Geoscience Reference
In-Depth Information
Electric potential (normalised)
10
0
−10
25
30
35
40
45
50
0
5
10
15
20
Time (ms)
(a)
Background corrected potential
0.02
0
−0.02
0
5
10
15
20
25
30
35
40
45
50
Time (ms)
(b)
Pressure ield at focus point B (normalised)
P
(
B, t
)
2
0
−2
0
5
10
15
20
25
30
35
40
45
50
Time (ms)
(c)
Figure 6.5
Beamforming at point B.
a)
Time series of the electrical potential at electrode E45. The time series shows both the
seismoelectric conversions and the coseismic field. The interface response is not detectable.
b)
Difference of two time series: the
electric potential in the top graph minus the electric potential recorded at the same location but for a homogeneous background
(reference model). There is no conversion which is consistent with the fact that point B is not associated with a heterogeneity.
c)
Time series of the pressure field at point B,
P
(B,
t
).
Well A (injector)
Well B (producer)
Water saturation at snapshot T3
water
oil
PML
2340
0.65
0.6
2360
PML
0.55
2380
Reservoir
0.5
0.45
2400
0.4
2420
0.35
2440
0.3
0.25
50
100
150
200
Offset (m)
Seismic sources and receivers
Figure 6.6
Sketch of the domain used for modeling. The total modeling domain is a 410 m× 250 m rectangle. Injector Well A,
located at position
x
=0 m, is also used for the seismic source. Production and recording Well B is located at
x
= 250 m. The
discretization of the domain comprises a finite-element mesh of 205 × 125 rectangular cells. Twenty-eight receivers are located in
Well B, approximately 30 m away from the nearest PML boundary (the PML boundary layers are shown in gray). (
See insert
for color representation of the figure
.)
