There is much interest in gas hydrates in relation to their potential role as an important driver for climate change and as a major new energy source; however, many questions remain, not least the size of the global hydrate budget. Much of the current uncertainty centres on how hydrates are physically stored in sediments at a range of scales. This volume details advances in our understanding of sediment-hosted hydrates, and contains papers covering a range of studies of real and artificial sediments containing both methane hydrates and CO2 hydrates. The papers include an examination of the techniques used to locate, sample and characterize hydrates from natural, methane-rich systems, so as to understand them better. Other contributions consider the nature and stability of synthetic hydrates formed in the laboratory, which in turn improve our ability to make accurate predictive models.
The occurrence of gas hydrates in large quantities worldwide, and their immense energy potential have prompted concerted efforts into their exploration and understanding over the last many years. During this time, geophysical characterization of natural gas hydrate occurrences by seismic and other methods have gained prominence, and such studies have been reported from time to time. However, no compilation of such studies was ever attempted. This SEG publication, Geophysical Characterization of Gas Hydrates (Geophysical Developments No. 14), is the first book on the topic that focuses on documenting various types of geophysical studies that are carried out for the detection and mapping of gas hydrates.
This world atlas presents a comprehensive overview of the gas-hydrate systems of our planet with contributions from esteemed international researchers from academia, governmental institutions and hydrocarbon industries. The book illustrates, describes and discusses gas hydrate systems, their geophysical evidence and their future prospects for climate change and continental margin geohazards from passive to active margins. This includes passive volcanic to non-volcanic margins including glaciated and non-glaciated margins from high to low latitudes. Shallow submarine gas hydrates allow a glimpse into the past from the Last Glacial Maximum (LGM) to modern environmental conditions to predict potential changes in future stability conditions while deep submarine gas hydrates remained more stable. This demonstrates their potential for rapid reactions for some gas hydrate provinces to a warming world, as well as helping to identify future prospects for environmental research. Three-dimensional and high-resolution seismic imaging technologies provide new insights into fluid flow systems in continental margins, enabling the identification of gas and gas escape routes to the seabed within gas hydrate environments, where seabed habitats may flourish. The volume contains a method section detailing the seismic imaging and logging while drilling techniques used to characterize gas hydrates and related dynamic processes in the sub seabed. This book is unique, as it goes well beyond the geophysical monograph series of natural gas hydrates and textbooks on marine geophysics. It also emphasizes the potential for gas hydrate research across a variety of disciplines. Observations of bottom simulating reflectors (BSRs) in 2D and 3D seismic reflection data combined with velocity analysis, electromagnetic investigations and gas-hydrate stability zone (GHSZ) modelling, provide the necessary insights for academic interests and hydrocarbon industries to understand the potential extent and volume of gas hydrates in a wide range of tectonic settings of continental margins. Gas hydrates control the largest and most dynamic reservoir of global carbon. Especially 4D, 3D seismic but also 2D seismic data provide compelling sub-seabed images of their dynamical behavior. Sub-seabed imaging techniques increase our understanding of the controlling mechanisms for the distribution and migration of gas before it enters the gas-hydrate stability zone. As methane hydrate stability depends mainly on pressure, temperature, gas composition and pore water chemistry, gas hydrates are usually found in ocean margin settings where water depth is more than 300 m and gas migrates upward from deeper geological formations. This highly dynamic environment may precondition the stability of continental slopes as evidenced by geohazards and gas expelled from the sea floor. This book provides new insights into variations in the character and existence of gas hydrates and BSRs in various geological environments, as well as their dynamics. The potentially dynamic behavior of this natural carbon system in a warming world, its current and future impacts on a variety of Earth environments can now be adequately evaluated by using the information provided in the world atlas. This book is relevant for students, researchers, governmental agencies and oil and gas professionals. Some familiarity with seismic data and some basic understanding of geology and tectonics are recommended.
Gas hydrates are ice-like crystalline substances that form a rigid cage of water molecules and entrap hydrocarbon and non-hydrocarbon gas by hydrogen bonding. Natural gas hydrate is primarily composed of water and methane. These are solid, crystalline, ice-like substances found in permafrost areas and deepwater basins around the world. They naturally occur in the pore space of marine sediments, where appropriate high pressure and low temperature conditions exist in an adequate supply of gas (mainly methane). Gas hydrates are considered as a potential non conventional energy resource. Methane hydrates are also recognized as, an influence on offshore platform stability, a major factor in climate change contributing to global warming and a significant contribution to the ocean carbon cycle. The proposed book treats various geophysical techniques in order to quantify the gas hydrate reserves and their impact on environment. The primary goal of this book is to provide the state of art for gas hydrate exploration. The target audiences for this book are non-specialist from different branches of science, graduate students and researchers.
