Computing rotation data using a gradient of translational data

Patent metadata

Field	Value
Publication number	US-9594174-B2
Application number	US-201414158115-A
Country	US
Kind code	B2
Filing date	Jan 17, 2014
Priority date	Feb 1, 2013
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

Translational data in a first direction is measured by particle motion sensors contained in an elongated housing of a sensor device provided at an earth surface. The particle motion sensors are spaced apart along a second, different direction along a longitudinal axis of the elongated housing. Rotation data around a third direction is computed based at least in part on computing a gradient of the translational data with respect to the second direction.

First claim

What is claimed is:

1. A method of seismic surveying, comprising:
actuating a seismic source to transmit impulses into an earth subsurface;
receiving, by a seismic sensor system, translational data in a first direction measured by particle motion sensors contained in an elongated housing of a seismic sensor device provided at a ground surface, wherein at least one of the particle motion sensors is proximate the ground surface, the particle motion sensors spaced apart along a second, different direction along a longitudinal axis of the elongated housing, and receiving translational data in a third direction measured by additional particle motion sensors in the elongated housing, the translational data in the first and third directions corresponding at least partially to the impulses; and
recording the translational data in the first direction and the translational data in the third direction, wherein for the translational data in the first direction and the translational data in the third direction that are measured by the particle motion sensors where at least one of the particle motion sensors is proximate the ground surface, a relationship applies where a rotation data around the third direction is based on a gradient of the translational data in the first direction with respect to the second direction, and a rotation data around the first direction is based on a gradient of the translational data in the third direction with respect to the second direction.

2. The method of claim 1 , wherein the at least one of the particle motion sensors proximate the ground surface records a wavefield just below the ground surface, the method further comprising:
approximating the rotation data around the third direction as the gradient of the translational data in the first direction with respect to the second direction; and
approximating the rotation data around the first direction as the gradient of the translational data in the third direction with respect to the second direction.

3. The method of claim 1 , further comprising placing the seismic sensor device at the ground surface using automatic placement equipment to drive a portion of the seismic sensor device into the ground surface.

4. The method of claim 1 , wherein the seismic sensor device is without any particle motion sensors spaced apart along any direction different from the second direction.

5. The method of claim 1 , wherein the particle motion sensors are spaced apart along the second direction by a distance that is less than a wavelength of a target signal for measurement by the seismic sensor device.

6. The method of claim 1 , wherein the particle motion sensors are spaced apart along the second direction by a distance that is less than or equal to 0.3 times a wavelength of a target signal for measurement by the seismic sensor device.

7. The method of claim 1 , wherein the particle motion sensors are spaced apart along the second direction by a distance that is less than or equal to 0.1 times a wavelength of a target signal for measurement by the seismic sensor device.

8. The method of claim 1 , wherein the second direction is a vertical direction, and wherein the first and third directions are horizontal directions, the first direction being orthogonal with respect to the third direction.

9. The method of claim 1 , further comprising:
computing divergence data based at least in part on computing a gradient of translational data in the second direction with respect to the second direction.

10. The method of claim 1 , wherein receiving the translational data comprises receiving the translational data measured by the particle motion sensors provided on integrated circuit chips in the seismic sensor device.

11. The method of claim 10 , wherein the particle motion sensors include microelectromechanical systems (MEMS) sensors.

12. The method of claim 1 , wherein one of the particle motion sensors is located below the ground surface and another one of the particle motion sensors is located above the ground surface.

13. The method of claim 1 , wherein the particle motion sensors are below the ground surface.

14. The method of claim 1 , wherein the rotation data around the third direction is a rate of rotation around the third direction, and the rotation data around the first direction is a rate of rotation around the first direction.

15. The method of claim 1 , wherein the relationship specifies that a magnitude of the rotation data around the third direction is equal to a magnitude of the gradient of the translational data in the first direction with respect to the second direction, and that a magnitude of the rotation data around the first direction is equal to a magnitude of the gradient of the translational data in the third direction with respect to the second direction.

16. The method of claim 15 , further comprising transmitting, by the seismic sensor device, the translational data in the first and third directions to a system to compute the rotation data around the first and third directions.

17. The method of claim 1 , wherein the relationship specifies that the rotation data around the third direction is equal to the gradient of the translational data in the first direction with respect to the second direction, and that the rotation data around the first direction is equal to a negative of the gradient of the translational data in the third direction with respect to the second direction.

18. The method of claim 1 , further comprising placing the seismic sensor device at the ground surface by driving a spike at a bottom portion of the seismic sensor device into the ground surface.

19. The method of claim 1 , wherein the elongated housing comprises a hollow tubular structure, and wherein the particle motion sensors are contained completely within the hollow tubular structure.

20. The method of claim 19 , wherein the hollow tubular structure includes protrusions in the form of a helical screw on an outside of the hollow tubular structure.

21. The method of claim 19 , wherein the hollow tubular structure includes protrusions on an outside of the hollow tubular structure that form vertical fins.

22. An article comprising at least one non-transitory machine-readable storage medium storing instructions that upon execution cause a system to:
receive translational data in a first direction measured by particle motion sensors contained in an elongated housing of a sensor device provided at a ground surface, wherein at least one of the particle motion sensors is proximate the ground surface, the particle motion sensors spaced apart along a second, different direction along a longitudinal axis of the elongated housing; and
compute rotation data around a third direction that is approximated as a gradient of the translational data with respect to the second direction.

23. The article of claim 22 , wherein the instructions upon execution cause the system to further:
correct the translational data for at least one of a tilt angle and an azimuth angle of the sensor device.

24. The article of claim 22 , wherein the translational data is received from the particle motion sensors that are spaced apart along just the second direction, without being spaced apart in a different direction.

25. The article of claim 22 , wherein the second direction is a vertical direction, and the first and third directions are horizontal directions.

26. The article of claim 22 ,

Assignees

• Westerngeco Llc

Inventors

• Goujon Nicolas
• Edme Pascal
• Kashubin Artem
• Muijzert Everhard Johan

Classifications

• G01V1/162 Primary

  Details · CPC title

• G01V13/00

  Manufacturing, calibrating, cleaning, or repairing instruments or devices covered by groups G01V1/00 – G01V11/00 · CPC title

• G01V1/30

  Analysis (G01V1/50 takes precedence) · CPC title

• G01V1/185

  with adaptable orientation, e.g. gimballed · CPC title

• Y10T29/49002

  Electrical device making · CPC title