Continuous seismic reservoir monitoring using a common focus point method
A method of continuous seismic reservoir monitoring includes receiving a plurality of seismic data sets associated with a reservoir during a period, where the plurality of seismic data sets corresponds to seismic data received at different times during the period. The reservoir includes a plurality of reflectors, where each reflector has a reflection coefficient. For each of the plurality of seismic data sets, the reflection coefficients of the plurality of reflectors are determined by iteratively updating common focus point (CFP) operators associated with the plurality of reflectors and a plurality of acquisition surface locations. The reflection coefficients corresponding to different seismic data sets are compared to determine changes of the reflection coefficients during the period. The changes of the reflection coefficients are displayed.
1. A method for continuous seismic reservoir monitoring of seismic reservoirs, comprising:
receiving a plurality of seismic data sets associated with a reservoir during a period of time, wherein the plurality of seismic data sets corresponds to seismic data received at different times during the period of time, and the reservoir includes a plurality of reflectors, wherein each reflector has a reflection coefficient;
for each of the plurality of seismic data sets, determining reflection coefficients of the plurality of reflectors by iteratively updating common focus point (CFP) operators associated with the plurality of reflectors and a plurality of acquisition surface locations;
comparing the reflection coefficients corresponding to different seismic data sets to determine changes of the reflection coefficients during the period of time; and
displaying, for presentation to a user as part of the continuous seismic reservoir monitoring, the changes of the reflection coefficients, including:
displaying, relative to x and y directions of a target horizon, differences of normalized root mean square (NRMS) amplitudes of the changes of the reflection coefficients; and
representing amplitudes of the differences of the NRMS amplitudes of changes of the reflection coefficients using different colors mapped to a color spectrum of a continuous range of a NRMS amplitudes.
2. The method of claim 1 , wherein each CFP operator indicates a propagation time between a particular reflector and a particular acquisition surface location.
3. The method of claim 1 , wherein iteratively updating CFP operators associated with the plurality of reflectors and the plurality of acquisition surface locations comprises, for a particular reflector z m and a particular acquisition surface location z 0 , calculating an updated CFP operator at (i+1)th iteration using
F
(
i
+
1
)
(
z
0
,
z
m
)
=
F
(
i
)
(
z
0
,
z
m
)
Δ
F
(
i
)
(
z
0
,
z
m
)
and
Δ
F
(
i
)
(
z
0
,
z
m
)
=
e
i
ω
Δ
T
(
i
)
2
,
where ΔT (i) is a residue propagation time determined based on differential time shift (DTS) gathers in ith iteration.
4. The method of claim 3 , further comprising for the particular reflector zm and the particular acquisition surface location z 0 , determining an initial CFP operator based on an initial estimate of a propagation time between the particular reflector zm and particular acquisition surface location z 0 .
5. The method of claim 1 , further comprising, for each of the plurality of seismic data sets, generating a three-dimensional seismic image of the reservoir based on the determined reflection coefficients of the plurality of reflectors.
6. The method of claim 1 , wherein the plurality of acquisition surface locations comprises seismic source locations and seismic receiver locations.
7. The method of claim 1 , wherein the reservoir comprises a hydrocarbon liquid.
8. A system for continuous seismic reservoir monitoring of seismic reservoirs, comprising:
a computer memory; and
one or more hardware processors interoperably coupled with the computer memory and configured to perform operations comprising:
receiving a plurality of seismic data sets associated with a reservoir during a period of time, wherein the plurality of seismic data sets corresponds to seismic data received at different times during the period of time, and the reservoir includes a plurality of reflectors, wherein each reflector has a reflection coefficient;
for each of the plurality of seismic data sets, determining reflection coefficients of the plurality of reflectors by iteratively updating common focus point (CFP) operators associated with the plurality of reflectors and a plurality of acquisition surface locations;
comparing the reflection coefficients corresponding to different seismic data sets to determine changes of the reflection coefficients during the period of time; and
displaying, for presentation to a user as part of the continuous seismic reservoir monitoring, the changes of the reflection coefficients, including:
displaying, relative to x and y directions of a target horizon, differences of normalized root mean square (NRMS) amplitudes of the changes of the reflection coefficients; and
representing amplitudes of the differences of the NRMS amplitudes of changes of the reflection coefficients using different colors mapped to a color spectrum of a continuous range of a NRMS amplitudes.
