Methods and systems for acquiring seismic data

• US 20030202424A1
• Filed: 04/18/2003
• Published: 10/30/2003
• Est. Priority Date: 04/24/2002
• Status: Active Grant

• Current Assignee: Ascend Geo LLC
• Original Assignee: Ascend Geo LLC
• Inventors: Stewart, Robert, Fockler, Todd J., Favret, Paul D., Burkholder, Scott K.
• Granted Patent: US 6,934,219 B2
• Time in Patent Office: Days
• US Class Current: 367/42
• CPC Class Codes: G01V 1/24 Recording seismic data

Abstract

Methods and systems are provided for acquiring seismic data. Data are collected representing acoustic signals received from the Earth at distinct geographic locations. Data representing an ambient signal at the distinct geographic locations are also collected. For each of the geographic locations, a known time dependence of the ambient signal is correlated with a time dependence of the collected acoustic-signal data to define time-correlated acoustic signal data. The collected acoustic-signal data for the distinct geographic locations are synchronized from the time-correlated acoustic-signal data.

Claims

1. A method for acquiring seismic data, the method comprising:

collecting data representing acoustic signals received from the Earth at a plurality of distinct geographic locations;

collecting data representing an ambient signal at the plurality of distinct geographic locations;

for each of the plurality of geographic locations, correlating a known time dependence of the ambient signal with a time dependence of the collected acoustic-signal data to define time-correlated acoustic signal data; and

synchronizing the collected acoustic-signal data for the plurality of distinct geographic locations from the time-correlated acoustic-signal data.

2. The method recited in claim 1 further comprising analyzing the synchronized acoustic-signal data to identify a subterranean feature.

3. The method recited in claim 2 wherein analyzing the synchronized acoustic-signal data comprises generating an acoustic hologram from the synchronized acoustic-signal data.

4. The method recited in claim 1 wherein collecting data representing acoustic signals is performed continuously at each of the distinct geographic locations for a period of time that exceeds one minute.

5. The method recited in claim 1 wherein collecting data representing acoustic signals is performed continuously at each of the distinct geographic locations for a period of time that exceeds one hour.

6. The method recited in claim 1 wherein collecting data representing acoustic signals is performed continuously at each of the distinct geographic locations for a period of time that exceeds one day.

7. The method recited in claim 1 wherein collecting data representing acoustic signals is performed continuously at each of the distinct geographic locations for a period of time that exceeds one week.

8. The method recited in claim 1 further comprising embedding the collected data representing the ambient signal into the collected data representing acoustic signals received from the Earth.

9. The method recited in claim 1 wherein collecting data representing acoustic signals received from the Earth comprises receiving acoustic data generated in response to a human-initiated event.

10. The method recited in claim 1 wherein the plurality of distinct geographic locations are at different depths with respect to the surface of the Earth.

11. The method recited in claim 1 wherein the ambient signal comprises an electromagnetic broadcast signal.

12. The method recited in claim 1 wherein the ambient signal comprises a time-reference signal.

13. A system for acquiring seismic data, the system comprising:

a plurality of collectors distributed at a plurality of distinct geographic locations, wherein each such collector is adapted to;

collect data representing acoustic signals received from the Earth; and

collect data representing an ambient signal; and

a processor coupled with a computer-readable storage medium having a computer-readable program embodied therein for directing operation of the processor, the computer-readable program including;

instructions for correlating a known time dependence of the ambient signal with a time dependence of the collected acoustic-signal data to define time-correlated acoustic-signal data; and

instructions for synchronizing the collected acoustic-signal data for the plurality of geographic locations from the time-correlated acoustic-signal data.

14. The system recited in claim 13 wherein the computer-readable program further includes instructions for analyzing the synchronized acoustic-signal data to identify a subterranean feature.

15. The system recited in claim 13 wherein each such collector includes a data store capable of storing data collected continuously over a period of time that exceeds one week.

16. The system recited in claim 13 wherein each such collector is further adapted to embed the collected data representing the ambient signal into the collected data representing acoustic signals received from the Earth.

17. The system recited in claim 13 wherein the ambient signal comprises an electromagnetic broadcast signal.

18. The system recited in claim 13 wherein the ambient signal comprises a time-reference signal.

19. A seismic sensor data recorder comprising:

a signal preprocessor adapted for receiving a continuous stream of sensor data from a seismic sensor;

a radio receiver adapted for receiving a continuous stream of an ambient radio signal;

an analog-to-digital converter in communication with the signal preprocessor and the radio receiver, wherein the analog-to-digital converter is adapted to convert the. sensor data to a digital sensor-data stream and to convert the continuous stream of the ambient radio signal to a digital radio-signal stream; and

a processing unit in communication with the analog-to-digital converter adapted to receive and process the digital radio-signal stream and the digital sensor-data stream for storage in a memory.

20. The seismic sensor data recorder recited in claim 19 wherein the processing unit is further adapted to embed the digital radio-signal stream into the digital sensor-data stream prior to storage in the memory.

21. The seismic sensor data recorder recited in claim 19 wherein the processing unit is adapted to encode the digital radio-signal stream and the digital sensor-data stream as separate channels in the memory.