Automated operation of wellsite pumping equipment

• US 10,415,562 B2
• Filed: 12/19/2016
• Issued: 09/17/2019
• Est. Priority Date: 12/19/2015
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Kajita, Marcos, Lopez, Miguel Angel, Jwair, Hassanain A., Bobadilla Larios, Manuel Alfonso, Faught, Edwin Guy
• Primary Examiner(s): Everett, Christopher E.
• Application Number:
  US16/063,329
• Publication Number:
  US 20180363640A1
• Time in Patent Office: 1,002 Days
• CPC Class Codes: E21B 43/12 Methods or apparatus for controlling the flow of the obtained fluid to or in wells E21B43/25 takes precedence; valve arrangements E21B34/00
• CPC Class Codes: E21B 43/2607 Surface equipment specially adapted for fracturing operations
• CPC Class Codes: E21B 44/00 Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
• CPC Class Codes: F04B 47/00 Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps by using positive or negative pressurised fluid medium acting directly on the liquid to be pumped F04F1/00
• CPC Class Codes: F04B 47/02 the driving mechanisms being situated at ground level F04B47/12 takes precedence
• CPC Class Codes: F04B 49/06 Control using electricity regulating by means of floats actuating electric switches F04B49/04
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 49/08 Regulating by delivery pressure
• CPC Class Codes: F04B 49/106 Responsive to pumped volume
• CPC Class Codes: G05B 19/04 Programme control other than numerical control, i.e. in sequence controllers or logic controllers G05B19/418 takes precedence
• CPC Class Codes: G05B 19/042 using digital processors G05B19/05 takes precedence
• CPC Class Codes: G05B 2219/41108 Controlled parameter such as gas mass flow rate

Abstract

Automated operation of well site pumping equipment, including generating a mathematical belief model for maintaining an interrelationship between flow rate achievable by a pump unit discharge pressure of the pump unit, and probability of achieving the flow rate at corresponding discharge pressure. Speed of the pump unit is controlled to achieve a target speed based on a flow rate set-point and the mathematical belief model and updating the mathematical belief model at least while the target speed is achieved. Updating the mathematical belief model may include increasing the probability of achieving the flow rate set-point when actual flow rate of the pump unit is not less than the flow rate set-point and decreasing the probability of achieving the flow rate set-point when the actual flow rate of the pump unit is less than the flow rate set-point.

Claims

1. An apparatus comprising:

a controller comprising a processor and a memory including computer program code,

wherein the controller is operable to automatically control flow rate discharged by a pump unit by;

controlling speed of the pump unit to achieve a target speed based on a flow rate set-point and an interrelationship between;

flow rate achievable by the pump unit;

discharge pressure of the pump unit; and

probability of achieving the flow rate at a corresponding discharge pressure; and

at least while the target speed is achieved;

increasing the probability of achieving the flow rate set-point when actual flow rate of the pump unit is not less than the flow rate set-point; and

decreasing the probability of achieving the flow rate set-point when the actual flow rate of the pump unit is less than the flow rate set-point.

2. The apparatus of claim 1 wherein the controller is further operable to generate a mathematical belief model characterizing the interrelationship.

3. The apparatus of claim 2 wherein the controller is operable to generate the mathematical belief model based partly on predetermined flow rate and pressure specifications of the pump unit.

4. The apparatus of claim 1 further comprising the pump unit.

5. The apparatus of claim 4 wherein the pump unit comprises a pump at least indirectly driven by a prime mover, and wherein the actual flow rate is of fluid that is pressurized and discharged by the pump.

6. The apparatus of claim 1 wherein controlling the speed of the pump unit to achieve the target speed is further based on a probability threshold set-point which limits the actual flow rate of the pump unit to a flow rate having a probability that is within the probability threshold.

7. A method comprising:

generating a mathematical belief model for maintaining an interrelationship between;

flow rate achievable by a pump unit;

discharge pressure of the pump unit; and

probability of achieving the flow rate at a corresponding discharge pressure; and

operating a controller comprising a processor and a memory including computer program code to automatically control flow rate discharged by the pump unit by;

controlling speed of the pump unit to achieve a target speed based on a flow rate set-point and the mathematical belief model; and

updating the mathematical belief model at least while the target speed is achieved by;

increasing the probability of achieving the flow rate set-point when actual flow rate of the pump unit is not less than the flow rate set-point; and

decreasing the probability of achieving the flow rate set-point when the actual flow rate of the pump unit is less than the flow rate set-point.

8. The method of claim 7 wherein generating the mathematical belief model is based partly on predetermined flow rate and pressure specifications of the pump unit.

