Determining
Seismic
Stratigraphic Features Using Dip-Guided Symmetry
Attribute
Abstract
Objectives Symmetry is a fundamental attribute
in human visual perception as well as many natural structures. As described herein, a symmetry analysis may be used as a new
seismic
attribute
to measure the degree of chaotic in
seismic
data. Symmetry is a new type of
seismic
volumetric
attribute
which is sensitive to the
seismic
amplitude variations and therefore, strongly correlates with discontinuities and curvatures associated with imaged geologic surfaces. The 3-D symmetry
attribute
can be used as a tool to identify faults, fractures, channels and other stratigraphic features. Procedures We first calculate the dip
attribute
with 2-D log-Gabor filter array, then use the dip
attribute
as a guide to build a 3-D window for the degree of symmetry evaluation. For each sample in the volume we evaluate the 180-degree rotational symmetry in its neighborhood. The neighborhood is defined by a 3-D cylindrical window which is corrected by the dip angle. The 180 degree rotational symmetry is then evaluated by comparing pairs of traces opposite to the window center and an overall degree of symmetry is derived for the whole window. In our implementation GPU computing technologies are used to optimize performance. Results Symmetry
attribute
provides a sharp stratigraphic image. Compared with other existing
attribute
calculation techniques, such as correlation-based, semblance-based, variance-based, eigenstructure-based, gradient structure tensor-based, and least-square-based a symmetry
attribute
calculation more effectively shows subtle local symmetry variations in a circular pattern of adjacent
seismic
wave forms. Conclusions Symmetry
attribute
is a new
seismic
attribute
which provides higher resolution imaging of many subtle stratigraphic features that may be missed using other types of
attribute
analysis. An
attribute
based on the symmetry data can be used to provide a high quality
seismic
attribute
suitable for fault, channel and geo-body picking.
AAPG Datapages/Search and Discovery Article #90189 © 2014 AAPG Annual Convention and Exhibition, Houston, Texas, USA, April 6–9, 2014