Traditional notions of security are premised on the primacy of state security. In relation to energy security, traditional policy thinking has focused on ensuring supply without much emphasis on socioeconomic and environmental impacts. Non-traditional security (NTS) scholars argue that threats to human security have become increasingly prominent since the end of the Cold War, and that it is thus critical to adopt a holistic and multidisciplinary approach in addressing rising energy needs. This volume represents the perspectives of scholars from across Asia, looking at diverse aspects of energy security through a non-traditional security lens. The issues covered include environmental and socioeconomic impacts, the role of the market, the role of civil society, energy sustainability and policy trends in the ASEAN region.

Why another book about Ore Deposits? There are a number of factors which motivated us to write this text and which may provide an answer to this question. Firstly our colleagues are predominantly mining engineers and minerals processing technologists, which provides us with a different perspective of ore deposits from many academic geologists. Secondly we have found that most existing texts are either highly theoretical or merely descriptive: we have attempted to examine the practical implications of the geological setting and genetic models of particular ore deposit types. We have written the text primarily for undergraduates who are taking options in Economic Geology towards the end of a Degree Course in Geology. However, we hope that the text will also prove valuable to geologists working in the mining industry. The text is to a large extent based on a review of the existing literature up to the end of 1984. However, we have visited most of the mining districts cited in the text and have also corresponded extensively with geologists to extend our knowledge beyond the published literature. Nonetheless writing a text-book on Ore Deposits is a demanding task and it is inevitable that sins of both omission and commission have been committed. We would therefore welcome comments from readers which can be incorporated in future editions. RICHARD EDW ARDS KEITH ATKINSON Cmnhome School ( n\1illcs April 1985 Glossary Adit A horizontal, or near horizontal, passage from the surface into a mme.

This text was originally written for use with the videotape program of the same title. Numbered video cassettes correspond to the following chapters of the book: Tape Chapter(s) Tape Chapter(s) 1 1-2. 2. 1 11 3. 4 2 2. 2. 2-2. 3 12 3. 5. 1-3. 5. 2 3 2. 4 13 3. 5. 3 4 2. 5-2. 6 14 3. 5. 4-3. 6. 3 5 2. 7-2. 8 15 3. 7-3. 7. 2 6 3 16 3. 8-4 7 3. 1 17 4. 1 8 3. 2-3. 2. 1 18 4. 2-4. 4 9 3. 2. 2-3. 2. 3 19 5 10 3. 3 Complete information about the videotape program, Seismic Exploration for Sandstone Reservoirs may be obtained from: IHRDC, 137 Newbury St. , Boston, MA 02116, (617) 536-0202. Acknowledgements Thanks are expressed to the authors, companies and professional associations who have allowed the use of their material in the course. The author and publisher are grateful for permission to reproduce material whose copyright belongs as follows: Figures: 2. 4-3 (Widess) SEG; 2. 4-4 (Prescott) Continental Oil Company; 3-1 (Le Blanc) AAPG; 3-2 (MacKenzie) AAPG; 3. 1-1 Seiscom Delta; 3. 1-3 (Schramm et al. ) AAPG; 3. 1-4 (Lamer et al. ) Western Geophysical Company; 3. 2. 2-2 Prakla Seismos; 3. 2. 2-3 (Leung et al. ) Amoco Europe; 3. 2. 2-4 (Newman et al. ) S&A Geophysical; 3. 2. 3-2 Seiscom Delta; 3. 3-1 (Taner) Seiscom Delta; 3.

This book accompanies a videotape program of the same name. The combined videotape and book, referred to as a module of instruction, was one of three prepared by IHRDC on a joint basis with Mobil Oil Corporation during 1980. The three modules, one each in geology, geophysics and petroleum engineering, were produced to determine whether this medium of instruction would provide an effective way of teaching recent graduates and those individuals changing specialties, "what they need to know, when they need to know it." The major observations Of the pilot production stage were that properly designed and properly used, video-assisted instruction is effective, effiCient, and convenient. With the confidence that this instructional medium provides one way for the interna tional petroleum industry to train young graduates in exploration and production, IHRDC sought financial and advisory support from a limited number Of companies to undertake the development of the BaSiC Technical Video Library for the E&P Specialist. To date the following companies have agreed to serve as Sponsors: Mobil, AGIP, ARAMCO, Cities Services, Dome Petroleum Ltd., Gulf, Phillips, Standard Oil of California/ Chevron, and Texaco."

