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The spatial filtering from core-scale conductivity to the conductivity measured by a slug test Wang, Bin
Abstract
In the thesis, I investigate the measurement process of the slug test, an important and efficient engineering technique employed to probe aquifer properties. The objective is to determine the scale at which a slug test 'measures' hydraulic conductivity. To determine the scale, I conceptualize slug test measurement process in a system and filtering framework. I quantify, through numeric experiments, the spatial filtering effect of the slug test upon the core-scale hydraulic conductivity field. I examine the role of specific storage on this filtering effect. I develop two approaches to identify the system filter that epitomizes the filtering system — measurement process: spectral analysis with Wiener filtering and numerical perturbation. In heterogeneous media, system linearity is analyzed and the inverse estimation of the system output is evaluated. With the spectral approach, I optimally estimate the system filter in the presence of measurement noise. In homogeneous media where the spectral approach cannot be used, I apply the numerical perturbation approach. The spectral analysis and numerical perturbation are two conceptually different but complementary approaches. I analyze the nonparametric form of the system filter in heterogeneous media of various spatial variability and specific storage values. I determine the empirical parametric expression of equivalent filter width versus specific storage in homogeneous media. It is found that: 1. In both heterogeneous and homogeneous media, the equivalent filter width increases linearly with respect to log [mathematical formula which cannot be reproduced here; see pdf] 2. In homogeneous media, the filter amplitude decreases away from the wellbore by an approximate [mathematical formula which cannot be reproduced here; see pdf]. 3. A preliminary analysis of the role of heterogeneity characteristics upon the slugtest filtering was undertaken. The slug-test filtering was not strongly influenced by heterogeneity characteristics for log-conductivity variances less than 0.7. At variances less than 0.3, anisotropy in the conductivity field caused anisotropy in the slug-test filtering. These effects were not quantified in this thesis. In the end, I discuss the possible engineering and theoretical applications of the spatial filtering approach and make recommendations for future work.
Item Metadata
Title |
The spatial filtering from core-scale conductivity to the conductivity measured by a slug test
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1995
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Description |
In the thesis, I investigate the measurement process of the slug test, an important and
efficient engineering technique employed to probe aquifer properties. The objective is to
determine the scale at which a slug test 'measures' hydraulic conductivity. To determine
the scale, I conceptualize slug test measurement process in a system and filtering framework.
I quantify, through numeric experiments, the spatial filtering effect of the slug test
upon the core-scale hydraulic conductivity field. I examine the role of specific storage on
this filtering effect.
I develop two approaches to identify the system filter that epitomizes the filtering
system — measurement process: spectral analysis with Wiener filtering and numerical
perturbation. In heterogeneous media, system linearity is analyzed and the inverse estimation
of the system output is evaluated. With the spectral approach, I optimally
estimate the system filter in the presence of measurement noise. In homogeneous media
where the spectral approach cannot be used, I apply the numerical perturbation approach.
The spectral analysis and numerical perturbation are two conceptually different
but complementary approaches.
I analyze the nonparametric form of the system filter in heterogeneous media of various
spatial variability and specific storage values. I determine the empirical parametric
expression of equivalent filter width versus specific storage in homogeneous media. It is
found that:
1. In both heterogeneous and homogeneous media, the equivalent filter width increases
linearly with respect to log [mathematical formula which cannot be reproduced here; see pdf]
2. In homogeneous media, the filter amplitude decreases away from the wellbore by
an approximate [mathematical formula which cannot be reproduced here; see pdf].
3. A preliminary analysis of the role of heterogeneity characteristics upon the slugtest
filtering was undertaken. The slug-test filtering was not strongly influenced
by heterogeneity characteristics for log-conductivity variances less than 0.7. At
variances less than 0.3, anisotropy in the conductivity field caused anisotropy in
the slug-test filtering. These effects were not quantified in this thesis.
In the end, I discuss the possible engineering and theoretical applications of the spatial
filtering approach and make recommendations for future work.
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Extent |
14237754 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-02-09
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0052911
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
1995-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.