Publication Date:
2010-03-01
Description:
This study uses one-dimensional convolution seismic models to better understand which features of slope turbidite systems can (or cannot) be observed on real seismic data, aiming to improve subsurface seismic interpretation. Synthetic seismic sections and cubes were built from reservoir-scale three-dimensional facies models of the outcropping Ainsa turbidite system. This turbidite system developed in a foredeep and wedge-top depositional setting within a slope system. The turbidite system consists of laterally and vertically stacked sandstone- and debrite-dominated channel fills, grading into heterolithic and mudstone units, with intercalations of slump-deformed mudstone-rich units. Typical petrophysical values for subsurface Cenozoic sediments were assumed for the seismic models, which are presented at 25-, 50-, and 75-Hz resolution. Seismic models enabled the comparison between architectural and facies distributions observed in the outcrops and the geological models to their possible seismic expression in the subsurface. Comparisons show how seismic expression degrades when seismic resolution decreases. By using models at different geological scales, the effects of each heterogeneity scale are identified. Precise delineation of the internal architecture and facies distribution within channel complexes is beyond the reach of all seismic frequencies. The position of channel complex tops and margins is uncertain because of their gradual character. Differentiating between sandstone- and debrite-filled channels is not straightforward, and bed-scale heterogeneities within the sandstone-dominated channels are barely distinguishable in the seismic data. The net-to-gross predictive capability of root-mean-square amplitude extractions varies depending on the seismic frequency and unit thickness. Oriol Falivene received his Ph.D. in reservoir-scale facies modeling of outcrop analogs from the Geomodels Institute-Group of Geodynamics and Basin Analysis (University of Barcelona) in January 2007. He worked for a year and a half for BP in London on reservoir modeling and sedimentology-stratigraphy. He is currently working for Shell International Exploration and Production, doing research in stratigraphic forward modeling and its application to hydrocarbon exploration. Pau Arbués received his degree in geology in 1987 from the Universitat Autonoma de Barcelona. He has worked as an independent consultant for 11 years, contracting research for the Servei Geologic de Catalunya and various oil companies. For the last 11 years, he has been working as a researcher in sedimentology for the Geomodels-Geodynamics and Basin Analysis Group (Universitat de Barcelona). Juanjo Ledo is professor of geophysics at the Universitat de Barcelona since 2003. He received his Ph.D. in 1996 from the Universitat de Barcelona, and after that, he did a PostDoc at the Geological Survey of Canada in Ottawa (1997–2002). In 2002, he obtained a Ramón y Cajal award from the Spanish Government to return to the Universitat de Barcelona. His research interest includes the geophysical characterization of reservoirs at different scales, joint interpretation of geophysical (mainly EM) and geological data of near-surface geological structures as well as investigation of the crust and upper mantle. Beatriz Benjumea received a Ph.D. (1999) in geophysics from the University of Granada (Spain). Her postdoctoral experience included near-surface seismics research at the Geological Survey of Canada. She currently works at the Institut Geologic de Catalunya (Spain) and collaborates as an assistant teacher in the master course of geophysics of the University of Barcelona (Spain). Her research interests include application of shallow seismic reflection and refraction methods to determine and characterize near-surface structures and its integration with other geophysical and geological data. Josep Anton Muñoz is a professor of structural geology at the Universitat de Barcelona. He received his Ph.D. in 1985 from the Universitat de Barcelona and worked for the Servei Geologic de Catalunya from 1985 to 1990, when he joined the Universitat de Barcelona. His research interests include the structure of thrust and fold belts, tectonosedimentary relationships, tectonics of collisional orogens, and construction of three-dimensional structural models. He is currently the director of the Geomodels Research Institute. Oscar Fernández obtained his Ph.D. in earth sciences from the Universitat de Barcelona in 2004. Since then, he has consulted worldwide on structural geology for Midland Valley Exploration and has been part of the FracPerm development team for Roxar. He is currently part of the Geoscience and Subsurface Description team in the Exploration and Production Technology group in BP. Sara Martínez-Loriente did her final undergraduate report dealing with the generation of synthetic seismic profiles within the Group of Geodynamics and Basin Analysis (University of Barcelona) in 2006. She is currently undertaking her Ph.D. in the Marine Technology Unit of the CSIC. She spent the last three years learning the acquisition, processing, and interpretation of multichannel seismic profiles, as well as refraction and wide-angle reflection seismic data.
Print ISSN:
0149-1423
Electronic ISSN:
1943-2674
Topics:
Geosciences
Permalink