Gas hydrates collect and store both thermogenic and biogenic methane generated in deep ocean sediments that, over geologic time, forms vast methane repositories. Offshore Gas Hydrates: Origins, Development, and Production presents gas hydrates as an emerging, clean energy source possibly more abundant than all other fossil fuels and especially important for countries geographically and economically restricted from conventional fossil fuel resources. The book explores feasible methods to produce offshore hydrate gas, the means to store and transport the remotely produced gas, new hydrate inhibitors for conventional and hydrate production in ultra-deep waters, instability manifestations of seafloor hydrates, and hydrate roles in complex ecological scenarios. Complementing production and drilling method presentations are computer simulation studies, hydrate field tests, and seismic and logging developments. Offshore Gas Hydrates delivers a well-developed framework for both the oil and gas researcher and corporate engineer to better exploit this future unconventional resource, empowering the oil and gas professional with the latest data and information on sophisticated challenges that offshore hydrates present. - Addresses the technical, economic, and environmental problems of producing hydrate gas. - Introduces the overlooked and unchartered role of microbes in catalyzing offshore hydrate formations with attendant effects on stability/dissociation. - Reviews the latest world-wide field tests, research, and case studies involving seafloor hydrates, inclusive of most known hydrate provinces. - Displays two videos within the e-book only: (1) hydrates, carbonates, chemosynthetic communities, and natural hydrocarbon leakages on the seafloor at the Mississippi Canyon hydrate observatory site; (2) hydrate nucleation, migration and self-packing in a laboratory test cell under the influence of anionic surfactants. - Extends deep-water hydrate knowledge regarding the hydrate formation and protective cover for microbes within the extreme environment of Mars.
Gas hydrates represent one of the world’s largest untapped reservoirs of energy and, according to some estimates, have the potential to meet global energy needs for the next thousand years. "Methane Gas Hydrate" examines this potential by focusing on methane gas hydrate, which is increasingly considered a significant source of energy. "Methane Gas Hydrate" gives a general overview of natural gas, before delving into the subject of gas hydrates in more detail and methane gas hydrate in particular. As well as discussing methods of gas production, it also discusses the safety and environmental concerns associated with the presence of natural gas hydrates, ranging from their possible impact on the safety of conventional drilling operations to their influence on Earth’s climate. "Methane Gas Hydrate" is a useful reference on an increasingly popular energy source. It contains valuable information for chemical engineers and researchers, as well as for postgraduate students.
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.
This book is a companion to “Natural Gas Hydrate in Oceanic and Permafrost Environments” (Max, 2000, 2003), which is the first book on gas hydrate in this series. Although other gases can naturally form clathrate hydrates (referred to after as ‘hydrate’), we are concerned here only with hydrocarbon gases that form hydrates. The most important of these natural gases is methane. Whereas the first book is a general introduction to the subject of natural gas hydrate, this book focuses on the geology and geochemical controls of gas hydrate development and on gas extraction from naturally occurring hydrocarbon hydrates. This is the first broad treatment of gas hydrate as a natural resource within an economic geological framework. This book is written mainly to stand alone for brevity and to minimize duplication. Information in Max (2000; 2003) should also be consulted for completeness. Hydrate is a type of clathrate (Sloan, 1998) that is formed from a cage structure of water molecules in which gas molecules occupying void sites within the cages stabilize the structure through van der Waals or hydrogen bonding.
Recent discoveries from ice-core and marine sediments suggest that global climate systems can change from glacial to near-interglacial temperatures within decades. In order to explain this phenomenon, the authors (all affiliated with the Department of Geological Sciences, U. of California) advance a hypothesis that suggests that the massive energy needed for these changes came for the release of "frozen" methane hydrates (clathrates) stored in marine sediments on continental margins. They argue that the release of the methane caused feedback processes that would explain the surprisingly rapid changes. Annotation copyrighted by Book News, Inc., Portland, OR.
