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1
Battah, Sam Jordan. "Natural gas hydrate production." Curtin University of Technology, Department of Chemical Engineering, 2002. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=15554.
Full textAbstract:
The concept which led to the establishment of the research in natural gas hydrate production, was born by Dr. Robert Amin (currently Professor of Petroleum Engineering at Curtin University and Chair of the Woodside Research Foundation) and Alan Jackson of Woodside Energy. The intended research in this field is to establish the viability of utilizing a synthesised natural gas hydrate as a means to allow a cheaper form of transportation of natural gas from the wellhead to the customer in direct competition with liquefied natural gas (LNG). Natural gas exists in ice-like formations called hydrates found on or under sea-beds and under permafrost. Hydrates trap methane molecules inside a cage of frozen water, where the amount of hydrates trapped is dependent on surrounding formation pressure. The amount of natural gas trapped in hydrates is largely unknown, but it is very large. A number of scientists believe that hydrates contain more than twice as much energy as all the world's coal, oil, and natural gas combined, hence making it a viable option of fuel in the 21st century, in a world constantly seeking cleaner sources of energy. The feasibility of production of natural gas hydrates on offshore installations and onshore facilities makes this development a viable option. As such this technology requires detailed research and development in a laboratory environment coupled with a pilot plant construction for commercial operation. Current estimates for onshore based facilities for the production of hydrates show a cost reduction of approximately 25% compared with LNG plants of the same energy capacity.There are two major issues which require detailed research and development in order to progress this technology. First is the enhancement of the hydrates production by the use of other additives, and second, the continuous production at near atmospheric pressures. Other research related to transport methodology and re-gasification will be essential for the overall success of this technology, however, this work is outside the scope of this research.
2
Battah, Sam. "Natural gas hydrate production." Thesis, Curtin University, 2002. http://hdl.handle.net/20.500.11937/1221.
Full textAbstract:
The concept which led to the establishment of the research in natural gas hydrate production, was born by Dr. Robert Amin (currently Professor of Petroleum Engineering at Curtin University and Chair of the Woodside Research Foundation) and Alan Jackson of Woodside Energy. The intended research in this field is to establish the viability of utilizing a synthesised natural gas hydrate as a means to allow a cheaper form of transportation of natural gas from the wellhead to the customer in direct competition with liquefied natural gas (LNG). Natural gas exists in ice-like formations called hydrates found on or under sea-beds and under permafrost. Hydrates trap methane molecules inside a cage of frozen water, where the amount of hydrates trapped is dependent on surrounding formation pressure. The amount of natural gas trapped in hydrates is largely unknown, but it is very large. A number of scientists believe that hydrates contain more than twice as much energy as all the world's coal, oil, and natural gas combined, hence making it a viable option of fuel in the 21st century, in a world constantly seeking cleaner sources of energy. The feasibility of production of natural gas hydrates on offshore installations and onshore facilities makes this development a viable option. As such this technology requires detailed research and development in a laboratory environment coupled with a pilot plant construction for commercial operation. Current estimates for onshore based facilities for the production of hydrates show a cost reduction of approximately 25% compared with LNG plants of the same energy capacity.There are two major issues which require detailed research and development in order to progress this technology. First is the enhancement of the hydrates production by the use of other additives, and second, the continuous production at near atmospheric pressures. Other research related to transport methodology and re-gasification will be essential for the overall success of this technology, however, this work is outside the scope of this research.
3
Battah, Sam. "Natural gas hydrate production /." Full text available, 2002. http://adt.curtin.edu.au/theses/available/adt-WCU20041207.145646.
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4
Gunnarsson, Marcus. "Gas Production in Distant Comets." Doctoral thesis, Uppsala University, The Uppsala Astronomical Observatory, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-2148.
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Molecular spectroscopy at radio wavelengths is a tool well suited for studying the composition and outgassing kinematics of cometary comae. This is particularly true for distant comets, i.e. comets at heliocentric distances greater than a few AU, where the excitation of molecules is inefficient other than for rotational energy levels. At these distances, water sublimation is inefficient, and cometary activity is dominated by outgassing of carbon monoxide.
An observing campaign is presented, where the millimeter-wave emission from CO in comet 29P/Schwassmann-Wachmann 1 has been studied in detail using the Swedish-ESO Submillimetre Telescope (SEST). Coma models have been used to analyse the spectra. The production of CO is found to have two separate sources, one releasing CO gas on the nuclear dayside, and one extended source, where CO is produced from coma material, proposed to be icy dust grains.
Radio observations of many molecules in comet C/1995 O1 (Hale-Bopp) have been carried out in a long-term international effort using several radio telescopes. An overview of the results is presented, describing the evolution of the gas production as the comet passed through the inner Solar system. Spectra recorded using the SEST, primarily of CO, for heliocentric distances from 3 to 11 AU are analysed in detail, also using coma models.
The concept of icy grains constituting the extended source discovered in comet 29P/Schwassmann-Wachmann 1 is examined by theoretical modelling of micrometre-sized ice/dust particles at 6 AU from the Sun. It is shown that that such grains can release their content of volatiles on timescales similar to that found for the extended source.
5
Alp, Doruk. "Gas Production From Hydrate Reservoirs." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606241/index.pdf.
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In this studygas production by depressurization method from a hydrate reservoir containing free gas zone below the hydrate zone is numerically modeled through 3 dimensional, 3 phase, non-isothermal reservoir simulation. The endothermic nature of hydrate decomposition requires modeling to be non-isothermal
hence energy balance equations must be employed in the simulation process. TOUGH-Fx, the successor of the well known multipurpose reservoir simulator TOUGH2 (Pruess [24]) and its very first module TOUGH-Fx/Hydrate, both developed by Moridis et.al [23] at LBNL, are utilized to model production from a theoretical hydrate reservoir, which is first studied by Holder [11] and then by Moridis [22], for comparison purposes. The study involves 2 different reservoir models, one with 30% gas in the hydrate zone (case 1) and other one with 30% water in the hydrate zone (case 2). These models are further investigated for the effect of well-bore heating. The prominent results of the modeling study are: &
#8226
In case 1, second dissociation front develops at the top of hydrate zone and most substantial methane release from the hydrate occurs there. &
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In case 2 (hydrate-water in the hydrate zone), because a second dissociation front at the top of hydrate zone could not fully develop due to high capillary pressure acting on liquid phase, a structure similar to ice lens formation is observed. &
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Initial cumulative replenishment (first 5 years) and the replenishment rate (first 3.5 years) are higher for case 2 because, production pressure drop is felt all over the reservoir due to low compressibility of water and more hydrate is decomposed. Compared to previous works of Holder [11] and Moridis [22], amount of released gas contribution within the first 3 years of production is significantly low which is primarily attributed to the specified high capillary pressure function.
6
Kosmidis, Vasileios. "Integrated oil and gas production." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407995.
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7
Claricoates, Jane. "Gas production during peat decay." Thesis, Queen Mary, University of London, 1990. http://qmro.qmul.ac.uk/xmlui/handle/123456789/25734.
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Decay and accumulation of blanket peat in the Northern Pennine region of England are considered, both in quantitative and qualitative terms. Productivity on the surface of these peat bogs is not unusually high, suggesting that a low decay rate may be responsible for the accumulation of the peat. Considerable study has formerly been made of the aerobic decay processes, at the expense of the parallel anaerobic processes, which have largely hitherto been considered negligible. Yet a current mathematical model of peat accumulation suggests that it is likely to be the anaerobic decay rate which determines the total depth of peat which may accumulate. Further, such models intimate that a very small absolute change in the anaerobic decay rate will have an unexpectedly large effect on the potential steady state depth of peat. The present study concentrates on obtaining measurements of anaerobic decay rates, and on identifying the possible limiting environmental factors of the decay. The design of a sampler to collect gas samples in situ from blanket peat is described. The components of particular interest in the samples are CH4 and C02. Gas concentrations down eight peat profiles at two sites are monitored over two seasons. Simultaneous surface flux measurements above pool, lawn and hummock microhabitats are also made. Water level, temperature, pH, redox potential, depth of the sulphide zone and total sulphide concentration are recorded on each field visit. The results from the gas sample analyses are discussed in relation to the environmental factors and in relation to our present understanding of peat decay rates and their consequences on peat accumulation. The anaerobic decay rate is calculated, and is confirmed to be several orders of magnitude less than that in the overlying aerobic peat. It is shown that the methane is not fossil, but is continually being produced at all depths. Rates of gas production are calculated. Annual methane and carbon dioxide losses from entire peat bogs are calculated to contribute a significant amount to carbon cycling, on a site-specific and global scale.
8
Grover, Tarun. "Natural gas hydrates - issues for gas production and geomechanical stability." Texas A&M University, 2008. http://hdl.handle.net/1969.1/86049.
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Natural gas hydrates are solid crystalline substances found in the subsurface. Since
gas hydrates are stable at low temperatures and moderate pressures, gas hydrates are
found either near the surface in arctic regions or in deep water marine environments
where the ambient seafloor temperature is less than 10°C. This work addresses the
important issue of geomechanical stability in hydrate bearing sediments during different
perturbations.
