Efficient damped pulsed energy transmitter

Patent metadata

Field	Value
Publication number	US-11619760-B2
Application number	US-202117356992-A
Country	US
Kind code	B2
Filing date	Jun 24, 2021
Priority date	Jun 24, 2021
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

A device for generating oscillating signals includes an energy transfer device configured to apply an oscillating signal to a sensitive volume, and a resonant tuning circuit including the energy transfer device. The tuning circuit includes a tuning capacitor configured to cause the tuning circuit to resonate at a selected frequency, and an energy storage device. The transmitting device also includes a controller configured to apply a pulse sequence to the tuning circuit having a series of pulses, the energy storage device configured to retain electrical energy at an end of a first pulse, and discharge the electrical energy to the tuning circuit at an onset of a next pulse of the pulse sequence.

First claim

What is claimed is:

1. A device for generating oscillating signals, comprising:
an energy transfer device configured to apply an oscillating signal to a sensitive volume; and
a resonant tuning circuit including the energy transfer device, the tuning circuit including a tuning capacitor configured to cause the tuning circuit to resonate at a selected frequency, and an energy storage device; and
a controller configured to apply a pulse sequence to the tuning circuit having a series of pulses, the energy storage device configured to retain electrical energy at an end of a first pulse, and discharge the electrical energy to the tuning circuit at an onset of a next pulse of the pulse sequence.

2. The device of claim 1 , wherein the energy transfer device includes an inductive coil.

3. The device of claim 2 , wherein the energy transfer device and the tuning circuit are configured to emit a nuclear magnetic resonance (NMR) pulse sequence into the sensitive volume.

4. The device of claim 2 , wherein the tuning circuit includes a dissipating component configured to dissipate residual energy from the tuning circuit at the end of the first pulse, the energy storage device configured to retain a portion of the residual energy and discharge the portion to the tuning circuit at the onset of the next pulse.

5. The device of claim 4 , wherein the energy storage device includes a detuning capacitor, the dissipating component includes a dump resistor in series with the detuning capacitor, and the detuning capacitor and the dump resistor are connected in parallel to the tuning capacitor and the inductive coil.

6. The device of claim 5 , wherein the tuning capacitor is connected in series to a first switch, and the detuning capacitor is connected in series to a second switch.

7. The device of claim 6 , wherein the tuning circuit is configured to be put into a transmit mode to emit an oscillating pulse signal during a pulse duration, and subsequently put into a dump mode at an end of the pulse duration to dissipate the residual energy.

8. The device of claim 7 , wherein the first switch is closed and the second switch is open during the transmit mode, and the first switch is open and the second switch is closed during the dump mode, the detuning capacitor retaining the portion of the residual energy during the dump mode.

9. The device of claim 8 , wherein the first switch is closed and the second switch is opened at an onset of the next pulse, the detuning capacitor configured to release the portion of the residual energy during the next pulse.

10. The device of claim 1 , wherein the device is configured to be deployed in a borehole in a subterranean region, the device connected to a processor configured estimate a property of the subterranean region based on detecting signals from the sensitive volume as a result of the emitted pulse sequence.

11. A method of generating oscillating signals comprising:
disposing a transmission device proximate to a sensitive volume, the transmission device including an energy transfer device configured to apply an oscillating signal to the sensitive volume, and a resonant tuning circuit including the energy transfer device, the tuning circuit including a tuning capacitor configured to cause the tuning circuit to resonate at a selected frequency, and an energy storage device; and
applying, by a controller, a pulse sequence having a series of pulses to the tuning circuit, wherein the applying includes retaining electrical energy in the energy storage device at an end of a first pulse, and discharging the electrical energy to the tuning circuit at an onset of a next pulse of the pulse sequence.

12. The method of claim 11 , wherein the energy transfer device includes an inductive coil.

13. The method of claim 12 , wherein applying the pulse sequence is applied as a nuclear magnetic resonance (NMR) pulse sequence into the sensitive volume.

14. The method of claim 12 , wherein the tuning circuit includes a dissipating component configured to dissipate residual energy from the tuning circuit at the end of the first pulse, and applying the pulse sequence includes retaining a portion of the residual energy at the energy storage device and discharging the portion to the tuning circuit at the onset of the next pulse.

15. The method of claim 14 , wherein the energy storage device includes a detuning capacitor, the dissipating component includes a dump resistor in series with the detuning capacitor, and the detuning capacitor and the dump resistor are connected in parallel to the tuning capacitor and the inductive coil.

16. The method of claim 15 , wherein the tuning capacitor is connected in series to a first switch, and the detuning capacitor is connected in series to a second switch.

17. The method of claim 16 , wherein applying the pulse sequence includes putting the tuning circuit into a transmit mode to emit an oscillating pulse signal during a pulse duration, and subsequently putting the tuning circuit into a dump mode at an end of the pulse duration to dissipate the residual energy.

18. The method of claim 17 , wherein the first switch is closed and the second switch is open during the transmit mode, and the first switch is open and the second switch is closed during the dump mode, the detuning capacitor retaining the portion of the residual energy during the dump mode.

19. The method of claim 18 , wherein the first switch is closed and the second switch is opened at an onset of the next pulse, the detuning capacitor releasing the portion of the residual energy during the next pulse.

20. The method of claim 11 , wherein the transmission device is disposed in a borehole in a subterranean region, the device connected to a processor configured estimate a property of the subterranean region based on detecting signals from the sensitive volume as a result of the emitted pulse sequence.

Assignees

• Boulaknadal Youssef
• Forgang Stanislav
• Rocheleau Ryan
• Ramirez Marc Stephen
• Baker Hughes Oilfield Operations Llc

Inventors

• Boulaknadal Youssef
• Forgang Stanislav
• Rocheleau Ryan
• Ramirez Marc Stephen

Classifications

• G01R33/448

  Relaxometry, i.e. quantification of relaxation times or spin density (G01R33/50 takes precedence) · CPC title

• G01V3/32 Primary

  operating with electron or nuclear magnetic resonance · CPC title

• G01N24/081

  Making measurements of geologic samples, e.g. measurements of moisture, pH, porosity, permeability, tortuosity or viscosity · CPC title

• G01R33/3628 Primary

  Tuning/matching of the transmit/receive coil · CPC title

• G01R33/3808

  Magnet assemblies for single-sided MR wherein the magnet assembly is located on one side of a subject only; Magnet assemblies for inside-out MR, e.g. for MR in a borehole or in a blood vessel, or magnet assemblies for fringe-field MR · CPC title