Dynamic power optimization system and method for electric submersible motors

Patent metadata

Field	Value
Publication number	US-11613974-B2
Application number	US-202217862608-A
Country	US
Kind code	B2
Filing date	Jul 12, 2022
Priority date	Jan 5, 2017
Publication date	Mar 28, 2023
Grant date	Mar 28, 2023

Abstract

A system comprises an electric submersible pump (ESP) motor electrically coupled to a variable speed drive (VSD) that outputs voltage to the ESP motor. The system comprises a magnet on a shaft of the ESP motor and a downhole sensor coupled to the magnet, wherein the downhole sensor is to measure a magnetic flux of the magnet. The system comprises a VSD controller to control the VSD, wherein the VSD controller comprises a processor and a non-transitory memory storage having instructions stored thereon that are executable by the processor to perform operations comprising: obtaining a measurement of at least one pump performance variable and a motor current for a first period of time to establish a first data set and making a first adjustment to a voltage output from the VSD to the ESP motor, the first adjustment having a first adjustment type.

First claim

The invention claimed is:

1. A system comprising:
an electric submersible pump (ESP) motor electrically coupled to a variable speed drive (VSD) that outputs voltage to the ESP motor;
a magnet on a shaft of the ESP motor and a downhole sensor coupled to the magnet, wherein the downhole sensor is to measure a magnetic flux of the magnet; and
a VSD controller to control the VSD, wherein the VSD controller comprises,
a processor; and
a non-transitory memory storage having instructions stored thereon that are executable by the processor to perform operations comprising:
obtaining a measurement of at least one pump performance variable and a motor current for a first period of time to establish a first data set;
making a first adjustment to a voltage output from the VSD to the ESP motor, the first adjustment having a first adjustment type, wherein the first adjustment type is one of increasing or decreasing the voltage output;
sensing the at least one pump performance variable and the motor current for a second period of time, after the first adjustment, to establish a second data set;
differencing the first data set with the second data set to determine a change in the motor current from the first data set to the second data set; and
making a second adjustment to the voltage output from the VSD to the ESP motor in response to the change in the motor current and a change in the at least one pump performance variable, the second adjustment comprising one of:
an adjustment of the first adjustment type if the change in the motor current is a drop and the at least one pump performance variable in the second data set is maintained between an upper threshold and a lower threshold; or
an adjustment opposite the first adjustment type if one of:
 the change in the motor current is a rise and the at least one pump performance variable in the second data set is maintained between the upper threshold and the lower threshold; or
 if the change in the motor current is a drop and the at least one pump performance variable in the second data set deviates one of above the upper threshold or below the lower threshold.

2. The system of claim 1 , wherein the at least one pump performance variable comprises revolution rate of the shaft of the ESP motor.

3. A method comprising:
operating an electric submersible pump (ESP) motor downhole in a well, the ESP motor electrically connected to a variable speed drive (VSD) proximate to the well, the VSD outputting voltage to the ESP motor and at least partially controlled by a programmable logic controller (PLC) with non-transitory memory storage,
storing instructions which, when executed by a computer, cause following steps to be performed dynamically in a loop:
reading a revolution rate of the ESP motor using a magnet attached to a shaft of the ESP motor and measuring a motor current, for a first period of time to establish a first data set;
making a first adjustment to a voltage output from the VSD to the ESP motor, the first adjustment having a first adjustment type, wherein the first adjustment type is one of increasing or decreasing the voltage output;
sensing the revolution rate and the motor current for a second period of time, after the first adjustment, to establish a second data set;
differencing the first data set with the second data set to determine a change in the motor current from the first data set to the second data set; and
making a second adjustment to the voltage output from the VSD to the ESP motor in response to the change in motor current and a change in the revolution rate, the second adjustment comprising one of:
an adjustment of the first adjustment type if the change in current is a drop and the revolution rate in the second data set is maintained between an upper threshold and a lower threshold; or
an adjustment opposite the first adjustment type if one of:
 the change in current is a rise and the revolution rate in the second data set is maintained between the upper threshold and the lower threshold; or
 if the change in current is a drop and the revolution rate in the second data set deviates one of above the upper threshold or below the lower threshold.

4. The method of claim 3 ,
wherein sensing the revolution rate of the ESP motor comprises measuring a magnetic flux of the shaft of the motor as the shaft rotates and
wherein the magnetic flux of the shaft is measured using a downhole sensor coupled below the motor, the downhole sensor measuring the magnetic flux of the magnet attached to the shaft.

5. The method of claim 3 , further comprising calculating power usage of the ESP motor from measured motor current and the voltage output to the motor and logging the power usage so calculated.

6. The method of claim 3 , wherein the loop is repeated iteratively during operation of the ESP motor.

7. The method of claim 3 ,
wherein the voltage output to the motor is adjusted and changed in increments of between 0.5 Volts and 20.0 Volts inclusive, and
wherein a size of the increment is dynamically changed during iterations of the loop.

8. The method of claim 7 , wherein the voltage output to the motor is adjusted every five minutes.

9. The method of claim 3 , further comprising logging the adjustments in the direction of the voltage output to the ESP motor.

10. A computer-readable medium having instructions stored thereon that are executable by a processor to perform operations comprising:
controlling a variable speed drive (VSD) that is electrically connected to an electric submersible pump (ESP) motor that is operating downhole in a well, wherein the controlling comprises,
reading a revolution rate of the ESP motor using a magnet attached to a shaft of the ESP motor and measuring a motor current, for a first period of time to establish a first data set;
making a first adjustment to a voltage output from the VSD to the ESP motor, the first adjustment having a first adjustment type, wherein the first adjustment type is one of increasing or decreasing the voltage output;
sensing the revolution rate and the motor current for a second period of time, after the first adjustment, to establish a second data set;
differencing the first data set with the second data set to determine a change in the motor current from the first data set to the second data set; and
making a second adjustment to the voltage output from the VSD to the ESP motor in response to the change in the motor current and a change in the revolution rate, the second adjustment comprising one of:
an adjustment of the first adjustment type if the change in the motor current is a drop and the revolution rate in the second data set is maintained between an upper threshold and a lower threshold; or
an adjustment opposite the first adjustment type if one of:
the change in the motor current is a rise and the revolution rate in the second data set is maintained between the upper threshold and the lower threshold; or
if the change in the motor current is a drop and the revolution rate in the second data set deviates one of above the upper threshold or below the lower threshold.

11. The computer-readable medium of claim 10 , wherein the controlling comprises calculating power usage of the ESP motor from measured motor current and the voltage output to the motor.

12. The computer-readable medium of claim 10 , wherein sensing the revolution rate of the ESP motor comprises measuring a magnetic flux of the shaft of the motor as the shaft rotates.

Assignees

• Halliburton Energy Services Inc

Inventors

• Janger Luke Golden
• Ashbaugh Ryan Bridwell
• Self David Linn
• Nowitzki Wesley John
• Beck David C

Classifications

• H02P6/28

  Arrangements for controlling current (H02P6/10 takes precedence) · CPC title

• H02K5/132

  Submersible electric motors (H02K5/128 takes precedence) · CPC title

• F04D15/0066

  by changing the speed, e.g. of the driving engine · CPC title

• H02K11/215

  Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements · CPC title

• F04D13/10

  adapted for use in mining bore holes · CPC title