Enhancing well fluid recovery
A system usable with a well includes a waveform generator for enhancing fluid recovery from a reservoir by controlling a production pump or an injection pump downhole in the well with waveform signals to create a pressure wave which propagates into the reservoir and enhances the recovery of the fluid.
1. A system, comprising:
a pump disposed downhole in a well to create a fluid flow of a pumped fluid through the pump between an Earth surface of the well and a reservoir;
a variable speed drive to control a rotational speed of a motor of the pump;
a controller operatively connected to the variable speed drive for enhancing a fluid recovery from the reservoir;
a control logic in the controller to continually vary a rotational speed of the motor of the pump;
the control logic controlling the motor to continually vary a momentum of the pumped fluid inside a pump housing of the pump and inside a production tubing connected to the pump to create reflected cyclic pressure waves against the pump housing and the production tubing;
the pump housing and the production tubing transmitting the pressure waves into the reservoir; and
a vibrational energy of the pressure waves enhancing the fluid recovery.
2. The system of claim 1 , further comprising at least one pressure sensor disposed downhole in the well and communicatively coupled with the controller, wherein the controller varies a momentum of the pumped fluid inside a pump housing of the pump and inside a production tubing connected to the pump to create reflected cyclic pressure waves against the pump housing and the production tubing, based on at least a pressure datum from the pressure sensor.
3. The method of claim 2 , wherein the at least one pressure datum comprises an indication of a pressure at an outlet of the pump, an intake of the pump, or a sandface pressure.
4. The system of claim 1 , wherein the fluid comprises injection fluid.
5. The system of claim 1 , wherein the pressure wave incident upon the reservoir has a pressure amplitude of approximately between 50-200 pounds per square inch (psi) and a frequency of less than approximately 1 Hertz, to deliver vibrational energy to the reservoir.
6. The system claim 1 , further comprising a vibration sensor communicatively coupled with the controller;
wherein the vibration sensor measures a vibration of the pump; and
the controller tunes the measured vibration according to a feedback loop to maximize a sandface pressure of the well as conditions in the reservoir change.
7. The system of claim 1 , wherein the controller varies the speed of the pump at a frequency of approximately 0.02 to 0.5 Hertz over a sequence of different waveforms.
8. A waveform generator, comprising:
a waveform generation logic to create a waveform signal for controlling a motor of a downhole pump;
a connector for transmitting the waveform signal to a speed controller of the motor;
the waveform generation logic varying a speed of the downhole pump to create changes in a fluid momentum of a fluid being pumped within the downhole pump resulting in pressure waves inside the downhole pump;
wherein a housing of the downhole pump transmits the pressure waves created by the changes in fluid momentum into the reservoir to increase a flow of a hydrocarbon from the reservoir.
9. The waveform generator of claim 8 , wherein the fluid comprises well fluid, and the downhole pump is part of a lift system to communicate the well fluid to the surface of the well.
10. The waveform generator of claim 8 , wherein the fluid comprises an injection fluid, and the downhole pump is part of an injection system to inject the fluid into the well.
11. The waveform generator of claim 8 , wherein the pressure waves have a pressure amplitude of approximately between 50-200 pounds per square inch (psi) and a frequency of less than approximately 1 Hertz.
12. The waveform generator of claim 8 , wherein the downhole pump comprises an electrical submersible pump or a progressive cavity pump.
13. The waveform generator of claim 8 , further comprising a connection to at least one sensor to measure at least one characteristic of the well fluid;
wherein the waveform generator tunes the waveform controlling the motor based on ongoing changes in the at least one characteristic.
14. The waveform generator of claim 13 , wherein the at least one sensor comprises a pressure sensor or a vibration sensor.
15. The waveform generator of claim 14 , wherein the at least one sensor comprises a pressure sensor to measure a pressure of the well fluid, a pressure at an outlet of the pump, a pressure at an intake of the pump, or a sandface pressure.