Seismic Coal Exploration

Author: L. Dresen
Publisher: Elsevier
ISBN: 1483287068
Format: PDF, Kindle
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The efficient mining of hard coal in deep coal mines using highly mechanized longwall techniques requires information on the geological structure ahead of the operating face. Even minor tectonic faults with throws of only a few metres mean a loss in productivity, as they present severe working problems for underground mining equipment. Because investment costs to install a mechanized face are high, "insurance" in the form of spare capacity by both machine shifts or spare faces is uneconomic. Thus, to reduce mining costs it is essential to delineate the geology prior to mining. Today, the only effective geophysical tool to detect and to map minor faults in front of the coal cutter is in-seam seismics using channel, or so called seam waves. The techniques are well established and successfully applied for more than two decades. In-Seam Seismics covers the entire range of elementary and advanced topics in mathematics, physics and data processing of dispersive channel waves. The results of analogue and numerical modelling provide a thorough understanding of transmission, reflection, recording and interpretation of seam waves and coal seam disturbances. Fire damp proof instrumentation, target orientated underground layouts, processing and interpretation of real data impart the state-of-the-art of in-seam seismics. Selected and well-rounded case histories complete the presentation of in-seam seismics. They can help the mining engineer to come to a decision to plan and to apply in-seam seismics in case of underground mining problems. A clear text, only formulae which are necessary, many carefully designed figures, an extended list of references and a lucid index make it easy for the reader to get acquainted with seam waves or to promote the technique of in-seam seismics.

Experimental Acoustic Inversion Methods for Exploration of the Shallow Water Environment

Author: Andrea Caiti
Publisher: Springer Science & Business Media
ISBN: 9401141126
Format: PDF, Kindle
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In recent years, research on acoustic remote sensing of the ocean has evolved considerably, especially in studying complex physical and biological processes in shallow water environments. To review the state of the art, an international workshop was held at Carvoeiro, Portugal, in March 1999, bringing together leading international researchers in the field. In contrast to much of the recent theoretical work, emphasis was placed on the experimental validation of the techniques. This volume, based on presentations at this workshop, summarizes a range of diverse and innovative applications. The invited contributions explore the use of acoustics to measure bottom properties and morphology, as well as to probe buried objects within the sediment. Within the water column, sound is applied to imaging of oceanographic features such as currents and tides or monitoring of marine life. Another key theme is the use of sound to solve geometric inverse problems for precise tracking of undersea vehicles. Audience: This volume should be useful both to the novice seeking an introduction to the field and to advanced researchers interested in the latest developments in acoustic sensing of the ocean environment. The workshop was sponsored by the Fundação para a Ciêcia e a Tecnologia (Portuguese Foundation for Science and Technology).

Seismic Waves and Rays in Elastic Media

Author: Michael A. Slawinski
Publisher: Elsevier
ISBN: 9780080439303
Format: PDF, Kindle
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This book seeks to explore seismic phenomena in elastic media and emphasizes the interdependence of mathematical formulation and physical meaning. The purpose of this title - which is intended for senior undergraduate and graduate students as well as scientists interested in quantitative seismology - is to use aspects of continuum mechanics, wave theory and ray theory to describe phenomena resulting from the propagation of waves. The book is divided into three parts: Elastic continua, Waves and rays, and Variational formulation of rays. In Part I, continuum mechanics are used to describe the material through which seismic waves propagate, and to formulate a system of equations to study the behaviour of such material. In Part II, these equations are used to identify the types of body waves propagating in elastic continua as well as to express their velocities and displacements in terms of the properties of these continua. To solve the equations of motion in anisotropic inhomogeneous continua, the high-frequency approximation is used and establishes the concept of a ray. In Part III, it is shown that in elastic continua a ray is tantamount to a trajectory along which a seismic signal propagates in accordance with the variational principle of stationary travel time.

Progressive Technologies of Coal Coalbed Methane and Ores Mining

Author: Volodymyr Bondarenko
Publisher: CRC Press
ISBN: 1315740311
Format: PDF, Mobi
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Presenting new technologies in underground coal extraction, with special attention to mine galleries support and maintenance, load mechanism of "massif-support system-safety system" systems, analysis of face equipment for thin coal seams mining and substantiation of rational stoping parameters. Advanced surface mining technologies of coal and ore are discussed in an original form, stability calculations of internal dumps and open-cut faces are presented, as well as examination of land surface subsidence using modern methods of calculation experiments. Special attention is given to the complex mining of mineral resources, such as: iron ore, coal deposits with drilling advance degassing wells, methane extraction from coal and anthropogenic deposits, heat receipt from mine water with help of thermal pumps. The unique geological conditions for mining in Poland and the Ukraine require a new technological approach for mining thin and very thin coal seams with thickness of 1 meter and less, using selective coal extraction methods, leaving rock behind in the mine. Relevant technological solutions are discussed in this volume. Further, technological process control during coal seams underground gasification is described together with pressure-temperature conditions of gas hydrates formation from gaseous mixtures of various content. Substantiation is also given to gas hydrates extraction technologies development and 21st century new pulse technologies of well drilling and a temperature mode of a rock-cutting tool and equipment with cryogenic-gravel filters is examined. Gas extraction processes located in flooded deposits with uniform and macroheterogeneous collectors are presented with the description of an effective methodology of two-subbench technology of ore deposits extraction.

Seismic Inversion Deconvolution Dual sensor technology

Author: Enders A. Robinson
Publisher: Pergamon Pr
ISBN: 9780080436272
Format: PDF
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The objective of seismic exploration is to delineate the subsurface structure of the earth. A large variety of computer-processing methods are available to transform the observed seismic data into a form that is more useful to the seismic interpreter. An important subdivision of these methods comes under the heading "Seismic Inversion and Deconvolution". Most seismic data are recorded either by geophone that measures particle velocity, or else by hydrophone that measures pressure. A dual sensor incorporates both a geophone and a hydrophone so simultaneous measurements of both particle velocity and pressure are obtained. Unprecedented improvements in inversion and deconvolution are made possible through the use of "Dual-Sensor Technology". The purpose of Seismic Inversion and Deconvolution, Part B: Dual-Sensor Technology is to provide the fundaments of dual-sensor technology. Previous work together with new results are brought together into a self contained whole. By using dual sensors in the acquisition of seismic data, new avenues are opened up that revolutionize all aspects of seismic inversion and deconvolution. Dual-sensor technology can lead to images of the subsurface of the earth that were previously thought unattainable. The implications for the oil industry are far reaching. Great new reserves of petroleum are waiting to be discovered through the use of dual sensor technology. Today, the main application of this work is with ocean bottom cable (OBC) methods. However, it is anticipated that dual sensor technology will soon be applied not only to all aspects of seismic oil exploration, but also to other disciplines involved with remote sensing.