9. The method of claim 7 further comprising inputting the mathematical belief model into the controller.

10. The method of claim 7 wherein generating the mathematical belief model is performed by the controller.

11. The method of claim 7 wherein each point along the mathematical belief model is associated with a speed of the pump unit and a gear of a transmission that are collectively operable to produce the flow rate at the corresponding discharge pressure.

12. The method of claim 7 wherein the pump unit comprises a prime mover operatively connected with a fluid pump via a transmission, and wherein controlling the speed of the pump unit comprises:

determining a target transmission gear to achieve the target speed; and

adjusting gears of the transmission until the target transmission gear is achieved.

13. The method of claim 7 wherein the probability of the mathematical belief model increases as the flow rate that is achievable by the pump unit decreases.

14. The method of claim 7 wherein the probability of the mathematical belief model increases as the discharge pressure of the pump unit decreases.

15. The method of claim 7 wherein controlling the speed of the pump unit to achieve the target speed is further based on a probability threshold set-point which limits the actual flow rate of the pump unit to a flow rate having a probability that is within the probability threshold.

16. A method comprising:

generating a mathematical model for a pump unit defining a relationship between a flow rate that is achievable by the pump unit at a corresponding discharge pressure and a probability of achieving the flow rate at the corresponding discharge pressure;

inputting a target flow rate into a controller comprising a processor and a memory including computer program code; and

operating the controller to automatically control flow rate of the pump unit by automatically;

selecting a target pump unit speed corresponding to the target flow rate;

adjusting speed of the pump unit until the target pump unit speed is achieved;

recording actual flow rate and actual discharge pressure of the pump unit; and

updating the mathematical model by;

increasing the probability of achieving the target flow rate by the pump unit if the recorded actual flow rate is not less than the target flow rate; and

decreasing the probability of achieving the target flow rate by the pump unit if the recorded actual flow rate is less than the target flow rate.

17. The method of claim 16 wherein the mathematical model for the pump unit is initially based on flow rate and discharge pressure performance specifications of the pump unit.

18. The method of claim 16 wherein each point along the mathematical model is associated with a speed of the pump unit and a transmission gear of a transmission.

19. The method of claim 16 wherein the probability of the mathematical model increases as the flow rate that is achievable by the pump unit increases.

20. The method of claim 16 wherein the probability of the mathematical model increases as the discharge pressure of the pump unit decreases.

21. The method of claim 16 wherein operating the controller to automatically control the flow rate of the pump unit further comprises, before selecting the target pump unit speed corresponding to the target flow rate:

determining if the target flow rate is within the mathematical model; and

if the target flow rate is within the mathematical model, the target pump unit speed is a first target pump unit speed and the target flow rate is a first target flow rate;

or

if the target flow rate is outside of the mathematical model, operating the controller further comprises automatically;

selecting a second target pump unit speed corresponding to a second target flow rate, wherein the second target pump unit speed is less than the first target pump unit speed, and wherein the second target flow rate is less than the first target flow rate;

adjusting speed of the pump unit until the second target pump unit speed is achieved;

recording actual flow rate and actual discharge pressure of the pump unit; and

updating the mathematical model by;

increasing the probability of achieving the second target flow rate by the pump unit if the recorded actual flow rate is not less than the second target flow rate; and

decreasing the probability of achieving the second target flow rate by the pump unit if the recorded actual flow rate is less than the second target flow rate.

22. The method of claim 16 wherein the target pump unit speed is a first target pump unit speed, and wherein, if the recorded flow rate is less than the target flow rate, operating the controller further comprises automatically:

selecting a second target pump unit speed, wherein the second target pump unit speed is greater than the first target pump unit speed;

adjusting speed of the pump unit until the second target pump unit speed is achieved;

recording actual flow rate and actual discharge pressure of the pump unit; and

updating the mathematical model by;

increasing the probability of achieving the target flow rate by the pump unit if the recorded actual flow rate is not less than the target flow rate; and

associating the second target pump unit speed with the target flow rate.

23. The method of claim 16 further comprising inputting a probability threshold set-point, wherein selecting the target pump unit speed comprises selecting a pump unit speed corresponding to a flow rate having a probability to be achieved that is substantially equal to the probability threshold set-point.

24. The method of claim 16 wherein selecting the target pump unit speed corresponding to the target flow rate is further based on a probability threshold set-point which limits the target pump unit speed to a pump unit speed corresponding to a flow rate having a probability that is not less than the probability threshold set-point.

25. The method of claim 16 wherein the pump unit comprises

a prime mover operatively connected with a fluid pump via transmission, and

wherein operating the controller to automatically control the flow rate of the pump unit further comprises:

selecting a target transmission gear that corresponds to the target flow rate; and

adjusting transmission gears until the target transmission gear is achieved.