Characterization of fluvial architectural elements using a three-dimensional outcrop data set: Escanilla braided system, South-Central Pyrenees, Spain

Hydrocarbon recovery in clastic reservoirs depends essentially on how well we understand the precise architecture of sand bodies and intercalated shaly baffles and barriers. Various methods have been developed for enriching the fundamental data collection from outcrop analogs; these include Terrestrial Laser Scanning (ground-based lidar), digital photogrammetry, high-precision GPS survey, etc. The three-dimensional outcrop data sets collected using these methods are critical for understanding the link between seismic-scale and well-scale data in the subsurface. This study illustrates a methodology for integrating three-dimensional outcrop data, interpreting that data, and integrating the resulting interpretations with data from traditional outcrop measurements. A reservoir model of a fluvial sequence from the Escanilla Formation in the Ainsa Basin of northern Spain was produced using this methodology. Three-dimensional aerial photographs and laser scanner outcrop capture techniques provide a robust and flexible data set that can spatially constrain the modeling of observed features. The three-dimensional outcrop reconstruction, coupled with sequence stratigraphy concepts, enables the morphology, size, and distribution of key architectural elements to be modeled in subsurface reservoirs. The reservoir model constructed from these data allows geologists and reservoir engineers to evaluate the critical differences between real and modeled heterogeneities and provides a mechanism for an improved understanding of modeling subsurface reservoirs.