I analyzed extensive data collected from the literature on the types of sediments
where hydrates have been found during various offshore expeditions. To better
understand the hydrate bearing sediments in offshore environments, I divided these data
into different sections. The data included water depths, pore water salinity, gas
compositions, geothermal gradients, and sedimentary properties such as sediment type,
sediment mineralogy, and sediment physical properties. I used the database to determine
the types of sediments that should be evaluated in laboratory tests at the Lawrence
Berkeley National Laboratory.
The TOUGH+Hydrate reservoir simulator was used to simulate the gas production
behavior from hydrate bearing sediments. To address some important gas production
issues from gas hydrates, I first simulated the production performance from the
Messsoyakha Gas Field in Siberia. The field has been described as a free gas reservoir
overlain by a gas hydrate layer and underlain by an aquifer of unknown strength. From a
parametric study conducted to delineate important parameters that affect gas production
at the Messoyakha, I found effective gas permeability in the hydrate layer, the location of perforations and the gas hydrate saturation to be important parameters for gas
production at the Messoyakha. Second, I simulated the gas production using a hydraulic
fracture in hydrate bearing sediments. The simulation results showed that the hydraulic
fracture gets plugged by the formation of secondary hydrates during gas production.
I used the coupled fluid flow and geomechanical model "TOUGH+Hydrate-
FLAC3D" to model geomechanical performance during gas production from hydrates in
an offshore hydrate deposit. I modeled geomechanical failures associated with gas
production using a horizontal well and a vertical well for two different types of
sediments, sand and clay. The simulation results showed that the sediment and failures
can be a serious issue during the gas production from weaker sediments such as clays.
9
Jang, Jaewon. "Gas production from hydrate-bearing sediments." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41145.
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Gas hydrates are crystalline compounds made of gas and water molecules. Methane hydrates are found in marine sediments and permafrost regions; extensive amounts of methane are trapped in the form of hydrates. The unique behavior of hydrate-bearing sediments requires the development of special research tools, including new numerical algorithms (tube- and pore-network models) and experimental devices (high pressure chambers and micromodels). Hydraulic conductivity decreases with increasing variance in pore size distribution; while spatial correlation in pore size reduces this trend, both variability and spatial correlation promote flow focusing. Invading gas forms a percolating path while nucleating gas forms isolated gas bubbles; as a result, relative gas conductivity is lower for gas nucleation than for gas invasion processes, and constitutive models must be properly adapted for reservoir simulations. Physical properties such as gas solubility, salinity, pore size, and mixed gas conditions affect hydrate formation and dissociation; implications include oscillatory transient hydrate formation, dissolution within the hydrate stability field, initial hydrate lens formation, and phase boundary changes in real field situations. High initial hydrate saturation and high depressurization favor gas recovery efficiency during gas production from hydrate-bearing sediments. Even a small fraction of fines in otherwise clean sand sediments can cause fines migration and concentration, vuggy structure formation, and gas-driven fracture formation during gas production by depressurization.
10
Knudsen, Brage Rugstad. "Production Optimization in Shale Gas Reservoirs." Thesis, Norwegian University of Science and Technology, Department of Engineering Cybernetics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-10035.
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Natural gas from organic rich shales has become an important part of the supply of natural gas in the United States. Modern drilling and stimulation techniques have increased the potential and profitability of shale gas reserves that earlier were regarded as unprofitable resources of natural gas. The most prominent property of shale gas reservoirs is the low permeability. This is also the reason why recovery from shale gas wells is challenging and clarifies the need for stimulation with hydraulic fracturing. Shale gas wells typically exhibit a high initial peak in the production rate with a successive rapid decline followed by low production rates. Liquid accumulation is common in shale wells and is detrimental on the production rates. Shut-ins of shale gas wells is used as a means to prevent liquid loading and boost the production. This strategy is used in a model-based production optimization of one and multiple shale gas well with the objective of maximizing the production and long-term recovery. The optimization problem is formulated using a simultaneous implementation of the reservoir model and the optimization problem, with binary variables to model on/off valves and an imposed minimal production rate to prevent liquid loading. A reformulation of the nonlinear well model is applied to transform the problem from a mixed integer nonlinear program to a mixed integer linear program. Four numerical examples are presented to review the potential of using model-based optimization on shale gas wells. The use of shut-ins with variable duration is observed to result in minimal loss of cumulative production on the long term recovery. For short term production planning, a set of optimal production settings are solved for multiple wells with global constraints on the production rate and on the switching capacity. The reformulation to a mixed integer linear program is shown to be effective on the formulated optimization problems and allows for assessment of the error bounds of the solution.
11
Iverson, Erik Boyd. "Windowless gas targets for neutron production." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/10337.
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12
Diazgranados, Jonathan. "Gas production forecasting using automatic type curve matching." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1331.
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Thesis (M.S.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains xii, 131 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 81-82).
13
Juell, Aleksander. "Production Optimization of Remotely Operated Gas Wells." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-15934.
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14
Igboanusi, Udennaka Paul. "Properties and Production of Natural Gas Hydrates." Thesis, Imperial College London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.519605.
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15
Pulec, Z., J. Stursa, O. Lebeda, V. Zach, and J. Ralis. "New gas target system for 83Rb production." Helmholtz-Zentrum Dresden - Rossendorf, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-165646.
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Introduction
Short-lived isomer 83mKr (T½ = 1.83 h) is an ideal calibration source in several low-energy experiments like or KATRIN (determining the neutrino rest mass, monitoring high voltage stability and investigation of the main spectrometer properties) or XENON (detection of the dark matter).
The isomer 83mKr is formed by decay of 83Rb (T½ = 86.2 d) that can be produced predominantly via the reaction 84Kr(p,2n)83Rb by irradiation of natKr (57 % abundance of 84Kr).
The design and construction of the new gas target for effective production of radionuclide 83Rb as well as target processing will be shortly described.
Material and Methods
For the target design, we selected the following criteria: minimizing activation of target components; efficient cooling system allowing higher beam currents; easy handling; high life-time of the target chamber (low impact of the irradiation and radionuclide separation process on the target chamber surface and 83Rb recovery).
The target consists of three parts:
1. Water cooled aluminium (alloy EN 6082) mechanical interface for easy connection of the target to the beam line. It also serves as a beam collimator (diameter 9 mm).
2. Holder of He-cooled foils (vacuum separation foil – Havar 0.025 mm, target body window – Ti 0.1 mm).
3. Aluminium (alloy EN 6082) water cooled target body with 150mm long cone-shaped target chamber of the volume 27.1 ml. Internal surface of the chamber is nickel-coated.
The target filled with natural Kr of purity 0.9999 and absolute pressure 13 bar was irradiated on the external beam of the isochronous cyclotron U-120M of the NPI AS CR. The proton beam energy was set so that it is decreased after deg-radation in the separation foils to 25.6 MeV. Beam energy loss in the natural Kr gas filling is 9.6 MeV. The target was tested up to 25 µA beam current.
After irradiation, the target is left for a week to let the short-lived activation products to decay. Then, 83Rb is washed out from the target walls by two portions of freshly prepared de-ionized water, target is rinsed by high-purity ethanol and dried. The two portions of 83Rb aqueous solution are then connected and activity and radionuclidic purity of the product is determined via γ-spectrometry (HPGe detector). Large-distance sample-detector measurements of the target prior and after the separation are used in order to determine recovery of 83Rb.
Results and Conclusion
The new gas target for routine production of 83Rb was successfully designed, tested and im-plemented for regular 83Rb production. Six-hour irradiation with 15 µA proton beam resulted repeatedly in ca 300 MBq of 83Rb (EOB). Besides 83Rb, we identified in the separated product also 84Rb (T½ = 32.82 d) at levels ca 31 % of the 83Rb activity (EOB) and 86Rb (T½ = 18.631 d) at levels ca 8 % of the 83Rb activity (EOB). Both radionuclidic impurities do not disturb the use of 83Rb, since none of them emanates any radioactive krypton isotope. Moreover, their relative content decreases in time. Rubidium isotopes are recovered from the target almost quantitatively (98–99 %).
16
Hill, Damon J. "The production and extraction of landfill gas." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335797.
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Hunt, Lisa Marie. "Gas dissolution phenomena in crude oil production." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361547.
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18
Olsen, Susanne Kelly. "Catalytic membrane reactors for synthesis gas production from natural gas via partial oxidation." Thesis, Robert Gordon University, 2004. http://hdl.handle.net/10059/626.
