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Characterizing Static and Dynamic Reservoir Connectivity of Deep Water Slope Deposits Using Detailed Outcrop-Based Facies Models, Tres Pasos Formation, Magallanes Basin, Chile

Abstract

A better understanding of deep-water slope deposits is becoming increasingly important as petroleum exploration ventures progressively further offshore. With well costs of 100's of millions of dollars, limited seismic resolution and sparse well control, other methods of insight into these systems are of increased importance. Leveraging outcrop analogs can aid in understanding the effects of intra- and inter-channel architecture, which is beyond the resolution of seismic imaging and is difficult to deduce with well data. Information produced from the study of outcrop analogs can influence reservoir management decisions, including well planning and recovery optimization. Detailed slope channel facies models, based on the Laguna Figueroa section of the well-exposed Tres Pasos Formation in Chilean Patagonia, elucidate facies connectivity and the effects of intra-channel heterogeneity on fluid flow. Sedimentary data includes over 1,600 meters of cm-scale measured section and over 100 paleoflow measurements collected along the Laguna Figueroa study area (∼2.5km long and 130m thick). Additionally, 310 meters of gamma ray scintillometer transects were collected; measurements were spaced at 30 cm increments to mimic industry data resolution. Thousands of differential GPS points (10 cm accuracy) were surveyed in order to delineate key stratigraphic surfaces, including channel boundaries. Based on the outcrop data a detailed, half-meter scale base-case model of inter-channel element architecture was developed to reflect observed facies geometries. Additionally, three bypass drape and channel-width configurations were applied to the base case model. Static and dynamic connectivity analyses were run using these cases in order to characterize intra- and inter-channel facies controls on connectivity in three dimensions and to explore fluid flow metrics such as sweep and recovery efficiency. Furthermore, as models generally must to be upscaled for flow simulation, we investigated which components are critical to maintain during the upscaling process to preserve accurate fluid flow predictions. Our results show that by utilizing quantitative outcrop-based analogs for channel slope settings we can further our understanding of how the fine-scale sedimentological detail and geometric architecture of deep-water channels affects fluid flow and hydrocarbon recovery. Ultimately, this work aims to help mitigate the risks of connectivity by building more predictive models.