Safety in Offshore Drilling: The Role of Shallow Gas Surveys, Proceedings of an International Conference (Safety in Offshore Drilling) organized by the Society for Underwater Technology and held in London, U.K., April 25 & 26, 1990

290 Pages·1990·12.66 MB·English

by  Paul K. Prince (auth.)

Advances in
Underwater Technology,
Ocean Science and
Offshore Engineering
Volume 25
Safety in Offshore Drilling
The Role of Shallow Gas Surveys
ADVANCES IN UNDERWATER TECHNOLOGY
OCEAN SCIENCE AND OFFSHORE ENGINEERING
Vol. 1. Developments in Diving Technology
Vol. 2. Design and Installation of Subsea Systems
Vol. 3. Offshore Site Investigation
Vol. 4. Evaluation, Comparison and Calibration of Oceanographic
Instruments
Vol. 5. Submersible Technology
Vol. 6. Oceanology
Vol. 7. Subsea Control and Data Acquisition
Vol. 8. Exclusive Economic Zones
Vol. 9. Stationing and Stability of Semi-submersibles
Vol. 10. Modular Subsea Production Systems
Vol. II. Underwater Construction: Development and Potential
Vol. 12. Modelling the Offshore Environment
Vol. 13. Economics of Floating Production Systems
Vol. 14. Submersible Technology: Adapting to Change
Vol. 15. Technology Common to Aero and Marine Engineering
Vol. 16. Oceanology , 88
Vol. 17. Energy for Islands
Vol. 18. Disposal of Radioactive Waste in Subsea Sediments
Vol. 19. Diverless and Deepwater Technology
Vol. 20. Subsea International '89:
Second Generation Subsea Production Systems
Vol. 2I. NOT: Advances in Underwater Inspection Methods
Vol. 22. Subsea Control and Data Acquisition: Technology and
Experience
Vol. 23. Subtech '89. Fitness for Purpose
Vol. 24. Advances in Subsea Pipeline Engineering and Technology
Vol. 25. Safety in Offshore Drilling.
The Role of Shallow Gas Surveys
CONFERENCE PLANNING COMMITTEE
D.A. Ardus, British Geological Survey
C.D. Green, Shell Internationale Petroleum Maatschappij
J. Pritchard, Society for UnLlerwater Technology
Advances in
Underwater Technology,
Ocean Science and
Offshore Engineering
Volume 25
Safety in Offshore Drilling
The Role of Shallow Gas Surveys
Proceedings of an International Conference
(Safety in Offshore Drilling)
organized by the Society for Underwater Technology
and held in London, U.K., April 25 & 26, 1990.
edited by
D.A. Ardus
British Geological Survey
and
C.D. Green
SIPM, The Netherlands
KLUWER ACADEMIC PUBLISHERS
DORDRECHT I BOSTON I LONDON
Library of Congress Cataloging-in-Publication Data
Safety ln offshore drlillng the role of shallow gas surveys I edited
by D.A. Ardus. C.D. Green.
p. cm. -- (Advances ln underwater technology. ocean SClence.
and offshore englneerlng ; v. 25)
Proceedlngs of a conference held ln London. Jan. 23-24. 1990 and
organlzed by SOC1Bty for Underwater Technology.
ISBN-13: 978-94-010-6785-0 e-ISBN-13: 978-94-009-0669-3
001: 10.1007/978-94-009-0669-3
1. Gas well drl lilng--Safety measures--Congresses. 2. Gas
reservolrs--Congresses. 3. Selsmlc prospectlng--Congresses.
I. Ardus. D. A. II. Green. C. D. • 1948- III. Soclety for
Underwater Technology. IV. Serles.
TN871.3.S26 1990
822' .3331--dc20 90-5120
ISBN-13: 978-94-010-6785-0
Published by Kluwer Academic Publishers,
P.O. Box 17,3300 AA Dordrecht, The Netherlands.
Kluwer Academic Publishers incorporates
the publishing programmes of
D. Reidel, Martinus Nijhoff, Dr W. Junk and MTP Press.
Sold and distributed in the U.S.A. and Canada
by Kluwer Academic Publishers,
101 Philip Drive, Norwell, MA 02061, U.S.A.
In all other countries, sold and distributed
by Kluwer Academic Publishers Group,
P.O. Box 322, 3300 AH Dordrecht, The Netherlands.
Printed on acid-free paper
All Rights Reserved
© 1990 Society for Underwater Technology
Softcover reprint of the hardcover 1st edition 1990
No part of the material protected by this copyright notice may be reproduced or
utilized in any form or by any means, electronic or mechanical
including photocopying, recording, or by any information storage and
retrieval system, without written permission from the copyright owner.
Contents
PARTI-ThITRODUCTION
CHAPTER! Current Drilling Practice and the Occurrence of Shallow Gas
P.K. Prince -BP Exploration 3
CHAPTER 2 Shallow Gas and Gas Seepages: A Dynamic Process?
A.G. Judd -Sunderland Polytechnic 27
PART II - ACQUISmON
CHAPTER 3 High Resolution Seismic Source Specifications
Applications and Misapplications
C.R. Price -Geodetic International, Inc. 53
CHAPTER 4 Enhanced Seismic Methods for Marine Hazard Surveys
P. Newman -Consultant (formerly with Horizon Exploration Ltd.) 75
CHAPTERS Field Quality Control of Marine Data Acquisition -Past, Present,
Future
S.G. Middleton -Hydrosearch Associates Ltd. 87
PART ill -PROCESSING, ANALYSIS AND INTERPRETATION
CHAPTER 6 Processing Procedures for High Resolution Seismic Data
K.P. Games -Gardline Surveys 103
CHAPTER 7 Shallow Gas Detection Using AVO Processing of High Resolution
Seismic Data
A.R. Townsend and T.L. Armstrong -Total Oil Marine pIc 133
CHAPTERS Shallow Gas Reservoirs and Migration Paths over a Central North
