AUTOMATIC CHOKE OPTIMIZATION AND SELECTION FOR MANAGED PRESSURE DRILLING

• US 20160298401A1
• Filed: 12/12/2014
• Published: 10/13/2016
• Est. Priority Date: 12/12/2014
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: COTTEN, Nancy Suzan, MILLER, Eric, POOL, Charles Michael
• Granted Patent: US 9,988,866 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: E21B 21/08 Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure valve arrangements therefor E21B21/10
• CPC Class Codes: E21B 21/106 Valve arrangements outside the borehole, e.g. kelly valves valves specifically for maintaining circulation of drilling fluid while connecting or disconnecting tubular joints E21B21/019
• 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: G05B 19/05 Programmable logic controllers, e.g. simulating logic interconnections of signals according to ladder diagrams or function charts
• CPC Class Codes: G05B 2219/13095 Pid regulator

Abstract

A choke valve assembly, system, and method can be used with a drill string in a wellbore to aid in controlling the bottom hole pressure during drilling of the wellbore. The choke valve assembly can have a primary choke and one or more supplemental chokes, where these choke valves each have a controllable range relative to the flow and pressure of drilling fluid passing through the assembly. A control unit can automatically actuate the primary choke and one or more supplemental chokes in order to both maintain the choke valves within their controllable ranges and concurrently maintain a consistent boom hole pressure in the connected wellbore.

Claims

1. A choke valve assembly, comprising:

a primary choke in fluid communication with an outlet;

a secondary choke in fluid communication with the primary choke and the outlet; and

a control unit operatively coupled to the primary choke and the secondary choke, wherein the control unit is programmed with instructions to automatically adjust the secondary choke to keep a coefficient of flow (C_v) of the primary choke within a primary choke controllable range.

2. The choke valve assembly according to claim 1, wherein the control unit automatically adjusts the secondary choke when a gas or a fluid within the primary choke drives the C_v of the primary choke toward a limit of the primary choke controllable range.

3. The choke valve assembly according to claim 1, wherein the control unit is programmed with the primary choke controllable range based on physical characteristics of the primary choke.

4. The choke valve assembly according to claim 1, wherein the control unit is programmed with a secondary choke operational range based on physical characteristics of the secondary choke.

5. The choke valve assembly according to claim 1, further comprising a user interface coupled to the control unit for either or both of monitoring and controlling the primary choke and the secondary choke.

6. The choke valve assembly according to claim 1, further comprising one or more supplementary choke valves operatively coupled to the control unit, wherein the control unit is further programmed with instructions to automatically adjust the one or more supplementary choke valves to keep the C_v of the primary choke within the primary choke controllable range.

7. The choke valve assembly according to claim 6, wherein the control unit automatically adjusts the one or more supplementary choke valves when a gas or a fluid within the primary choke drives the C_v toward a limit of the primary choke controllable range.

8. The choke valve assembly according to claim 6, wherein the control unit is programmed with one or more supplementary choke valves operational ranges based on physical characteristics of the one or more supplementary choke valves.

9. The choke valve assembly according to claim 6, further comprising a user interface coupled to the control unit for either or both of monitoring and controlling the primary choke, secondary choke, and the one or more supplementary choke valves.

10. A drill string choke valve system, comprising:

a drill string deployed in a wellbore;

a choke valve assembly coupled to and in fluid communication with the drill string deployed in the wellbore, wherein a flow of drilling return fluid generated by operation of the drill string passes through the choke valve assembly at a controlled pressure, the choke valve assembly comprising;

a primary choke in fluid communication with an outlet;

a secondary choke in fluid communication with the primary choke and the outlet; and

a control unit operatively coupled to the primary choke and the secondary choke, wherein the control unit is programmed with instructions to automatically adjust the secondary choke to keep a coefficient of flow (C_v) of the primary choke within a primary choke controllable range.

11. The system according to claim 10, wherein the control unit automatically adjusts the secondary choke when a gas or a fluid within the primary choke drives the C_v of the primary choke toward a limit of the primary choke controllable range.

12. The system according to claim 10, wherein the control unit is programmed with the primary choke controllable range based on physical characteristics of the primary choke.

13. The system according to claim 10, wherein the control unit is programmed with a secondary choke operational range based on physical characteristics of the secondary choke.

14. The system according to claim 10, further comprising a user interface coupled to the control unit for either or both of monitoring and controlling the primary choke and the secondary choke.

15. The system according to claim 10, further comprising one or more supplementary choke valves operatively coupled to the control unit, wherein the control unit is further programmed with instructions to automatically adjust the one or more supplementary choke valves to keep the C_v of the primary choke within the primary choke controllable range.

16. The system according to claim 15, wherein the control unit automatically adjusts the one or more supplementary choke valves when a gas or a fluid within the primary choke drives the C_v toward a limit of the primary choke controllable range.

17. The system according to claim 15, wherein the control unit is programmed with one or more supplementary choke valves operational ranges based on physical characteristics of the one or more supplementary choke valves.

18. The system according to claim 15, further comprising a user interface coupled to the control unit for either or both of monitoring and controlling the primary choke, secondary choke, and the one or more supplementary choke valves.

19. A method for controlling a choke valve assembly, comprising:

opening a primary choke to allow gas or fluid flow through the primary choke;

monitoring a primary choke valve coefficient of flow (C_v) in the primary choke with a control unit;

determining if the primary choke C_v is within a controllable range; and

automatically adjusting a secondary choke in fluid communication with the primary choke based on the C_v to allow an amount of gas or fluid to flow through the secondary choke in order to maintain or return the primary choke C_v within the controllable range.

20. The method according to claim 19, further comprising maintaining a bottom hole pressure in a wellbore through a drill string coupled to and in fluid communication with the primary choke and the secondary choke.

21. The method according to claim 19, wherein automatically adjusting the secondary choke is an incremental adjustment, such that the method further comprises:

monitoring the primary choke for a set period of time after adjusting the secondary choke;

after the set period of time, again determining if the primary choke C_v is within the controllable range; and

adjusting the secondary choke until the primary choke C_v is within the controllable range.

22. The method according to claim 19, further comprising actuating the secondary choke by a percentage of the total actuating range of the secondary choke over a set time period until the primary choke C_v is within the controllable range.

23. The method according to claim 19, further comprising automatically adjusting one or more supplementary choke valves in fluid communication with the primary choke based on the C_v to allow the amount of gas or fluid through the one or more supplementary choke valves in order to maintain or return the primary choke C_v within the controllable range.

24. The method according to claim 20, further comprising maintaining the bottom hole pressure in a wellbore through the drill string coupled to and in fluid communication with the primary choke, the secondary choke, and the one or more supplementary choke valves.

25. The method according to claim 23, wherein automatically adjusting the one or more supplementary choke valves is an incremental adjustment, such that the method further comprises:

monitoring the primary choke for a set period of time after adjusting the one or more supplementary choke valves;

after the set period of time, again determining if the primary choke C_v is within the controllable range; and

adjusting the one or more supplementary choke valves until the primary choke C_v is within the controllable range.

26. The method according to claim 23, wherein adjustment of the one or more supplementary choke valves is incremental, actuating the one or more supplementary choke valves by a percentage of the total actuating range of the one or more supplemental choke valves over a set time period, until the primary choke C_v is within the controllable range.

27. The method according to claim 23, further comprising:

operating the choke valve assembly to apply a consistent backpressure in the wellbore; and

adjusting or programming a control unit with parameters to define the primary choke C_v, and an operational range of either or both of the secondary choke and the one or more supplemental choke valves.