In 1866 William P. Blake, professor of mineralogy, geology and mining at the College of California, parent to the University of California, Berkeley, prepared as a report to the State Board of Agriculture an "Annotated Catalog of the Principal Mineral Species Hitherto Recognized in California and the adjoining States and Territories. " Seventy-seven mineral species appeared on the list. It was the beginning of a series that became known as Minerals of California. This first catalog was followed in 1884 and 1886 by a list of 135 species compiled by H. G. Hanks, the first state mineralogist of California, and pub. lished in the fourth and sixth State Mining Bureau reports. Then beginning in 1914 with a volume prepared by A. S. Eakle, professor of mineralogy at the Uni versity of California, Berkeley, the Division of Mines and Geology published new editions in the series at approximately ten-year intervals. Author Year Mineral Species A. S. Eakle 1914 352 A. S. Eakle 1923 417 A. Pabst 1938 446 J. Murdoch and R. W. Webb 1948 516 J. Murdoch and R. W. Webb 1956 523 J. Murdoch and R. W. Webb 1966 602 (For a more detailed review of the Minerals of California series, see I. Campbell, 1966, pp. 13-19. ) For over 100 years the series has served those who have a historic, scientific or economic interest in California minerals."

This volume contains the papers presented at the North European Margin Symposium which was held at the Norwegian Institute of Technology in Trondheim from 9 to 11th May 1983. The idea for the meeting was conceived by the Geology and Geophysics Committee of the Norwegian Petroleum Society, in meetings consisting of R P F Hardman, J Freake, I Gausland, A M Spencer, R G Todd, F Aamodt, E Nysaether and G Kobjl,iSrnsen. The Trondheim meeting was planned and organized by an Organizing and Editing Subcommittee consisting of E Holter, 0 S Johnsen, A Ml,iSrk, E Nysaether, P Songstad, A M Spencer and A Spinnangr. There were 216 participants at the meeting in Trondheim and 34 papers were given, most of which were invited. The meeting was opened by Dr K S Heier, Director of the Norwegian Geological Survey and a concluding address was given by E Bergsager of the Norwegian Petroleum Directorate, who talked about future exploration in Norway.

This little book is different. It is written, primarily, for geologists, reservoir engineers, and log analysts. Why? Because today's seismic method is more than a tool for reconnaissance exploration, for finding structures; it has become a tool for studying the discovered reservoir-its extent, its barriers, its variations of thickness, and its trends of porosity. Today, the geophysicist, the geolog ist, the engineer, and the log analyst can do great things together. Because the book is not written primarily for geophysi cists, it can skip much of the "mechanics" of the seismic method. The reader who reaches the last page (bless him ) will not be able to practise the seismic method, but he will understand how the seismic method can help to solve his problems. It may also be of value to those practitioners of the seismic method-in the field or in the processing centre-who already know the mechanics of the method, but would like to take a broader view. 1 1 Seismics and Structure Of all the geophysical methods working from the surface, there is only one which is widely accepted for studies of individual petroleum reservoirs-the seismic reflection method. We would dearly love to have something better, but alas ... Reduced to its essentials, the method is this: we make a bang, and we listen for echoes."

Although considera bIe efforts are now being made to find new sources of energy, alI the experts are agreed that hydrocarbons will have to provide the greater part of our energy needs for a generation ahead. Exploration for and production of hydrocarbons therefore pose a serious problem for our future, as much for the quantitative satisfaction of our requirements as for our search for self-sufficiency in energy. As a direct result of improvements in technology throughout the world, geophysics has progressively enlarged its field of influence in the realms of exploration and production. But amongst the various geophysical methods available, seismic reflection has gradually become accepted as the basic tool of the oiI prospector. Reflection seismology has reached and consolidated this position because it has shown itself to be capable of adapting to the increasing complexity of the requirements of exploration. Initially directed towards geometric mapping of the sub-surface, it became the means of detection of structural traps in geotectonically quiescent regions, and thereafter in increasingly complex surroundings. It has enabled us to clothe the structural framework with a lithology, initially approximate, but becoming more and more precise, assisting the explorer to locate stratigraphic traps. Further developments enable us under favourable circumstances to estimate the quality of the deposits and to detect the presence of fluids and of their interfaces; it then becomes an unrivalled tool for the producer, both in the development of deposits and in the application of enhanced recovery methods.

