DIMACS TR: 99-03
Massive Data Set Analysis in Seismic Explorations for Oil and Gas in Crystalline Basement Interval
Authors: Ilya Muchnik, Vadim Mottl and Vladimir Levyant
ABSTRACT
On the basis of the optimization-based approach to the analysis of massive
ordered data sets, a new method is proposed for computer-aided interpretation
of seismic exploratory data from the so-called crystalline basement of the
Earth mantle, which underlies the relatively thin sedimentary cover having
been, up to now, the almost exceptional object of seismic explorations.
The seismic exploratory data sets, seismic sections and cubes, are a
class of, respectively, two- and three-dimensional data arrays, which
are analyzed in the course of gas and oil reserves prospecting with the
purpose of studying the structure of the underground rock mass. The
seismic data sets consist of synchronous records of reflected seismic
signals registered by a large number of geophones (seismic sensors)
placed along a straight line or in the nodes of a rectangular
lattice on the earth surface. As the source of the initial
seismic pulse, usually serves a series of explosions, responses
to which are averaged in a special manner. The vertical time axis
forming the resulting two- or three-dimensional picture is identified
with depth, so that the peculiarities of the reflected signal under the
respective sensor carry an information on the local properties of the
rock mass at the respective point of the underground medium. In contrast
to the above-lying sedimentary cover, the absence of pronounced reflecting
surfaces in a crystalline body results in a great difficulty of inferring
the geological information from the basement interval of the seismic
picture. The new method of seismic data analysis proposed in this work
is aimed at finding fractured zones of the basement rock mass capable
to accumulate oil or gas. The essence of the method consists in numerical
evaluating distinctions in the local spatial texture of the seismic picture
that are caused by differences in physical properties of fractured and
monolith rock. The problem of estimating the local texture over the whole
data array at once is set as that of minimizing an objective function in
that the texture model parameters at all the elements of the array occur
as its arguments. A special separable structure of the objective function
provides a high speed of the optimization procedure.
Paper Available at:
ftp://dimacs.rutgers.edu/pub/dimacs/TechnicalReports/TechReports/1999/99-03.ps.gz
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