Sea Diapir
R.S.K. Salisbury -Britsurvey Ltd 167
vi
CHAPTER 9 Philosophy of Advanced Interpretations
B.P. Meier -SIPM, The Netherlands 181
CHAPTER 10 Signature. The Future Approach to Reliable Shallow Gas Detection
J.P. Williams and M. Sarginson -Hydrosearch Associates Ltd. 193
PART IV -APPUCATION OF GEOPHYSICAL DATA
CHAPTER 11 Prediction of Shallow Gas From Seismic Data
R. Kanestrf/lm, A. SkAInes, P. Riste, T. Eide and S. Strandenes -Norsk
Hydro A/S 211
PART V -PROCEDURES, REGULATIONS AND GUIDELINES
CHAPTER 12 Quantitative Gas Hazard Analysis: Present Limitations and the Way
Forward
P. Conn and J. Arthur -Consultants 235
CHAPTER 13 UKOOA Recommended Procedures for Mobile Drilling Rig Site
Surveys (Geophysical and Hydrographic). Shallow Gas Aspects
P.M. Walker -Shell (UKOOA Survey Committee representative) 257
Rapporteur's Summary
Dr. C.D. Green -SIPM, The Netherlands 291
Society for Underwater Technology
The Society was founded in 1966 to promote the further understanding of the
underwater environment. It is a multi-disciplinary body with a worldwide
membership of scientists and engineers who are active or have a common
interest in underwater technology, ocean science and offshore engineering.
Committees
The Society has a number of Committees to study such topics as:
Diving and Submersibles
Offshore Site Investigation and Geotechnics
Environmental Forces and Physical Oceanography
Ocean Resources
Subsea Engineering and Operations
Education and Training
Conference and Seminars
An extensive programme is organized to cater for the diverse interests and needs
of the membership. An annual programme usually comprises four conferences
and a much greater number of one-day seminars plus evening meetings and an
occasional visit to a pl~ce of technical interest. The Society has organized over
100 seminars in London, Aberdeen and other appropriate centres during the
past·decade. Attendance at these events is available at significantly reduced
levels of registration fees for Members or staff of Corporate Members.
Publications
Proceedings of the more recent conferences have been published in this series of
Advances in Underwater Technology, Ocean Science and Offshore Engineering.
These and other publications produced separately by the Society are available
through the Society to members at a reduced cost.
Journal
The Society's quarterly journal Underwater Technology caters for the whole
spectrum of the inter-disciplinary interests and professional involvement of its
readership. It includes papers from authoritative international sources on such
subjects as:
Diving Technology and Physiology
viii SOCIETY FOR UNDERWATER TECHNOLOGY
Civil Engineering
Submersible Design and Operation
Geology and Geophysics
Subsea Systems
Naval Architecture
Marine Biology and Pollution
Oceanography
Petroleum Exploration and Production
Environmental Data
An Editorial Board has responsibility for ensuring that a high standard of
quality and presentation of papers reflects a coherent and balanced coverage of
the Society's diverse subject interests; through the Editorial Board, a procedure
for assessment of papers is conducted.
Endowment fund
A separate fund has been established to provide tangible incentives to students
to acquire knowledge and skills in underwater technology or related aspects of
ocean science and offshore engineering. Postgraduate students have been
sponsored to study to MSc level and subject to the growth of the fund it is hoped
to extend this activity.
Awards
An annual President's Award is presented for a major achievement in underwater
technology. In addition there is a series of sponsored annual awards by some
Corporate Members for the best contribution to diving operations, oceanography,
diverless intervention technology and the best technical paper in the Journal.
FURTHER INFORMATION
If you would like to receive further details, please contact
Society for Underwater Technology, The Memorial Building, 76 Mark Lane,
London EC3R 7JN.
Telephone: 071·481 0750; Telex: 886841 I Mar E G; Fax: 071·4814001.
Part I
Introduction
CURRENT DRILLING PRACTICE AND THE OCCURRENCE OF SHALLOW GAS
Paul K Prince
BP Exploration
INTRODUCTION
Shallow gas presents a major worldwide problem to the drilling
industry. The records show that approximately one third of all
blowouts have been caused by shallow gas. This proportion
is equally applicable over the recent past. During the period
June 1988 to June 1989 shallow gas was responsible for four
of the twelve blowouts that occurred. Fifteen people were
killed in three of the four shallow gas blowouts. Drilling
rigs were lost in all four incidents.
Planning a well to reduce the chance of a shallow gas blowout
depends to a major extent on the provision of an accurate
prognosis of the geology and gas risk in shallow sections of
the well.
3
Volume 25: Safety in Offshore Drilling. 3-25.
© 1990 Society for Underwater Technology_