Teses / dissertações sobre o tema "Unconventional water"

Due to stringent environmental regulations on the disposal and management of the traditional diesel oil-based mud used for drilling difficult formations such as shale, there is the necessity to develop an environmentally friendly drilling mud. Vegetable oils such as Jatropha have proven to be a comparable alternative to diesel oil. However, there have been concerns of compatibility of the vegetable oils with the chemical additives and the ability to achieve a low oil-water ratio mud, which is beneficial to low fluid loss for enhanced wellbore stability. The focus of this study is to achieve a novel low oil-water ratio invert emulsion using Jatropha oil and egg yolk as an emulsifier. Shale-fluid interaction and the economic viability of the mud were also evaluated. The findings from this study show that the low oil-water ratio invert emulsion is beneficial to reducing fluid loss for enhanced wellbore stability and the reduction of oil retention on cuttings, thereby reducing cost of disposal and environmental impact. The mud was formulated without a fluid loss additive, wetting agent, secondary emulsifier and the need for high water content, thereby savings could also be made in material costs. The results from this experimental study demonstrated that the electrical stability of the mud emulsified by egg yolk at a test temperature of 48.9 and 120˚C for any variation, were 398 and 289V respectively. Comparatively, the mud emulsified with a standard emulsifier versacleanVB gave stability values of 201 and 188V thus indicating higher stability with the egg yolk. Moreover, the 50/50 oil-water ratio mud gave stability values of 353 and 258V hence, giving plastic viscosity of 36 cP, at the yield point of 17 Ib/100 ft² and 30 minutes fluid loss of 6ml with filter cake of 1.7 mm. This resulted to 50% reduction in fluid loss over the conventional 70/30 oil-water ratio mud, which was emulsified with the standard emulsifier with stability values of 480 and 393V, plastic viscosity of 31cP, yield point of 17 Ib/100 ft² and fluid loss of 12 ml with filter cake of 3.2 mm. Using the X-Ray Computed Tomography (CT) Scanner, the shale-fluid interaction also showed a volume increase by 11 and 23% of the core sample when immersed into water based mud from one to 7 days respectively. The result indicates that a high interaction with the fluid are possible, thus leading to a non-stable condition compared to 0.88 and 2.53% obtained from diesel and jatropha oil based muds. There was negligible variation in the structure of the samples exposed to diesel and jatropha oil based muds, which further suggests the suitability of jatropha as diesel substitute. The economic analysis of 50/50 oil-water ratio invert emulsion equally showed a potential saving of 57.91% of the $65.31 of the cost of formulation and 47.5% of $60 of the cost of disposal of the conventional diesel oil-based mud. This has the potential to equate to saving of $37.82 per barrel of invert emulsion formulated and $28.50 per barrel disposed.

One can use unlicensed and often very inexpensive radios for unconventional communication (underwater- and underground) links. However, one can go further, and use these radios as sensors rather than communication links. Such communication links and sensors can have important application in hydroscience. While the attenuation of RF signals is high in these mediums, by using the wireless sensor network (WSN) paradigm of multi-hop and retransmission, reliable networks can be formed underwater and underground. One no longer needs to think of RF modules as only a source of data transmission. This revelation lends itself to thinking of these modules as inexpensive RF wave generators at prescribed unlicensed frequencies. Analyzing the received signal strength indicator (RSSI) of a link over time, one can infer changes in the medium from the changes in RSSI. In this thesis, I develop a simple mathematical model to relate changes in RSSI to changes in the medium. Additionally, five experimentally validated examples demonstrate the possibility of non-traditional uses for RF modules. Demonstrated sensor possibilities include soil moisture estimation, leaf wetness measurement, and vegetation water content estimation. This thesis served to validate the use of inexpensive unlicensed RF modules as more than just communication links through air, but as links in unconventional media, and more importantly as measurement instruments.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.
Numbering for pages 3-4 duplicated. Cataloged from PDF version of thesis.
Includes bibliographical references (pages 183-195).
conventional reserves has led to a boom in the use of hydraulic fracturing to recover oil and gas in North America. Among the most significant challenges associated with hydraulic fracturing is water resource management, as large quantities of water are both consumed and produced by the process. The management of produced water, the stream of water associated with a producing well, is particularly challenging as it can be hypersaline, with salinities as high as nine times seawater. Typical disposal strategies for produced water, such as deep well injection, can be unfeasible in many unconventional resource settings as a result of regulatory, environmental, and/or economic barriers. Consequently, on-site treatment and reuse-a part of which is desalination-has emerged as a strategy in many unconventional formations. However, although desalination systems are well understood in oceanographic and brackish groundwater contexts, their performance and design at significantly higher salinities is less well explored. In this thesis, this gap is addressed from the perspective of two major themes: energy consumption and scale formation, as these can be two of the most significant costs associated with operating high-salinity produced water desalination systems. Samples of produced water were obtained from three major formations, the Marcellus in Pennsylvania, the Permian in Texas, and the Maritimes in Nova Scotia, and abstracted to design-case samples for each location. A thermodynamic framework for analyzing high salinity desalination systems was developed, and traditional and emerging desalination technologies were modeled to assess the energetic performance of treating these high-salinity waters. A novel thermodynamic parameter, known as the equipartition factor, was developed and applied to several high-salinity desalination systems to understand the limits of energy efficiency under reasonable economic constraints. For emerging systems, novel hybridizations were analyzed which show the potential for improved performance. A model for predicting scale formation was developed and used to benchmark current pre-treatment practices. An improved pretreatment process was proposed that has the potential to cut chemical costs, significantly. Ultimately, the results of the thesis show that traditional seawater desalination rules of thumb do not apply: minimum and actual energy requirements of hypersaline desalination systems exceed their seawater counterparts by an order of magnitude, evaporative desalination systems are more efficient at high salinities than lower salinities, the scale-defined operating envelope can differ from formation to formation, and optimized, targeted pretreatment strategies have the potential to greatly reduce the cost of treatment. It is hoped that the results of this thesis will better inform future high-salinity desalination system development as well as current industrial practice.
by Gregory P. Thiel.
Ph. D.

