THE IMPACT OF BED- TO GEOBODY-ARCHITECTURE ON RESERVOIR PREDICTION: HYPOTHESIS-BASED MODELING IN A DEEP-WATER DEPOSITIONAL ENVIRONMENT

Heterogeneity controls fluid flow in porous media and can have significant implications for contaminant transport, aquifer storage and recovery, CO2 sequestration and hydrocarbon recovery. Heterogeneities can either be depositional, structural or diagenetic in nature. Geocellular fluid flow models aid in predicting storage and transport of fluids in the shallow (10’s to 100’s of meters) and deep (1000’s of meters) subsurface. Depositional architecture impacts fluid flow by controlling locations of extremes in permeability. Extremes such as low permeability flow barriers and high permeability thief zones can create regions of rapid transport or, conversely, compartmentalization. Forward modeling including depositional architecture is a valuable tool to help understand how bed- to geobody-scale architecture impacts fluid flow. Where the architecture cannot be defined, such modeling is valuable to test hypotheses of possible architectures.

We present outcrop-constrained bed- to geobody-scale models (i.e., grid cells 2 m areally and 0.25 m vertically) to elucidate the fundamental impact of deep-water channel element architecture on fluid flow. Models are constructed from the Laguna Figueroa section of the well-exposed Upper Cretaceous Tres Pasos Formation in Chilean Patagonia. The models are based on observations and statistical analyses from > 1,600 meters of cm-scale measured section from an ~2.5 km long by 130 m thick outcrop belt. Fluid flow from a single channel element model are compared to those from a model composed of two stacked channel elements. This simplified approach presents predictable patterns in the relationship between the stacking patterns and internal architecture of sub-seismic scale channel element architecture and fluid flow connectivity.