Digital sensor streamers and applications thereof

• US 10,139,505 B2
• Filed: 08/09/2011
• Issued: 11/27/2018
• Est. Priority Date: 08/09/2011
• Status: Active Grant

• Current Assignee: PGS Geophysical As (PGS ASA)
• Original Assignee: PGS Geophysical As (PGS ASA)
• Inventors: Tenghamn, Stig Rune Lennart, Barr, Frederick James
• Primary Examiner(s): Lobo, Ian J
• Application Number:
  US13/206,002
• Publication Number:
  US 20130039149A1
• Time in Patent Office: 2,667 Days
• Field of Search: 367 20
• CPC Class Codes: G01V 1/164 Circuits therefore
• CPC Class Codes: G01V 1/201 Constructional details of seismic cables, e.g. streamers integrated optoseismic systems G01V1/226; line connectors in general H01R, transducer mountings in general G10K11/004

Abstract

A disclosed data acquisition system includes one or more streamers having multiple spaced apart sensor units. At least one sensor unit includes at least one digital sensor employing a quantized feedback loop to produce a digital output signal. A data recording system collects and stores data from the sensor units. The quantized feedback loop may be adapted to exert a quantized force on the sensing element. A described method for acquiring data includes deploying at least one streamer having multiple spaced apart sensor units, where at least a portion of the sensor units include a digital sensor employing a quantized feedback loop to produce a digital output signal. A stimulus event is triggered. Data is received from the sensor units and stored.

Claims

1. A geophysical survey system, comprising:

at least one streamer having a plurality of spaced apart sensor units, at least one of the sensor units including at least one digital hydrophone sensor, the hydrophone sensor comprising a piezoelectric sensing element and employing a quantized feedback loop to produce a digital output signal, wherein the quantized feedback loop is configured to exert a quantized force on the piezoelectric sensing element; and

a data recording system configured to collect and store data from the sensor units.

2. The system of claim 1, wherein the piezoelectric sensing element is configured to move or deform in response to an input stimulus.

3. The system of claim 2, wherein the at least one digital hydrophone sensor comprises an integrator coupled to the piezoelectric sensing element and a one-bit quantizer configured to produce a quantized signal responsive to an output of the integrator.

4. The system of claim 3, wherein the at least one digital hydrophone sensor comprises a counter configured to convert the quantized signal into the digital output signal.

5. The system of claim 2, wherein the at least one digital hydrophone sensor comprises an integrator coupled to the piezoelectric sensing element and a multi-bit quantizer configured to produce a quantized signal responsive to an output of the integrator.

6. The system of claim 5, wherein the at least one digital hydrophone sensor comprises a decimation filter that converts the quantized signal into the digital output signal.

7. The system of claim 1, wherein at least a portion of the sensor units are configured to produce an output signal dependent upon a seismic input signal.

8. The system of claim 1, wherein at least a portion of the sensor units provide a digital three-axis acceleration sensing and digital pressure sensing.

9. The system of claim 1, wherein at least a portion of the sensor units are spaced a distance of less than 59 inches (150 centimeters) from one another.

10. The system of claim 1, wherein at least a portion of the sensor units are spaced a distance of less than 14 inches (35 centimeters) from one another.

11. The system of claim 1, wherein the digital output signals of a number of sensor units are averaged together to form a combined digital output signal, and wherein the data recording system stores the combined digital output signal.

12. A geophysical survey method, comprising:

deploying at least one streamer having a plurality of spaced apart sensor units, wherein at least a portion of the sensor units comprise a digital hydrophone sensor, the hydrophone sensor comprising a piezoelectric sensing element and employing a quantized feedback loop to produce a digital output signal, wherein the quantized feedback loop is configured to exert a first quantized force on the piezoelectric sensing element;

triggering a stimulus event;

receiving data from the sensor units; and

storing the data.

13. The method of claim 12, wherein as part of producing a digital output signal, the digital hydrophone sensor transforms an input stimulus into motion or deformation of the piezoelectric sensing element.

14. The method of claim 13, wherein the digital hydrophone sensor integrates a sensing element signal and performs a one-bit quantization to produce a quantized signal.

15. The method of claim 14, wherein the digital hydrophone sensor exerts a second quantized force on the piezoelectric sensing element in response to the quantized signal.

16. The method of claim 15, wherein the digital hydrophone sensor counts values in the quantized signal to convert the quantized signal into the digital output signal.

17. The method of claim 12, wherein the digital output signals represent a seismic input signal.

18. The method of claim 12, wherein the digital output signals represent three-axis acceleration sensing and digital pressure sensing.

19. The method of claim 12, wherein deploying the at least one streamer includes constraining at least a portion of the sensor units to be spaced a distance of less than 14 inches (35 centimeters) from one another.

20. The method of claim 15, wherein the first quantized force is the same as the second quantized force.