will allow the determination of the pressure-saturation relationship for bi- and three-phase systems. To reach this goal, it was necessary to transform a standard ceramic porous stone in a hidrophobic porous stone (repellent to water), through a chemical treatment of the standard porous stone in a solution containing a substance commercially known as Glassclad 18. This new equipment allows the control of the volume changes of water and oil within a soil sample for different suction. Preliminary tests have been carried out with a mixture composed by 70% of sand and 30% of silt; the first material were collected in the state of the Rio Grande do Sul (Brazil) and the second in the state of Santa Catarina. Both materials have their physical properties well known.

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