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Extracting Meaningful Information from Seismic Attributes

Chopra, Satinder 1; Marfurt, Kurt J.2
1 Arcis Corporation, Calgary, AB, Canada.
2 University of Oklahoma, Norman, OK.

Seismic attributes form an integral part of most interpretation projects completed today. But for extracting more accurate information from seismic attributes, the input seismic data needs to be optimally processed. The term ‘optimally’ essentially means that any or all distortion effects, whether near-surface, or amplitude/phase related, or others are taken care of during processing if not totally eliminated. When such pre-stack or poststack data are loaded on workstations, they may still show a certain amount of noise level. This noise could be of various sorts - acquisition related, processing artifacts or random. We have analyzed three important considerations for computation of geometric attributes taking the coherence attribute as an example. These three considerations are 1. data conditioning 2. using dip-steering option for data with reflector dips and 3. the choice of algorithm. We show that structure-oriented filtering run on seismic data sharpens the subsurface features of interest and tones down the background noise. Coherence attribute generated on such seismic volumes yields crisper features. Dip-steering option when used in coherence computation results in clearer looking volumes that are devoid of any structural contour patterns and so prevent misleading interpretation. Finally, a coherence algorithm based on the method of eigen-decomposition of covariant matrices called Energy-ratio algorithm demonstrates the superior performance than other available algorithms.

In this presentation we focus our attention on conditioning of seismic data for derivation of attributes from them. Besides this, we also discuss the use of some of the procedural steps for noise filtering and dip-steering options for computation of some geometric attributes like coherence and curvature. Finally in this context, we also discuss the impact the choice of algorithm can have on the final results. These three considerations when adhered to in conjunction yield superior displays for interpretation and should be embraced by seismic interpreters.

 

AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009