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.

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.

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).

Gas hydrates in their natural environment and for potential industrial applications (Volume 2).

The first comprehensive presentation of methods and algorithms used in basin modeling, this text provides geoscientists and geophysicists with an in-depth view of the underlying theory and includes advanced topics such as probabilistic risk assessment methods.

Natural gas hydrate, a solid form of natural gas and water, occurs in nature in association with deep permafrost and in offshore environments adjacent to continental margins. This report presents results of a gas hydrate research well project located at the north-eastern edge of the Mackenzie Delta. The project brought together researchers from North America and Japan to undertake the first investigation of a natural gas hydrate occurrence beneath permafrost that included extensive dedicated coring and associated engineering and scientific studies. The report compiles papers from the project in the following categories: an overview of the project, including drilling operations; a regional overview of gas hydrate occurrences, permafrost conditions, and geology in the project area; geology and biostratigraphy of the drilled cores; physical properties and geochemistry of the cores; characteristics of the gas hydrate, including chemical and physical analyses; downhole geophysics; and regional gas hydrate occurrences, production, and climate change considerations. Includes author index.