Thesis (S.M. in Technology and Policy)-- Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 129-135).
The emergence of large-scale hydrocarbon production from shale reservoirs has revolutionized the oil and gas sector, and hydraulic fracturing has been the key enabler of this advancement. As a result, the need for water treatment has increased significantly and became a major cost driver for producers. What to do with the flowback water in light of scarce disposal facilities and substantial handling costs is a major impediment to the development of the natural gas resource, particularly in the Marcellus shale. This thesis explores the technical, economic and regulatory issues associated with water treatment in the shale plays and identifies best practice water management pathways based upon the Marcellus shale characteristics. The key factors that affect the choice of water treatment options and infrastructure investments are identified and investigated in detail. These include, among others, proximity to disposal facilities, transportation costs, potential for wastewater reuse and make-up water requirements. The study is supplemented by an analysis of the flowback water geochemistry and an examination of the chemical components, like barium and strontium hardness ions, that can restrict the potential of flowback water reuse. Important insights that will help inform the policy debate on how to best address both the environmental and operational water issues associated with hydraulic fracturing in the Marcellus region are derived through this study. Better reporting and monitoring of wastewater volumes is one of the main recommendations of this thesis. A wastewater management and reporting system that focuses on the optimization of water reuse among producers and facilitates information sharing could offer significant efficiencies in terms of reducing costs and minimizing negative environmental impacts. Furthermore, desalination technologies are currently cost prohibitive especially for onsite use. A governmental effort to identify and promote the development of desalination technologies that can effectively remove salts without being prohibitively expensive could help develop a sustainable water management solution.
by Christina Karapataki.
S.M.in Technology and Policy

Technology and innovation have increased the economic viability of horizontal drilling and multi-stage hydraulic fracturing, leading to the rapid increase in unconventional resource development in North America over the past fifty years. The quick development of the unconventional industry has been met with debate and criticism regarding industry methods/standards, volumes of water used, and impacts on the environment. In parallel, the field of water use metrics has also experienced a surge in popularity, most notably with the application of the water footprinting concept to evaluate the water use of businesses and countries alike. However, water use metrics evaluating water use impact have not been applied in the context of evaluating water use in unconventional oil and gas (UOG), which have instead focused on completing water use inventories. In this thesis, water use practices during UOG have been critically reviewed and analyzed to identify water sources and volume patterns. The review of water use practices in UOG is then used to develop criteria for evaluating common water use metrics to determine their applicability for inventorying and assessing the impacts of water use in UOG. A decision tree has been proposed and developed to facilitate the selection of water use inventory and impact metrics. Finally, a case study implements the selected Water Stress Index (WSI) framework to complete a regional water use inventory and midpoint impact assessment within the Montney unconventional play trend in British Columbia, Canada. Uncertainty analysis is performed under present and future scenarios to evaluate inherent parameter, model, and scenario uncertainties. While water use metrics do not replace site-specific assessment, they are important components of effective water management and can inform decision making, data collection and prioritization, and existing and future regional water stress conditions.
Other UBC
Graduate

Master of Science
Department of Geology
Sambhudas Chaudhuri
The exploration and development of unconventional shale plays provide an opportunity to study the hydrocarbon generation process. These unconventional plays allow one to investigate the interactions between the fluid, mineral, and organic material that occur in a hydrocarbon-generating source bed, before any changes in composition that may occur during secondary migration or post migration processes. Previous studies have determined the chemical constituents of formation waters collected from conventional reservoirs after secondary migration has occurred. This investigation targets formation waters collected from the Woodford shale that acts as both source and reservoir, therefore samples have yet to experience any changes in composition that occur during secondary migration. This investigation focuses on the major element and trace element chemistry of the formation water (Cl, Br, Na, K, Rb, Mg, Ca, Sr, and Rare Earth Elements), which has been compared to chemical constituents of the associated crude oil and kerogens. Analytical data for this investigation were determined by the following methods; Ion Chromatography, Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). The information is used to assess the presence of different sources of water that constitute the formation water, and also to investigate interaction between different minerals and formation waters within the source beds. The formation water data also yields new insights into compartmentalization of oil-gas rich zones within the source beds.

Hydraulic fracturing operations utilized for shale gas production result in the generation of a large volume of flowback and produced water that contain suspended material, salts, hydrocarbons, metals, chemical additives, and naturally-occurring radioactive material. The water is impounded at drilling sites or treated off-site, resulting in significant generation of residual solids. These are either buried on site or are disposed in lined landfills. The objective of this study was to determine the levels of heavy metals and other elements of concern that will leach from these residual solids when placed in typical disposal environments. For this purpose, laboratory leaching experiments were employed wherein representative samples were brought into contact with a liquid to determine the constituents that would be leached by the liquid and potentially released into the environment. The samples used included sludge resulting from the physicochemical treatment of process water (TS), sludge solidified with cement kiln dust (SS), raw solids obtained by gravity separation of process water (RS), and drilling mud (DM). The samples were subjected to both single extraction (i.e. Shake Extraction Test, SET) and multiple extraction (i.e. Immersion Test, IT) leaching tests. For the shake extraction test, samples were mixed with a specific amount of leaching solution without renewal over a short time period. In the immersion test, samples were immersed in a specific amount of leaching solution that was periodically renewed over a longer period of time. For both these tests, analyses were performed on the filtered eluate. The tests were performed as per standards with modifications. Distilled de-ionized water, synthetic acid rain (pH ~ 4.2), weak acetic acid (pH ~ 2.88), and synthetic landfill leachate were used as leaching solutions to mimic specific disposal environments. Alkali metals (Li, K, Na), alkaline earth metals (Ba, Ca, Mg, Sr) and a halide (Br), which are typically associated with Marcellus shale and produced waters, leached at high concentrations from most of the residual solids sample. The SS sample, due to its stabilization with CKD, had a lower extraction efficiency as compared to the unconsolidated TS and RS samples. In EF 2.9 and EF SLL, the leaching took place under acidic conditions, while for EF DDI and EF 4.2, the leaching occurred in alkaline conditions. EF 2.9 and EF SLL were determined to be the most aggressive leaching solutions, causing the maximum solubility of most inorganic elements. Thus, high amounts of most EOCs may leach from these residual solids in MSW landfills disposed under co-disposal conditions. Agitation, pH and composition of the leaching solution were determined to be important variables in evaluating the leaching potential of a sample. The results of this study should help with the design of further research experiments being undertaken to develop environmentally responsible management/disposal strategies for these residual solids and also prove useful for regulatory authorities in their efforts to develop specific guidelines for the disposal of residuals from shale gas production operations.
Master of Science

