Fluvial systems and their associated deposits host globally important mineral deposits, water reserves and hydrocarbons. Crucial to the extraction of these resources is an understanding of heterogeneity distribution within deposits of fluvial systems. To constrain and predict heterogeneity distribution within fluvial deposits, outcrop data together with lidar and drone derived virtual outcrop models have been collected from the Salt Wash Distributive Fluvial System (DFS) in Utah and Colorado. The study records an analysis of sedimentary architecture, facies distribution and intra-channel heterogeneity of five study sites within the proximal, medial and distal reaches of the Salt Wash DFS. Specifically the fluvial style, lateral variability of fluvial architecture, intrachannel and overbank ratio, grainsize, channel body and storey width:thickness ratios and intrachannel heterolthics at outcrops considered representative of the proximal, medial and distal portions of a DFS have been documented. Data from the study sites have been used to generate 3D reservoir models. The models have been subject to flow simulation to better understand the significance of hetergenity variability within fluvial reservoirs at an 'inter-well' scale (approximatley 0.1 km2). An indepth workflow and methodology for measuring and describing DFS channel bodies and for the construction of a reservior flow simulation model from outcrop derived data are presented here. Data collection has involved mapping and measuring; palaeocurrents, barscale accretion surfaces, storey dimensions, channel body dimensions, facies and intrachannel heterolithics. Results show clear trends within channel channel bodies and associated deposits such as, intra channel heterogenity channel body percentage, channel body grain size, storey/channel body width thickness; which can be predicted within a distributive fluvial system context, ultimately leading to better subsurface interpretation with smaller datasets. This field based study of the Salt Wash DFS, coupled with virtual outcrop models has provided a quantitive analys's of channel body architectures and facies distributions. Additionally, field work conducted on point bar deposits now illustrates the limitations of 2D outcrops when attempting to describe meandering or braided fluvial deposits and why this may have resulted in gross underestimation of meanderbelt deposits in the fluvial rock record.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:759995 |
| Date | January 2018 |
| Creators | Swan, Alistair Michael |
| Contributors | Hartley, Adrian J. ; Howell, John A. ; Owen, Amanda |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=239012 |
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