Proceedings of the NATO Advanced Research Workshop, Digne, France, September 16-22, 1988

In all the industries in which I do management consulting, each manager considers his own industry to be truly "unique. " Of course, each is different in some respects, and each has its own quirks and features. However, the similarities among in dustries far outweigh the differences. The critical dynamics and the management issues have a great deal in common. However, there are, I believe, two industries (or segments of industries) that have an important critical uniqueness that does distinguish them from the rest. One of these is the exploration for undiscovered natural resources, notably for oil and gas; the other is research. In these two in dustry segments, the competition is not nearly so much one firm against another as it is each firm against "nature," or-if you prefer-against the unknown. This uniqueness not only sets these two industry segments apart from the rest, it also helps us to see what they have in common with each other: - Pure scientific talent, ability, and genius have direct commercial value. - We do not have the zero sum game of competition in the market place. A discovery by one firm does not usually perceptably lessen the opportunity of a "competitor" for a discovery. On the contrary, a discovery by one firm usually increases the knowledge of the whole industry, increasing com petitors' opportunity for discovery. - We see the source of continuing life for the rest of the firm."

An accessible account of the ways in which the world's plant life affects the climate. It covers everything from tiny local microclimates created by plants to their effect on a global scale. If you ve ever wondered how vegetation can create clouds, haze and rain, or how plants have an impact on the composition of greenhouse gases, then this book is required reading."

This book is written as a practical field manual to effective. Each geolOgist has to develop his/her be used by geologists engaged in mineral explo own techniques and will ultimately be judged on ration. It is also hoped that it will serve as a text results, not the process by which these results and reference for students in Applied Geology were reached. In mineral exploration, the only courses of universities and colleges. The book 'right' way of doing anything is the way that aims to outline some of the practical skills that locates ore in the quickest and most cost-effective turn the graduate geologist into an explo manner. It is preferable, however, for an individ rationist: . It is intended as a practical 'how to' ual to develop his/her own method of operation book, rather than as a text on geological or ore after having tried, and become aware of, those deposit theory. procedures which experience has shown to work An explorationist is a professional who search well and which are generally accepted in indus try as good exploration practice. es for ore bodies in a scientific and structured way. Although an awkward and artificial term, The chapters of the book approximately fol this is the only available word to describe the low the steps which a typical exploration pro totality of the skills which are needed to locate gramme would go through. In Chapter 1, the and define economic mineralization."

Mineral deposits are non-renewable; they do not grow in the ground. Sustainable use of finite mineral wealth requires that revenues from mineral extraction be invested in renewable wealth, education and infrastructure, machines and other production equipment, or in financial assets. Different countries, states and provinces have done so with a varying degree of success. Investing for Sustainability: The Management of Mineral Wealth highlights mineral rents investment funds in Norway, Alaska and Alberta, all of which derive considerable revenues from the production of petroleum bound to diminish over time. The book examines the institutional and political framework in which these funds are embedded and how successfully they have been used for making non-renewable petroleum wealth permanent. Investing for Sustainability: The Management of Mineral Wealth begins with a discussion of the elusive concept of sustainability. New technology and substitution has made a resource like peat obsolete long before it became exhausted physically. Jevons' famous book "The Coal Question" is discussed at some length as a case of unwarranted concern about the depletion of resources. The book also highlights other cases which strike a less happy note. Nauru, one of the smallest sovereign states in the world, has for decades lived off phosphate resources that are now running out. Nauru attempted to make its phosphate wealth permanent through investment funds but failed. Despite its success with its Permanent Fund, less of the oil wealth of Alaska has been made permanent than would appear warranted, and the same is true of Alberta and Norway. Judging from the experiences of the three funds, and the current political debate in Norway, Investing for Sustainability: The Management of Mineral Wealth suggests that it is essential that the citizenry at large benefit directly from mineral rents investment funds if they are to succeed.

Discussing all aspects of offshore surveying in a single volume, this book provides all algorithms necessary to develop complete software suites, and gives a large number of quality control criteria. It is invaluable to professional surveyors, offshore engineers and geophysicists, providing them with a wealth of data in a single volume. It is also a valuable reference work for hydrographic surveyors, seismic navigators and operations geophysicists. This book brings together information on spheroids, datums, projections and binning; gives a complete listing of UKOOA P1/90 and P2/91 formats for data transfer; a field guide to the calibration of radio navigation systems and compasses, acoustic and laser measuring devices; GPS, including calibration, use and differential techniques; field manual for quality control of all aspects of offshore surveying; listing of typical specifications for inclusion in survey contracts; and a comprehensive glossary of relevant terms for offshore surveying.

