Downhole Quartz Gauge with Minimal Electronics

• US 20140311235A1
• Filed: 03/13/2014
• Published: 10/23/2014
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Sercel Incorporated (CGG)
• Original Assignee: Sercel-Grc Corporation (CGG)
• Inventors: Patton, William M., Kirikera, Goutham R., Behr, Suzanne M., Sawyer, Tracy, Thornberry, Anthony
• Granted Patent: US 9,506,340 B2
• Time in Patent Office: Days
• US Class Current: 73/152.52
• CPC Class Codes: E21B 47/00 Survey of boreholes or wells monitoring pressure or flow of drilling fluid E21B21/08
• CPC Class Codes: E21B 47/06 Measuring temperature or pressure
• CPC Class Codes: E21B 47/07 Temperature
• CPC Class Codes: G01H 11/06 by electric means
• CPC Class Codes: G01H 13/00 Measuring resonant frequency
• CPC Class Codes: G01L 19/0092 Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature G01L9/025, G01L9/045, G01L9/065, G01L9/085, G01L9/105, G01L9/125, G01L19/02, G01L19/04 take precedence; measuring two or more variable G01D21/02; temperature sensors with pressure compensation G01K1/26
• CPC Class Codes: G01L 9/0022 of a piezoelectric element
• CPC Class Codes: G01V 1/44 using generators and receivers in the same well G01V1/52 takes precedence

Abstract

A system and method of monitoring a pressure, temperature, and/or vibration of a hostile environment without requiring the use of active electronics or an oscillator circuit in that environment. The system and method interrogate a resonant pressure sensor and a resonant or passive temperature sensor connected to a transmission line and located at least 100 feet (30.48 m) away from a network analyzer. The system and method use the reflected frequencies from the sensors to determine the pressure, temperature, and/or vibration. If the sensors are networked by the transmission line or a network filter, the reflected portion can include the reflected transmission energy. The applied signal and reflected portion travel along the transmission line, which is preferably impedance matched to that of the system. If a multi-conductor cable is used, the effects of the cable'"'"'s length and temperature are compensated for via a system calibration when in field use.

Claims

1. A system for use in monitoring pressure, temperature, and/or vibration, the system comprising a network analyzer, at least one resonant sensor, and a transmission line connecting the network analyzer to the at least one resonant sensor, the transmission line being at least 100 feet (30.48 m) in length, the network analyzer including an oscillating signal generator and a signal detector, the network analyzer:

applying an incident energy in the form of an oscillating signal along a transmission line connected to the at least one resonant sensor and frequency sweeping the oscillating signal from one reference frequency to another reference frequency across the resonant sensor with the expected resonance of the at least one resonant sensor being between the two reference frequencies;

receiving a reflected portion of the incident energy from the at least one resonant sensor being passed back along the transmission line;

measuring the received reflected portion of the incident energy; and

identifying a change in the reflected portion of the incident energy across the swept frequencies.

2. A system according to claim 1 further comprising means for increasing the reflected portion of the incident energy relative to the applied incident energy.

3. A system according to claim 2 wherein the increasing means is a fixed resister which substantially matches system impedance load.

4. A system according to claim 1 further comprising a second resonant sensor.

5. A system according to claim 4 wherein the at least one resonant sensor and the second resonant sensor are connected in parallel.

6. A system according to claim 4 wherein the network analyzer sweeps the at least one resonant sensor and the second resonant sensor at the same time.

7. A system according to claim 4 wherein the at least one resonant sensor and the second resonant sensor are separated by the transmission line or a network filter.

8. A system according to claim 7 wherein the reflected portion of the incident energy includes a reverse transmission energy.

9. A system according to claim 1 further comprising a passive temperature sensor, the passive temperature sensor being connected to the network analyzer by the transmission line.

10. A system according to claim 7 further comprising an isolation circuit located between the passive temperature sensor and the at least one resonant sensor.

11. A system according to claim 1 wherein the transmission line is a tubing encapsulated conductor cable having at least one conductor.

12. A system according to claim 1 wherein the oscillating signal is an RF sinusoidal signal generated by an RF signal generator.

13. A system according to claim 1 wherein the at least one resonant sensor is a quartz pressure crystal or a quartz temperature crystal.

14. A method of monitoring pressure, temperature, and/or vibration, the method comprising the steps of:

applying an incident energy in the form of an oscillating signal along a transmission line connected to at least one resonant sensor, the applying step frequency sweeping the oscillating signal from one reference frequency to another reference frequency across the at least one resonant sensor with the expected resonance of the at least one resonant sensor being between the two reference frequencies;

receiving a reflected portion of the incident energy from the at least one resonant sensor being passed back along the transmission line;

measuring a phase and magnitude of the received reflected portion of the incident energy; and

identifying a change in the received reflected portion of the incident energy across the swept frequencies;

wherein the applying, receiving, measuring, and identifying steps are performed by a network analyzer, the network analyzer including an oscillating signal generator and a signal detector, the transmission line connecting the network analyzer to the at least one resonant sensor being at least 100 feet (30.48 m) in length.

15. A method according to claim 14 further comprising the step of increasing the reflected portion of the incident energy relative to the applied incident energy by matching a system impedance load of the at least one resonant sensor.

16. A method according to claim 14 further comprising a second resonant sensor, the network analyzer performing the applying, receiving, measuring, and identifying steps on the second resonant sensor.

17. A method according to claim 16 wherein the at least one resonant sensor and the second resonant sensor are swept by the network analyzer at the same time.

18. A system according to claim 16 wherein the at least one resonant sensor and the second resonant sensor are separated by the transmission line or a network filter.

19. A method according to claim 18 wherein the reflected portion of the incident energy includes a reverse transmission energy.

20. A method according to claim 14 wherein a second sensor is a passive temperature sensor connected to the network analyzer by the transmission line.

21. A method according to claim 20 wherein an isolation circuit is located between the passive temperature sensor and the at least one resonant sensor.

22. A method according to claim 14 wherein the transmission line is a tubing encapsulated conductor cable having at least one conductor.

23. A method according to claim 14 wherein the oscillating signal is an RF sinusoidal signal generated by an RF signal generator.

24. A method according to claim 14 wherein the at least one resonant sensor is a quartz pressure crystal or a quartz temperature crystal.