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Natural gas obtained during the extraction of liquid hydrocarbons is often undesired due to the lack of infrastructure to transport the natural gas to an onshore location. As a result the natural gas is often flared causing economic waste and environmental concern. It would therefore be desirable to either convert the natural gas into some other substance which can be transported easily, or transport the natural gas in a liquid state. In that way, new field development will be more financially viable through the use of the extensive infrastructure and technology already in place in the offshore industry for transporting liquid hydrocarbons. It is considered that one feasible way of utilising offshore produced natural gas, is to convert it into synthetic gas (syngas) which can in turn be used to produce gases and fluids such as methanol, ammonia or a synthetic crude oil that can be readily pumped through the same pipelines as the produced oil. For the production of synthetic gas, membrane technology presents an attractive advantage improving conversion efficiency by operating as catalyst support, which then also increases the catalyst dispersion, resulting in optimal catalyst load and complete consumption of oxygen and methane in the partial oxidation. In the present investigation, an enhanced catalyst-dispersed ceramic membrane for low-cost synthesis gas production suitable for gas-to-liquids has been prepared, characterised and tested in a self-designed membrane reactor. The effect of temperature and feed flow rates has been studied and a kinetic model has been developed. In the novel membrane reactor, an active porous layer is located on both sides facing the oxygen and methane containing gas, adjacent is a second active porous layer and is supported by layers with increasing pore radii. Here the active porous layer on the bore side enhances the reaction between permeated oxygen and fuel species. In this study, it has also been demonstrated that the oxygen is activated prior to contacting the methane inside the membrane. This often results in 100% oxygen conversion, CO selectivity higher than 96% and syngas ratio (1-1/2 C O) of 2.2 to 1.8. Another advantage of the developed membrane system is that it can be used in high temperatures (> 1273.15K) and high pressure (80bars) processes with no variation on the flow rates, due to the mechanical strength of the ceramic support used.
19
Choi, Jong-Won. "Geomechanics of subsurface sand production and gas storage." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39493.
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Improving methods of hydrocarbon production and developing new techniques for the creation of natural gas storage facilities are critically important for the petroleum industry. This dissertation focuses on two key topics: (1) mechanisms of sand production from petroleum reservoirs and (2) mechanical characterization of caverns created in carbonate rock formations for natural gas storage. Sand production is the migration of solid particles together with the hydrocarbons when extracted from petroleum reservoirs. It usually occurs from wells in sandstone formations that fail in response to stress changes caused by hydrocarbon withdrawal. Sand production is generally undesirable since it causes a variety of problems ranging from significant safety risks during high-rate gas production, to the erosion of downhole equipment and surface facilities. It is widely accepted that a better understanding of the mechanics of poorly-consolidated formations is required to manage sand production; which, in turn, enables the cost effective production of gas and oil resources. In this work, a series of large-scale laboratory experiments was conducted in fully saturated, cohesionless sand layers to model the behavior of a petroleum reservoir near a wellbore. We directly observed several key characteristics of the sand production phenomenon including the formations of a stable cavity around the wellbore and a sub-radial flow channel at the upper surface of the tested layer. The flow channel is a first-order feature that appears to be a major part of the sand production mechanism. The channel cross section is orders of magnitude larger than the particle size, and once formed, the channel becomes the dominant conduit for fluid flow and particle transport. The flow channel developed in all of our experiments, and in all experiments, sand production continued from the developing channel after the cavity around the borehole stabilized. Our laboratory results constitute a well constrained data set that can be used to test and calibrate numerical models employed by the petroleum industry for predicting the sand production phenomenon. Although important for practical applications, real field cases are typically much less constrained. We used scaling considerations to develop a simple analytical model, constrained by our experimental results. We also simulated the behavior of a sand layer around a wellbore using two- and three-dimensional discrete element methods. It appears that the main sand production features observed in the laboratory experiments, can indeed be reproduced by means of discrete element modeling. Numerical results indicate that the cavity surface of repose is a key factor in the sand production mechanism. In particular, the sand particles on this surface are not significantly constrained. This lack of confinement reduces the flow velocity required to remove a particle, by many orders of magnitude. Also, the mechanism of channel development in the upper fraction of the sample can be attributed to subsidence of the formation due to lateral extension when an unconstrained cavity slope appears near the wellbore. This is substantiated by the erosion process and continued production of particles from the flow channel. The notion of the existence of this surface channel has the potential to scale up to natural reservoirs and can give insights into real-world sand production issues. It indicates a mechanism explaining why the production of particles does not cease in many petroleum reservoirs. Although the radial character of the fluid flow eventually stops sand production from the cavity near the wellbore, the production of particles still may continue from the propagating surface (interface) flow channel. The second topic of the thesis addresses factors affecting the geometry and, hence, the mechanical stability of caverns excavated in carbonate rock formations for natural gas storage. Storage facilities are required to store gas when supply exceeds demand during the winter months. In many places (such as New England or the Great Lakes region) where no salt domes are available to create gas storage caverns, it is possible to create cavities in limestone employing the acid injection method. In this method, carbonate rock is dissolved, while CO₂ and calcium chloride brine appear as products of the carbonate dissolution reactions. Driven by the density difference, CO₂ rises towards the ceiling whereas the brine sinks to the bottom of the cavern. A zone of mixed CO₂ , acid, and brine forms near the source of acid injection, whereas the brine sinks to the bottom of the cavern. Characterization of the cavern shape is required to understand stress changes during the cavity excavation, which can destabilize the cavern. It is also important to determine the location of the mixture-brine interface to select the place of acid injection. In this work, we propose to characterize the geometry of the cavern and the location of the mixture-brine interface by generating pressure waves in a pipe extending into the cavern, and measuring the reflected waves at various locations in another adjacent pipe. Conventional governing equations describe fluid transients in pipes loaded only by internal pressure (such as in the water hammer effect). To model the pressure wave propagation for realistic geometries, we derived new governing equations for pressure transients in pipes subjected to changes in both internal and external (confining) pressures. This is important because the internal pressure (used in the measurement) is changing in response to the perturbation of the external pressure when the pipe is contained in the cavern filled with fluids. If the pressure in the cavern is perturbed, the perturbation creates an internal pressure wave in the submerged pipe that has a signature of the cavern geometry. We showed that the classic equations are included in our formulation as a particular case, but they have limited validity for some practically important combinations of the controlling parameters. We linearized the governing equations and formulated appropriate boundary and initial conditions. Using a finite element method, we solved the obtained boundary value problem for a system of pipes and a cavern filled with various characteristic fluids such as aqueous acid, calcium chloride brine, and supercritical CO₂ . We found that the pressure waves of moderate amplitudes would create measurable pressure pulses in the submerged pipe. Furthermore, we determined the wavelengths required for resolving the cavern diameter from the pressure history. Our results suggest that the pressure transients technique can indeed be used for characterizing the geometry of gas storage caverns and locations of fluid interfaces in the acid injection method.
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Jung, Jongwon. "Gas production from hydrate-bearing sediments:geo-mechanical implications." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/42841.
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Gas hydrate consists of guest gas molecules encaged in water molecules. Methane is the most common guest molecule in natural hydrates. Methane hydrate forms under high fluid pressure and low temperature and is found in marine sediments or in permafrost region. Methane hydrate can be an energy resource (world reserves are estimated in 20,000 trillion m3 of CH4), contribute to global warming, or cause seafloor instability. Research documented in this thesis starts with an investigation of hydrate formation and growth in the pores, and the assessment of formation rate, tensile/adhesive strength and their impact on sediment-scale properties, including volume change during hydrate formation and dissociation. Then, emphasis is placed on identifying the advantages and limitations of different gas production strategies with emphasis on a detailed study of CH4-CO2 exchange as a unique alternative to recover CH4 gas while sequestering CO2. The research methodology combines experimental studies, particle-scale numerical simulations, and macro-scale analyses of coupled processes.
21
Firat, Fatih. "Gas Phase Reaction Kinetics Of Boron Fiber Production." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605188/index.pdf.
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In the production of boron fibers using CVD technique, boron deposition and dichloroborane formation reactions take place in a reactor. Boron deposition reaction occurs at the surface while formation of dichloroborane is the result of both gas phase and surface reactions.
A CSTR type of reactor was designed and constructed from stainless steel to investigate the gas phase reaction kinetics and kinetic parameters of boron fibers produced from the reaction of boron trichloride and hydrogen gases in a CVD reactor. The gases were heated by passing through the two pipes which were located into the ceramic furnace and they were mixed in the CSTR. The effluent gas mixture of the reactor was quenched by passing through a heat exchanger. An FT-IR spectrophotometer was connected to the heat exchanger outlet stream to perform on-line chemical analysis of the effluent gas mixture. Experiments were carried out at atmospheric pressure and a reactor temperature range of 300-600 ºC with different inlet reactant concentrations. The analysis of the FT-IR spectra indicated that the gas phase reaction and the surface reaction started at reactor temperatures above 170 º
C and 500º
C, respectively. It was concluded that reaction rate of the product increased with an increase in the inlet concentration of both reactants (BCl3 and H2) and with an increase in the reactor temperature. The gas phase reaction rate was expressed in terms of a th and b th orders with respect to the inlet concentrations of BCl3 and H2. The activation energy of the gas phase reaction, a and b were found to be 30.156 , 0.54 and 0.64, respectively. The correlation coefficient was 0.9969.
22
Nathanaelsson, Lena, and Linda Sandström. "Statistical evaluation of in vitro gas production kinetics." Thesis, Umeå universitet, Institutionen för matematik och matematisk statistik, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-51348.
