Method and device to acquire seismic data
View Patent ↗Streamer and method for deploying the streamer for seismic data acquisition related to a subsurface of a body of water. The method includes a step of releasing into the body of water, from a vessel, a body having a predetermined length together with plural detectors provided along the body; a step of towing the body and the plural detectors such that the plural detectors are submerged; and a step of configuring plural birds provided along the body, to float at a predetermined depth from a surface of the water such that a first portion of the body has a curved profile while being towed underwater.
1. A streamer for collecting seismic data related to a subsurface of a body of water, the streamer comprising:
a body having a predetermined length;
plural detectors provided along the body; and
plural birds provided along the body, wherein the birds are configured to float, when deployed under water, at predetermined depths from a surface of the water such that a first portion of the body has a non-linear, variable-depth profile while being towed underwater and the non-linear, variable-depth profile is a parameterized curve.
2. The streamer of claim 1 , wherein the parameterized curve is a parabola, a circle or a hyperbola.
3. The streamer of claim 1 , further comprising:
a second portion having a flat profile connected to the first portion.
4. The streamer of claim 1 , wherein the non-linear, variable-depth profile is described by z(h), which is a depth of a point of the first portion relative to the surface of the water, and satisfies the following equation:
z
(
h
)
=
z
0
+
s
0
h
(
1
-
0.5
(
h
h
c
)
)
for
h
≤
h
c
,
where h is a horizontal distance between the point and a first detector provided on the body, z 0 is a depth of the first detector relative to the surface of the water, s 0 is a non-zero slope of the body at the first detector of the streamer, and h c is a predetermined horizontal distance between the first detector and an end of the non-linear, variable-depth profile.
5. The streamer of claim 4 , further comprising:
a second portion, connected to the first portion, the second portion being described by equation z(h)=z 0 +s 0 ·0.5·h c for h>h c .
6. The streamer of claim 4 , wherein a projection of the entire body on a line substantially parallel to the surface of the water is less than h c .
7. The streamer of claim 1 , wherein the non-linear, variable-depth profile stays substantially the same during the towing.
8. The streamer of claim 1 , further comprising:
a second portion, connected to the first portion, the second portion having birds and detectors and having a flat profile.
9. The streamer of claim 8 , wherein the second portion is substantially parallel to the surface of the water.
10. The streamer of claim 1 , wherein the plural detectors include only hydrophones.
11. The streamer of claim 1 , wherein no portion of the body, detectors or birds are anchored to the subsurface.
12. A method for seismic data acquisition related to a subsurface of a body of water, the method comprising:
towing a body having a predetermined length together with plural detectors provided along the body;
configuring plural birds provided along the body, to float at predetermined depths from a surface of the water such that a first portion of the body has a non-linear, variable-depth profile while being towed underwater, the non-linear, variable-depth profile being a parameterized curve; and
recording with the plural detectors the seismic data generated in the body of the water while towing the body.
13. The method of claim 12 , wherein the parameterized curve is a parabola, a circle or a hyperbola.
14. The method of claim 12 , wherein a second portion of the streamer has a flat profile and is connected to the first portion.
15. The method of claim 12 , wherein the non-linear, variable-depth profile is described by z(h), which is a depth of a point of the first portion relative to the surface of the water, and satisfies the following equation:
z
(
h
)
=
z
0
+
s
0
h
(
1
-
0.5
(
h
h
c
)
)
for
h
≤
h
c
,
where h is a horizontal distance between the point and a first detector provided on the body, z 0 is a depth of the first detector relative to the surface of the water, s 0 is a non-zero slope of the body at the first detector of the streamer, and h c is a predetermined horizontal distance between the first detector and an end of the non-linear, variable-depth profile.
16. The method of claim 15 , further comprising:
towing a second portion, connected to the first portion, the second portion being described by equation z(h)=z 0 +s 0 ·0.5·h c for h>h c .
17. The method of claim 15 , wherein a projection of the entire body on a line substantially parallel to the surface of the water is less than h c .
18. The method of claim 12 , wherein the non-linear, variable-depth profile stays substantially the same during the towing.
19. The method of claim 12 , further comprising:
towing a second portion, connected to the first portion, the second portion having birds and detectors and having a flat profile.
20. A method for deploying a streamer for seismic data acquisition related to a subsurface of a volume of water, the method comprising:
releasing into the volume of water, from a vessel, a body having a predetermined length together with plural detectors provided along the body;
towing the body and the plural detectors such that the plural detectors are submerged; and
configuring plural birds provided along the body, to float at predetermined depths from a surface of the water such that a first portion of the body has a non-linear, variable-depth profile while being towed underwater, the non-linear, variable-depth profile being a parameterized curve.