Geology Reference
In-Depth Information
concept of seismic trace inversion is introduced in
Chapter 9
.
Chapter 10
outlines some key applications
of seismic amplitudes such as the description of reser-
voir properties from seismic and the use of amplitude
information in prospect evaluation and reserves
determination.
The broad scope of the subject inevitably means
that geophysicists need to work closely with petro-
physicists, geologists and engineers. Often this is
easier said than done. To quote Ross Crain (
2013
):
'
Geophysicists engaged in seismic interpretation
seldom use logs to their full advantage. This sad state
is caused, of course, by the fact that most geophysi-
cists are not experts in log analysis. They rely heavily
on others to edit the logs and do the analysis for them.
But, many petrophysicists and log analysts have no
idea what geophysicists need from logs, or even how
to obtain the desired results
1.3 The practice of seismic rock physics
The practice of seismic rock physics depends to a
large extent on the application. In some cases, simply
fluid substituting the logs in a dry well and generating
synthetic gathers for various fluid fill scenarios may
be all that is needed to identify seismic responses
diagnostic of hydrocarbon presence. On the other
hand, generating stochastic inversions for reservoir
prediction and uncertainty assessment will require a
complete rock physics database in which the elastic
properties of various lithofacies and their distribu-
tions are defined in an effective pressure context.
Either way, the amount of knowledge required to
master the art of seismic rock physics is a daunting
prospect for the seismic interpreter.
.
Effectively, the use of rock physics in seismic
interpretation blurs the distinctions between subsur-
face disciplines. This topic introduces the subject
from a practical viewpoint with a description of how
it works and how connections are made between the
various disciplines. Whilst there is good practice,
there is no single workflow to follow. It is hoped that
the perspective presented here will be a source of
encouragement to those eager to learn the trade as
well as providing ideas for creative hydrocarbon
exploration and development.
'
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