caa a22 4500 463162552 CHVBK 20180406164752.0 cr unu---uuuuu 170326e20071001xx s 000 0 eng 10.1007/s11242-006-9080-5 doi (NATIONALLICENCE)springer-10.1007/s11242-006-9080-5 Tracer transport in a fractured chalk: X-ray CT characterization and digital-image-based (DIB) simulation [Elektronische Daten] [W. Zhu, J. Liu, D. Elsworth, A. Polak, A. Grader, J. Sheng, J. Liu] A digital-image-based simulation methodology is applied to evaluate the influence of heterogeneous porosity on the evolution of tracer concentrations in imaged tracer tests. Maps of computed tomography (CT)-number are calibrated relative to average porosity, and then thresholded to define porosity maps. These data are then used to automate the distribution of parameters within a finite element representation of the geometry. The technique is applied to characterize the variability of the porosity, the hydraulic conductivity, and the diffusivity for an artificially fractured chalk core (30×5cm). X-ray CT was used both to characterize the initial condition of the core, and then to concurrently monitor the transport of an NaI tracer within the fracture and into the surrounding matrix. The X-ray CT imaging is used to characterize the heterogeneous rock porosity, based on which the hydraulic conductivity, and diffusivity of the chalk were defined and were directly imported into our newly developed three-dimensional FEMLAB-based multiple physics simulator. Numerical simulations have confirmed the observed tracer transport behaviors: (1) The different tracer-penetration distances imaged in the matrix above and below the horizontal fracture are indicative of a greater tracer mass penetrating into the lower matrix; and (2) Transport in the matrix below the fracture was enhanced. The computer simulated tracer concentration distributions compare favorably with those monitored by X-ray CT. Springer Science+Business Media, Inc., 2006 Tracer diffusion nationallicence Rock heterogeneity nationallicence Porosity nationallicence DIB simulation nationallicence Imaging nationallicence C : Concentration in terms of mass fraction (dimensionless) nationallicence D : Diffusion coefficient (m2/s) nationallicence f k ( i , j ) : Discrete function to express the digital image in RGB color space, where k=1, 2, and 3 (dimensionless) nationallicence g : Gravity acceleration (vector) (m/s2) nationallicence H , S , I : Hue, saturation and intensity for HSI color space of the digital image (dimensionless) nationallicence k : Permeability (m2) nationallicence M , N : Number of pixels in horizontal and vertical directions for a digital image (dimensionless) nationallicence P : Fluid pressure (Pa) nationallicence R , G , B : Red, green, and blue components for RGB color space of digital image (dimensionless) nationallicence S s : The specific storativity of the porous medium (1/m) nationallicence t : Time (s) nationallicence u l ( u i l ) : Pore velocity vector of fluid (m/s) nationallicence ϕ : Porosity (dimensionless) nationallicence μ l : Liquid dynamic viscosity (Pa·s) nationallicence ρ l : Liquid density (kg/m3) nationallicence Zhu W. School of Oil and Gas Engineering, The University of Western Australia, 6009, Crawley, WA, Australia aut Liu J. School of Oil and Gas Engineering, The University of Western Australia, 6009, Crawley, WA, Australia aut Elsworth D. Department of Energy and Geo-Environmental Engineering, Penn State University, University Park, USA aut Polak A. Department of Civil and Environmental Engineering, Technion, Israel Institute of Technology, 32000, Haifa, Israel aut Grader A. Department of Energy and Geo-Environmental Engineering, Penn State University, University Park, USA aut Sheng J. School of Oil and Gas Engineering, The University of Western Australia, 6009, Crawley, WA, Australia aut Transport in Porous Media Springer Netherlands 70/1(2007-10-01), 25-42 0169-3913 70:1<25 2007 70 11242 https://doi.org/10.1007/s11242-006-9080-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11242-006-9080-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zhu W. School of Oil and Gas Engineering, The University of Western Australia, 6009, Crawley, WA, Australia aut NATIONALLICENCE 700 1- Liu J. School of Oil and Gas Engineering, The University of Western Australia, 6009, Crawley, WA, Australia aut NATIONALLICENCE 700 1- Elsworth D. Department of Energy and Geo-Environmental Engineering, Penn State University, University Park, USA aut NATIONALLICENCE 700 1- Polak A. Department of Civil and Environmental Engineering, Technion, Israel Institute of Technology, 32000, Haifa, Israel aut NATIONALLICENCE 700 1- Grader A. Department of Energy and Geo-Environmental Engineering, Penn State University, University Park, USA aut NATIONALLICENCE 700 1- Sheng J. School of Oil and Gas Engineering, The University of Western Australia, 6009, Crawley, WA, Australia aut NATIONALLICENCE 773 0- Transport in Porous Media Springer Netherlands 70/1(2007-10-01), 25-42 0169-3913 70:1<25 2007 70 11242 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer