Modular projector for marine seismic source

Patent metadata

Field	Value
Publication number	US-10201833-B2
Application number	US-201415300060-A
Country	US
Kind code	B2
Filing date	Oct 30, 2014
Priority date	Oct 31, 2013
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

An apparatus is disclosed which may include a plurality of marine seismic sources. According to some embodiments, these marine seismic sources may include a plurality of piezoelectric components. Such an apparatus may provide a useful sound pressure level for conducting marine seismic surveying. According to some embodiments, a conduit may be coupled between the plurality of marine seismic sources and a gas reservoir external to the plurality of marine seismic sources. The conduit may in some embodiments have at least one adjustable dimension for changing a frequency of the apparatus. The apparatus may be used in a method of marine seismic surveying.

First claim

The invention claimed is:

1. A method, comprising:
towing a stack of marine seismic sources including at least one manifold having a plurality of port connectors configured to couple to each of the marine seismic sources, each marine seismic source comprises
a structural member that defines a perimeter, a first side, and a second side opposite the first side and disposed about and extending along an axis of symmetry;
a port defined through the perimeter of the structural member and coupled to one of the plurality of port connectors;
a first disc being planar and extending continuously from the axis of symmetry radially to the structural member and coupled on the first side of the structural member;
a second disc being planar and extending continuously from the axis of symmetry radially to the structural member and coupled on the second side of the structural member;
a cavity defined within the structural member between the first and second discs, the cavity contains a volume of gas;

distorting at least the first disc axially; and
producing, via the stack of seismic sources, acoustic energy in a frequency range of 3 Hz to 10 Hz in response to distorting at least the first disc axially.

2. The method of claim 1 , wherein the seismic sources are part of a towable sled.

3. The method of claim 1 , further comprising at least one gas reservoir coupled to the stack of marine seismic sources via a conduit coupled to the at least one manifold.

4. The method of claim 3 , further comprising:
adjusting a resonance frequency of the at least one marine seismic source by changing at least one dimension of the conduit.

5. The method of claim 4 , wherein adjusting the resonance frequency further comprises moving, via a motor, a first portion of the conduit relative to a second portion of the conduit.

6. The method of claim 1 , wherein each marine seismic source further comprises a first piezoelectric member adhered to the first disc outside the cavity, the first piezoelectric member comprising a plurality of segmented piezoelectric components and the producing further comprises driving the first piezoelectric member with a sinusoidal voltage.

7. The method of claim 1 , wherein the towing includes towing at a water depth of between 50 and 100 meters.

8. The method of claim 1 , wherein producing acoustic energy further comprises producing at a sound pressure level in the range of 195 to 200 dB.

9. The method of claim 1 , further comprising:
wherein towing the stack of marine seismic sources further comprises towing a plurality of stacks of marine seismic sources;
wherein producing acoustic energy results in production of acoustic energy at a first sound pressure level; and
in response to a failure of a first stack the marine seismic sources of the plurality of stacks of marine seismic sources, producing, via a second stack of marine seismic sources acoustic energy at a second sound pressure level that is between 0 dB and −2 dB of the first sound pressure level.

10. A system, comprising:
a seismic array comprising a first stack of seismic sources and including at least one manifold having a plurality of port connectors configured to couple to each of the seismic sources, each seismic source including
a structural member that defines a perimeter, a first side, and a second side opposite the first side and disposed about and extending along an axis of symmetry;
a port defined through the perimeter of the structural member and coupled to one of the plurality of port connectors;
a first disc being planar and extending continuously from the axis of symmetry radially to the structural member and coupled on the first side of the structural member;
a second disc being planar and extending continuously from the axis of symmetry radially to the structural member and coupled on the second side of the structural member;
a cavity defined within the structural member between the first and second discs, the cavity contains a volume of gas; and

wherein the system is operable to produce acoustic energy in a frequency range of 3 Hz to 10 Hz by distorting at least the first disc axially when the system is located at a water depth of between 50 and 100 meters.

11. The system of claim 10 , wherein the system is operable to produce acoustic energy at a sound pressure level of 195 to 200 dB.

12. The system of claim 10 , wherein the seismic array further comprises:
a gas reservoir; and
a conduit coupled to the first stack of marine seismic sources, the conduit fluidly couples the cavity to the gas reservoir.

13. The system of claim 12 , wherein the conduit has at least one dimension that is adjustable, and wherein adjustments of the at least one dimension are operable to change a resonance frequency of the system.

14. The system of claim 13 , wherein the at least one dimension includes a length of the conduit and a cross-sectional area of the conduit.

15. The system of claim 13 , wherein the at least one dimension is adjustable via a portion of the conduit disposed within the gas reservoir.

16. The system of claim 10 , wherein the system is operable to produce acoustic energy at a first sound pressure level by way of the first stack of marine seismic sources and a second stack of marine seismic sources, and wherein, in response to a failure of the first stack of marine seismic sources, the system is operable to produce, via at least the second stack of marine seismic sources, acoustic energy at a second sound pressure level that is between 0 dB and −2 dB of the first sound pressure level.

17. An apparatus, comprising:
a plurality of stacks of marine seismic sources, each of the plurality of stacks including at least one manifold having a plurality of port connectors configured to couple to each of the marine seismic sources and each marine seismic source including a structural member defining a perimeter including a port defined therethrough and coupled to one of the plurality of port connectors and including a first disc and a second disc each being planar and extending continuously from an axis of symmetry radially and in a spaced relationship to one another to attach to the structural member to define a cavity containing a volume of gas therebetween;
a gas reservoir; and
a conduit coupled between the gas reservoir and at least one of the plurality of stacks of marine seismic sources through the at least one manifold;
wherein the conduit is operable to permit a resonating flow of gas between the gas reservoir and the at least one of the plurality of stacks of marine seismic sources, and wherein the apparatus is operable to produce acoustic energy by distorting at least the first disc axially.

18. The apparatus of claim 17 , wherein the apparatus is operable to produce the acoustic energy in a frequency range of 3 Hz to 10 Hz when the apparatus is located at a water depth of between 50 and 100 meters.

19. The apparatus of claim 18 , wherein the frequency range is 3 Hz to 5 Hz.

20. The apparatus of claim 18 , wherein a sound pressure level of the acoustic energy is between 195 dB and 200 dB.

21. The apparatus of claim 17 , further comprising a motor operable to adjust at least one dimension of the conduit to adjust a resonance frequency of the apparatus.

22. The apparatus of claim 21 , further comprising a computer-readable medium having stored thereon a lookup table, wherein the apparatus is configured to adjust the at least one dimension of the conduit based at least in part on the lookup

Assignees

• Pgs Geophysical As
• Geospectrum Tech Inc

Inventors

• Armstrong Bruce
• Yeatman Paul
• Traetten Øystein
• Oscarsson Mattias
• Voldsbekk Rune
• Tønnessen Rune

Classifications

• G10K9/125

  with a plurality of active elements · CPC title

• G01V1/159

  using piezoelectric or magnetostrictive driving means (generating mechanical vibrations by using piezoelectric or magnetostrictive effect in general, B06B1/06, B06B1/08) · CPC title

• G01V1/145

  by deforming or displacing surfaces {, e.g. by mechanically driven vibroseis™} · CPC title

• G01V1/38

  specially adapted for water-covered areas (G01V1/28 takes precedence) · CPC title

• G01V1/135

  by deforming or displacing surfaces of enclosures {, e.g. by hydraulically driven vibroseis™} · CPC title