Modelling of Effects of Porosity on Methane Hydrates Dissociation via Thermal Stimulation Method

Methane hydrate has a high potential to be an alternative energy resource of the future as it exists in enormous quantities in permafrost regions worldwide. There were various models have been developed to simulate the production of methane gas from the methane hydrates by using different kind of extraction methods. In this study, the Clarke-Kim-Bishnoi model has been selected as it is much more simplified compared to other models and its flexibility to study the formation as well as decomposition of the methane hydrate. The model is used to simulate the effect of changing porosity, different constant pressure at various temperature to the methane hydrate dissociation rate. The temperature is varied as to represent the thermal stimulation method process. The graph of temperature vs. dissociation rate is used to analyze the results. The result shows that as the temperature increases, the dissociation rate will also increases until the methane hydrate completely dissociated. Besides that, higher porosity will results in slightly faster dissociation rate. It has also been found that the dissociation rate for methane hydrate is higher than ethane hydrate. This study has a high potential to be extended for detailed research as it would provide more information on the modelling of gas production from hydrates in porous media

Gas Hydrates Investigation: Flow Assurance for Gas Production and Effects on Hydrate-bearing Sediments

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

Modelling of Effects of Porosity on Methane Hydrates Dissociation via Thermal Stimulation Method

Methane hydrate has a high potential to be an alternative energy resource of the future as it exists in enormous quantities in permafrost regions worldwide. There were various models have been developed to simulate the production of methane gas from the methane hydrates by using different kind of extraction methods. In this study, the Clarke-Kim-Bishnoi model has been selected as it is much more simplified compared to other models and its flexibility to study the formation as well as decomposition of the methane hydrate. The model is used to simulate the effect of changing porosity, different constant pressure at various temperature to the methane hydrate dissociation rate. The temperature is varied as to represent the thermal stimulation method process. The graph of temperature vs. dissociation rate is used to analyze the results. The result shows that as the temperature increases, the dissociation rate will also increases until the methane hydrate completely dissociated. Besides that, higher porosity will results in slightly faster dissociation rate. It has also been found that the dissociation rate for methane hydrate is higher than ethane hydrate. This study has a high potential to be extended for detailed research as it would provide more information on the modelling of gas production from hydrates in porous media

Solvents, Ionic Liquids and Solvent Effects

Solvents and ionic liquids are ubiquitous within our whole life since ancient times and their effects are actually being studied through basic sciences like Chemistry, Physics and Biology as well as being researched by a large number of scientific disciplines.This book represents an attempt to present examples on the utility of old and new solvents and the effects they exercise on several fields of academic and industrial interest. The first section, Solvents, presents information on bio-solvents and their synthesis, industrial production and applications, about per and trichloroethylene air monitoring in dry cleaners in the city of Sfax (Tunsia) and on the synthesis of polyimides using molten benzoic acid as the solvent. The second section, Ionic Liquids, shows information about the synthesis, physicochemical characterization and exploration of antimicrobial activities of imidazolium ionic liquid-supported Schiff base and its transition metal complexes, the technology of heterogenization of transition metal catalysts towards the synthetic applications in an ionic liquid matrix, the progress in ionic liquids as reaction media, monomers, and additives in high-performance polymers, a pre-screening of ionic liquids as gas hydrate inhibitor via application of COSMO-RS for methane hydrate, the extraction of aromatic compounds from their mixtures with alkanes from ternary to quaternary (or higher) systems and a review on ionic liquids as environmental benign solvent for cellulose chemistry. The final section, Solvent Effects, displays interesting information on solvent effects on dye sensitizers derived from anthocyanidins for applications in photocatalysis, about the solvent effect on a model of SNAr reaction in conventional and non-conventional solvents, and on solvent effects in supramolecular systems

Phase equilibria modelling of petroleum reservoir fluids containing water, hydrate inhibitors and electrolyte solutions

Formation of gas hydrates can lead to serious operational, economic and safety problems in the petroleum industry due to potential blockage of oil and gas equipment. Thermodynamic inhibitors are widely used to reduce the risks associated with gas hydrate formation. Thus, accurate knowledge of hydrate phase equilibrium in the presence of inhibitors is crucial to avoid gas hydrate formation problems and to design/optimize production, transportation and processing facilities. The work presented in this thesis is the result of a study on the phase equilibria of petroleum reservoir fluids containing aqueous salt(s) and/or hydrate inhibitor(s) solutions. The incipient equilibrium methane and natural gas hydrate conditions in presence of salt(s) and/or thermodynamic inhibitor(s) have been experimentally obtained, in addition to experimental freezing point depression data for aqueous solution of methanol, ethanol, monoethylene glycol and single or mixed salt(s) aqueous solutions, are conducted. A statistical thermodynamic approach, with the Cubic-Plus-Association equation of state, has been employed to model the phase equilibria. The hydrate-forming conditions are modelled by the solid solution theory of van der Waals and Platteeuw. Predictions of the developed model have been validated against independent experimental data from the open literature and the data generated in this work. The predictions were found to agree well with the experimental data.Joint Industrial Project (JIP) Gran

