Multi-Resolution Stacking of Seismic Attribute Calculations Based on Post-Stack Seismic Characteristics to Enhance Image Quality

Abstract

Post-stack seismic data are highly varying, with the characteristics of amplitude, frequency, and phase changing substantially throughout the seismic signal. Traditionally, when calculating seismic attributes, a set of parameters is selected, and the computation is run on an entire cube of data. Obtaining reasonable results throughout the cube has proven to be difficult due to factors such as signal attenuation. The major drawback of having a static operator size is that the calculation radius of the seismic attribute is either overestimated or underestimated, which leads to either losing information or adding geological noise to the results because the operator size is too small or too big for the current calculation. In this study, we use recently published techniques (Ramfjord and Aqrawi, 2016, Delineating structural geology in poststack seismic data with the use of an adaptive signal decomposition technique) to first implement a method in which seismic attributes were run in multiple resolutions and later stacked to identify key structural features. We focused our study on the identification and highlighting of fault and salt features in the seismic data and doing so on a coherence-based attribute and on a texture-based attribute measuring chaos in the seismic signal (Iske and Randen, 2005. Mathematical methods and modeling in hydrocarbon exploration and production). Identifying the various operator sizes to run the attributes was based on the features of interest. Larger operator calculation results were correlated with smaller ones through stacking, mainly to reduce noise and outliers. To validate this work, we used a data in the Norwegian North Sea and another in offshore Netherlands. Both data sets have challenging structural components and exhibit a varying seismic signal throughout. The validation was performed as a comparison study between the traditional approach and our multi-resolution approach to imaging. The results showed a significant reduction in noise, improved continuity, and enhanced imaging quality of geological features such as salt bodies and fault structures. This method is a new way of approaching seismic attribute calculation as a whole and can be applied to various attributes. It is unique in that it accounts for and tunes its calculations to the seismic signal and the geological features of interest. Our results show improvements in detection and imaging when compared to traditional methods, with a substantial reduction in noise.

AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017