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At the Forage Research Centre, Swedish University of Agricultural Sciences in Umeå a technique has been developed to describe the degradation of feeds in ruminant animals. The development of this technique has been made in collaboration with Dr J.W. Cone, Nutrition and Food, Animal Sciences Group of Wageningen UR, Lelystad, the Netherlands. Experiments have been performed in laboratories where feed samples have been incubated with rumen fluid and the amount of gas produced during the digestion has been measured continuously. These feed samples were analysed at three separate occasions. The purpose of this thesis was to identify and describe statistical procedures for detecting differences between feeds analysed within the same laboratory as well as differences between the same feeds analysed in two different laboratories (in Sweden and the Netherlands). To determine the rate of digestion and to describe to what extent feeds are digested in the rumen a gas production model was fitted, using non linear regression. In order to test whether there are significant differences between the feeds, three methods were applied. For each method, the variances were estimated differently. In the first method, Hotelling’s T2 tests and two sample t tests were performed. From these tests, differences between the feeds that were analysed within the same laboratory were detected whereas no differences between the same feeds analysed in two different laboratories could be found. In the other two methods, tests were performed using an assumption of normality. These two methods detected a larger number of differences between the feeds than the first method, primarily due to extremely underestimated variances. The first method is to be preferred since the estimated variances in this method are unbiased. This causes the result to be more reliable. For future experiments it is recommended that the feed samples are analysed at considerably more than three occasions. This would lead to better estimations in the first method and consequently the result would be enhanced.
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Zheng, Qing-ping. "Soot production in a tubular gas turbine combustor." Thesis, Cranfield University, 1994. http://hdl.handle.net/1826/3910.
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Soot production in gas turbine combustors is not desirable since it is the major source
of exhaust smoke emission and its thermal radiation to the combustor liner deteriorates the liner
durability. Soot formation involves comparatively slow chemistry and equilibrium can not be
applied to soot modelling in the combustor flow field.
. The exact sooting process in the
combustor is poorly understood given both the complexity and the limited experimental data
available. The work reported in this thesis seeks to first develop in-situ techniques for
retrieving spatially-resolved soot properties, mainly soot particle volume fraction, from within
the combustor and also to apply the measured results to comparisons with predicted soot
concentrations.
Two probing methods have been demonstrated which also incorporate a laser absorption
technique. The sight probe proves to be more reliable in the present measurements. The
evaluation of the physical probing techniques in sooty laboratory flames reveals that the flame
structure will not be substantially distorted by the probe. The disturbance caused by the probe
is localised, a feature which is evident in the reported water flow visualization test. The
necessary inert gas purge can be minimised to reduce the local aerodynamic perturbation. The
measured soot volume fraction distributions are comparable with sooting levels reported in
flame studies in the literature. The peak soot volume fractions are located off-axis,
characteristic of the fuel atornization. The measurementsin the primary zone are restricted by
the multi-phase character of the flow, where soot absorption can not be readily discriminated
from fuel droplet scattering. Measurements are reported over a range of air-fuel ratios, inlet
pressures and temperatures.
Time-averageds calard istributionsa t the nominald ilution sectionh ave beeno btained
in addition to the soot measuremenut sing probe sampling and standard gas analysis.
Correlationso f carbond ioxide with mixture fraction reveala clear relationshipa t overall lean
conditionsc onsistenwt ith widely usedm odelleda ssumptions.T here are less well-correlated
relationshipsb etweent emperaturea ndm ixture fraction, possiblyd ue to the influenceo f scalar
fluctuationsa nda lsoo f the scalard issipationr ate. Sootl oadingi n the presentf low conditions
is characteristicallylo w, basedo n the mixture fraction ands ootv olumef raction data. Thermal
radiation in the visible spectrum shows a distinct narrow band spectra in addition to the soot
continuum, which is believed to arise fromC2radical emission. The mean radiation intensities,
predictedb y usingt he measuredte mperaturea nds ootc oncentrationre sults,a rei n generallo wer
than the measured mean intensities. Temperature fluctuation levels may be particularly
influential in some of these calculations.
Sootm odellingi n the combustohr asb eenu ndertakenb y applyinga n extendedla minar
flamelet concept. The two-equations oot formation model has beenp rimarily developedo n
laminar flames. The comparisono f the computationa nd measuremenstu ggeststh at this soot
model holds promise in the context of prediction in the combustor. In the absenceo f a
satisfactoryt heoreticald escriptiono f the fuel-air burning in the combustor,w heret he liquid
kerosinee mployedis replacedb y gaseoups ropane,t he computeds calarp rofiles are inconsistent
in some importantr espectsw ith the measuredo nes. This exerts a major effect on the soot
predictioni n terms of the quantitatived etail in the computationw, hich is howeverc rucial for
the soot model development. The original flow field modelling needs to be improved for the
purpose of further soot model refinement.
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GonzaÌlez, Mariana Valeria. "Enhancing gas production in mesophilic anaerobic digestion (MAD)." Thesis, University of Surrey, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431096.
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Hopkins, Frances Elizabeth. "Ocean acidification and marine biogenic trace gas production." Thesis, University of East Anglia, 2010. https://ueaeprints.uea.ac.uk/10582/.
Full textAbstract:
The oceanic uptake of anthropogenic CO2 emissions is leading to an alteration of seawater carbonate chemistry, manifested as increasing [H+], falling [CO32-] and a drop in seawater pH. Over the coming centuries this process, termed “ocean acidification”, is expected to negatively impact marine biota, with implications for marine biological and biogeochemical processes. In this thesis, the impact that such changes may have on the net production of a range of climatically- and atmospherically-important marine biogenic trace gases, including halocarbons and dimethyl sulphide (DMS), is assessed through a mesocosm phytoplankton bloom CO2 perturbation experiment, two laboratory CO2 incubation experiments on natural seawater samples, and at a volcanically-acidified shallow marine fieldsite in Italy. Large and significant reductions in DMS and DMSP concentrations under future high CO2 conditions were observed during the mesocosm experiment (mean decreases of 57 percent and 24 percent, respectively), a finding in strong support of a previous study (Avgoustidi 2007). Furthermore, concentrations of iodocarbons showed large decreases, with mean decreases under high CO2 ranging from 59 to 93 percent. Results for the laboratory incubation experiments also showed a reduction in iodocarbon concentrations (when normalised to chlorophyll a) under high CO2. These changes may be the result of shifts in plankton community composition in response to the high CO2 conditions, and/or impacts on dissolved organic matter and the bacterial communities involved in the formation of these compounds. The response of bromocarbons was less clear cut during the experimental studies. Following investigations at a naturally-acidified fieldsite in Italy, it was concluded that this site was a poor natural analogue to the impact of future ocean acidification on marine trace gas production. Taking the results of the mesocosm and laboratory incubations into consideration, a combined decrease in both DMS and iodocarbons in response to ocean acidification may have considerable impacts on future atmospheric chemistry and global climate.
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Ricci, Patricia. "Greenhouse gas emissions from contrasting beef production systems." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/9370.
Full textAbstract:
Agriculture has been reported to contribute a significant amount of greenhouse gases to the atmosphere among other anthropogenic activities. With still more than 870 million people in the world suffering from under-nutrition and a growing global food demand, it is relevant to study ways for mitigating the environmental impact of food production. The objective of this work was to identify gaps in the knowledge regarding the main factors affecting greenhouse gas (GHG) emissions from beef farming systems, to reduce the uncertainty on carbon footprint predictions, and to study the relative importance of mitigation options at the system level. A lack of information in the literature was identified regarding the quantification of the relevant animal characteristics of extensive beef systems that can impact on methane (CH4) outputs. In a meta-analysis study, it was observed that the combination of physiological stage and type of diet improved the accuracy of CH4 emission rate predictions. Furthermore, when applied to a system analysis, improved equations to predict CH4 from ruminants under different physiological stages and diet types reduced the uncertainty of whole-farm enteric CH4 predictions by up to 7% over a year. In a modelling study, it was demonstrated that variations in grazing behaviour and grazing choice have a potentially large impact upon CH4 emissions, which are not normally mentioned within carbon budget calculations at either local or national scale. Methane estimations were highly sensitive to changes in quality of the diet, highlighting the importance of considering animal selectivity on carbon budgets of heterogeneous grasslands. Part of the difficulties on collecting reliable information from grazing cattle is due to some limitations of available techniques to perform CH4 emission measurements. Thus, the potential use of a Laser Methane Detector (LMD) for remote sensing of CH4 emissions from ruminants was evaluated. A data analysis method was developed for the LMD outputs. The use of a novel technique to assess CH4 production from ruminants showed very good correlations with independent measurements in respiration chambers. Moreover, the use of this highly sensitive technique demonstrates that there is more variability associated with the pattern of CH4 emissions which cannot be explained by the feed nutritional value. Lastly, previous findings were included in a deterministic model to simulate alternative management options applied to upland beef farming systems. The success of the suggested management technologies to mitigate GHG emissions depends on the characteristics of the farms and management previously adopted. Systems with high proportion of their land unsuitable for cropping but with an efficient use of land had low and more certain GHG emissions, high human-edible returns, and small opportunities to further reduce their carbon footprint per unit of product without affecting food production, potential biodiversity conservation and the livelihood of the region. Altogether, this work helps to reduce the uncertainty of GHG predictions from beef farming systems and highlights the essential role of studies with a holistic approach to issues related to climate change that encompass the analysis of a large range of situations and management alternatives.
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Vandegriff, Jon D. "Metal production in quasars through jet-gas interactions /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487947501136537.