Oceanic basalts are the most abundant rock type found at the earth's surface, and as such they have been the subject of considerable research, particularly since the concept of sea-floor spreading became widely accepted. This book provides a review of these rocks, first dicussing how we sample the ocean floor and what we know about the structure of the oceanic crust, followed by an overview of the various regional settings (Pacific crust, Atlantic crust, marginal basins, seamounts and islands) and finally examines the main processes (and their interactions) which prevail during the generation and emplacement of oceanic basalt magmas. This is a volume for geologists, geochemists and geophysicists and a source of reference for advanced undergraduate students and postgraduates in these disciplines.

An Introduction to Geological Structures and Maps is a concise and accessible textbook providing simple structural terminology and map problems which introduce geological structures. It is a perfect introduction to mapping for students of geology, engineering geology and civil engineering.

Each topic is explained and illustrated by figures, and exercises follow on successive maps. If students are unable to complete an exercise, they can read on to obtain more specific instructions on how theory may be used to solve the problem. An appendix at the end of the book provides the solutions.

This new, eighth edition contains simplified introductory matter to make the subject as easy to grasp as possible. Colour photographs illustrating geological structures bring the subject to life and a new map from the British Geological Survey illustrates a real area. There is more on outcrop patterns, which will help students to think in 3D, and on structures and the relationship of topography to geological structure. Cliff sections have been added to reinforce the concept of apparent dip. The section on planetary geology has been more closely tied to igneous geology to aid understanding of the connection between the two. Finally, a new map on economic geology has been added for the benefit of engineering students.

A geological glossary helps students to understand and memorise key terms and a new, colourful, text design enlivens the appearance of this popular book.

Table of Contents

List of Plates

Preface to the current edition

Preface to previous editions

Key to maps

Chapter 1 Strata - the ground rules

Chapter 2 Horizontal strata

Contours

Horizontal and vertical strata in the landscape

Geological maps

Chapter 3 Dipping strata

Structure contours (strike lines)

Construction of structure contours

True and apparent dip

Calculation of the thickness of a bed

Width of outcrop

Inliers and outliers

Exercises using geological survey maps

Chapter 4 Three-point problems

Construction of structure contours

Depth in boreholes

Insertion of outcrops

Chapter 5 Unconformities

Overstep

Overlap

Sub-unconformity outcrops

Exercises using geological maps

Chapter 6 Folding

Anticlines and synclines

Asymmetrical folds

Way-up criteria

Similar and concentric folding

Two possible directions of strike

Exercise on published geological survey map

Chapter 7 Map solution without structure contours 1

Chapter 8 Faults

Normal and reversed faults

The effects of faulting on outcrops

Classification of faults

Calculation of the throw of a fault

Faults and economic calculations

Wrench or tear faults

Pre- and post-unconformity faulting

Structural inliers and outliers

Posthumous faulting

Isopachytes

Exercises on published geological survey maps

Chapter 9 Map solution without structure contours 2

Chapter 10 More folds and faulted folds

Plunging folds

Calculation of the amount of plunge

The effects of faulting on fold structures

Displacement of folds by strike-slip (wrench) faults

Calculation of strike-slip displacement

Faults parallel to the limbs of a fold

Sub-surface structures

Posthumous folding

Polyphase folding

Bed isopachytes

Exercises on geological survey maps

Chapter 11 Igneous and impact features

Pyroclastic rocks

Concordant intrusions

Disordant intrusions

Impact features

Exercise on geological survey map

Impact features

Chapter 12 Economic problems

Chapter 13 Complex structures

Nappes

Thrust faults

Axial plane cleavage

Description of a geological map

The geological history of Map 45

Exercise on geological survey map

Appendix

Glossary

Index

The former Soviet Union possessed some of the world's largest reserves of energy and mineral resources. With the dissolution of the country in 1991, the former Soviet republics are now exercising complete control over their mining industries. The new Commonwealth of Independent States (CIS) consists of several new nations, well-endowed in hydrocarbons, metals, and industrial materials; efforts are now underway to boost development activities and attract foreign investment. Commonwealth members today are implementing policies to regulate energy and mineral development and enhance economic growth. This book provides a comprehensive overview of the energy and minerals industries of the CIS and other former Soviet republics outside the Commonwealth. Prospects for international cooperation and trade in hydrocarbons, metals, and nonmetals are examined, as are opportunities for joint ventures and technology transfers in mining. Economic relations between the CIS and several Asian nations are also analyzed. Contributors to the book from throughout the Commonwealth, Asia, Europe, and North America have a wide variety of backgrounds in the energy and mineral fields, including government, academia, and industry.

