Download or read book Prediction of Gas hydrate Equilibrium Stability and Kinetic Nucleation in Porous Media written by Yali Zhang and published by . This book was released on 2020 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Natural gas-hydrates are crystalline inclusion compounds with gas molecules (guest compounds) trapped within a host lattice formed by water molecules in an ice-like hydrogen-bonded framework. Natural gas-hydrates have the potential to become an important carbon-based resource addressing the increasing energy demand, and they pose a risk in terms of climate change. Accurate estimates of gas-hydrates global inventory, understanding of formation and dissociation processes of gas-hydrates, and evaluation of their environmental impact require models that accurately describe gas-hydrate stability in sediments and predict gas-hydrate kinetic nucleation processes. The hypothesis driving this work is that incorporation of selected sediment properties, i.e., surface energies and pore diameter, can lead to more accurate predictions of hydrate equilibrium, stability and nucleation in porous media. In this work, a model for gas-hydrate equilibrium in porous media was developed from basic thermodynamic principles and tested against available experimental data published in the scientific literature. The proposed model predicts reported experimental data with high accuracy for the range of pore sizes (3.4 ~ 24.75 nm) of different materials reported in the literature. It was found that the wettability of the pore surface affects the shape of the hydrate phase inside the pore and consequently influences the equilibrium pressures of gas-hydrates formed in porous media. A predictive macroscopic mathematical model describing the kinetic nucleation of gas-hydrates was developed based on Classical Nucleation Theory (CNT) in order to formulate correction factors for three types of interfaces mostly encountered in natural sediments (gas-liquid interface, liquid-solid interface and three-phase boundary lines). This approach, which incorporates the interfacial properties of sediments, can efficiently provide a fundamental understanding on the dependence of the formation mechanism of gas hydrates on a wide range of interfacial properties (wettability, substrate size, interfacial tension). The model predicts that hydrate nucleation is energetically favorable on confined surfaces with smaller contact-angle values, i.e., hydrophilic surfaces. Comparison between different types of interfaces leads to the conclusion that the nucleation of gas hydrates preferentially occurs in larger sediment pores. At the beginning of methane hydrate formation, for example, hydrate will preferentially nucleate at the gas-liquid interface. With the increase of hydrate volume or growth of the hydrate phase, the center of crystal growth moves towards the liquid-solid interface. In natural systems, gas hydrates form first on the concave liquid/solid interface and gas/liquid interface in sandstone sediments, gas/liquid interface and gas/liquid/solid triple boundary line in clay sediments and gas/liquid interface in pipeline with oil droplets. The inclusion of sediment properties in the model for gas-hydrate equilibrium in sediments predict experimental data within a margin of %AAD lower than 2%, a significant improvement upon previous modeling attempts. Additionally, the inclusion of sediment properties in the models for kinetic nucleation of gas hydrates result in mathematical models that capture the qualitative information obtained from examination of gas-hydrate core samples. Therefore, the hypothesis of the present work was proven."--Abstract.
Download or read book Comparison of Kinetic and Equilibrium Reaction Models InSimulating the Behavior of Gas Hydrates in Porous Media written by George J. Moridis and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study we compare the use of kinetic and equilibrium reaction models in the simulation of gas (methane) hydrates in porous media. Our objective is to evaluate through numerical simulation the importance of employing kinetic versus equilibrium reaction models for predicting the response of hydrate-bearing systems to external stimuli, such as changes in pressure and temperature. Specifically, we (1) analyze and compare the responses simulated using both reaction models for production in various geological settings and for the case of depressurization in a core during extraction; and (2) examine the sensitivity to factors such as initial hydrate saturation, hydrate reaction surface area, and numerical discretization. We find that for systems undergoing thermal stimulation and depressurization, the calculated responses for both reaction models are remarkably similar, though some differences are observed at early times. Given these observations, and since the computational demands for the kinetic reaction model far exceed those for the equilibrium reaction model, the use of the equilibrium reaction model often appears to be justified and preferred for simulating the behavior of gas hydrates.
Download or read book Solid Deposition in Hydrocarbon Systems written by G. D. Holder and published by . This book was released on 1994 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Few experimental data are available for gas hydrate equilibrium conditions in the presence of mixed electrolytes and/or methanol. In the first three years of this four-year project, experimental hydrate equilibrium data on propane and two mixtures of methane and carbon dioxide in several solutions containing electrolytes and methanol were obtained in our laboratory. In addition, a discrepancy in the literature on the experimental data for propane hydrates in 10 mass percent NaCl solution was resolved by (i) obtaining fresh data in our laboratory using two different experimental methods and by (ii) comparing the experimental data with predictions using a thermodynamically rigorous method. The existing methods for predicting hydrate equilibrium conditions are not suitable for systems containing mixed electrolytes and mixed solvents. Ten thermodynamic models to compute component activities in such solutions were surveyed. The activities are needed for hydrate equilibrium computations. Of these, two models were integrated with a hydrate equilibrium prediction method. One model was found to be satisfactory for engineering calculations. Besides thermodynamics, a good understanding of the kinetics of hydrate formation and decomposition is also essential. Experimental kinetic data on hydrate nucleation were successfully modelled. A unified approach for describing the kinetics of hydrate nucleation, growth and decomposition was presented.
