Print this pageThe Empirical Relationship Between Water Saturation and Seismic Wave 
Attenuation
in Unconsolidated Sand
Jie Shen
Louisiana
State
University,
Department
of
Geology
and
Geophysics,
Baton
Rouge,
LA,
USA
[email protected]
Compressional
(P)
and
shear
(S)
waves
have
long
been
used
to
study
the
subsurface.
However,
current
constitutive
models
and
fluid-substitution
models
derived
from
hard-rock
cases
do
not
properly
predict
seismic
velocities
in
water
saturated
unconsolidated
sand.
The
current
empirical
model
for
explaining
seismic
wave
attenuation
as
a
function
of
water
saturation
in
sandstone
does
not
fit
data
for
unconsolidated
sand.
While
P-wave
and
S-wave
velocity
analysis
can
teach
us
much
about
the
elastic
properties
of
soils,
seismic
attenuation
can
tell
us
much
about
the
inelastic
properties
of
the
pore
fluids.
I
seek
to
use
the
attenuation
of
seismic
P- waves
and
S-waves
to
determine
water
saturation
in
unconsolidated
sand.
I
collect
P-wave
and
S-wave
data,
varying
water
saturation
in
a
sand
filled
tank
that
can
be
filled
with
water
to
any
depth
desired.
I
also
deploy
moisture
meters
to
directly
measure
water
saturation
in
unconsolidated
sand.
From
the
experimental
data,
I
extract
the
seismic
wave
attenuation
for
different
water
saturations
and
determine
the
empirical
relationship
between
the
seismic
wave
attenuation
and
water
saturation
in
unconsolidated
sand.
The
results
should
be
applied
to
estimate
water
saturation
seismically
in
unsaturated
unconsolidated
sand
and
carry
implications
for
reservoir
characterization,
soil
evaluation
and
contamination
remediation.
Understanding
seismic
characterization
of
unconsolidated
sediments
will
provide
information
on
soils
and
related
geological
environments
for
interpretation
of
seismic
measurements
in
sediments.
AAPG Search and Discovery Article #90183©2013 AAPG Foundation 2013 Grants-in-Aid Projects