Method, system and signal generator for treating a device to resist formation and build-up of scale deposits
A method of treating a device to resist formation and build-up of scale deposits at the device is provided. The device is located in a fluid-containing conduit. The method comprises feeding a radio frequency (RF) signal into a line connected to a device located in a fluid-containing conduit; and propagating the RF signal along the line to the device to resist formation and/or build-up of scale deposits at the device. A system for treating a device to resist formation and build-up of scale deposits at the device is also provided. A signal generator operable to generate an RF signal for treating a device to resist formation and build-up of scale deposits at the device is also provided. The signal generator is operable to feed the RF signal into a line connected to the device and to propagate the RF signal along the line to the device to resist formation and/or build-up of scale deposits at the device.
1 . A method for treating an electric submersible pump (ESP) to resist formation and build-up of scale deposits at the ESP, the ESP being located in a fluid-containing conduit, the method comprising:
introducing a variable, pulsed radio frequency (RF) signal into a primary coil of a transformer;
transferring the RF signal to a power line connected to the ESP located in a fluid-containing conduit via a first terminal of a secondary coil of the transformer connected to the power line, a second terminal of the secondary coil being operably grounded, and the power line being for providing power to the ESP; and
propagating the RF signal and an associated electromagnetic field along a signal path defined by the power line to the ESP and throughout the ESP to resist formation and/or build-up of scale deposits at the ESP.
2 . The method of claim 1 , wherein the power line is electrically insulated and the RF signal is propagated within insulation.
3 . The method of claim 1 , wherein the power line is a single phase of a three-phase power cable.
4 . The method of claim 1 , wherein the power line is a shielding layer of a cable.
5 . The method of claim 1 , wherein the fluid-containing conduit comprises a well.
6 . The method of claim 1 , further comprising:
selecting a parameter of the RF signal based on a parameter of the ESP prior to propagating the RF signal, wherein the parameter of the RF signal comprises at least one of signal strength, frequency, voltage and current.
7 . The method of claim 6 , wherein the parameter of the ESP comprises at least one of a distance of the ESP from a feed point of the RF signal, and a length of the power line.
8 . The method of claim 1 , wherein the transferring the RF signal comprises transferring the RF signal to the power line at a location uphole of the ESP.
9 . The method of claim 8 , wherein the location is outside of a well.
10 . The method of claim 1 , wherein the power line is configured to pass through a valve arrangement to the ESP.
11 . The method of claim 1 , wherein the RF signal is fed into the power line at an electrical junction box.
12 . The method of claim 11 , wherein the RF signal is fed to multiple lines electrically connected at the electrical junction box, the power line including the multiple lines.
13 . A system for treating an electric submersible pump (ESP) to resist formation and build-up of scale deposits at the ESP, the ESP being located in a fluid-containing conduit, the system comprising:
an ESP located in a fluid-containing conduit;
a power line connected to the ESP;
a signal generator comprising a transformer comprising a primary coil and a secondary coil; and
a microcontroller operable to generate a variable, pulsed radio frequency (RF) signal to be introduced into the primary coil and transferred to the power line connected to the ESP located in the fluid-containing conduit via a first terminal of the secondary coil connected to the power line, a second terminal of the secondary coil being operably grounded, and the power line being for providing power to the ESP, the signal generator further operable to propagate the RF signal and an associated electromagnetic field along a signal path defined by the power line to the ESP and throughout the ESP to resist formation and/or build-up of scale deposits at the ESP.
14 . The method of claim 1 , wherein the transferring the RF signal into the power line comprises inducting the RF signal into the power line.
15 . The method of claim 14 , wherein the inducting the RF signal comprises establishing a field around the power line to transfer the RF signal into the power line.
16 . The method of claim 1 , further comprising transferring the RF signal to the secondary coil of the transformer, the secondary coil connected to armour of the power line connected to the ESP located in the fluid-containing conduit.
17 . The method of claim 1 , wherein the secondary coil is operably connected to ground to form a current return path.
18 . The method of claim 1 , wherein a frequency of the RF signal is between 100 and 220 kHz.