Claims
- 1. A sensing apparatus which is affixed to a metal wellbore device containing fluid, the metal wellbore device located in an earth formation traversed by the wellbore device, said sensing apparatus comprising:
a) a housing in electrical contact with the metal wellbore device; b) an electrode in electrical contact with the fluid; c) insulation between said electrode and said housing; d) a sensor which senses a condition of at least one of the earth formation, the wellbore device, and the fluid, and e) circuitry coupled to said sensor and to said electrode, said circuitry generating a wireless signal related to a determination of said condition sensed by said sensor by generating a signal having a voltage difference between said electrode and the wellbore device.
- 2. A sensing apparatus according to claim 1, wherein:
said housing, said electrode, and said insulation provide ahydraulic seal between the fluid and the formation.
- 3. A sensing apparatus according to claim 1, wherein:
said electrode and said insulation provide a hydraulic seal between the fluid and the formation.
- 4. A sensing apparatus according to claim 1, wherein:
said housing, said electrode, and said insulation are adapted to be flush with a surface of the metal wellbore device.
- 5. A sensing apparatus according to claim 1, wherein:
said circuitry applies an alternating voltage difference between said electrode and one of said housing and the metal wellbore device.
- 6. A sensing apparatus according to claim 1, wherein:
said circuitry includes a rectifier which supplies power to said sensor.
- 7. A sensing apparatus according to claim 1, wherein:
said sensor senses at least one of temperature, pressure, resistivity, fluid constituents, and fluid properties of the formation.
- 8. A sensing apparatus according to claim 1, further comprising:
a second sensor which senses a condition of at least one of the earth formation and the wellbore device, said second sensor coupled to said circuitry.
- 9. A sensing apparatus according to claim 1, wherein:
said housing is mounted to an outer surface of the wellbore device.
- 10. A system for obtaining information about an earth formation traversed by a wellbore having a metal wellbore device containing conductive fluid therein, said system including:
a) an interrogator movable in said metal wellbore device; and b) at least one sensing apparatus which is affixed to the metal wellbore device and which extends into the formation, said at least one sensing apparatus including an electrode in electrical contact with the fluid, a housing in electrical contact with the metal wellbore device, insulation between said electrode and said housing, a sensor which senses a condition of at least one of the earth formation, the wellbore device, and the fluid, and circuitry coupled to said sensor and to said electrode, said circuitry generating a wireless signal related to a determination of said condition sensed by said sensor by generating a signal having a voltage difference between said electrode and the wellbore device, wherein said interrogator is adapted to detect an indication of said signal.
- 11. A system according to claim 10, wherein:
said interrogator comprises an elongate conducting body, a core of high magnetic permeability material which surrounds a portion of said elongate conducting body, and a conductive winding wound about said high magnetic permeability material.
- 12. A system according to claim 11, wherein:
said magnetic core is fixed to said elongate conducting body.
- 13. A system according to claim 10, wherein:
said interrogator comprises a pair of interrogator electrodes which generate a voltage difference therebetween.
- 14. A system according to claim 10, wherein:
said interrogator is adapted to generate a current signal which is forced to flow in the conductive fluid, and said electrode is adapted to sense said current signal.
- 15. A system according to claim 10, wherein:
said housing, said electrode, and said insulation provide a hydraulic seal between the fluid and the formation.
- 16. A system according to claim 10, wherein:
said electrode and said insulation provide a hydraulic seal between the fluid and the formation.
- 17. A system according to claim 10, wherein:
said circuitry applies an alternating voltage difference between said electrode and one of said housing and the metal wellbore device.
- 18. A system according to claim 10, wherein:
said sensor senses at least one of temperature, pressure, resistivity, fluid constituents, and fluid properties of the formation.
- 19. A system according to claim 10, wherein:
said at least one sensing apparatus comprises a plurality of substantially identical sensing apparatus spaced along the metal wellbore device.
- 20. A system according to claim 19, wherein:
said plurality of substantially identical sensing apparatus are spaced both longitudinally and azimuthally along the metal wellbore device.
