High resolution 3D seismic interpretation of Mesozoic carbonate reservoir geobodies, examples from the US Gulf of Mexico
In this study, we used an offshore 3D dataset provided by TGS and another onshore 3D legacy dataset. Together, these 2 surveys cover tens of thousands of square kilometers of Mesozoic carbonates in the Gulf of Mexico (GOM). The offshore volume images several upper Jurassic to Lower Cretaceous carbonate shelf margins of the Northeastern GOM along the Florida Escarpment while the onshore volume only shows Albian margins in the Maverick Basin, an intrashelf basin located in the western GOM. To interpret these two 3D volumes, we used a combination of traditional horizon mapping with Paleoscan automatic horizon stack extraction to generate hundreds of accurate horizon-slices that were painted with a color blending of 3 spectral decomposition bands (25, 40, and 55 Hz). This high-resolution seismic geomorphology techniques allows to extract the seismic expression of complex carbonate geomorphology and to image the spatial and temporal distribution of single carbonate architectural element that have the potential to be reservoir geobodies in the subsurface. We will show examples of beach/strand-plain accretion of the Upper Jurassic Smackover ramp, evaporite karst and dissolution features of the uppermost Jurassic shelf, reticular ridges interpreted has being coral-stromatoporid/Lithocodium reef buildups on the Berriasian shelf, spectacular sinuosidal tidal bars and channels of the upper Aptian shelf as well as Albian patch reef and bar complex along the Maverick Intrashelf margin. Finally, we will compare a karst network is located at the Albian shelf edge that extend for 2-5 km in the sip direction and more than 40 km in the strike direction with seismic model of a size equivalent modern cave. These large regional seismic volumes image large portion of entire carbonate shelf, margin to slope systems at a high-enough resolution that allows to image and interpret individual architectural elements and their spatio-temporal evolution. Precise horizon-slices combined with spectral decomposition blending provides a level of details that cannot be seen on traditional vertical or time/depth slices only.
In this study, we used an offshore 3D dataset provided by TGS and another onshore 3D legacy dataset. Together, these 2 surveys cover tens of thousands of square kilometers of Mesozoic carbonates in the Gulf of Mexico (GOM). The offshore volume images several upper Jurassic to Lower Cretaceous carbonate shelf margins of the Northeastern GOM along the Florida Escarpment while the onshore volume only shows Albian margins in the Maverick Basin, an intrashelf basin located in the western GOM. To interpret these two 3D volumes, we used a combination of traditional horizon mapping with Paleoscan automatic horizon stack extraction to generate hundreds of accurate horizon-slices that were painted with a color blending of 3 spectral decomposition bands (25, 40, and 55 Hz). This high-resolution seismic geomorphology techniques allows to extract the seismic expression of complex carbonate geomorphology and to image the spatial and temporal distribution of single carbonate architectural element that have the potential to be reservoir geobodies in the subsurface. We will show examples of beach/strand-plain accretion of the Upper Jurassic Smackover ramp, evaporite karst and dissolution features of the uppermost Jurassic shelf, reticular ridges interpreted has being coral-stromatoporid/Lithocodium reef buildups on the Berriasian shelf, spectacular sinuosidal tidal bars and channels of the upper Aptian shelf as well as Albian patch reef and bar complex along the Maverick Intrashelf margin. Finally, we will compare a karst network is located at the Albian shelf edge that extend for 2-5 km in the sip direction and more than 40 km in the strike direction with seismic model of a size equivalent modern cave. These large regional seismic volumes image large portion of entire carbonate shelf, margin to slope systems at a high-enough resolution that allows to image and interpret individual architectural elements and their spatio-temporal evolution. Precise horizon-slices combined with spectral decomposition blending provides a level of details that cannot be seen on traditional vertical or time/depth slices only.
