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Downscaling in complex geological environments using multiple-point geostatistics Jef Caers and Sebastien Strebelle Jef Caers Sebastien Strebelle Department of Petroleum Engineering ChevronTexaco Stanford University Exploration & Production Tech. Co. Stanford, CA 94305-2220 P. O. Box 6019 USA San Ramon, CA 94583-2324 Geological information and seismic data provide two complementary sources of information, at different scales, to model reservoir architecture. The true challenge in data integration is to merge both scales into a single reservoir model. Seismic allows identifying features at 10's of feet, while logs provide information on a much smaller scale. Conceptual geological models may provide information on reservoir heterogeneity at almost all scales. Application of modeling techniques that incorporate consistently all scales of data may provide significant improvements in reservoir prediction. In this presentation we outline a new geostatistical method for solving this difficult scale and data integration problem and apply it to an actual reservoir. Multiple-point geostatistics is introduced as a novel approach to downscaling large-scale seismic properties into finer scale rock facies, without suffering from some of the traditional limitations of geostatistical or other inversion methods. Multiple-point geostatistics relies on the so-called training image as a measure for describing geological continuity at all scales, rather than the traditional variogram. A data integration scheme is introduced that allows one to make maximal use of the physics of the downscaling problem, yet without compromising geological continuity. A reservoir case serves to demonstrate this novel idea. Caers, J., Strebelle, S. and Payrazyan, K., 2002. Stochastic integration of seismic and geology: a submarine channel saga. The Leading Edge, 21, November 2002. Strebelle, S., Payrazyan, K. and Caers, J., 2002. Modeling of a deepwater turbidite reservoir conditional to seismic data using multiple-point geostatistics. In: SPE Annual Conference and Technical Exhibition, San Antonio, SPE# 77425. 16p. Caers, J., Avseth, P. and Mukerji, T., 2001. Geostatistical integration of rock physics, seismic amplitudes and geological models in North-Sea turbidite systems. The Leading Edge, 20, March 2001. Strebelle, S. 2002. Conditional simulation of complex geological structures using multiple-point statistics. Math. Geol., Jan 2002