Exploration of Gas Hydrates – Geophysical Techniques – Abstract Energy is the integral part for the sustenance of human beings. The resources that are being used for generation of energy have to be efficient in terms of economics and emitting least pollutants. Energy derived from fossil fuels resources (fossil fuel energy) is primarily utilized for generation of electricity, industrial production and other day-to-day necessities of the life. Petroleum i.e. oil, natural gas (primarily methane) and coal are the main constituents of the fossil fuel. Energy derived from geothermal resources contributes to about 0.3% with electricity generating capacity of global energy consumption. Primary geothermal provinces are located in tectonic regions are confined to rims of the Pacific Ocean; the region characterized by most active earthquakes and volcanoes and is popularly called the Ring of Fire. Another important energy resource that is extensively promoted is the use of nuclear energy.
Publication Date: October 11, 2010 | ISBN-10: 3642142338 | ISBN-13: 978-3642142338 | Edition: 1st Edition.
Naresh Kumar Thakur (Author), Sanjeev Rajput (Author)
The energy produced by the fission process is about millions of times the energy produced by the combustion of an atom of carbon from coal. Different forms of energy associated with natural resources such as sun (solar energy) and oceans. They are quite extensive and inexhaustible and considered as renewable form of energy. The kinetic energy associated with wind, tides, oceanic waves can be utilized to generate electricity. The potential and kinetic energy associated with hydrothermal means and being utilized for generation of electricity works out to be most cost effective and least pollutant. This chapter provides an overview of different forms of energy and their impact on human life.
Exploration of Gas Hydrates – Geophysical Techniques
Ever since time immemorial energy has become the integral part for the survival human beings. The mankind has been constantly putting endeavors to optimize and utilize natural resources as source of energy to meet the growing need of the energy and welfare of society. The availability of different forms resources in a region governs their utilization as energy.
Exploration of Gas Hydrates – Geophysical Techniques -introduction part 1
“Exploration of Gas Hydrates: Geophysical Techniques” adds an important dimension to the story of Natural Gas Hydrates from an energy perspective. Natural Gas Hydrates present an enormous opportunity and also a series of challenges if they are to be exploited on a large scale to bring vast quantities of a relatively clean fuel to market. Among these challenges, characterization and especially quantification of the methane hydrate resource present on our continental margins is of primary concern at this point in time. Geophysics is the best tool we have to meet this challenge. Seismic reflection methods have been used for several decades as the primary means to detect of gas hydrates in continental margins. However, while the detection of gas hydrates in marine sediments is relatively straightforward from analysis of the anomalous amplitude and phase of reflectors, the accurate determination of gas hydrate quantities in subsurface space is an altogether more difficult task. As a pre-requisite, seismic acquisition parameters must be specified that adequately illuminate and sample the subsurface in a highly repeatable way, and with sufficient spatial resolution and dynamic range for the task. This requires “industry standard” seismic acquisition equipment and protocols rather than the more common standards used for academic research.
Exploration of Gas Hydrates – Geophysical Techniques – introduction part 2
Even then, quantification of gas hydrate and free gas volumes is only possible by taking a highly systematic approach to seismic data processing and analysis that incorporates forward modelling, inversion and calibration steps. The data analysis must be conducted within the proper geological context, which informs realistic and sufficiently flexible rock physics models of the sediment-fluid-hydrate-gas system. While seismic methods remain at the cornerstone of geophysical assessment of hydrate resources, the increasing role and value of marine controlled source electromagnetic methods is also well demonstrated. Resistivity responses to hydrate and gas volumes are generally more linear than the seismic responses, and taken together, electromagnetics plus seismics provide an excellent framework for reducing uncertainties in rock property assignments and therefore volumetric calculations of hydrates and gas in place. Downhole logging, direct sampling and geochemical analysis then provide the final ground-truth needed to validate and calibrate the rock physics models used in the three-dimensional Earth volume. This book outlines such an approach to quantitative geophysical data analysis, with special reference to India’s National Gas Hydrates research programme. While making excellent use of the experience of this concerted effort in marine geophysical, geological investigations on the continental margins of the Indian Subcontinent, the authors have also drawn upon type examples from many other localities worldwide where hydrates have been studied in detail. This compilation of real data examples, with good quality figures and explanations is an especially valuable resource for scientists interested in natural gas hydrate occurrences and their geophysical expression. Doctors Thakur and Rajput have put in one place an up-to-date review of geophysical methods applied to methane hydrate resource evaluation, and provided the big picture context to reinforce the relevance of this topic to a wider audience.
Exploration of Gas Hydrates – Geophysical Techniques
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.