--> Abstract: Deep-Water Lithofacies Prediction from Seismic Using AVO—Multiple Offset Forward Seismic Modeling of Deep-Water Outcrops, by Lars Seidler, Anthony Sprague, and Michael Farrell; #90039 (2005)
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Deep-Water Lithofacies Prediction from Previous HitSeismicNext Hit Using AVO—Multiple Offset Forward Previous HitSeismicNext Hit Modeling of Deep-Water Outcrops

Lars Seidler, Anthony Sprague, and Michael Farrell
ExxonMobil Upstream Research Company, Houston, TX

Detailed interpretation of amplitude variance with offset (AVO) data indicates that deep-water lithofacies can be directly predicted from Previous HitseismicNext Hit. The information has two main applications; Firstly, it can be applied to better describe deep-water reservoir architecture. Secondly, the improved Previous HitseismicNext Hit information, in particular from high-quality data from West Africa, can aid to a better conceptual understanding of deep-water systems in 3D. Several datasets from West Africa have been used to derive acoustical properties for deep-water lithofacies associations. The AVO-response of lithofacies depends on their porosity and shale content, and this makes it possible to distinguish 7 deep-water lithofacies associations. Deep-water outcrop cross-sections from Karoo, South Africa and Brushy Canyon, Texas were then populated with the subsurface rock properties and forward Previous HitseismicNext Hit modeled generating multiple offset 2D Previous HitseismicNext Hit lines. The results show that the outcrop architecture can be misinterpreted without using the AVO-information. On zero-Previous HitphaseNext Hit near/far data, few reflectors follow stratigraphic surfaces such as channel or channel complex boundaries, leading to misinterpretation. Sidelobes and lack of impedance contrast between lithofacies can lead to wrong assessment of reservoir volumes and architecture. A+B quadrature-Previous HitphaseNext Hit Previous HitseismicNext Hit, which is a direct sand indicator, best images the outcrop architecture given that it incorporates the AVO-response of the lithofacies. It is therefore possible to distinguish finer-grained channel margin and overbank low-density turbidites from coarser-grained high-density channel axis turbidites. It is concluded that AVO information from Previous HitseismicTop can significantly improve stratigraphic interpretations, and lead to better reservoir prediction.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005