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Buba, Ibrahim Muhammad. "Direct estimation of gas reserves using production data." Texas A&M University, 2003. http://hdl.handle.net/1969/153.
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Kryger, Kyle Wesley. "Production of Natural Gas from Algae Plant Design." Thesis, The University of Arizona, 2010. http://hdl.handle.net/10150/146598.
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The goal of the project is to design a plant that is capable of converting an algae feedstock into compressed natural gas (CNG). This product is intended to be sold as a green replacement for CNG produced using traditional methods. In addition to CNG, hydrogen gas is produced; this product will be sold as a biofuel as well. The CNG produced in this process is created by gasifying algae in supercritical water and then reacting the algal matter over an Ru/C catalyst. The resulting gas is then purified and compressed to produce CNG and hydrogen. A process hazard analysis was conducted to identify and help reduce safety and environmental hazards. An economic analysis showed that the plant's net present value is ($37.5 million); therefore, it was not recommended that the plant be built at this time. Future work includes developing a cheap Ru/zirconia catalyst to replace the expensive Ru/C catalyst currently used in the process. Designs for vessels containing supercritical fluids should also be evaluated to find ways to minimize purchase and installation cost. In addition, pilot scale testing of specific pieces of equipment is required to ensure innovations included in the design function as expected.
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Hülse, Eduardo Otte. "Robust production optimization of gas-lifted oil fields." reponame:Repositório Institucional da UFSC, 2015. https://repositorio.ufsc.br/xmlui/handle/123456789/158823.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia de Automação e Sistemas, Florianópolis, 2015.Made available in DSpace on 2016-02-09T03:08:04Z (GMT). No. of bitstreams: 1 337432.pdf: 1873519 bytes, checksum: 40fce035101e01804e1bc88f7e1ea3a5 (MD5) Previous issue date: 2015
Com a crescente demanda por energia fóssil as operadoras petrolíferas têm buscado determinar planos operacionais que otimizam a produção dos campos em operação para satisfazer a demanda do mercado e reduzir os custos operacionais. Neste contexto, a pesquisa operacional tem se mostrado uma importante ferramenta para determinação dos planos de produção de curto prazo para campos de petróleo complexos. Alguns trabalhos já desenvolveram estratégias para a otimização integrada da produção que visam auxiliar engenheiros de produção e operadores a atingir condições de operação ótimas. Estes avanços científicos atestam o potencial da área de otimização integrada da produção de campos, justificando a busca por estratégias de otimização global e integradas de ativos. Contudo, a incerteza dos parâmetros que caracterizam o reservatório, os poços, fluidos e os diversos processos de produção não vem sendo considerada pelos modelos e algoritmos de otimização da produção diária. Considerando os modelos de produção de curto prazo, estas incertezas podem ser atribuídas a erros de medição , comportamento oscilatório dos sistemas, modelos imprecisos, entre outros. A influência da incerteza dos parâmetros em problemas de otimização tem, desde tempos, sido foco da comunidade de programação matemática. E já foi verificado que soluções de problemas de otimização podem apresentar significativa sensibilidade à pertubações nos parâmetros do dado problema, podendo levar a soluções não factíveis, subótimas ou ambas. Assim, buscando tornar as abordagens de otimização existentes mais confiáveis e robustas às incertezas intrínsecas dos sistemas de produção, esta dissertação investiga a modelagem e tratamento de incertezas na otimização diária da produção e propõe formulações em programação matemática para otimização robusta da produção de poços operados por gas-lift. As formulações representam curvas amostradas através de dados simulados ou medidos que refletem as incertezas dos sistemas de produção. Estas representações levam a formulações robustas em programação matemática inteira mista obtidas pela aproximação das curvas de produção através de linearização por partes. Além disso, este trabalho apresenta os resultados de uma analise computacional comparativa da aplicação da formulação robusta e da formulação nominal a um campo de petróleo em ambiente de simulação, porém considerando simuladores multifásicos amplamente empregados pela indústria do petróleo e gás, que representam a fenomenologia muito próximo da realidade. O primeiro capítulo apresenta a problemática em que estão envolvidos os desenvolvimentos realizados nesta dissertação e um resumo dos capítulos subsequentes. No segundo capítulo alguns conceitos fundamentais são apresentados para a compreensão do trabalho desenvolvido. Este capítulo é dividido em três partes. A primeira parte inicia apresentando brevemente a indústria de petróleo e gás com uma perspectiva histórica, econômica e dos processos envolvidos. Na sequência são expostos conceitos básicos de engenharia de petróleo necessários para o entendimento do sistema de produção utilizado ao longo a dissertação  i.e. gas-lift. Finalmente, o problema de otimização da produção é situado dentro do problema maior, que é o gerenciamento completo das operações de um campo de petróleo, seguido de uma revisão da literatura no que se refere a abordagens clássicas para otimização da produção de campos operados por gas-lift. A segunda parte é uma descrição compacta sobre modelagem de problemas de otimização utilizando programação matemática e na menção dos métodos de solução deste tipo de problema utilizados na parte experimental desta dissertação. A terceira parte começa com uma revisão sobre incerteza em problemas de otimização e sobre as decisões de modelagem enfrentadas quando na presença de problemas de otimização incertos. Na sequência o paradigma de otimização robusta é introduzido e é apresentada uma compilação de alguns dos principais resultados da área de otimização robusta linear. Além disso, ao fim, alguns pontos específicos da teoria de otimização robusta são apresentados pela suas relevâncias para o desenvolvimento da teoria dos capítulos seguintes. O terceiro capítulo inicia com uma discussão sobre as origens das incertezas nos modelos de produção para então prover uma revisão bibliográfica dos poucos trabalhos que mencionam ou lidam com incerteza em sistemas de produção. Na sequência, a incerteza é examinada na perspectiva do problema de otimização. Um sistema simples é usado para exemplificar a metodologia de otimização robusta desenvolvida nesta dissertação. O quarto capítulo apresenta dois problemas padrões de otimização da produção, um contendo poços satélites e outro com poços e completação submarina. Para ambos uma formulação em programação linear inteira mista é descrita considerando valores nominais para todos os parâmetros. Então, para cada problema uma reformulação robusta é implementada considerando incerteza nas curvas de produção do poço. A metodologia utilizada para o primeiro problema é a mesma detalhada no capítulo três, e para o segundo uma extensão da metodologia é proposta para poder lidar com restrições de igualdade incertas. No quinto capítulo são apresentados resultados experimentais de um problema de otimização da produção de um campo com poços satélites. Os resultados obtidos com otimização clássica (nominal) e com otimização robusta são então comparados em um campo de produção sintético instanciado em um simulador multifásico comercial. A solução robusta se mostrou indicada para cenários de operação mais críticos onde factibilidade e segurança são prioridade. No capítulo final uma análise dos resultados obtidos na dissertação é feita sob a perspectiva do possível emprego das técnicas desenvolvidas na indústria de óleo e gás. Apesar de à primeira vista os resultados serem conservadores e de sua utilização parecer limitada, existe potencial para a metodologia ser empregada no caso de situações que priorizam segurança. Além disso a metodologia aqui desenvolvida pode servir como ponto inicial para pesquisas e desenvolvimentos futuros. Uma breve descrição de possíveis trabalhos futuros é feita ao final deste capítulo. O apêndice traz a descrição de algoritmos de amostragem de curvas côncavas desenvolvidos para os experimentos numéricos realizados na dissertação.
Abstract : Managing production of complex oil fields with multiple wells and coupled constraints remains a challenge for oil and gas operators. Some technical works developed strategies for integrated production optimization to assist production engineers in reaching best operating conditions. However, these works have neglected the uncertainties in the well-performance curves and production processes, which may have a significant impact on the operating practices. The uncertainties may be attributed to measurement errors, oscillating behavior, and model inaccuracy, among others. To this end, this dissertation investigates how uncertainty might be considered in daily production optimization and proposes formulations in mathematical programming for robust production optimization of gas-lifted oil fields. The formulations represent system-measured and simulated sample curves that reflect the underlying uncertainties of the production system. The representations lead to robust mixed-integer linear programming formulations obtained from piecewise-linear approximation of the production functions. Further, this work presents results from a computational analysis of the application of the robust and nominal formulations to a representative oil fields available in simulation software.
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Lundberg, Susanne. "Comparative LCA of Electrolyzers for Hydrogen Gas Production." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254353.