Since the Arab oil embargo of 1974, it has been clear that the days of almost limitless quantities of low-cost energy have passed. In addition, ever worsening pollution due to fossil fuel consumption, for instance oil and chemical spills, strip mining, sulphur emission and accumulation of solid wastes, has, among other things, led to an increase of as much as 10% in the carbon dioxide content of the atmosphere in this century. This has induced a warming trend through the 'greenhouse effect' which prevents infrared radiation from leaving it. Many people think the average planetary temperatures may rise by 4 DegreesC or so by 2050. This is probably true since Antarctic ice cores evidence indicates that, over the last 160000 years, ice ages coincided with reduced levels of carbon dioxide and warmer interglacial episodes with increased levels of the gas in the atmosphere. Consequently, such an elevation of temperature over such a relatively short span of time would have catastrophic results in terms of rising sea level and associated flooding of vast tracts of low-lying lands. Reducing the burning of fossil fuels makes sense on both economic and environmental grounds. One of the most attractive alternatives is geothermal resources, especially in developing countries, for instance in El Salvador where geothermal energy provides about a fifth of total installed electrical power already. In fact, by the middle 1980s, at least 121 geothermal power plants were operating worldwide, most being of the dry steam type.

Oil shales are broadly dermed as petroleum source rocks containing sufficiently high contents of organic matter (above ca 10-15 wt. %) to make utilisation a possibility. Like coal, the world's reserves of oil shales are vast being many times larger than those proven for crude oil. Indeed, some of the largest deposits occur in the USA and Europe where Estonia and Turkey have large reserves. The first recorded interest in oil shale retorting was an English patent in 1694 (Eele, Hancock and Porter, No. 330) which refers to distilling noyle from some kind of stone." The oil shale retorting industry dates back to the middle of the last century, notably Scotland, Estonia, France and Sweden in Europe. Indeed, my own Department at the University of Strathclyde has a historical link with James "Paraffin" Young, the founder of the Scottish oil shale industry who endowed a chair in Applied Chemistry. The growth of the oil industry saw the demise of the oil shale industry in most countries with the notable exception of Estonia, where kukersite has continued to be used for power generation and retorting. However, oil shale utilisation has attracted renewed attention since the early 1970s as a source of transport fuels and chemical feedstocks due to the the long term uncertainties over crude oil supplies.

In 1981 Chile's military government dictated a new Water Code that radically changed the country's previous water rights system by strengthening private property rights, favoring market incentives, and reducing state regulation. Against the Current: Privatization, Water Markets, and the State in Chile is the first empirical and interdisciplinary study of water markets in Chile, which is the leading international example of free market water policies. Against the Current: Privatization, Water Markets, and the State in Chile challenges the glowing reports given by neoliberals in Chile and the World Bank, showing that the results of this economic experiment have actually been rather mixed. Within the agricultural sector the Water Code has worked fairly well, although the market incentives to conserve water have been ineffective and water rights trading has been less active than expected. The Code's impact has been more negative at the level of river basins, where the institutional framework has revealed critical flaws in coordinating multiple water users and resolving conflicts. Against the Current: Privatization, Water Markets, and the State in Chile combines law, political economy, and geography to analyze the disadvantages, problems, and wider contexts of water markets. This book will appeal to everyone interested in property rights, market-friendly environmental policies, the political economy of sustainable development, and the intersection of economics with law and institutions.

In exploration seismology, data are acquired at multiple source and receiver posi tions along a profile line. These data are subsequently processed and interpreted. The primary result of this process is a subsurface image of the exploration target. As part of this procedure, additional information is also obtained about the subsurface material properties, e.g., seismic velocities. The methods that are employed in the acquisition and processing of exploration seismic data are internally consistent. That is, principally near vertical incidence seismic waves are generated, recorded and subsequently imaged. The data processing methods commonly used are based upon a small angle of incidence approximation, thus making the imaging problem tractable for existing data processing technology. Although tremendously successful, the limitations of this method are generally recognized. Current and future exploration goals will likely require the use of additional seismic waves, i.e., both compressional and shear precritical and postcritical reflections and refractions. Also, in addition to making better use of seismic travel times, recent efforts to directly incorporate seismic amplitude variations show that the approach may lead to a better understanding of subsurface rock properties. In response to more demanding exploration goals, recent data acquisition techniques have improved significantly by increasing the spatial aperture and incorporating a large number of closely spaced receivers. The need for better subsurface resolution in depth and position has encouraged the use of 240, 512, and even 1024 recorded data channels with receiver separations of 5 to 25 m."