Tracing back the source of contamination

From the time a contaminant is detected in an observation well, the question of where and when the contaminant was introduced in the aquifer needs an answer. Many techniques have been proposed to answer this question, but virtually all of them assume that the aquifer and its dynamics are perfectly known. This work discusses a new approach for the simultaneous identification of the contaminant source location and the spatial variability of hydraulic conductivity in an aquifer which has been validated on synthetic and laboratory experiments and which is in the process of being validated on a real aquifer

Design and Synthesis of Low Molecular Weight and Polymeric Surfactants for Enhanced Oil Recovery

Surfactants are defined as molecules able to lower the surface (or interfacial)tension at the gas/liquid, liquid/liquid, and liquid/solid interfaces. Due totheir properties, they are typically employed as detergents, emulsifiers, dispersants,wetting and foaming agents. In chemical enhanced oil recovery (cEOR), surfactantsare used as flooding agents, alone or in combination with polymers, alkali, and morerecently nanoparticles, to increase the microscopic displacement efficiency. Froma chemical point of view, surfactants are amphiphiles, meaning that they bear intheir structure both hydrophilic and hydrophobic moieties. Some naturally occurringsurfactants exists, but the majority are synthetic. The availability of syntheticsurfactants, allows a big variety of structures and properties. In this chapter, the mainclasses of surfactants will be reviewed, with focus on those used or proposed foruse for chemical enhanced oil recovery. After a general introduction about surfactantsand their main structural and physico-chemical properties, specific aspects ofdesign and synthesis will be discussed. Particular emphasis will be given to the mostrecent developments, which includes zwitterionic, gemini and polymeric surfactants.Own work of the author of this chapter in the field of polymeric surfactants will behighlighted

Prospects of Using Gas Hydrates in Power Plants

By adding water to fuels, several objectives are pursued, with the main ones being to stabilize combustion, minimize the anthropogenic gaseous emissions, homogenize and stabilize the fuel, as well as improve its fire and explosion safety. Water can be injected into the furnace as droplets or vapor and introduced as part of fuel samples. Water often serves as a coupling or carrier medium for the delivery of the main fuel components. In this paper, we compare the combustion behaviors of high-potential slurry fuels and gas hydrates. We also analyze the contribution of in slurries and gas hydrates to the combustion process. The values of relative combustion efficiency indicators are determined for gas hydrates and slurry fuels. The conditions are identified in which these fuels can be burned effectively in power plants. The research findings can be used to rationalize the alternative ways of using water resources, i.e., gas hydrate powder and promising composite fuel droplets. The results can also help predict the conditions for the shortest possible ignition delay, as well as effective combustion of gas hydrates as the most environmentally friendly new-generation alternative fue

Advanced Coupled THM Analysis in Geomechanics

This dissertation is aimed at advancing current understating and modeling of problems involving the complex soils systems. A wide range of problems are tackled here including those in: frozen soils; gas hydrate bearing sediments and compressed air energy systems. The soils considered here are affected by changes in temperature fluid pressures and mechanical stresses which would also result in phase change of the constituents in the pore structure. The research conducted here encompasses fundamental; experimental; constitutive and numerical modeling employing the use of coupled formulations. The environmental variables affecting the soil in each case are identified, new or enhanced theoretical formulations and constitutive laws are presented. Particular emphasis is placed on the mechanical constitutive equations, as they are especially important in geotechnical engineering. The formulations presented here are validated against a number of laboratory experiments and case histories that illustrate the relevance and implications of the developments described for geotechnical engineering practice

Gas hydrates in sustainable chemistry

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Hassanpouryouzband, A., Joonaki, E., Farahani, M. V., Takeya, S., Ruppel, C., Yang, J., English, N. J., Schicks, J. M., Edlmann, K., Mehrabian, H., Aman, Z. M., & Tohidi, B. Gas hydrates in sustainable chemistry. Chemical Society Reviews, 49(15), (2020): 5225-5309, doi:10.1039/c8cs00989a.Gas hydrates have received considerable attention due to their important role in flow assurance for the oil and gas industry, their extensive natural occurrence on Earth and extraterrestrial planets, and their significant applications in sustainable technologies including but not limited to gas and energy storage, gas separation, and water desalination. Given not only their inherent structural flexibility depending on the type of guest gas molecules and formation conditions, but also the synthetic effects of a wide range of chemical additives on their properties, these variabilities could be exploited to optimise the role of gas hydrates. This includes increasing their industrial applications, understanding and utilising their role in Nature, identifying potential methods for safely extracting natural gases stored in naturally occurring hydrates within the Earth, and for developing green technologies. This review summarizes the different properties of gas hydrates as well as their formation and dissociation kinetics and then reviews the fast-growing literature reporting their role and applications in the aforementioned fields, mainly concentrating on advances during the last decade. Challenges, limitations, and future perspectives of each field are briefly discussed. The overall objective of this review is to provide readers with an extensive overview of gas hydrates that we hope will stimulate further work on this riveting field.A. H. and K. E. were partially supported by funding from UKRI-EPSRC (grant number EP/S027815/1). C. R. was partially supported by DOE-USGS Interagency agreement DE-FE0023495. C. R. thanks L. Stern and W. Waite for insights that improved her contributions. E. J. is partially supported by Flow Programme project sponsored by Department for Business, Energy and Industrial Strategy (BEIS), UK. Any use of trade, firm or product name is for descriptive purposes only and does not imply endorsement by the U.S. Government