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The need for energy and fuels is predicted to grow within the next decades, in parallel to the need of decreasing the emissions to air and water to operate within the planetary boundaries. The alternatives to consider as energy or fuel options need to be environmentally friendly, evaluated over the whole life cycle. Hydrogen is one of the considered alternatives because it contains no carbon and has a good environmental performance when produced from renewable sources. It can be produced by a variety of methods, where electrolyzers have a good potential environmental impact if powered by renewable energy. Electrolyzers cleave water into hydrogen and oxygen, by using electricity and water. There are currently four technologies on the market or under development but there is a lack of LCA-studies that compare these. This study is an attributional LCA-study, evaluating the potential environmental performance of two electrolyzers: PEMEC and SOEC. The result from this study is thereafter compared to a parallel study of one other electrolyzer: Alkaline. The LCA study considers six impact categories: Abiotic Depletion (element), Abiotic Depletion (fossil), Acidification Potential, Eutrophication Potential, Global Warming Potential and Photochemical Ozone Creation Potential. The system boundary is set as cradle to gate. The electricity source for hydrogen production is evaluated in a sensitivity analysis, together with a scenario of future estimated developments. The electricity during hydrogen production has the highest impact of the life cycle for PEMEC and SOEC, where the energy source has a great impact on the result. PEMEC has the lowest potential environmental impact, in comparison to Alkaline and SOEC, which comes from low energy consumption and low weight of materials with high environmental impact.Energi- och bränslebehovet förväntas öka inom de närmsta decennierna, samtidigt som utsläpp till luft och vatten måste minska för att nå uppsatta klimatmål. De alternativ som tas fram behöver vara miljövänliga, med bra klimatresultat sett över hela livscykeln. Vätgas är ett alternativ som övervägs, på grund av högt energiinnehåll och låga utsläpp till följd av att den är fri från kol. Vätgas kan produceras med en mängd metoder, där genom elektrolys anses vara en av de bästa teknikerna ur miljösynpunkt. En elektrolysör producerar vät- och syrgas genom att sönderdela vatten med hjälp av elektricitet. Det finns fyra elektrolys-varianter på marknaden och under utveckling, men det saknas LCA-studier där dessa jämförs mot varandra. Denna studie är en bokförings LCA av två elektrolyser: PEMEC och SOEC, som jämförs med resultatet från en parallell studie av en annan elektrolys-typ: Alkalisk. Potentiell miljöpåverkan mättes i sex stycken kategorier: resursutarmning (fossila resurser och ämnen), försurning, övergödning, global uppvärmning och fotokemiskt marknära ozon. Systemgränsen är satt från råmaterialutvinning till vätgasproduktion. Valet av elektricitetskälla för vätgasproduktion utvärderas i en känslighetsanalys, tillsammans med påverkan av framtida teknikers konstruktion. Livscykelfasen ”produktion av vätgas” har övervägande högst påverkan över livscykeln för SOEC och PEMEC, där elektriciteten är den bidragande faktorn. Elektrolysmodellen PEMEC har uppskattningsvis lägst miljömässig påverkan över livscykeln. Den låga påverkan för PEMEC kan härledas till låg elektricitetsförbrukning under vätgasproduktionen samt låga vikter av material med hög miljömässig påverkan.
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Sundin, Camilla. "Environmental Assessment of Electrolyzers for Hydrogen Gas Production." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-260069.
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Hydrogen has the potential to become an important energy carrier in the future with many areas of applications, as a clean fuel for transportation, heating, power generation in places where electricity use is not fit, etc. Already today hydrogen plays a key role in numerous industries such as petroleum refineries and chemical industries. There are different production methods for hydrogen. Today, natural gas reforming is the most commonly used. With the growing importance of green production paths, hydrogen production by electrolysis is expected to grow. Two main electrolyzer technologies are used today; alkaline and polymer electrolyte membrane electrolyzer. High-temperature electrolyzers are also interesting techniques, where solid oxide is under development and molten carbonate electrolyzers is researched. In this thesis, a comparative life cycle analysis was performed on the alkaline and molten carbonate electrolyzer. Due to inaccurate inventory data for the molten carbonate electrolyzer, those results are excluded from the published thesis. The environmental performance of the alkaline electrolyzer technology was compared to that of the solid oxide and the polymer electrolyte membrane electrolyzers. The system boundaries were set as cradle to gate. Thereby, the life cycle steps included in the study are raw material extraction, electrolyzer manufacturing, hydrogen production, and transports in between these steps. The functional unit was chosen as 100 kg produced hydrogen gas. The results show that the polymer electrolyte membrane electrolyzer has the lowest environmental impact out of the compared technologies. It is also determined that the lifetime and the current density of the electrolyzers have significant impact on their environmental performance. Moreover, it is established that electricity for hydrogen production has the highest environmental impact out of the electrolyzers life cycle steps. Therefore, it is important to make sure that the electricity used for hydrogen production derives from renewable sources.Vätgas har potential att spela en viktig roll som energibärare i framtiden med många användningsområden, såsom ett rent bränsle för transporter, uppvärmning, kraftförsörjning där elproduktion inte är lämpligt, med mera. Redan idag är vätgas ett viktigt inslag i flera industrier, där ibland raffinaderier och kemiska industrier. Det finns flera metoder för att producera vätgas, där reformering av naturgas är den största produktionsmetoden idag. I framtiden spås vätgasproduktion med elektrolys bli allt viktigare, då hållbara produktionsprocesser prioriteras allt mer. Idag används främst två elektrolysörtekniker, alkalisk och polymerelektrolyt. Utöver dessa är högtemperaturelektrolysörer också intressanta tekniker, där fastoxidelektrolysören är under utveckling och smältkarbonatelektrolysören är på forskningsstadium. I det här examensarbetet har en jämförande livscykelanalys utförts på alkalisk- och smältkarbonatelektrolysören. På grund av felaktiga indata för smältkarbonatelektrolysören har dessa resultat uteslutits från den publika rapporten. Miljöpåverkan från den alkaliska elektrolysören har sedan jämförts med miljöpåverkan från fastoxid- och polymerelektrolytelektrolysörerna. Systemgränserna sattes till vagga till grind. De livscykelsteg som inkluderats i studien är därmed råmaterialutvinning, elektrolysörtillverkning, vätgasproduktion och transporter mellan dessa steg. Den funktionella enheten valdes till 100 kg producerad vätgas. Resultaten visar att polymerelektrolytteknologin har den lägsta miljöpåverkan utav de tekniker som jämförts. Resultaten påvisar också att livstiden och strömtätheten för de olika teknikerna har signifikant påverkan på teknikernas miljöpåverkan. Dessutom fastslås att elektriciteten för vätgasproduktion har högst miljöpåverkan utav de studerade livscykelstegen. Därför är det viktigt att elektriciteten som används för vätgasproduktionen kommer ifrån förnybara källor.
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Shmeleva, Mariia. "Geothermal Energy Production from Oil and Gas Wells." Thesis, KTH, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-245059.
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This Thesis presents an investigation of geothermal energy production and utilization for electricity generation on the petroleum fields. According to the global energy market in Russia, the leading position takes oil and gas industry. Experts say that most of large petroleum deposits are depleted and the water cut reaches up to 80-90%. To develop such fields and deposits is not economic attractive, that is why wells with high water cut, more than 95%, are turned into abandoned wells. The technology of obtaining geothermal energy from abandoned wells allows reusing already drilled deep wells to generate electricity in an environmentally friendly way. It is especially relevant in oilfields isolated from the grids. In this work the scheme of geothermal energy extraction and utilization is presented. Based on the knowledge of heat exchange in a well and foreign experience a mathematical model describing heat exchange between injected fluid and surrounding rocks in a double pipe was developed. Apart from that the main factors affecting the efficiency of geothermal heat extraction and electricity generation were thoroughly examined. Furthermore, the economic and ecological effect from electricity production by ORC was defined.Denna avhandling presenterar en undersökning av produktion av geotermisk energi och utnyttjande av elproduktion på petroleumsområdena. Enligt den globala energimarknaden i Ryssland tar ledande position olje- och gasindustrin. Experter säger att de flesta stora oljefyndigheter är utarmade och vattnets snitt når upp till 80-90%. Att utveckla sådana fält och insättningar är inte ekonomiskt attraktiva, det är därför brunnar med högvattenskärning, mer än 95%, förvandlas till övergivna brunnar. Tekniken för att erhålla geotermisk energi från övergivna brunnar möjliggör återanvändning av redan borrade djupa brunnar för att generera el på ett miljövänligt sätt. Det är särskilt relevant i oljefält isolerade från nätet. I detta arbete presenteras systemet för geotermisk energiutvinning och -utnyttjande. Baserat på kunskapen om värmeväxling i en brunn och utländsk erfarenhet utvecklades en matematisk modell som beskriver värmeväxling mellan injicerad vätska och omgivande stenar i ett dubbelrör. Bortsett från detta undersöktes de viktigaste faktorerna som påverkar effektiviteten av geotermisk utvinning och elproduktion. Vidare definierades den ekonomiska och ekologiska effekten av elproduktion av ORC.
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Sadeq, Dhifaf Jaafar. "Gas Hydrates Investigation: Flow Assurance for Gas Production and Effects on Hydrate-bearing Sediments." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/75809.
Full textAbstract:
This thesis was aimed to study gas hydrates in terms of their equilibrium conditions in bulk and their effects on sedimentary rocks. The hydrate equilibrium measurements for different gas mixtures containing CH4, CO2 and N2 were determined experimentally using the PVT sapphire cell equipment. We imaged CO2 hydrate distribution in sandstone, and investigated the hydrate morphology and cluster characteristics via μCT. Moreover, the effect of hydrate formation on the P-wave velocities of sandstone was investigated experimentally.
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Tesfaslasie, Samson. "Automatic type curve matching for predicting gas wells production." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=916.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains xv, 113 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 67-68).
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Hveding, Haakon Andreas. "Production, Liquefaction and Transport of Low-Processed Natural Gas." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-11262.
