Suitability of Archie's Law for Interpreting Electrical Resistivity Data

57 Pages·2012·8.62 MB·English

by  Kamini Singha

Advances in Geophysical Tools
for Estimating Hydrologic
Parameters and Processes
Kamini Singha
Hydrologic Science and Engineering
Colorado School of Mines

With contributions from: Andrew Binley, Fred Day-Lewis,
Tim Johnson, Niklas Linde, Burke Minsley, Dale Rucker,
Frédéric Nguyen, Jonathan Nyquist, Adam Pidlisecky,
Lee Slater, Remke Van Dam, Jan van der Kruk
Motivation
Need to quantify the operation of aquifer
parameters controlling flow and transport
• To determine availability of water for removal
• To assess risk & create schemes for contaminant cleanup

hydraulic contaminant
conductivity concentration
high
Z
Z
low
Y
X
X
[Singha, CSM]
Motivation
The
problem…
[Hartman et al., JCH, 2007]
[British Geological Survey, 2004]
[British Geological Survey, 2004]
[Binley, Lancaster]
Motivation
We have these:
[Binley, Lancaster]
Motivation
Or we might be lucky
and have one of these:
[LeBlanc et al., 1991, WRR, Large-scale natural gradient tracer test in sand and gravel, Cape
Cod, Massachusetts, 1, Experimental design and observed tracer movement]
Advantages of Geophysics
Geophysics offers advantages over conventional sampling
to the hydrologist because of:
High data sampling density
Relative lower cost of measurements
Minimally invasive
Larger measurement volume
[Binley, Lancaster]
Scale of measurement
Acquisition approaches
near this end of the
chart provide
low resolution
information over large
spatial extents
m
l
a 4
N n 0
O o 1 Airborne/Satellite
i o
IT ge 1t (G, H)
A R 0 Surface
1
GITS ~ 20 G(Ge)ophysics
l
E a 1 Crosshole
V c o
N o t measurements (G,H)
L 2
I -0 Wellbore and well tests (H)
F 1
O ~ Logging (G,H)
r
S o
E y 1
L ro -01 Core
A tatn o Measurements
C rio t (G,H)
S oP 4
b -0
a 1
L ~
~10-3 to 1 ~10-1 to 10 ~10 to 102 m
Acquisition approaches
near this end of the High Moderate Low
chart provide
high resolution
RELATIVE RESOLUTION
information over small
spatial extents
[Rubin and Hubbard, 2005, Hydrogeophysics]
History
Early geophysical studies concentrated on defining
lithological boundaries and other subsurface structures.

[Zohdy, 1965, GW,
Geoelectrical and
seismic refraction
investigations near
San Jose, California]
Moving Forward with Static Images
• Can distinguish lithologic units in some
geologic settings
• Characteristics of GPR reflectors differs with
depositional environment
[Jol and Smith, 1991, CJES, Ground Penetrating Radar of Northern Lacustrine Deltas]