Xavier Janson, Sergey Fomel, 2011. "3-D Forward Seismic Model of an Outcrop-Based Geocellular Model", Outcrops Revitalized: Tools, Techniques and Applications, Ole J. Martinsen, Andrew J. Pulham, Peter D.W. Haughton, Morgan D. Sullivan
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Because of their fast acoustic velocity, their ability to create steep slopes, and their important postdepositional diagenetic modification, carbonate rocks are notoriously more difficult to image and interpret using seismic than siliciclastic rocks. This paper shows how building a 3-D synthetic seismogram based on well-constrained outcrop-based 3-D geocellular models can help in seismic interpretation and seismic-based reservoir characterization. Workflow to populate a 3-D geological model with velocity is presented that is based on building statistical distribution of velocity per facies or lithostratigraphic units or diagenetic features and extrapolating velocity through the model using stochastic Gaussian simulation. A 3-D model built from Lower Permian deep-water carbonate gravity flows is used to demonstrate the complexity of interpreting intricate 3-D geometries using 2-D planar seismic slices and to assess volumetric error associated with the intrinsic resolution loss of seismic. Modern karst morphology is used to assess the seismic response of caves, sinkholes, or karst topography in seismic. Finally, a Permian dolomitized ramp-crest grainstone complex is used to test the sensitivity of prestack techniques to pore-type changes in grainy carbonate rocks. These few examples illustrate the strength of building a well-calibrated 3-D synthetic seismogram based on a 3-D geocellular model so that some of the complexity of seismic response of carbonate rocks might be unraveled.