Here is another contribution in the continuing series on Computer Methods in the Geosciences. As its title suggests, this volume will be of interest to explorational geochemists who want to analyze their own data on a personal computer (PC). To make it easy for the user, the programs and two trial data sets are provided on the accompanying diskettes. And, by supplying the diskettes, another first is accom plished for the series: instant involvement and interaction for the user. Although other books in the series have provided listings of computer pro grams, Exploration-Geochemical Data Analysis with the IBM PC is the first to supply diskettes. The diskettes, along with the instructions outlined in the text, eliminate the bother (and errors) of pu tting the programs in man ually. The suite of programs for handling and sorting data files; computing and displaying summary statistics; and working with logarithms, geochemical thresholds, and regression - will give geochemists a good repertoire for geochemical exploration data analysis. The diskettes are easy to use and have been tested thoroughly."

variegated seismological conditions has been accumulated. The method has been developed further in two main directions: - the perfection of the techniques and equipment of three-component field studies incorporating a continuous control of the identity of equipment both in deep boreholes and on the surface; - the creation of efficient and straightforward software for the automatic processing of PM data. Whereas the early stages of development of the method have been conspicuous chiefly by the use of polarization for the discrimination of the wave field, in recent years the emphasis shifts to the use of polarization parameters to obtain additional information about the Earth. This is especially important, as the polarization parameters are very sensitive to inhomogeneities in cross-section and enable those parameters of the Earth to be studies which cannot be obtained from kinematics. Here one should especially mention the polarization of transverse waves, which can act as one of the most reliable parameters for identifying and studying anisotropic properties of the Earth. At present various modifications of PM are being developed applicable both to uphole - (PM RW = reflected waves method, PM CDP = common-depth-point method, PM refracted-wave method, PM of regional studies utilizing earthquakes) and to downhole observations (PM VSP = vertical seismic profiling). Not all the PM modifications are developing at the same rate. The method which has up to now been developed most extenSively is PM VSP.

GOLD: History and Genesis of Deposits is the product of an effort by the Society of Economic Geologists to publish materials that will expand knowl edge concerning timely, specific topics important to the study of economic geology and to economic geologists. A volume on gold was selected for a general review-type publication because of the importance of the gold mining industry in the 1980s. The officers and council of the Society of Economic Geologists authorized the preparation of this book on gold in 1981, and Dr. Robert W. Boyle was selected as its author. Dr. Boyle has extensive experience in the study of gold deposits. He has an international reputation and a broad interest and understanding of the gold mining industry, the origin of gold deposits, and the history of gold as a metal and ore from prehistoric times to recent. Dr. Boyle uses important publications on gold deposits as source materials to document the various pathways of geological thought over time to introduce the reader to modern concepts. The book contains a wealth of information concerning gold."

Shallow Gas determination, prior to drilling, is carried out using 'Engineering Seismic' survey methods. Seismic acquisition data quality is fundamental in achieving this objective as both the data processing methods and interpretation accuracy are subject to the quality of the data obtained. The recent application of workstation based data analysis and interpretation has clearly demonstrated the importance of acquisition data quality on the ability to determine the risks of gas with a high level of confidence. The following pages summarise the 5 primary issues that influence acquisition data QC, suggests future trends and considers their potential impact. The primary issues covered in this paper are: A. Seismic B. Positioning C. QC Data Analysis D. Communications E. Personnel 90 SAFETY IN OFFSHORE DRll.LING FIELD QC ...................... PRIMARY COMPONENTS COMMERCIAL TECHNICAL 1 OPERATIONAL FIGURE 1 HYDROSEARCH The often complex influences of Technical, Commercial and Operational constraints on the acquisition of high quality data require careful management by the QC supervisor in order to achieve a successful seismic survey data set. The following pages only consider the Technical aspects of QC and assume that no Commercial or Operational restrictions are imposed in the achievement of optimum data quality. It is noted however, that such restrictions are frequently responsible for significant compromise in data coverage and quality during routine rig site surveys.