This master thesis is consisted of literature search and practise part with focusing on the theme of abrasive water jet cutting. Introductory chapters deal with various methods and principles water jet cutting. Following chapters deal with quality of cutting surface by abrasive water jet cutting. After these chapters is introduced machine equipment of water jet cutting technology. At the end of this theoretical part are listed advantages and comparison with other unconventional technologies. In the practical part is solved design of machinery with regard to manufacturing technology of component flange in series 630 000 pieces per year. Last chapter describes economic evaluation of production.

Master's thesis, elaborated within Master's degree, submits a proposal of suitable technology for manufacturing “column foot“ part, which attaches filtration unit to the ground. Material is 6 mm thick sheet steel in accordance with ČSN 41 1375 norm. Run (/production batch) of the part is 4 000 pieces per year. On the basis of literary study about unconventional technologies for flat sheet metal production 3 technologies were suggested: plasma cutting, water jet cutting and laser cutting. These technologies were technologically and economically analyzed. At the end thesis evaluates whether purchase of respective machine would pay out for the firm or they should continue to buy parts from cooperation company.

The master thesis contains a literature search dealing with the unconventional technology of water jet cutting. The first part is aimed to description of the water jet technology and shows the possibilities of controlling and awarding data for cutting. Follows the chapter about the influences of the input parameters to a surface quality and machining accuracy. The thesis also giving an account of ecological factors of the water jet cutting. The description of the whole technology for production of the sprocket is a part of the thesis. The last part of the thesis is solving the economics of the water jet cutting technology, especially for production of the sprocket with comparing dependency of the cutting conditions.

Analysis of the technological possibility ray methods of protoplasm, laser and water jet on the part of needs company Pars Nova a.s.. Propsal concrete of unconventional method. Process layout and exigencies of working designed method. Security and ecological diversification of designed method. Technical – economics evaluation contribution designed of unconventional technology.

This dissertation thesis is focused on explaining the broad issue of the non-conventional machining by an abrasive water jet. Introductory chapters deal with various techniques and methods of water-jet cutting and analyze them. Then the following text provides us with a detailed description of the machine itself so that people can understand the way how this technology works. The third chapter is focused on the quality of the resulting surface and the possibility of affecting it by technological parameters. This part is connected with the practical part of my thesis, in which the resultant surfaces of various materials made by different cutting parameters were compared. Subsequent section outlines the development of this technology. The last chapter contains technical and economic evaluation.

In diploma thesis there is elaborated the analysis of assumed development of water jet technology and there is analyzed the level of water jet method in production. There are introduced the possibilities of new applications of water jet machining and the possibilities of it’s future development. There is think over the enlargement of this method in next 5 years. Simultaneously there is solved the question of techno economic operation severity of this technology.

The diploma thesis consists of the three main parts. The first part deals with the theoretical description of the laser technology and other unconventional technologies. In the second part, the thesis is focused on testing the parameters of the laser and evaluating the most suitable parameters. In the last part the diploma thesis deals with comparison of unconventional technologies in terms of cut quality

The diploma thesis deals with unconventional technology of material separation by water jet with abrasive. It describes the influence and specification of technological parameters of the water jet on the quality of the cutting surface. The work contains an experiment, where the aim was to achieve from the theory the influence of tech-nological parameters on surface roughness on composite materials from glass fiber and carbon fiber.

This study deals with unconventional materials cutting technology with a fo-cus on abrasive water jet cutting and CO2 laser. The thesis is divided into theoretical and experimental section. The theoretical part describes principles and functions of nonconventional technologies, the basic division and practical applications. The practical part is focused on choosing the best technology with the production of samples and their subsequent comparison. The thesis recommends producer and type of the machine which best meets requirements on basis of the test results.

