00FRONT2
00FRONT2
00FRONT2
Dave Marsden
Certain figures in this manual are copyright and are reproduced with the permission
of the copyright owners; notably the SEG and EAGE. The source of each figure is
noted on the slide where known, and a complete citation appears in the bibliography
and reading list at the end of the manual.
The figures on the cover of the manual (starting bottom left and moving clockwise)
are from:
1. Actis Geoscience Ltd
2. PGS Seres brochure
3. MacKay, S., and Abma, R., 1992, Imaging and velocity estimation with
depth focusing analysis, Geophysics, v. 57, no. 12, p. 1608.
4. Actis Geoscience Ltd
5. D-S brochure
Acknowledgement
The author is particularly indebted to the following organisations for permission to
copy material:
Society of Exploration Geophysicists for figures which originally appeared in
Geophysics, Leading Edge, SEG Annual Meeting Abstracts and Seismic Data
Processing by Oz Yilmaz.
European Association of Geoscientists and Engineers for figures which
originally appeared in Geophysical Prospecting and in The Marmousi
Experience.
To Amoco and Amoco (U.K.) Exploration Company for many illustrations
collected over an eighteen year period.
To Paradigm Geophysical (UK) Ltd for many illustrations.
Other sources of material are acknowledged as appropriate. In a very few instances
the author has made use of illustrations, of unknown origin. Apologies are offered to
the original owners of these data for any offence caused and due acknowledgement
will be made should their true origin come to light.
Foreword
Every effort has been made to check the accuracy of statements, formulae and
figures. These have been drawn from a wide variety of sources and experience. The
author must make it clear that he cannot be held responsible for possible
misunderstandings or errors arising from the use of the material in this manual.
The course material is pitched at two levels. Firstly the author is unaware of any text
book or training course aimed at the seismic interpreter who is usually charged with
making structure maps in depth from seismic data initially recorded in time. Whilst
there are text books that describe methods of velocity measurement and imaging in
depth they are aimed at what one might term technical geophysicists, those with a
strong background in math and physics, and usually involved in seismic processing.
In many companies, and in many parts of the world, seismic interpretation and depth
conversion are done by structural geologists or those with a geological background
and who have very little math beyond that taught in school up to the age of 16 or 18
years of age. This course is aimed specifically at this group of interpreters who have
a geological background.
Secondly, in some companies and some parts of the world, seismic interpreters have
an M.Sc. in Geophysics as a background and for these interpreters there are some
more advanced topics scattered throughout the course that deal with more complex
situations and consequently involve more maths. These advanced topics are largely
beyond methods found in conventional seismic interpretation and mapping softwares.
Many of the exercises are also pitched at these two groups. Many of the main
exercises may be done with no more than a straight edge and calculator by those
unfamiliar with the use of spreadsheets. The majority of these exercises also have a
spreadsheet version. There are also a number of more advanced exercises that can
only be done in spreadsheets. These more advanced exercises either replicate more
obscure but never-the-less important techniques available in the commercial
software or they offer techniques in spreadsheet form for which there are no
commercial software solutions available. In all of the spreadsheets there are hidden
answer sheets which may be revealed from the format>worksheet>unhide menu.
The worksheets have specifically not been formatted since most advanced users
prefer to define their own layout and formatting styles. However, the collection of
worksheets form a library of techniques that may be saved as templates, formatted
as you will and even linked to each other for increased efficiency in project work.