Download or read book Nucleation of Gas Hydrates written by Nobuo Maeda and published by Springer Nature. This book was released on 2020-08-15 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces readers to experimental techniques of general utility that can be used to practically and reliably determine nucleation rates. It also covers the basics of gas hydrates, phase equilibria, nucleation theory, crystal growth, and interfacial gaseous states. Given its scope, the book will be of interest to graduate students and researchers in the field of hydrate nucleation. The formation of gas hydrates is a first-order phase transition that begins with nucleation. Understanding nucleation is of interest to many working in the chemical and petroleum industry, since nucleation, while beneficial in many chemical processes, is also a concern in terms of flow assurance for oil and natural gas pipelines. A primary difficulty in the investigation of gas hydrate nucleation has been researchers’ inability to determine and compare the nucleation rates of gas hydrates across systems with different scales and levels of complexity, which in turn has limited their ability to study the nucleation process itself. This book introduces readers to experimental techniques that can be used to practically and reliably determine the nucleation rates of gas hydrate systems. It also covers the basics of gas hydrates, phase equilibria, nucleation theory, crystal growth, and interfacial gaseous states. Given its scope, the book will be of interest to graduate students and researchers in the field of hydrate nucleation.
Download or read book Encyclopedia of Chemical Processing written by Sunggyu Lee and published by Taylor & Francis US. This book was released on 2006 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collecting information of vital interest to chemical, polymer, mechanical, electrical, and civil engineers, as well as chemists and chemical researchers, this "Encyclopedia "supplies nearly 350 articles on current design, engineering, science, and manufacturing practices-offering expertly written articles on technologies at the forefront of the field to maximize and enhance the research and production phases of current and emerging chemical manufacturing practices and techniques.
Download or read book Advances in Natural Gas Formation Processing and Applications Volume 3 Natural Gas Hydrates written by Mohammad Reza Rahimpour and published by Elsevier. This book was released on 2024-02-16 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Natural Gas: Formation, Processing, and Applications. Volume 3: Natural Gas Hydrates comprises an extensive eight-volume series delving into the intricate realms of both the theoretical fundamentals and practical methodologies associated with the various facets of natural gas. Encompassing the entire spectrum from exploration and extraction to synthesis, processing, purification, and the generation of valuable chemicals and energy, these volumes also navigate through the complexities of transportation, storage challenges, hydrate formation, extraction, and prevention. In Volume 3 titled Natural Gas Hydrates, the fundamental aspects of natural gas hydrates, their associated disasters, and case studies are introduced. This book delves into the intricate details of hydrate structures, physio-chemical properties, and thermodynamics, offering a comprehensive understanding. This volume also explores hydrates as an energy source and covers their dissociation methods. A significant focus is placed on the challenges of natural gas hydrates formation in pipelines, accompanied by prevention techniques. Additionally, this book discusses the discovery and extraction of natural gas hydrates from oceans, shedding light on related geophysical indicators. Introduces characteristics and properties of natural gas hydrates Describes pipeline natural gas hydrates and prevention methods Discusses oceanic natural gas hydrates and extraction methods
Download or read book Gas Hydrates written by Carlo Giavarini and published by Springer Science & Business Media. This book was released on 2011-09-06 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas hydrates are both a huge energy resource and an environmental challenge. They have a significant impact on society because of their applications to the future of energy, protection of the environment and fuel transportation. Gas Hydrates opens up this fascinating, multidisciplinary field to non-specialists. It provides a scientific study of gas hydrates that considers their potential as an energy source while assessing the possible risk to the environment. The authors also examine the feasibility of using these natural compounds for storing and transporting gases such as methane and carbon dioxide. Diagrams and photos are used throughout Gas Hydrates to help readers understand the scientific and technical content. Each section has been designed so it can be read independently by academics and professionals in the oil and gas industry, as well as by all those with an interest in how hydrates combine to be an energy resource, an industrial challange and a geological hazard.
