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Seismic
Facies Maps: A Quick Exploration Tool
ADDY, SUNIT K. , CGG Petrosystems, Houston, Texas
seismic facies with well information and predicting
lithology away from the well using seismic facies map has been used successfully
in several instances. But in most cases seismic facies maps are results
of a process of visually recognizing the reflection patterns in the seismic
data and classifying them into descriptive classes such as, continuous,
sigmoidal, discontinuous, hammocky, transparent etc. This is a process,
which is painstakingly slow and interpretative. The maps are manually drawn
and are subject to change from interpreter to interpreter. Since the shape
of the seismic traces contain all relevant information, such as, reflection
patterns, phase, frequency, amplitude etc., a classification of the trace
shapes using the computational power of a modern computer should result
into a similar map showing areas of similar trace shapes which can in turn
be interpreted as a seismic facies map.
In this session, I would like to present a case history in which seismic
facies maps were generated by Stratimagic, CGG Petrosystems' latest 3D
stratigraphic interpretation system utilizing a neural network classification
technology. The process is extremely fast and many facies classifications
can be performed in a relatively short time for several horizon intervals
in the seismic volume. This patented technology is licensed from Elf Aquitaine.
In a 3D survey in central south Texas using seismic facies maps, we were
able to identify porosity in Edwards limestone, define the Sligo reef trend,
map complex channel systems in the upper Wilcox and Frio sections and determine
the extent of lower Wilcox onlapping sands in the Lavaca channel.
The process is fast and the ability to create numerous facies maps quickly
and repetitively in the beginning of an exploration phase
enables the interpreter
to effectively scan through the data and to concentrate in areas of significance.
AAPG Search and Discovery Article #90936©1998 AAPG Southwest Section Meeting, Wichita Falls, Texas