Full textAbstract:
The pre-processing and liquefaction of LNG is very energy demanding in addition to having a high level of complexity. This motivates for finding alternative value chains and technologies for gas transportation and various concepts have been proposed based on natural gas in liquid phase. These can be split into two main principles; liquefaction with solids formation, and storage under pressure. Due to the increased temperature and solubility, freezable components will not form solids as easily in the pressurized concepts allowing less pre-treatment of the gas. The evaluated concepts in this thesis are Liquefied Unprocessed Well Stream (LUWS) with controlled solids formation, and three pressurized storage concepts; Aker Solutions Heavy Liquid Gas (HLG), ExxonMobils Pressurized Liquefied Natural Gas (PLNG) and Chevrons Liquefied Heavy Gas (LHG). All are presented in a high level survey together with similar ideas and patents in the first part of the thesis.Value chain evaluations are carried out for the different concepts and positive contributions, uncertainty and possible difficulties are discussed. The different patents filed, with solutions to some of the difficulties associated with the concepts, are also explained and presented. As the different gas products will have a less pure composition compared to LNG, the gas treating part of the value chains will be moved downstream of the liquefaction for all the new concepts. Through simplified simulations in PRO/II, energy requirements and specifications of the product liquid for the different concepts are found. The gas composition is adjusted to avoid freeze out of any kind for the pressurized liquids. The power needs for liquefaction are drastically decreased with increased pressure, giving smaller and less complex liquefaction plants. For a HLG concept at 20 bars, the power need is around halved, while for LHG at 50 bars it is between 25-39% compared to LNG, depending on the amount of heavy hydrocarbons in the LHG. The amount of flash gas needed for power production is as a direct result reduced by 70%.Water removal will still be necessary for all the concepts as hydrates will form easily at high pressures and low temperatures. The only exception is for the LUWS concept, where a smaller amount of water possibly could be allowed to form hydrates in a controlled way together with hydrocarbons and CO2.The reduced requirements for the gas means alternative processes for pre-treatment can be utilized and the thermal energy needs for these decreased at the liquefaction site. CO2 removal may be done by a membrane system or similar as the CO2 concentration can be around 1,4 and 6 mole% for a pressure of 12 and 50 bars respectively without the forming of solids. At the receiving site, a system similar to the CRYEX process can be implemented to remove the CO2 and allow storage of gas as LNG at atmospheric pressure.Estimations of the weight of the steel pressure vessels have been calculated for all the pressure levels. Due to the extremely high weight and the large amount of steel needed, the vessels must be constructed by an alternative building material for the high pressure ranges. A fiber reinforced plastic is suggested used with a steel or aluminum liner retaining the liquid. If successfully manufactured, these vessels would significantly reduce the weight and make HLG/LHG possible to implement.
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Binder, Benjamin Julian Tømte. "Production Optimization in a Cluster of Gas-Lift Wells." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19043.
Full textAbstract:
Subsea petroleum extraction systems may be large and complex, and many decisions affect the production. Maintaining high production levels is not a trivial task. As decisions are made based on available information and experience, better decisions come with better information. Decision support tools may provide essential information to achieve better production levels.In this master thesis, different methods are proposed as decision support tools. The aim is to increase the production from a part of a subsea production system, consisting of a manifold with seven producing wells and two flowlines, given certain system constraints. The methods are based on well models and numerical optimization, and both static and dynamic optimization is considered. The well models are non-linear, and binary decisions are also present. The problems that arise are complex MINLP problems, and are solved by combining ’brute force’, ’Branch & Bound’, and a nonlinear solver. The solution of the problems is implemented in MATLAB, and tested on predefined test scenarios, with no, little or extensive dynamics present. The performance is assessed by simulations, and by calculating the resulting average production.It was found that static optimization to decide the well settings, such as valve openings and flowline routing, has a great potential to increase the oil production from the system. The results when applying a dynamic approach to the system were not conclusive, but the methods proposed showed no indications of any major performance increase, relative to applying only static optimization.
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Md, Saad Juniza. "Dry reforming of waste plastics for synthesis gas production." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/15698/.
Full textAbstract:
Thermal processing is an effective technique for recycling waste plastics in a sustainable way. The pyrolysis of waste plastics, followed by reforming reactions of the pyrolysis products generates syngas (hydrogen and carbon monoxide) that has a vast array of applications. To date, the steam reforming process has been the most researched technology for syngas production from waste plastics. However, this process produces a large amount of carbon dioxide. Due to the concern related to global warming associated with the emissions of carbon dioxide into the atmosphere, the recycling of carbon dioxide through the pyrolysis-reforming of waste plastic, (dry reforming) is environmentally attractive. The dry reforming process was the focus of this research. A preliminary thermogravimetric and kinetic analysis was conducted in order to have a general understanding on the effect of CO2 in a waste plastics pyrolysis. The results show that most plastics required lower activation energy with the presence of CO2 in the pyrolysis atmosphere (N2:CO2 ratio of 7:3). A two-stage pyrolysis-catalytic dry reforming reactor was used to investigate various process conditions and types of catalyst to maximise syngas production. The two-stage fixed bed reaction systems increased the H2 in both a N2 or CO2 atmosphere. Ni/Al2O3 based catalysts with different metal promoters (Mg, Cu and Co) were selected for the investigation of pyrolysis-dry reforming of waste plastics. Among the catalysts tested, the Ni-Co/Al2O3 catalyst presented the highest catalyst activity resulting in a syngas production of 149.42 mmolsygas g-1plastic with 58% carbon dioxide conversion, also no detectable carbon formation on the catalyst surface was observed. The dry reforming reaction was also favoured with the Ni-Co/Al2O3 catalyst with high cobalt content. Various process parameters such as catalyst preparation method, reforming temperature, CO2 feed input rate and catalyst to plastic ratio were tested. It was found that the addition of steam in the catalytic-dry reforming process manipulated the H2/CO molar ratio, based on the type of catalyst used and the CO2/steam feed ratio. Better catalyst activity in relation to H2 production was observed for the Ni-Mg/Al2O3 catalyst and Ni-Co/Al2O3 catalyst favoured CO production. Different types of plastics; individual and mixed plastics from different waste treatment plants were also processed through the catalytic-dry reforming process to determine the syngas production and catalyst activity of Ni-Co/Al2O3 catalyst. This research has suggested that the use of carbon dioxide as the reforming agent in the dry reforming process of waste plastics was comparable to the current reforming technology with an optimum syngas production of 148.6 mmol g-1SWP.
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Morrison, Christine Evon. "PRODUCTION OF ETHANOL FROM THE FERMENTATION OF SYNTHESIS GAS." MSSTATE, 2004. http://sun.library.msstate.edu/ETD-db/theses/available/etd-07022004-175606/.
Full textAbstract:
Ethanol produced from lignocellulosic agricultural products and waste is an environmentally-friendly alternative to petroleum-derived fuel. Lignocellulosic biomass is gasified producing synthesis gas, which is composed of CO, CO2, and H2. Synthesis gas is fermented via anaerobic biocatalyst. The bacterium was grown in a fructose-rich medium then concentrated in ethanol production medium for synthesis gas fermentation. While the known ethanol-producing bacterium Clostridium ljungdahlii was used to provide baseline values for synthesis gas utilization and ethanol production, synthesis gas fermentation were conduced with a culture discovered at Mississippi State University. Additionally, efforts were made to isolate other anaerobic cultures capable of fermenting synthesis gas to ethanol.
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Saleh, Amer Mohamed. "Well test and production prediction of gas condensate reservoirs." Thesis, Heriot-Watt University, 1992. http://hdl.handle.net/10399/813.
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Wu, Cheng-Tar. "A non-syn-gas catalytic route to methanol production." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:55fc52d7-2026-4fc3-b671-7ead365d099a.
