Seismic attribute analysis in hydrothermal dolomite, devonian slave point formation, Northeast British Columbia, Canada

Abstract

Recent advances in visualization technology and seismic attribute analysis are beginning to revolutionize the landscape of 3‐D seismic interpretation. This presentation focuses on the interpretive use of post‐stack seismic attributes for seismic reservoir characterization. Multiple seismic attributes facilitate structural interpretation and recognition of seismic stratigraphy, but as importantly, they may offer clues to lithology typing and estimation of fluid content from seismic data. Potential benefits include reduction of stratigraphic and structural drilling risks, seismic reservoir characterization in exploration settings, and value increase of new and vintage 3D seismic data. Immediate improvements in drilling risk reduction can be obtained by using multiple seismic attributes. This enhancement occurs because each seismic attribute computation resembles a non‐linear filter that decomposes reflection data into its constituents, and, as a consequence, use of multiple seismic attributes restores much of the discriminating information retained in the originally recorded wavefield (Barnes, 2001; Taner, 2001). Thus, each seismic attribute, for instance, amplitude, inadvertently contains only a subset of the total information recorded, since a single seismic attribute represents only one numerical property of a propagating seismic wavefield. In this presentation, we advocate the use of geometric attributes in conjunction with relative acoustic impedance and frequency‐derived seismic attributes. In the past, use of geometric attributes was mostly limited to edge detection, where edges in the seismic data commonly represent faults or stratigraphic terminations (seismic facies changes). In this Devonian Slave Point Formation case study, we use post‐stack seismic attributes to • Determine the azimuths of conjugate fracture trends in the subsurface • Identify “leaky” vs. sealing fault segments and possible migration/charge/escape pathways. • Identify “sweet spots” in the subsurface Blind testing helped confirm validity of interpretational approach in identifying porous dolostone facies and has resulted in ranking of future prospect locations. 3‐D seismic examples are from northeast British Columbia, Canada (Bubbles Survey) and were provided by Olympic Seismic. Results from this case study should find application in seismic exploration for fractured and hydrothermally altered carbonates worldwide.