Use of autonomous moveable obstructions as seismic sources

• US 20020092701A1
• Filed: 05/18/2001
• Published: 07/18/2002
• Est. Priority Date: 04/26/2000
• Status: Active Grant

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Norris, Michael, Aronstam, Peter
• Granted Patent: US 6,662,899 B2
• Time in Patent Office: Days
• US Class Current: 181/102
• CPC Class Codes: G01V 1/40 specially adapted for well-logging
• CPC Class Codes: G01V 1/42 using generators in one well and receivers elsewhere or vice versa G01V1/52 takes precedence

Abstract

One or more autonomous devices are deployed in the well to provide a moveable sensor source or obstruction for coupling a tube wave seismic signal into the formation adjacent the well bore. The autonomous devices move in the well and provide moveable obstructions or discontinuities which couple tube waves existing in the well bore or production tubing into the formation adjacent the well bore. Wellbore tube wave energy is converted to body wave energy at minor borehole obstructions or irregularities that become sources of seismic energy. A well bore may contain a plurality of minor obstructions or discontinuities. Each obstruction or discontinuity position along the borehole has an associated unique waveform source coda that may be measured for processing the wavefield radiated into the earth formation surrounding the well bore. A plurality of sensors detects the radiated seismic energy after the seismic energy has transited intervening earth formations. The system may be employed as a permanent monitoring device for mineral resource management so that measurements may be acquired at many different times. A time lapse profile may be created that is representative of the temporal and areal changes in the petrophysical characteristics and mineral content or distribution of the intervening earth formation.

Claims

1. A system for acquiring seismic data from a well bore formed in a subsurface formation in response to acoustic signals induced in the formation, comprising:

an autonomous carrier in the well bore, the carrier adapted carry a seismic device comprising at least one of an obstacle, sensor or source and to move the device along at least a portion of the well bore; and

a sensor for detecting a response seismic signal in response to acoustic source signals induced in the subsurface formation.

2. The system of claim 1 wherein the carrier provides a moveable obstruction for converting a tube wave in the well bore to a body wave which radiates into the surrounding formation acoustic seismic signal.

3. The system of claim 2 further comprising:

a two-way communication link for providing data communication between a surface location and a receiver unit in the well bore for providing location control instructions to the carrier; and

a surface control unit for receiving the seismic data recovered by the receiver unit in the well bore over the two-way communication link.

4. The system of claim 2 wherein the at least one carrier stops at selected spaced apart locations in the well bore to convert tube waves to body waves which radiate into the formation adjacent the well bore.

5. The system of claim 3 wherein the carrier further includes a control circuit that controls the movement of the carrier in the well bore.

6. The system of claim 3 wherein a receiver unit controls the movement of the carrier in the well bore.

7. The system of claim 3 wherein the receiver unit controls the movement of the carrier in the well bore in response to command signals transmitted by a surface control unit to the receiver unit.

8. The system of claim 3 wherein the carrier includes a control circuit having a microprocessor and at least one memory unit carrying a program therein for use by the microprocessor.

9. The system of claim 3 wherein the location control instructions are upgraded by a receiver unit.

10. The system of claim 1 wherein the carrier is an autonomous device that can move along a portion of the well bore on its own power according to programmed instructions stored on the carrier.

11. The system of claim 1 wherein the well bore is formed from an ocean bottom.

12. The system of claim 11 further comprising a carrier deployed at the ocean bottom further comprising an attached seismic source for generating seismic signals.

13. The system of claim 12 further comprising a receiver unit at the ocean bottom for retrieving seismic data from a carrier comprising a sensor at the ocean bottom.

14. The system of claim 13 further comprising a third receiver at the surface for receiving seismic data from the receiver unit in the well bore and a second receiver unit at the ocean bottom.

16. The system of claim 15, wherein the carrier track is on the ocean bottom.

18. The method of claim 17 wherein the carrier provides a moveable obstruction for converting a tube wave in the well bore to a body wave which radiates into the surrounding formation acoustic seismic signal.

19. The method of claim 18 further comprising:

providing a two-way communication link for providing data communication between a surface location and a receiver unit in the well bore for providing location control instructions to the carrier; and

providing a surface control unit for receiving the seismic data recovered by the receiver unit in the well bore over the two-way communication link.

20. The method of claim 18 wherein the at least one carrier stops at selected spaced apart locations in the well bore to convert tube waves to body waves which radiate into the formation adjacent the well bore.

21. The method of claim 19 wherein the carrier further includes a control circuit that controls the movement of the carrier in the well bore.

22. The method of claim 19 wherein a receiver unit controls the movement of the carrier in the well bore.

23. The method of claim 19 wherein the receiver unit controls the movement of the carrier in the well bore in response to command signals transmitted by a surface control unit to the receiver unit.

24. The method of claim 19 wherein the carrier further comprises a control circuit having a microprocessor and at least one memory unit carrying a program therein for use by the microprocessor.

25. The method of claim 19 wherein the location control instructions are upgraded by a receiver unit.

26. The method of claim 17 wherein the carrier is an autonomous device that can move along a portion of the well bore on its own power according to programmed instructions stored on the carrier.

27. The method of claim 17 wherein the well bore is formed from an ocean bottom.

28. The method of claim 27 further comprising:

providing a carrier deployed at the ocean bottom further comprising an attached seismic source for generating seismic signals.

29. The method of claim 28 further comprising:

providing a receiver unit at the ocean bottom for retrieving seismic data from a carrier comprising a sensor at the ocean bottom.

30. The method of claim 29 further comprising:

providing a third receiver at the surface for receiving seismic data from the receiver unit in the well bore and a second receiver unit at the ocean bottom.

15. A system for acquiring seismic data from a well bore formed in a subsurface formation in response to acoustic signals induced in the formation, comprising:

an autonomous carrier outside of the well bore, the carrier adapted to move along a track outside of the well bore, the carrier carrying a seismic source for generating an acoustic seismic signal.

17. A method for acquiring seismic data from a well bore formed in a subsurface formation in response to acoustic signals induced in the formation, comprising:

providing an autonomous carrier in the well bore, the carrier adapted carry a seismic device comprising at least one of an obstacle, sensor or source and to move the device along at least a portion of the well bore; and

providing a sensor for detecting a response seismic signal in response to acoustic source signals induced in the subsurface formation.

31. A method for acquiring seismic data from a well bore formed in a subsurface formation in response to acoustic signals induced in the formation, comprising:

providing an autonomous carrier outside of the well bore, the carrier adapted to move along a track outside of the well bore, the carrier carrying a seismic source for generating an acoustic seismic signal.

32. The method of claim 31, wherein the carrier track is on the ocean bottom.