Download or read book Gas Hydrates 1 written by Daniel Broseta and published by John Wiley & Sons. This book was released on 2017-08-07 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas hydrates, or clathrate hydrates, are crystalline solids resembling ice, in which small (guest) molecules, typically gases, are trapped inside cavities formed by hydrogen-bonded water (host) molecules. They form and remain stable under low temperatures – often well below ambient conditions – and high pressures ranging from a few bar to hundreds of bar, depending on the guest molecule. Their presence is ubiquitous on Earth, in deep-marine sediments and in permafrost regions, as well as in outer space, on planets or comets. In addition to water, they can be synthesized with organic species as host molecules, resulting in milder stability conditions: these are referred to as semi-clathrate hydrates. Clathrate and semi-clathrate hydrates are being considered for applications as diverse as gas storage and separation, cold storage and transport and water treatment. This book is the first of two edited volumes, with chapters on the experimental and modeling tools used for characterizing and predicting the unique molecular, thermodynamic and kinetic properties of gas hydrates (Volume 1) and on gas hydrates in their natural environment and for potential industrial applications (Volume 2).
Download or read book Prediction of Gas Hydrate Equilibrium written by Babak Amir-Sardary and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Hydrates 2 written by Livio Ruffine and published by John Wiley & Sons. This book was released on 2018-04-16 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas hydrates in their natural environment and for potential industrial applications (Volume 2).
Download or read book Clathrate Hydrates of Natural Gases written by E. Dendy Sloan Jr. and published by CRC Press. This book was released on 2007-09-07 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrate research has expanded substantially over the past decade, resulting in more than 4,000 hydrate-related publications. Collating this vast amount of information into one source, Clathrate Hydrates of Natural Gases, Third Edition presents a thoroughly updated, authoritative, and comprehensive description of all major aspects of natural gas cla
Download or read book Hydrates of Natural Gas written by I︠U︡riĭ Fedorovich Makogon and published by . This book was released on 1981 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Natural Gas Hydrate written by M.D. Max and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 665 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1. THE BEGINNINGS OF HYDRATE RESEARCH Until very recently, our understanding of hydrate in the natural environment and its impact on seafloor stability, its importance as a sequester of methane, and its potential as an important mechanism in the Earth's climate change system, was masked by our lack of appreciation of the vastness of the hydrate resource. Only a few publications on naturally occurring hydrate existed prior to 1975. The first published reference to oceanic gas hydrate (Bryan and Markl, 1966) and the first publication in the scientific literature (Stoll, et a1., 1971) show how recently it has been since the topic of naturally occurring hydrate has been raised. Recently, however, the number of hydrate publications has increased substantially, reflecting increased research into hydrate topics and the initiation of funding to support the researchers. Awareness of the existence of naturally occurring gas hydrate now has spread beyond the few scientific enthusiasts who pursued knowledge about the elusive hydrate because of simple interest and lurking suspicions that hydrate would prove to be an important topic. The first national conference on gas hydrate in the U.S. was held as recently as April, 1991 at the U.S. National Center of the U.s. Geological Survey in Reston Virginia (Max et al., 1991). The meeting was co-hosted by the U.s. Geological Survey, the Naval Research Laboratory, and the U.S.
Download or read book Improved Predictions of Gas Hydrate Phase Equilibria written by Vijay T. John and published by . This book was released on 1982 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flow Assurance Solids in Oil and Gas Production written by Jon Steinar Gudmundsson and published by CRC Press. This book was released on 2017-09-13 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt: The precipitation and deposition of solids are a major challenge in the production of oil and gas. Flow assurance solids are formed because of unavoidable changes in temperature, pressure and composition of the oil-gas-water flowstream, from reservoir conditions to processing conditions. The advent of subsea production and the increased exploitation of heavy crudes have made flow assurance issues dominant in ensuring efficient and safe exploitation of hydrocarbon assets. Five troublesome flow assurance solids are described in the book: asphaltene, paraffin wax, natural gas hydrate, naphthenate and inorganic scale. These big-five solids are presented in stand-alone chapters. Each chapter is designed to be readable without clutter. Derivations of equations and descriptions of supporting details are given in several appendices. The book is intended for professional engineers and natural scientist working in E&P companies, engineering companies, service companies and specialized companies. An understanding of the big-five solids is required throughout the lifetime of oil and gas assets, from early development to abandonment. The technical, safety and environmental risks associated with deposition problems in near-wellbore formations, production tubing, wellhead equipment, flowlines and processing facilities, are relevant for decisions in the oil and gas industry and in outside regulatory and financial entities.
Download or read book Hydrates of Hydrocarbons written by I͡Uriĭ Fedorovich Makogon and published by Pennwell Books. This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrates of Hydrocarbons is the first book to address methods of hydrate removal and, most importantly, prevention of hydrate build-up. The book provides solutions formulated for drilling, pipeline, and chemical engineers in both the onshore and offshore environments, as well as educators in advanced petroleum and chemical engineering courses. It also offers timely information on the use of hydrate properties in new technologies and the production of gas from natural gas hydrate deposits.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2000 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
