Saudi Aramco: Company General Use Testing the Predictive Value
of Image-Based Computation of Relative Permeability Yildiray CINAR
The 2 nd KFUPM workshop on Digital Rock Physics April 8-9, 2015
Saudi Aramco Reservoir Management Department Copyright 2015, Saudi
Aramco. All rights reserved.
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Saudi Aramco: Company General Use Contributors Ph.D. Student:
Furqan Hussain (UNSW) Postdocs: Dr. Ji-Youn Arns (UNSW), Dr.
Michael Turner (ANU) Supervision for project & experiments: Dr.
Yildiray Cinar (UNSW) Supervision for computations: A/Prof
Christoph Arns (UNSW) Senior Advisor: Professor Val Pinczewski
(UNSW) UNSW = University of New South Wales, Sydney ANU =
Australian National University, Canberra
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Saudi Aramco: Company General Use Outline Previous Work
Experimental Approach Images of Saturation Distributions
Experimental Difficulties Computation of Relative Permeability
Concluding Remarks
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Saudi Aramco: Company General Use Workflow and Aim Digital Core
Analysis Core Sample Image Extraction Conventional Core Analysis
Image-based MODELLING Test of the predictive value of image-based
modelling for multiphase flow properties Facilities at UNSW &
ANU (Australia)
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Saudi Aramco: Company General Use Few studies have been
conducted (Auzerais et al., 1996; Turner et al., 2004; Jin et al.,
2007; Silin and Patzek, 2009; and Shabro et al., 2010) Previous
studies have had the following issues: Limited laboratory data for
validation Resolution of the micro-CT images Subset size used in
the computations Lack of imaged fluid distributions to validate
simulated fluid distributions Previous Work
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Saudi Aramco: Company General Use Experiments LDk mm Darcy -CT
scale Experiment 2150.2361.7 Conventional scale experiment
53250.2441.7 Steady-state experiments were performed on two sister
plugs (one large, one small) of Bentheim sandstone The small scale
core was imaged for fluid distributions after each steady-state
condition Experimental Design
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Saudi Aramco: Company General Use Current studyren
Porosity0.2440.23-0.24 Permeability (Darcy)1.72.7-3.0 IFT (mN/m)35
Large-scale Experimental Results
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Saudi Aramco: Company General Use Large-scale relative
permeability curves were used to choose injection ratios for small
scale experiment. A dry image was taken. Sample plasma cleaned for
strong and uniform wettability. Vacuum saturated with brine. 10, 90
and 100% of oil injection were chosen for small scale experiments.
(Oil=soltrol+iodododecane) These ratios represent following images
0% Dry image 10% Partially wet image (Wet-1) 90% Partially wet
image (Wet-2) 100% Partially wet image (Wet-3) Small-scale
Core
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Saudi Aramco: Company General Use Dry Image Tomogram
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Saudi Aramco: Company General Use Wet Image -1
(Registered)
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Saudi Aramco: Company General Use Wet Image 2 (Registered)
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Saudi Aramco: Company General Use Wet Image -3
(Registered)
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Saudi Aramco: Company General Use Wet Image - 1
(Segmented)
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Saudi Aramco: Company General Use Wet Image - 2
(Segmented)
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Saudi Aramco: Company General Use Wet Image - 3
(Segmented)
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Saudi Aramco: Company General Use ExperimentImaging
Porosity0.2440.223 Permeability (Darcy)1.72.0 Water
Saturation_wet10.590.62 Water Saturation_wet20.420.50 Water
Saturation_wet30.270.25 Experimental and Image Porosity &
Saturations
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Saudi Aramco: Company General Use Porosity and Saturation
Profiles
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Saudi Aramco: Company General Use Fluid distribution can be
obtained by Directly from wet images (image-based) Simulations run
over dry image (CDT-based) Image-based computation: A pressure
differential is imposed across the faces of the sub-volume (840 3
voxel) orthogonal to the axis of the plug and the flow rate is
computed for no- flow boundary conditions on the other faces of the
cube and no-slip condition at the solid-fluid interfaces. The
velocity field is determined by solving the Stokes equation and
mass conservation in the digitised pore-space image. The
computation is carried out using the finite-difference technique of
Shabro et al (2010). Effective permeability to each phase is then
computed using Darcys law. Computation of Relative
Permeability
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Saudi Aramco: Company General Use Imaged Simulated S w = 62% S
w = 50%S w = 25% S w = 60%S w = 53%S w = 23% Comparison between
Imaged and Simulated Distributions
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Saudi Aramco: Company General Use Large-scale Experiment vs.
Computations OIL WATER
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Saudi Aramco: Company General Use Snap-off Observed in Imaged
Distributions
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Saudi Aramco: Company General Use Comparisons between Models
Ramstadt et al. (2012) reported on Lattice-Boltzmann simulations of
relative permeabilities conducted on pore-space images for Bentheim
sandstone.
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Saudi Aramco: Company General Use Simulations on the images
generate similar fluid distributions to experimental fluid
distributions under steady-state conditions. Image-based modelling
predictions match with experimental data and are reliable. For a
homogeneous rock, large-scale experiments provide a better base for
testing the capability of image-based computations due to lesser
experimental inaccuracy. Relatively small imaged volume may be an
advantage in terms of rock typing (provided it captures REV well).
This study appeared in Transport in Porous Media 104 (1), 91- 107,
2014 Conclusions
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Saudi Aramco: Company General Use 840 3 and 1400 3 comparison
shows that the rock is fairly homogeneous Computations on Simulated
Fluid Distributions
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Saudi Aramco: Company General Use Current Study 840 3 21 3
pores and 1400 3 34 3 pores Arns et al. (2002) 5 X Correlation
length 750 3 (from two point function) ren et al. (1998) 30 3 pores
Kheem et al. (2002) 25 3 pores Minimum REV
Slide 26
Saudi Aramco: Company General Use Comparison of Phases in
Imaged Distributions