L’industrie textile est la plus polluante de tous les secteurs industriels. Ce secteur n’est seulement pas un grand consommateur d’eaux mais rejette aussi d’énormes quantités d’eaux usées chargées en sels, colorants, détergents, métaux lourds, matières organiques dégradables, des agents stabilisants, etc. Le rejet de ces eaux présente des risques pour les hydroécosystèmes, le sol et les plantes. En plus des effets néfastes des effluents textiles non traités sur l’environnement, s’ajoute le problème de la pénurie d’eau qui s’aggrave de plus en plus, la forte demande en eau dans le secteur agricole et le manque de fourrage dans certains pays dans le monde tel que la Tunisie. Dans ce sens, plusieurs procédés ont été développés pour traiter les effluents textiles à savoir l’oxydation chimique, la coagulation chimique, la biodégradation, l’adsorption et les procédés membranaires. Cependant, peu d'études se sont intéressées à l'impact de l'irrigation avec ces effluents traités sur les sols et les végétaux.L’objectif de cette thèse est la réutilisation des effluents textiles traités (ETT) en mettant en évidence des scénarios de valorisation agricole de ces effluents. Le travail consiste à soumettre les effluents secondaires (TB) d’une usine textile Tunisienne à des traitements supplémentaires par ultrafiltration (UF), nanofiltration (NF) et osmose inverse (OI). Etant donnée que les effluents de TB sont caractérisés par une salinité élevée, un scénario de couplage a été envisagé en mélangeant 50/50 (V : V) les eaux de traitement biologique (TB) avec les eaux de puits (S) (TB/S) et les eaux de NF (TB/NF). L'impact de l'irrigation avec ces eaux sur les paramètres physico-chimiques et biologiques d’un sol local et sur la croissance, la composition minérale et l’absorption des ETM chez une plante fourragère : Sesbania bispinosa a été évalué. Une caractérisation physico-chimique des eaux d’irrigation a été réalisée, ainsi qu’une évaluation du potentiel génotoxique des sols irrigués par les ETT.Les résultats indiquent que la qualité des ETT n’est pas stable dans le temps et varie en fonction des procédés de production. Le TB ne répond pas aux exigences de la norme NT 106.03 relative à la réutilisation des eaux usées en agriculture. Ces eaux sont caractérisées par un pH, CE et des teneurs en Na+, Cl- et SO42- élevées. Bien que les membranes NF et OI réduisent efficacement la salinité et les teneurs en ces éléments, et ne présentent pas de risque sur le sol et les plantes avec l’absence de pouvoir génotoxique des sols sur les plantes, ces techniques produisent des rejets hydriques plus concentrés. Par conséquent, le couplage des eaux de TB avec les eaux de puits constitue la meilleure alternative pour une valorisation agricole. Ce couplage a permis d’alléger la salinité des eaux de TB en réduisant les teneurs en éléments chimiques tel que Na+, Cl- et SO42-. La réutilisation de ces eaux a des fins agricoles n’a pas montré d’effets négatifs sur la croissance et la nutrition minérale de S.bispinosa, n’a pas présenté de risques sur la qualité physico-chimique du sol et a contribué à une amélioration de l’activité enzymatique dans le sol.Le couplage des eaux constitue donc une option de valorisation. C’est une solution simple et peu coûteuse qui, d’une part, aide à pallier le manque d’eau et, d’autre part, réduit les quantités d’eau rejetées dans l’environnement par les industries textiles
The textile industry is the most polluting of all industrial sectors. This sector is not only a large consumer of water, but it also discharges enormous quantities of wastewater loaded with salts, dyes, detergents, heavy metals, degradable organic materials, stabilizing agents, etc. The discharge of this water presents risks for hydro-ecosystems, soil, and plants. In addition to the harmful effects of untreated textile effluent on the environment, there is the problem of water scarcity which is becoming increasingly serious. the high demand for water in the agricultural sector, and the lack of fodder in some countries around the world such as Tunisia. In this sense, several processes have been developed to treat textile effluents such as chemical oxidation, chemical coagulation, biodegradation, adsorption, and membrane processes. However, few studies have focused on the impact of irrigation with these treated effluents on soils and plants.The objective of this thesis is the reuse of treated textile effluent (TTE) using scenarios of agricultural valorization of these waters. This work consists of submitting biological treatment (TB) effluents from a Tunisian textile factory to additional treatments by ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO). Given that TB effluents are characterized by high salinity, a coupling scenario was considered by mixing 50/50 (V: V) biological treatment water (TB) with well water (S) (TB/S) and NF waters (TB/NF). The impact of irrigation with these waters on the physicochemical and biological parameters of the soil and on the growth, mineral composition, and absorption of MTE in a forage plant: Sesbania bispinosa was evaluated. A physicochemical characterization of irrigation water was carried out with an evaluation of the genotoxic potential of soils irrigated by TTE.The results indicate that the quality of TTE is not stable over time and varies according to the production processes. TB does not meet the requirements of the NT 106.03 standard relating to the reuse of wastewater in agriculture. These waters are characterized by high pH, EC, and Na+, Cl- and SO42- contents. Although NF and RO membranes effectively reduce salinity and the contents of these elements and do not present any risk to the soil and plants with the absence of genotoxic effect of soils on plants, these techniques produce more concentrated water discharges. Consequently, the coupling of TB water with well water constitutes the best alternative for agricultural valorization. This coupling made it possible to reduce the salinity of TB water by reducing the contents of chemical elements such as Na+, Cl-, and SO42-. The reuse of this water for agricultural purposes did not show negative effects on the growth and mineral nutrition of S.bispinosa, did not present risks on the physico-chemical quality of the soil, and contributed to an improvement in enzymatic activity in the soil. Therefore, water coupling constitutes a valorization option. It is a simple and inexpensive solution which, on the one hand, makes it possible to overcome the lack of water and, on the other hand, reduces the quantities of water released into the environment by the textile industries

Les réservoirs dits « tight gas » sont constitués de grès de faible perméabilité ayant des propriétés petro-physiques susceptibles de nuire à la productivité du gisement. Une importante zone de transition est observée in situ dans laquelle ni l’eau ni le gaz ne sont suffisamment mobiles pour permettre une extraction industrielle : c’est ce que l’on appellera le « permeability jail ». Cette étude vise principalement à caractériser l’influence du chargement mécanique (via l’utilisation de différentes pressions de confinement) et de la nature des roches (roches provenant de différents puits et prélevées à différentes profondeurs) sur les courbes de perméabilité relative au gaz et les caractéristiques poro-mécaniques de ces roches. La porosité accessible à l’eau mesurée est de 2 à 12%. La perméabilité intrinsèque au gaz a mis en évidence de fortes disparités sans lien avec la porosité des échantillons. Une grande sensibilité de la perméabilité relative au confinement a été observée dès l’application de pressions de confinement de 15 à 30 MPa. Deux familles d’échantillons ont ainsi été identifiées. Les échantillons les plus perméables (perméabilité compris entre 100 – 1000 μD), sont peu sensibles au confinement et leur perméabilité relative ne chute qu’à partir de saturations de l’ordre de 50%. Les échantillons les moins perméables apparaissent beaucoup plus sensibles à la fois au confinement et à la saturation.Des méthodes classiquement utilisées dans le domaine pétrolier reposant sur l’interprétation d’essais de porosimétrie par intrusion mercure, ont également été mise en œuvre pour évaluer les perméabilités relatives et les comparer aux mesures expérimentales
So-called tight gas reservoirs are constituted of low permeability sandstones, which petro-physical properties may interfere with proper gas recovery. They have a low absolute permeability (below 0.1 mD under ambient conditions), a porosity lower than 10%, and a strong sensitivity to in situ stresses as compared to conventional reservoirs. Moreover, an important transition zone is observed in situ, where partial water saturation is present, and which may extend over several hundred meters over the free water table. In such zone, where water saturation is on the order of 40-50%, neither gas nor water seems sufficiently mobile for industrial extraction: this is the permeability jail. Our aim is to assess their actual petro-physical properties, namely porosity, gas permeability under varying hydrostatic stress and water saturation level, in relation with sandstone microstructure. Accessible water porosity measured is between 2 to 12%. The intrinsic permeability to gas did not appeared related to the porosity of samples. A high sensitivity of gas permeability to confinement was observed. Two families of samples were identified. The more permeable samples (permeability between 100-1000 μD), are relatively insensitive to confinement and their relative permeability decrease for water saturation higher than 50%. Less permeable samples appear much more sensitive to mechanical loading and saturation.Methods classically used in oil and gas industry based on the interpretation of mercury intrusion porosimetry tests have also been used to evaluate relative permeability and compared with experimental measurements

The present work deals with environmental sustainability and specific engineering solutions able to cope with such a global issue. Attention is focused on renewable energy and innovative fuels as effective strategies in contributing valuable techniques in order to face the need of mitigating environmental problems concerning climate change and global warming. The research study is targeted on optimized design and management of fluid machinery, and extensively on optimized energy conversion systems, conceptualized in accordance with current standards and regulations, governing the reference sector. The analysis investigates small energy supply from renewables (wind power) and innovative marine propulsion (alternative fuels and unconventional propulsion systems). Regulations and technical design are constantly focused for the study. The work proposes case solutions for energy design and management actions dealing with the theme of environmental sustainability: engineering analyses (design, technical-economical evaluation, performance results) for hybrid wind powered plants empowering SWRO (Sea Water Reverse Osmosis) desalination processes; engineering analyses (design, technical evaluation, performance results) for wind turbine rotors operating in sites characterized by a small wind resource; engineering analyses (design, technical evaluation, performance results) for marine ship propulsion empowered by LNG as an alternative sustainable fuel and by gas turbines as prime movers coupled to combined cycles as an innovative propulsion system (COGES configuration).

RBCCPS
Evaporation is one of the inherent processes of the earth’s ecosystem. Water bodies, earth’s surface and vegetation all contribute significantly towards the total evaporation which eventually leads to the formation of clouds. The factors which affect the total evaporation (evaporation & transpiration) are the surface temperature, ambient temperature, relative humidity, external wind speed, pressure, surface area and geometry. This thesis deals with the contributors of total evaporation individually viz. open water bodies; soil-like surfaces; and leaf-like surfaces. A ceramic infrared heater has been used to mimic the heating due to sun’s radiation in all the experiments which were conducted in the quiescent atmosphere. This thesis has been broadly categorized into two parts: - (a) evaporation from bare water surface; and (b) evaporation from a porous media. In part (a), we present experimental results on the evaporation from a bare water surface heated either from above using the infrared radiations or from below using immersed heaters. Heating from below leads to unstable stratification and convection while infrared heating from above leads to stable stratification. The effect of water-side convection on the evaporation from a bare water surface has been investigated and all the experimental results have been combined to obtain a power law relation between Sherwood number (Sh) and Rayleigh number (Ra). Part (b) of the thesis has been further split into three major categories: - (1) evaporation from spheres based conventional porous media; (2) evaporation from unconventional porous media containing rods, capillaries, and plates; and (3) evaporation from leaf-like surfaces. In all the experiments, a precision weighing balance was used to measure the evaporation rate. A thermal camera was used to get the surface temperature fields, and fluorescein dye mixed with water gave insightful results on the evaporation process. In particular the red deposits of fluorescein particles revealed the evaporation sites. In most of the experiments, the infrared heating was of the order of 1000W/m2. Different sized glass and acrylic containers were used in this thesis. Mono-disperse glass beads (closest to mimic the natural soils), stainless steel balls, sieved natural sand and hydrophobic Ball Grid Array balls have been used to create the spheres-based conventional porous media. Evaporation was found to undergo three stages which depended on the spheres size and the heat flux supplied. In the 1st stage of evaporation capillary film(s) pulls water from beneath the porous media to the top surface and the evaporation rate remained high, close to that obtained from a water surface. Capillary break-up occurs in the transition regime which is followed by the 2nd stage of evaporation where a new vaporization plane is formed within the porous media. In the 2nd stage, heat is conducted through the top dried layer to the water below where evaporation takes place and the evaporation rate drops drastically. Transition to 2nd stage happened earlier for coarser spheres at constant heat flux. Along with the wetting properties, the spheres size has been found to effect capillary break-up length (a measure of capillary film strength) and hence the duration of the stages of evaporation drastically. Surface images captured using the thermal camera clearly showed the presence of water till the capillary break-up. The capillary break-up length was also found to be affected significantly by the heat flux. Apart from the experimental findings of mono-disperse spheres, two layers of different sized glass spheres have also been investigated. The presence of complicated network of textural layering in the earth’s surface is a well-known fact. Preferential evaporation was clearly seen in the experiments with texturally layered porous media independent of the orientation viz. vertical or horizontal layering. The stacking positions are found to be critical in determining the overall evaporation characteristics. The geometry of a pore between three spheres in mutual contact is very complicated. Simpler pore geometry would be between two rods/plates in contact or three rods in mutual contact or stacks of either of these two. We call these types of the porous media as “Unconventional porous media” as they possess many unique features not shown by a conventional porous media. The evaporation characteristics of vertically stacked rods was found to be dominated by the corner films present in the near-zero radii contacts. Unlike the conventional porous media, the capillary break-up length was found not to depend on the rod diameter. The capillary break-up length for vertically stacked rods was larger than for the spheres case and was also found to be independent of the heat flux, for the range investigated in this thesis. A mathematical model has been developed for understanding the evaporation from the vertically stacked rods. Experiments with horizontally stacked pencil leads showed early capillary break-up while with horizontally stacked glass rods, capillary break-up was not observed. Experimental investigations of porous media containing vertically stacked plates have also been studied. Water trapped between two consecutive plates are treated as 2D source of evaporation. Plants regulate their O2-CO2 content via tiny holes present on the leaves called “Stomata”. The average size of a stoma is nearly 20μm and the total area covered by stomata is close to 5% of the leaf area. However the higher transpiration rates (60-70 % compared to a bare water source) sustained by a plant has remained a mystery for the phytologists. In view of this we mimic the leaf-type using regularly spaced holes on the silicon wafers from which water evaporates. The leaf-mimics had different hole-diameter but open area ratio was kept constant. In all the cases the evaporation ratio (ratio of the evaporation rate from the leaf mimic to that of the evaporation rate of a bare water surface at the same surface temperature) was found to increase at lower heat fluxes. With increasing the hole-size evaporation rate was found to decrease. The leaf-mimic with the smallest hole-size had the highest evaporation rate and the evaporation ratio increased from 0.46 at 800W/m2 to 0.64 at 400W/m2. The 3D nature of diffusion near these tiny holes enhances the evaporative flux which explains the high evaporation rates even for low open area ratios.

