--> --> Determining Seismic Stratigraphic Features Using Dip-Guided Symmetry Attribute
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Determining Previous HitSeismicNext Hit Stratigraphic Features Using Dip-Guided Symmetry Previous HitAttributeNext Hit

Abstract

Objectives Symmetry is a fundamental Previous HitattributeNext Hit in human visual perception as well as many natural structures. As described herein, a symmetry analysis may be used as a new Previous HitseismicNext Hit Previous HitattributeNext Hit to measure the degree of chaotic in Previous HitseismicNext Hit data. Symmetry is a new type of Previous HitseismicNext Hit volumetric Previous HitattributeNext Hit which is sensitive to the Previous HitseismicNext Hit amplitude variations and therefore, strongly correlates with discontinuities and curvatures associated with imaged geologic surfaces. The 3-D symmetry Previous HitattributeNext Hit can be used as a tool to identify faults, fractures, channels and other stratigraphic features. Procedures We first calculate the dip Previous HitattributeNext Hit with 2-D log-Gabor filter array, then use the dip Previous HitattributeNext Hit 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 Previous HitattributeNext Hit provides a sharp stratigraphic image. Compared with other existing Previous HitattributeNext Hit calculation techniques, such as correlation-based, semblance-based, variance-based, eigenstructure-based, gradient structure tensor-based, and least-square-based a symmetry Previous HitattributeNext Hit calculation more effectively shows subtle local symmetry variations in a circular pattern of adjacent Previous HitseismicNext Hit wave forms. Conclusions Symmetry Previous HitattributeNext Hit is a new Previous HitseismicNext Hit Previous HitattributeNext Hit which provides higher resolution imaging of many subtle stratigraphic features that may be missed using other types of Previous HitattributeNext Hit analysis. An Previous HitattributeNext Hit based on the symmetry data can be used to provide a high quality Previous HitseismicNext Hit Previous HitattributeTop suitable for fault, channel and geo-body picking.