Uncertainty analysis of fluvial outcrop data for stochastic reservoir modelling

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doi: 10.1144/1354-079303-615
Authors:Martinius, A. W.; Naess, A.
Author Affiliations:Primary:
Statoil Research Centre, Trondheim, Norway
Volume Title:Petroleum Geoscience
Source:Petroleum Geoscience, 11(3), p.203-214. Publisher: Geological Society Publishing House for EAGE (European Association of Geoscientists & Engineers, London, United Kingdom. ISSN: 1354-0793
Publication Date:2005
Note:In English. 55 refs.; illus., incl. 4 tables, geol. sketch map
Summary:Uncertainty analysis and reduction is a crucial part of stochastic reservoir modelling and fluid flow simulation studies. Outcrop analogue studies are often employed to define reservoir model parameters but the analysis of uncertainties associated with sedimentological information is often neglected. In order to define uncertainty inherent in outcrop data more accurately, this paper presents geometrical and dimensional data from individual point bars and braid bars, from part of the low net:gross outcropping Tortola fluvial system (Spain) that has been subjected to a quantitative and qualitative assessment. Four types of primary outcrop uncertainties are discussed: (1) the definition of the conceptual depositional model; (2) the number of observations on sandstone body dimensions; (3) the accuracy and representativeness of observed three-dimensional (3D) sandstone body size data; and (4) sandstone body orientation. Uncertainties related to the depositional model are the most difficult to quantify but can be appreciated qualitatively if processes of deposition related to scales of time and the general lack of information are considered. Application of the N0 measure is suggested to assess quantitatively whether a statistically sufficient number of dimensional observations is obtained to reduce uncertainty to an acceptable level. The third type of uncertainty is evaluated in a qualitative sense and determined by accurate facies analysis. The orientation of sandstone bodies is shown to influence spatial connectivity. As a result, an insufficient number or quality of observations may have important consequences for estimated connected volumes. This study will give improved estimations for reservoir modelling.
Sections:Petrology
Subsections:Sedimentary petrology
Subjects:Basin analysis; Basins; Clastic rocks; Depositional environment; Fluid phase; Fluvial sedimentation; Mesozoic; Models; Movement; Paleoenvironment; Petroleum; Petroleum exploration; Reservoir rocks; Risk assessment; Sandstone; Sedimentary basins; Sedimentary rocks; Sedimentary structures; Sedimentation; Simulation; Stochastic processes; Uncertainty; Visualization; Castilla-La Mancha Spain; Cuenca Spain; Europe; Iberian Peninsula; Southern Europe; Spain
Coordinates:N380200 N403800 W0005500 W0052500
Abstract Numbers:05M/3001
Record ID:2006039603
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from The Geological Society, London, London, United Kingdom
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