Publication Date:
2006-07-01
Description:
Using data from an outcrop characterization of a sandstone-rich turbidite channel fill (the so-called “Quarry outcrop” in the Ainsa basin), several stochastic facies models were constructed at bed-scale resolution (cells 2.5 m [8 ft] wide and 0.05 m [2 in.] thick). Several industry-standard reservoir-modeling algorithms were employed: truncated Gaussian simulation, sequential indicator simulation, multiple-point geostatistics, and object-based methods with varying degrees of complexity. The degree of similarity (i.e., realism) between realizations and the outcrop characterization was quantified through the use of several responses: (1) static connectivity, (2) effective permeability, and (3) recovery efficiency from waterflood simulations. Differences in the responses measured from the outcrop and facies models were observed: these are mostly algorithm related, instead of caused by soft data or different stochastic realizations. Differences increase greatly when the permeability of the heterolithic packages and mudstone beds (Ht-M) decreases and reflect the methods' ability to model the inclined and undulating Ht-M packages and beds that occur in the outcrop. These packages and beds can drape scours and sandstone beds with depositional topography and pinch-outs, producing sandstone thinning and dead ends. Object-based methods capable of introducing highly undulating Ht-M beds provided the most realistic models. Variogram-based and simple object-based methods failed to capture and reproduce the whole length of undulating beds. Multiple-point geostatistics provided realizations with responses intermediate between variogram-based and simple object-based methods and the more successful advanced object-based methods. The conditioning-to-hard-data capabilities of multiple-point geostatistics are higher than those of the object-based methods, which give them an added advantage. Oriol Falivene received his degree in geology in 2002 from the Universitat de Barcelona. Currently, he is finishing his Ph.D. dissertation dealing with reservoir-scale modeling of outcrop analogs in the Geomodels–Geodynamics and Basin Analysis Group (Universitat de Barcelona). His areas of study include turbidite and alluvial-fan reservoir analogs. Pau Arbués received his degree in geology in 1987 from the Universitat Autònoma de Barcelona. He has worked as an independent consultant for 11 years, contracting research for the Servei Geològic de Catalunya and various oil companies. For the last 7 years, he has been working as a researcher in sedimentology for the Geomodels–Geodynamics and Basin Analysis Group (Universitat de Barcelona). Andy Gardiner graduated in 1974 from Churchill College, Cambridge, before undertaking Ph.D. research on fluviodeltaic sedimentology at the University of Leeds. From 1978 to 1984, he taught in the Universities of Swansea and Liverpool, before spending 13 years with Robertson Research International, where he worked on a wide range of exploration and development studies. In 1997, Andy moved to Heriot-Watt University, where his research interests include reservoir modeling, using both outcrop-derived and generic reservoir geometries, with the aim of examining the impact of geological heterogeneity on hydrocarbon recovery. Gillian Pickup gained her B.Sc. degree and Ph.D. in astrophysics from Edinburgh University, but since then has worked on more down-to-earth subjects. She joined the Department (now Institute) of Petroleum Engineering at Heriot-Watt University in 1990 to work on a project assessing the effect of geological heterogeneity on oil recovery. Her main research interest is in upscaling, i.e., taking account of fine-scale structures in coarse-scale models. Recently, she has also started investigating the effects of uncertainty in reservoir models at different scales. 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 Geològic 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, at present, the director of the Geomodels Research Center. Lluís Cabrera is a professor of stratigraphy at the Universitat de Barcelona, where received his Ph.D. in 1983 and is, at present, the head of the Special Research Center (CER) of 3D Geological Modeling. His research interests include the application of clastic sedimentology, sequence stratigraphy, and the three-dimensional reconstruction and modeling of sedimentary bodies to the exploration, development, and production of coal and oil.
Print ISSN:
0149-1423
Electronic ISSN:
1943-2674
Topics:
Geosciences
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