Evaporation is one of the inherent processes of our planet earth as an ecosystem. Water bodies, earth’s surface and vegetation all contribute significantly towards the total evaporation which eventually leads to the formation of clouds. The physical processes governing the evaporation from these surfaces differ significantly and thus needs to be studied individually. The factors which affect the total evaporation (evaporation & transpiration) are the surface temperature, ambient temperature, relative humidity, external wind speed, pressure, surface area and geometry. The present investigation deals with evaporation from three different surfaces: open water bodies, soil-like surfaces, and leaf-like surfaces. A ceramic infrared heater (2kW, 230V) has been used as the heater, in order to mimic the natural process, in all the experiments which were conducted in quiescent atmosphere i.e. without any external wind. The present work has been broadly categorized into two parts: - (a) evaporation from bare water surface, and (b) evaporation from a porous media. In part (a), we present experimental results on the evaporation from a bare water surface heated either from above using the infrared radiations or from below using heater immersed in the water. Heating from below leads to unstable stratification while infrared heating from above leads to stable stratification. The effect of water-side convection on the evaporation from a bare water surface has been investigated and all the experimental results have been combined to obtain a power law relation between Sherwood number (Sh) and Rayleigh number (Ra). Part (b) of the thesis has been further split into three major categories: - (1) evaporation from spheres based conventional porous media; (2) evaporation from novel porous media; and (3) evaporation from leaf-like surfaces. Mono-disperse spheres-based (non-hygroscopic) conventional porous media are used to mimic the natural soils. Glass beads (0.10-0.16 mm to 2.5-3.0 mm diameter), Stainless steel balls (1 mm diameter), sieved natural sand (0.3-0.5 mm diameter) and hydrophobic Ball Grid Array balls (0.30; 0.50; 0.76 mm diameter) have been used to create the conventional porous media. The range of Bond number (Bo) spanned in the present investigation is 2.2 ∗ 10−4 − 1.2 ∗ 10−1 based on the spheres dimensions. The experiments were conducted either in a cylindrical vessel (63 mm diameter and 90 mm height) or in rectangular acrylic boxes having dimensions similar to that of the cylindrical vessel. The heat flux received by the top surface of the porous media in majority of the experiments was 1000W/m2 which is close to the average annual solar insolation on the earths’ surface. The evaporation from these soil-type surfaces was found to undergo different and distinct stages. In the 1st stage of evaporation, commonly known as the constant rate period (CRP) regime, where the water in a confined 3D porous media remains on the surface and a high evaporation rate is observed. Surface tension-driven formations of capillary film(s) which rise to the surface are seen during CRP. The strength of the capillary has been defined in terms of a characteristic length called the capillary break-up length. In the 2nd stage of evaporation often called a falling rate period (FRP) regime, the capillary film which was supplying water to the top surface of the porous media breaks-up. The break-up, also termed as the transition regime, leads to receding liquid-vapour menisci and heat is conducted through the top dried layer to the water below where evaporation takes place the evaporation rate drops. Along with the wetting properties, the spheres size has been found to effect capillary break-up length and hence the duration of the stages of evaporation drastically. Surface images captured using a thermal camera clearly showed the presence of water till the capillary break-up length. The capillary break-up length was also found to be affected significantly by the heat flux or in other sense we can say that the evaporation rate in CRP regime is critical in deciding its duration in a spheres-based conventional porous media. In the present investigation heat flux ranged from 250-2000W/m2. Visualization has been carried out using a solution of de-ionized water and fluorescein dye. The colour contrast property (orange if dry and green in the solution form) of the fluorescein particles has been used to observe the evaporation sites in the porous media and to differentiate between the 1st and 2nd stage of evaporation. Apart from the experimental findings of single stack of mono-disperse spheres, multiple layering have also been investigated. The presence of complicated network of textural layering in the earth’s surface is a well-known fact. Along with the preferential evaporation, evaporation enhancement & suppression are reported in the experiments with texturally layered porous media independent of the orientation viz. vertical or horizontal layering. The stacking positions are also found to be critical in determining the overall evaporation characteristics. The geometry of a pore between three spheres in mutual contact is complicated. A simpler geometry for a pore could be that between two rods/plates in contact or three rods in mutual contact or stacks of either of these two. We call these types of porous media as “Novel porous media” as they possess many unique features not seen in a conventional porous media consisting of spheres. For this class of experiments the materials used to create the novel porous media were: Glass rods (2 & 3 mm diameter and 75 mm length), Glass capillaries (1.1/1.5 mm and 75 mm length), Faber-Castell pencil leads (0.7 mm diameter and 75 mm length), Glass plates (cross sectional dimension of 42 mm x 102 mm and thickness of 1.85 mm) and Cover slips (cross sectional dimension of 22 mm x 60 mm and thickness of 0.130.16 mm). The evaporation characteristics of vertically stacked rod-based novel porous media was found to be dominated by the corner films present in the near-zero radii contacts. Unlike the conventional porous media, the capillary break-up in the vertically stacked rod-based novel porous media was found to be limited by the vertical extent of the rods and not on the rod diameter. Due to the same reason, capillary break-up of vertically stacked rod-based novel porous media was also found to be independent of the heat flux range investigated in the present work. The 2nd stage of evaporation in these types of novel porous media therefore does not hold the true meaning as it is not forced by the porous media. The effect of orientation has also been investigated and the surface roughness was found to affect the evaporation dynamics drastically in horizontally stacked rod-based novel porous media. However, it is the surface roughness which was found to be dominant in case of vertically stacked plate-based novel porous media. The average size of a stoma, tiny holes present on the leaves, is nearly 20μm and the population density in majority of the plants is close to 5% of the leaf area. However the higher transpiration rates (60-70 % compared to a bare water source) sustained by a plant has remained a mystery for the phytologists. To study this we mimic the leaf-type surfaces by manufacturing silicon wafers having through holes. The leaf-mimics had different hole-diameter but same open area. The leaf-mimic with the smallest hole-size was found to evaporate the most while with increasing the hole-size the evaporation was found to decrease. In all the types of the leaf-mimic the evaporation ratio (ratio of the evaporation rate from the leaf mimic to that of the evaporation rate of a bare water surface at the same surface temperature) was found to increase with decreasing heat fluxes. The 3D nature of diffusion near these tiny holes enhances the evaporative flux, owing to increase in the concentration gradient of water vapour, which explains the high evaporation rates observed in the present work.