- 21. A method for transmitting information in an earth formation traversed by a wellbore having a metal wellbore device containing fluid therein, the method comprising:
a) affixing at least one sensing apparatus to the metal wellbore device such that the sensing apparatus extends into the formation, said at least one sensing apparatus including an electrode in electrical contact with the fluid, a housing in electrical contact with the metal wellbore device, insulation between said electrode and said housing, a sensor which senses a condition of at least one of the earth formation, the wellbore device, and the fluid, and circuitry coupled to said sensor and to said electrode; b) sensing with said sensing apparatus a condition of at least one of the earth formation, the wellbore device, and the fluid; c) locating an interrogator device in the vicinity of the sensing apparatus; d) generating a wireless signal related to a determination of said condition sensed by said sensor by generating a signal having a voltage difference between said electrode and the wellbore device; e) receiving said wireless signal at said interrogator device; and f) causing an indication of said wireless signal to be obtained uphole.
- 22. A method according to claim 21, wherein:
said affixing comprises affixing a plurality of substantially identical sensing apparatus spaced along the metal wellbore device.
- 23. A method according to claim 22, wherein:
said plurality of substantially identical sensing apparatus are affixed both longitudinally and azimuthally along the metal wellbore device.
- 24. A method according to claim 24, wherein:
said locating comprises moving said interrogator device within the metal wellbore device to different locations in the vicinities of said plurality of sensing apparatus.
- 25. A method according to claim 21, wherein:
said locating comprises moving said interrogator device within the metal wellbore device.
- 26. A method according to claim 21, wherein:
said interrogator device comprises an elongate conducting body, a core of high magnetic permeability material which surrounds a portion of said elongate conducting body, and a conductive winding wound about said high magnetic permeability material.
- 27. A method according to claim 21, wherein:
said interrogator device comprises a pair of interrogator electrodes which generate a voltage difference therebetween.
- 28. A method according to claim 21, further comprising:
generating a current signal with said interrogator device which is forced to flow in the conductive fluid, and sensing said current signal at said electrode of the sensing device.
- 29. A method according to claim 28, wherein:
said current signal is a wakeup signal for said sensing device.
- 30. A method for identifying a place of interest in an earth formation traversed by a wellbore having a metal wellbore device containing fluid therein, the method comprising:
a) affixing a location indicator to the metal wellbore device at the place of interest, said at least one location indicator including an electrode in electrical contact with the fluid, a housing in electrical contact with the metal wellbore device, insulation between said electrode and said housing, and circuitry coupled to said electrode; b) generating a current signal with said sensing apparatus; c) moving a detecting device through the metal wellbore device and past said location indicator, said detecting device adapted to receive said current signal; d) identifying the place of interest by finding a sharp null in said current signal.
- 31. A method of interrogating a sensing apparatus that is affixed to a metal wellbore device, the method comprising:
a) locating an interrogator device in the vicinity of the sensing apparatus; b) receiving a wireless signal produced by the sensing apparatus at said interrogator device; and c) causing an indication of said wireless signal to be obtained uphole.
- 32. A method of transmitting information in an earth formation traversed by a wellbore having a metal wellbore device containing fluid therein, the metal wellbore device also having at least one sensing apparatus affixed to the metal wellbore device and extending into the formation, the at least one sensing apparatus including an electrode in electrical contact with the fluid, a housing in electrical contact with the metal wellbore device, insulation between the electrode and the housing, a sensor which senses a condition of at least one of the earth formation, the wellbore device, and the fluid, and circuitry coupled to the sensor and to the electrode, the method comprising:
a) locating an interrogator device in the vicinity of the sensing apparatus; b) receiving a wireless signal produced by the sensing apparatus and relating to said condition at said interrogator device; and c) causing an indication of said wireless signal to be obtained uphole.
Parent Case Info
[0001] This application is related to co-owned U.S. Ser. No. 10/163,784 to R. Ciglenec, et al. entitled “Well-Bore Sensor Apparatus and Method”, and to co-owned U.S. Ser. No. 09/428,936 to A. Sezginer, et al. entitled “Wellbore Antennae System and Method”, and to co-owned U.S. Pat. No. 6,426,91 and to co-owned U.S. Ser. No. 09/382,534 to R. Ciglenec et al. entitled “Reservoir Management System and Method”, and to co-owned U.S. Pat. No. 6,028,534, and to co-owned U.S. Pat. No. 6,234,257, and to U.S. Pat. No. 6,070,662, all of which are hereby incorporated by reference herein in their entireties.