9. The system of claim 8 , wherein each CFP operator indicates a propagation time between a particular reflector and a particular acquisition surface location.
10. The system of claim 8 , wherein iteratively updating CFP operators associated with the plurality of reflectors and the plurality of acquisition surface locations comprises, for a particular reflector z m and a particular acquisition surface location z 0 , calculating an updated CFP operator at (i+1)th iteration using
F
(
i
+
1
)
(
z
0
,
z
m
)
=
F
(
i
)
(
z
0
,
z
m
)
Δ
F
(
i
)
(
z
0
,
z
m
)
Δ
F
(
i
)
(
z
0
,
z
m
)
=
e
i
ω
Δ
T
(
i
)
2
where ΔT (i) is a residue propagation time determined based on differential time shift (DTS) gathers in ith iteration.
11. The system of claim 10 , wherein the operations further comprise, for the particular reflector zm and the particular acquisition surface location z 0 , determining an initial CFP operator based on an initial estimate of a propagation time between the particular reflector zm and particular acquisition surface location z 0 .
12. The system of claim 8 , wherein the operations further comprise, for each of the plurality of seismic data sets, generating a three-dimensional seismic image of the reservoir based on the determined reflection coefficients of the plurality of reflectors.
13. The system of claim 8 , wherein the plurality of acquisition surface locations comprises seismic source locations and seismic receiver locations.
14. The system of claim 8 , wherein the reservoir comprises a hydrocarbon liquid.
15. A non-transitory, computer-readable medium storing one or more instructions executable by a computer system to perform operations for continuous seismic reservoir monitoring of seismic reservoirs comprising:
receiving a plurality of seismic data sets associated with a reservoir during a period of time, wherein the plurality of seismic data sets corresponds to seismic data received at different times during the period of time, and the reservoir includes a plurality of reflectors, wherein each reflector has a reflection coefficient;
for each of the plurality of seismic data sets, determining reflection coefficients of the plurality of reflectors by iteratively updating common focus point (CFP) operators associated with the plurality of reflectors and a plurality of acquisition surface locations;
comparing the reflection coefficients corresponding to different seismic data sets to determine changes of the reflection coefficients during the period of time; and
displaying, for presentation to a user as part of the continuous seismic reservoir monitoring, the changes of the reflection coefficients, including:
displaying, relative to x and y directions of a target horizon, differences of normalized root mean square (NRMS) amplitudes of the changes of the reflection coefficients; and
representing amplitudes of the differences of the NRMS amplitudes of changes of the reflection coefficients using different colors mapped to a color spectrum of a continuous range of a NRMS amplitudes.
16. The non-transitory, computer-readable medium of claim 15 , wherein each CFP operator indicates a propagation time between a particular reflector and a particular acquisition surface location.
17. The non-transitory, computer-readable medium of claim 15 , wherein iteratively updating CFP operators associated with the plurality of reflectors and the plurality of acquisition surface locations comprises, for a particular reflector z m and a particular acquisition surface location z 0 , calculating an updated CFP operator at (i+1)th iteration using
F
(
i
+
1
)
(
z
0
,
z
m
)
=
F
(
i
)
(
z
0
,
z
m
)
Δ
F
(
i
)
(
z
0
,
z
m
)
Δ
F
(
i
)
(
z
0
,
z
m
)
=
e
i
ω
Δ
T
(
i
)
2
where ΔT (i) is a residue propagation time determined based on differential time shift (DTS) gathers in ith iteration.
18. The non-transitory, computer-readable medium of claim 17 , wherein the operations further comprise, for the particular reflector zm and the particular acquisition surface location z 0 , determining an initial CFP operator based on an initial estimate of a propagation time between the particular reflector zm and particular acquisition surface location z 0 .
19. The non-transitory, computer-readable medium of claim 15 , wherein the operations further comprise, for each of the plurality of seismic data sets, generating a three-dimensional seismic image of the reservoir based on the determined reflection coefficients of the plurality of reflectors.
20. The non-transitory, computer-readable medium of claim 15 , wherein the plurality of acquisition surface locations comprises seismic source locations and seismic receiver locations.