Unconventional natural gas extraction from the Marcellus Shale requires millions of gallons of water to fracture shale and release natural gas from the formation. This process produces water with high levels of total dissolved solids (TDS); and, efforts to recycle these fluids has stimulated microbial growth in produced water. The objective of this study was to analyze the ionic composition of and characterize microorganisms from Marcellus produced water samples. A semi-synthetic culture medium was designed with high TDS to enrich for halophilic microbes, which yielded robust cultures that were able to grow over a wide range of salinities. DNA extracted from aerobic cultures was used for 16s rDNA clone libraries and Automated Ribosomal Intergenic Spacer Analysis (ARISA). ARISA and 16S gene sequencing revealed differences in bacterial composition between Marcellus and freshwater samples. Sequencing of 16S gene indicated the presence of Halomonas, Thalassospira and other genera related to halophilic and petroleum degrading species.
Bayer School of Natural and Environmental Sciences
Environmental Science and Management (ESM)
MS
Thesis

Technologies such as horizontal wells and multi-stage hydraulic fracturing have made ultra-low permeability shale and tight gas reservoirs productive but the industry is still on the learning curve when it comes to addressing various production issues. Some of the problems encountered while hydraulically fracturing these reservoirs are the absence of frac barriers, thinner shales and the increased presence of geological hazards. Induced vertical fractures sometimes extend to an underlying aquifer and become a conduit to the well. We have developed a low-concentration, low-viscosity and delayed-crosslink polymeric gel system as a water shutoff agent for hydraulically-fractured tight gas and shale reservoirs, where some fractures might connect to water rich zones. The system also is a significant improvement over traditional flowing gels for fracture water shutoff in conventional reservoirs because of these features. The gel uses high molecular weight hydrolyzed polyacrylamide (HPAM) at low polymer concentrations with a delayed organic crosslinker. This crosslinker is more environmentally benign and provides much longer gelation time and stronger final gels than comparable polymer loadings with chromium carboxylate crosslinkers at higher temperatures. The low viscosity system allows low-pressure extrusion of gelant into the narrow-aperture fractures present in unconventional gas reservoirs. The gelant can be pumped at low pressures due to lower polymer concentrations and delayed gelation point. This allows the potential to seal problem zones that are producing excess water even when the fractures conducting water have very narrow apertures. By impeding water production, the gel system developed here can effectively delay water loading thereby avoiding abandonment or installation of expensive equipment with increased operational costs, thus extending life and reserves of unconventional gas wells.

