Adjusting control gain based on error sampling in automated cement mixing

Patent metadata

Field	Value
Publication number	US-11806897-B2
Application number	US-201716468648-A
Country	US
Kind code	B2
Filing date	Dec 12, 2017
Priority date	Dec 12, 2016
Publication date	Nov 7, 2023
Grant date	Nov 7, 2023

Abstract

Methods and apparatus for controlling a characteristic of a cement slurry at a cementing unit, including regulating a characteristic of the cement slurry employing a closed loop feedback arrangement in the cementing unit, and adjusting a gain of the closed loop feedback arrangement in response to sampling an error of the characteristic.

First claim

What is claimed is:

1. An apparatus operable to control a density or solids fraction of a cement slurry at a cementing unit, comprising:
a processor; and
a non-transitory computer readable memory including computer program code, wherein the processor, the memory, and the computer program code are collectively operable to:
regulate the density or the solids fraction of the cement slurry employing a proportional-integral-derivative (PID) control loop feedback arrangement in the cementing unit;
identify proportional, integral, and derivative gains of the PID control loop to be used for reducing a density error or a solids fraction error, based on information in a database, wherein the information includes historical gain values with resulting cementing errors associated with the historical gain values, wherein identifying the proportional, integral, and derivative gains includes identifying a subset of the proportional, integral, and derivative gains that is impacted by a feature of the cementing unit; and
adjust the proportional, integral, and derivative gains of the PID control loop feedback arrangement in response to the density error or the solids fraction error based on the identification, wherein adjusting the proportional, integral, and derivative gains alters a volumetric flow rate of at least one of a cement blend or a mix fluid to adjust the density or the solids fraction of the cement slurry.

2. The apparatus of claim 1 , wherein the processor, the memory, and the computer program code are collectively operable to further adjust one or more of the proportional, integral, and derivative gains of the PID control loop feedback arrangement in a same direction if the density error or the solids fraction error improves.

3. The apparatus of claim 1 , wherein the processor, the memory, and the computer program code are collectively operable to further adjust one or more of the proportional, integral, and derivative gains of the PID control loop feedback arrangement in an opposite direction if the density error or the solids fraction error degrades.

4. The apparatus of claim 1 , wherein the processor, the memory, and the computer program code are collectively operable to further adjust one or more of the proportional, integral, and derivative gains of the PID control loop feedback arrangement proportionally to the density error or the solids fraction error.

5. The apparatus of claim 1 , wherein the processor, the memory, and the computer program code are collectively operable to further adjust one or more of the proportional, integral, and derivative gains of the PID control loop feedback arrangement by employing a statistical algorithm that incorporates historical data of an operation of the cementing unit.

6. The apparatus of claim 5 wherein the historical data comprise cementing parameters that describe a state of the cementing unit.

7. The apparatus of claim 5 wherein the historical data is associated with at least one of a mix fluid flow rate for the cementing unit, a mix additive for the cementing unit, a mix age for the cementing unit, and a mix temperature for the cementing unit.

8. The apparatus of claim 1 , wherein adjusting the proportional, integral, and derivative gains of the PID control loop feedback arrangement is operative to alter a position of a knife gate that alters the volumetric flow rate of the cement blend or a position of a valve that alters the volumetric flow rate of the mix fluid.

9. The apparatus of claim 8 , wherein adjusting the proportional, integral, and derivative gains of the PID control loop feedback arrangement is further operative to (i) output a setpoint for the knife gate that is input into a knife gate PID controller that in turn outputs a control signal that causes the knife gate to alter the volumetric flow rate of the cement blend, or (ii) output a setpoint for the valve that is input into a valve PID controller that in turn outputs a control signal that causes the valve to alter the volumetric flow rate of the mix fluid.

10. A method for controlling a density or a solids fraction of a cement slurry at a cementing unit, the method comprising:
regulating the density or the solids fraction the cement slurry employing a proportional-integral-derivative (PID) control loop feedback arrangement in the cementing unit;
identify proportional, integral, and derivative gains of the PID control loop to be used for reducing a density error or a solids fraction error, based on information in a database, wherein the information includes historical gain values with resulting cementing errors associated with the historical gain values, wherein identifying the proportional, integral, and derivative gains includes identifying a subset of the proportional, integral, and derivative gains that is impacted by a feature of the cementing unit; and
adjusting the proportional, integral, and derivative gains of the PID control loop feedback arrangement in response to the density error or the solids fraction error based on the identification, wherein adjusting the proportional, integral, and derivative gains alters a volumetric flow rate of at least one of a cement blend or a mix fluid to adjust the density or the solids fraction of the cement slurry.

11. The method of claim 10 wherein the adjusting further comprises adjusting one or more of the proportional, integral, and derivative gains of the PID control loop feedback arrangement in a same direction if the density error or the solids fraction error improves.

12. The method of claim 10 wherein the adjusting further comprises adjusting one or more of the proportional, integral, and derivative gains of the PID control loop feedback arrangement in an opposite direction if the density error or the solids fraction error degrades.

13. The method of claim 10 wherein the adjusting further comprises adjusting one or more of the proportional, integral, and derivative gains of the PID control loop feedback arrangement proportionally to the density error or the solids fraction error.

14. The method of claim 10 wherein the adjusting further comprises adjusting one or more of the proportional, integral, and derivative gains of the PID control loop feedback arrangement by employing a statistical algorithm that incorporates historical data of an operation of the cementing unit.

15. The method of claim 14 wherein the historical data comprise cementing parameters that describe a state of the cementing unit.

16. The method of claim 14 wherein the historical data is associated with the cementing unit.

17. The method of claim 16 wherein the historical data is associated with at least one of a mix fluid flow rate for the cementing unit, a mix additive for the cementing unit, a mix age for the cementing unit, and a mix temperature for the cementing unit.

18. The method of claim 14 wherein the historical data is employed to predict future feedback gains based on a trend in the historical data.

19. The method of claim 10 , wherein adjusting the proportional, integral, and derivative gains of the PID control loop feedback arrangement is operative to alter a position of a knife gate that alters the volumetric flow rate of the cement blend or a position of a valve that alters the volumetric flow rate of the mix fluid.

20. The method of claim 19 , wherein adjusting the proportional, integral, and derivative gains of the PID control loop feedback arrangement is further operative to (i) output a setpoint for the knife gate that is input into a knife gate PID controller that in t

Assignees

• Schlumberger Technology Corp

Inventors

• Urdaneta Carlos Junior
• Dean James
• Montemayor Oscar
• Balsamy Rajnarayanan Subbu
• Nguyen Dinh Quy

Classifications

• B28C7/0418 Primary

  control systems therefor · CPC title

• B28C9/004 Primary

  Making slurries, e.g. with discharging means for injecting in a well or projecting against a wall · CPC title

• E21B33/13

  Methods or devices for cementing, for plugging holes, crevices or the like · CPC title

• G05B6/02

  electric · CPC title

• G05B11/36

  with provision for obtaining particular characteristics, e.g. proportional, integral, differential · CPC title