Full textAbstract:
At present, more than 80% of the world’s energy consumption and production of chemicals is originated from the use of fossil resources. There is a tremendous growing interest in utilising biomass molecules for energy provision due to their carbon neutrality. Lower alcohols such as methanol and ethanol if produced from biomass as transportation fuels as well as platform chemicals, can become strategically important for many energy/chemically starved countries. Currently, they are synthesised by indirect and inefficient processes. We show for the first time in this thesis study that ethylene glycol, the simplest representative of biomass-derived polyols, can be directly converted to these two lower alcohols by selective hydrogenolysis over modified Raney Ni and Cu catalysts in hydrogen atmosphere. This work provides essential information that may lead to the development of new catalysts for carbohydrate activation to methanol, a novel but important reaction concerning the important biomass conversion to transportable form of energy. Modification of electronic structure and the adsorption properties of Raney catalysts have therefore been achieved by blending with second metal(s). It is found that the activity and selectivity of this reaction can be significantly affected by this approach. In contrast, there is no subtle effect on methanol selectivity despite a great variation in the d-band centre positions of metal catalysts which show a distinctive effect on other products. Our result suggests that methanol is produced on specific surface sites independent from the other sites at an intrinsic rate and will not be converted to other products by the d-band alteration. On the other hand, it is reported in this thesis that a dramatic improvement in the combined selectivity to methanol/ethanol reaching 80% can be obtained over a Pd/Fe3O4 catalyst under relatively milder conditions (20 bar and 195 oC). This direct production of the non-enzymatic bio-alcohols is established over a carefully prepared co-precipitated Pd/Fe3O4 catalyst which gives a metallic phase of unexpectedly high dispersion ranging from small clusters to individual metal adatoms on defective iron oxide to give the required metal-support interaction for the novel synthesis. It is demonstrated that the small PdFe clusters on iron oxide surface provide the active species responsible for methanol production. In addition, a related Rh/Fe3O4 catalyst synthesised by co-precipitation is also shown to be selective for CO2 and H2 production from a direct methane-oxygen oxidation reaction. As a result, 2.7% conversion of methane with selectivity ratio of CO2/H2 = 4 in a mixed gas feed stream of CH2/O2 = 30 at 300 oC is obtained. The reaction is operated in a kinetically controlled regime at 300oC, where the CO formation from reverse water gas shift reaction is greatly suppressed. It is evident that the Rh/Fe3O4 acts as an interesting bifunctional catalyst for this reaction. This catalyst firstly gives a high dispersion of Rh which is expected to deliver a higher surface energy with enhanced activity. The Rh metal surface provides catalytically active sites for dissociation of methane to adsorbed hydrogen and carbon atoms effectively, and active oxygen on metal surface readily catalyses the carbon atoms to CO. Following these elementary reactions, the surface oxygen from Fe3O4 subsequently converts it to CO2 selectively at the metal-support interface. As a result, the novel study of catalytic biomass conversion and the discoveries of new catalysts are reported in this thesis.
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Gumus, Rhoda Habor. "Synthesis gas production from biogas using Ni-based catalyst." Thesis, Loughborough University, 2005. https://dspace.lboro.ac.uk/2134/33769.
Full textAbstract:
As a result of global climate changes brought about by human activity, more sustainable sources of energy are being sought as alternatives to fossil fuels. Biomass is of particular interest as a sustainable source of energy since it does not contribute to net CO2 emissions. Reforming of methane derived from biomass with CO2 may form the basis of an efficient means to produce synthesis gas which has many applications m the petrochemical and allied industries. The objective of this study was the investigation of CO2 reforming of methane (simulating biogas) over effective supported nickel catalysts capable of long term operation without significant loss of activity and stability.
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Holman, Travis Scott. "Analysis and optimization of coalbed methane gas well production." Thesis, Virginia Tech, 1996. http://hdl.handle.net/10919/44957.
Full textAbstract:
Coalbed methane wells have been used for many years as a viable means of
extracting quantities of methane gas for use as a clean and efficient energy source.
However, there is a limited understanding of many of the factors involved during the
extraction process. As the more easily attainable reservoirs are depleted, it is imperative
to gain a greater comprehension of these factors in order to develop techniques to
efficiently collect economical quantities of methane gas in the future.
For this investigation, an extensive database was compiled, consisting of a large set of parameters pertaining to the development of coalbed methane gas wells. Using the information contained in this database, a statistical analysis was performed in order to gain a better understanding of the relationships between the many factors involved in extracting quantities of methane gas from the ground. The results of this analysis showed that the majority of the parameters shown to have the greatest impact on methane production were heavily dependent upon the geology of the region. As a result, any attempt to exploit them for optimization exercises would be extremely difficult. Of the parameters shown to have the least dependence on naturally occurring phenomena, the amount of proppant sand used to hold fractures open within the well system after stimulation was shown to have the most impact
During the well stimulation procedure, the proppant sand is carried into the
fractures in the strata by a foam fracturing fluid. The sand acts to support the fracture
system, increasing the permeability of formation, and allowing the methane gas to flow to
the wellbore. By treating the sand particles with certain reagents, it is possible to render
them hydrophobic, making it possible for them to stick to the bubbles within the foam and
be carried deeper into the formation. Results of an investigation of sands treated to
different degrees of hydrophobicity have shown that such treatments significantly increase
the amount of sand distributed over a greater distance.
Master of Science
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Bock, Emily Maclauren. "Greenhouse Gas Production and Nutrient Reductions in Denitrifying Bioreactors." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/64278.
Full textAbstract:
The global nitrogen cycle has been disrupted by large anthropogenic inputs of reactive nitrogen to the environment. Excess nitrogen underlies environmental problems such as eutrophication, and can negatively affect human health. Managing the natural microbial process of denitrification is advocated as a promising avenue to reduce excess nitrogen, and denitrifying bioreactors (DNBRs) are an emerging technology harnessing this biochemical process. Previous DNBR research has established successful nitrate removal, whereas this study examines the potential to expand DNBR functionality to address excess phosphorus and mitigate the production of nitrous oxide, a potent greenhouse gas.
Results from a laboratory experiment supported the hypothesis that the addition of biochar, a charcoal-like soil amendment and novel organic carbon source in DNBR research, would increase nitrate and phosphorus removal as well as decrease the accumulation of nitrous oxide, an intermediate product of microbial denitrification.
In order more closely examine the ratio of the products nitrous oxide and inert dinitrogen, development of a novel analytical method to quantify dissolved gases in environmental water samples using gas chromatography mass spectrometry was undertaken. Although static headspace analysis is a common technique for quantifying dissolved volatiles, the variation in sample preparation has recently been revealed to affect the determination of dissolved concentrations of permanent gases and convolute comparison between studies. This work demonstrates the viability of internal calibration with gaseous standard addition to make dissolved gas analysis more robust to variable sample processing and to correct for matrix effects on gas partitioning that may occur in environmental samples.Master of Science
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Weber, Götz Mathias. "Hadronic gas models in particle production and phase transitions." Master's thesis, University of Cape Town, 1992. http://hdl.handle.net/11427/22004.
Full textAbstract:
In this work the methods of exact quantum number conservation in statistical mechanics are discussed and applied to the field of high energy nucleus-nucleus collisions. Various types of hadronic gas models are discussed as well as their merits and restrictions. Attempts to construct a phenomenological equation of state for nuclear matter are discussed in the context of the phase transition from hadronic matter to the quark-gluon plasma (QGP).
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Benavides, Rafael Esteban. "Gas Jet Process for Production of Sub-micron Fibers." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1365991608.
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Bock, Emily. "Greenhouse Gas Production and Nutrient Reductions in Denitrifying Bioreactors." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/64278.
Full textAbstract:
The global nitrogen cycle has been disrupted by large anthropogenic inputs of reactive nitrogen to the environment. Excess nitrogen underlies environmental problems such as eutrophication, and can negatively affect human health. Managing the natural microbial process of denitrification is advocated as a promising avenue to reduce excess nitrogen, and denitrifying bioreactors (DNBRs) are an emerging technology harnessing this biochemical process. Previous DNBR research has established successful nitrate removal, whereas this study examines the potential to expand DNBR functionality to address excess phosphorus and mitigate the production of nitrous oxide, a potent greenhouse gas.
Results from a laboratory experiment supported the hypothesis that the addition of biochar, a charcoal-like soil amendment and novel organic carbon source in DNBR research, would increase nitrate and phosphorus removal as well as decrease the accumulation of nitrous oxide, an intermediate product of microbial denitrification.
In order more closely examine the ratio of the products nitrous oxide and inert dinitrogen, development of a novel analytical method to quantify dissolved gases in environmental water samples using gas chromatography mass spectrometry was undertaken. Although static headspace analysis is a common technique for quantifying dissolved volatiles, the variation in sample preparation has recently been revealed to affect the determination of dissolved concentrations of permanent gases and convolute comparison between studies. This work demonstrates the viability of internal calibration with gaseous standard addition to make dissolved gas analysis more robust to variable sample processing and to correct for matrix effects on gas partitioning that may occur in environmental samples.Master of Science
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Richard, Udoh Richard. "SAND & FINES IN MULTIPHASE OIL AND GAS PRODUCTION." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-24075.
Full textAbstract:
This thesis work focuses on multiphase flow in the oil and gas industry. As differences in temperatures and pressures come to play from the reservoir to the surface, in tubing and in pipelines, gas tend to dissolve and evolve out from oil, with water and solid particles making their way into the production flow stream, giving rise to a multiphase gas-liquid-solid production and transportation. A review of sand and fines production worldwide was carried out and concluded that sand production is a common occurrence in the petroleum industry, present in all the major oil producing regions of the world. Multiphase flow patterns were equally discussed in this work stating the different flow regimes available in the vertical and horizontal pipe system. HYSYS was used to obtain fluid properties for volatile oil used in the determination of major parameters such as fluid velocities, hold-ups and pressure drop. Results did show that particle velocity to a large extent depended on the fluid velocity, which would always be higher with increasing amounts of gaseous phase present as experienced in annular and slug flow. The velocity profile chart showed the sand peak velocities in annular and slug flow as 13.2 m/s and 9.8 m/s. It was also observed that pressure drop along a pipe will under normal conditions tend give a positive slope when plotted against superficial fluid velocities.
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Kamalak, Adem. "Availability of starch and other nutrients from maize grains or silages." Thesis, University of Newcastle Upon Tyne, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312034.
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El-Usta, Shaaban. "High pressure combustion tube studies of medium and light oil." Thesis, University of Bath, 1998. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242524.
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