Excess water production is a major economic and environmental problem for the oil and gas industry. The cost of processing excess water runs into billions of dollars. Polymer gel technology has been successfully used in controlling water influx without damaging hydrocarbon production in conventional naturally fractured or hydraulically fractured reservoirs. However, there has been no systematic investigation on effectiveness and placement conditions of polymer gels for shutting off water flow from fractures with narrow apertures in shale and tight gas reservoirs. The existing polymer gels, like those based on Chromium(III) Acetate, as a crosslinker will exert very high extrusion pressure to effectively penetrate the narrow aperture fractures present in shale and tight gas reservoirs. This gives rise to a need for a new polymer gel system that can be used for selectively shutting off water flow from narrow aperture fractures in shale and tight gas reservoirs. The new gel system will have a longer gelation time than the existing polymer gels; this ensures minimum crosslinking of the gel by the time it reaches bottom hole. The gelant solution will be pumped at low pressure so that, it penetrates only pre-existing fractures in the formation with ease. This study for the first time focuses on developing an environmentally benign polymer gel system based on high molecular weight HPAM, as a base polymer and a commercial grade PEI as an organic crosslinker. Gel samples of different concentration ratios of the polymer and crosslinker were prepared and classified under Sydansk code of gel strength to find optimum concentration ratios that gave good gels. The gel system was characterized using Brookfield DV-III Ultra Rheometer and Fann-35 Viscometer.

The increase in unconventional shale gas extraction in Pennsylvania has resulted in an increased number of groundwater contamination claims. Well water quality was investigated in southern Butler County, PA where 387 unconventional gas wells have been drilled since 2006. A total of 121 households participated in a survey and 238 well water samples were tested. Specific conductivity, pH, and dissolved oxygen in these samples were measured in the field and seven anion concentrations and thirty metal concentrations were measured in the lab. A subset of 91 water wells was also tested for light hydrocarbons (methane, ethane, ethylene, propylene, propane, butane). Pennsylvania DEP file reviews were used to create GIS maps indicating legacy oil and gas, unconventional wells, and plot water testing results. Results indicate few wells had high quality groundwater, with 86% containing one or more contaminants above (secondary) Maximum Contaminant Levels, with manganese (56%), iron (47%), fluoride (18%), TDS (18%), pH (17%), aluminum (17%) the most common.
Bayer School of Natural and Environmental Sciences;
Environmental Science and Management (ESM)
MS;
Thesis;

Horizontal drilling and hydraulic fracture stimulation have enabled the economic development of unconventional resource plays. An average horizontal well in the Barnett Shale requires 3 to 4 million gallons of fresh water, 90% of which is used for hydraulic fracture stimulation. While the water consumption of Barnett Shale operations is less than 1% of total Region C consumption, extended drought conditions and competing demands for water resources are placing pressure on operators to reduce terminal water consumption. Strategies which reduce water requirements associated hydraulic fracture stimulation without compromising the efficiency and cost of energy production are essential in developing a comprehensive policy on energy-water management. Recycling and reuse technologies were evaluated on the basis of performance, cost, and capacity to treat reclaimed flowback water and oilfield brine. Recycling flowback fluids for future hydraulic fracture applications is the most practical repurposing of oilfield waste. The low TDS content of flowback derived from water-based fracs permits multiple treatment options. Mobile thermal distillation technology has emerged as the prevailing technique for recycling flowback water, yielding maximum water savings and reduced operating costs. The estimated cost of recycling flowback water by thermal distillation is $3.35/bbl. Compared to the current cost of disposal, recycling provides an opportunity to minimize waste and reduce the fresh water requirements of hydraulic fracture stimulation at an incremental cost. The stewardship role of the Texas Legislature is to protect the water resources of the state and to facilitate the Regional Water Planning Process, ensuring future water needs are met. The support and participation of the Legislature and other planning entities is critical in advancing the energy-water nexus. As operators pursue innovative water management practices to reduce terminal water consumption in the oilfield, the Barnett Shale positions itself as a model for sustainable water use in the development of unconventional shale resources. The cost of recycling and reuse technology limits the participation of small and mid-size operators who possess the greatest market share of the Barnett Shale. Funding for research and implementation of water-conscious strategies such as shared recycling facilities, CO2 capture and storage, and pipeline infrastructure would create multi-user opportunities to promote conservation and reduce net consumption of fresh water supplies. Through the integration of technology and policy, terminal water consumption in the Barnett Shale can be greatly diminished.
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Over 18 billion barrels of waste fluids are generated annually from oil and gas production in the United States. As a large amount of water is used for oilfield operations, treating and reusing produced water can cut the consumption of fresh water in well sites. This research has helped to develop a membrane process train for a mobile produced water treatment unit for treating oilfield produced brine for reuse. To design the process train, over 30 sets of combination tests at pilot laboratory scale were performed using pretreatment, microfiltration and nanofiltration processes. Membrane performance was selected based on high flux separation efficiency, high tolerance for solids and fluid treatments. Over 95 % solids rejection and greater than 80 % oil removal efficiency were obtained in all these tests. Process train (pre-treatment and membrane) performance was monitored by chemical analysis of permeate and models fitting experimental data for the process. From the results, hydrocarbon rejection was analyzed; total organic carbon rejection was 47.9 %, total carbon content averaged 37.3 % rejection and total inorganic carbon rejection was at 3.66 %. BTEX removal efficiency ranged from 0.98 % to 52.7 % with the progressive pretreatment methods of using cartridge filters. The nanofiltration membrane showed significant reduction in total dissolved solids and in both anionic and cationic species. The process train is seen to follow a sequence of treatment from cartridge and oil removal filter treatment to microfiltration treatment to ultrafiltration, followed by nanofiltration for the purpose of this research. Further research still needs to be done on to determine the kind of analytical test which will give real time feedback on effectiveness of filters. In summary, the process train developed by TAMU-GPRI possesses distinct advantages in treating oilfield produced brine using membrane technology. These advantages include high quality of permeate, reduced sludge and the possibility of total recycle water systems. The small space requirement, moderate capital costs and ease of operation associated with the use of the mobile unit membrane technology also makes it a very competitive alternative to conventional technologies.