Regulating downhole fluid flow rate using an multi-segmented fluid circulation system model
AssigneeHalliburton Energy Services, Inc.
InventorsXingyong Song, Jason D. Dykstra
Life of this patent
Estimating the term…
Abstract
A method for regulating a downhole fluid flow rate, in at least some embodiments, comprises partitioning a fluid circulation system into a sequence of segments, the sequence including a pump segment at one end and a drill bit segment at another end; obtaining a desired pressure for the drill bit segment; determining, for each of the segments in the sequence except for the drill bit segment, a desired pressure based at least in part on the desired pressure for a preceding segment in the sequence; determining a pump setting based on the desired pressure for the pump segment; and applying the pump setting to a pump used to move drilling fluid through the fluid circulation system.
Claims17
A method for regulating a downhole fluid flow rate, comprising:
- partitioning a fluid circulation system into a sequence of segments, said sequence including a pump segment at one end and a drill bit segment at another end;
- obtaining a desired pressure for the drill bit segment using a difference between a measured or estimated fluid flow rate for the drill bit segment and a desired fluid flow rate for the drill bit segment, the difference includes using a controller function:
- P
- N
- Desired
- =
- -
- K
- 1
-
- e
- 1
- A
- area
- +
- Gravity
- A
- area
- +
- Well
-
-
- Wall
-
-
- Friction
- A
- area
- +
- V
- .
- des
- A
- area
- wherein K1 is a positive control gain, e1=Vcuttings−Vdes and is a difference between an actual cutting velocity and a desired cutting velocity reference, Gravity is a gravity force of cuttings, Well Wall Friction is a friction force between cuttings and a well wall, Aarea is a wellbore cross section area, and {dot over (V)}des is a rate of change of Vdes;
- determining, for each of the segments in the sequence except for the drill bit segment, a desired pressure based at least in part on the desired pressure for a preceding segment in the sequence;
- determining a pump setting based on the desired pressure for the pump segment;
- and
- applying the pump setting to a pump used to move drilling fluid through the fluid circulation system.
A system comprising storage having software code which, when executed by a processor, causes the processor to:
- partition a fluid circulation system into a sequence of segments, said sequence including a pump segment at one end and a drill bit segment at another end;
- determine a desired pressure for the drill bit segment using a desired fluid flow rate for the drill bit segment using a controller function:
- P
- N
- Desired
- =
- -
- K
- 1
-
- e
- 1
- A
- area
- +
- Gravity
- A
- area
- +
- Well
-
-
- Wall
-
-
- Friction
- A
- area
- +
- V
- .
- des
- A
- area
- wherein K1 is a positive control gain, e1=Vcuttings−Vdes and is a difference between an actual cutting velocity and a desired cutting velocity reference, Gravity is a gravity force of cuttings, Well Wall Friction is a friction force between cuttings and a well wall, Aarea is a wellbore cross section area, and {dot over (V)}des is a rate of change of Vdes;
- determine, for each of the segments in the sequence except for the drill bit segment, a desired pressure based at least in part on the desired pressure for a preceding segment in the sequence;
- and
- operate a pump to move drilling fluid through said fluid circulation system based on the desired pressure for the pump segment.
The system of 10, wherein said desired pressure for the drill bit segment is determined using a controller function that accounts for a difference between the desired fluid flow rate for the drill bit segment and a measured or estimated fluid flow rate for the drill bit segment, and wherein the controller function further accounts for a rate of change of said difference.
A method for controlling the fluid flow rate of a fluid circulation system at a drill bit, comprising:
- obtaining a desired fluid flow rate at the drill bit;
- determining, in sequential fashion, a desired fluid pressure for each of a plurality of segments of the fluid circulation system, wherein a desired fluid pressure for a drill bit segment is determined based on the desired fluid flow rate at the drill bit using a controller function:
- P
- N
- Desired
- =
- -
- K
- 1
-
- e
- 1
- A
- area
- +
- Gravity
- A
- area
- +
- Well
-
-
- Wall
-
-
- Friction
- A
- area
- +
- V
- .
- des
- A
- area
- wherein K1 is a positive control gain, e1=Vcuttings−Vdes and is a difference between an actual cutting velocity and a desired cutting velocity reference, Gravity is a gravity force of cuttings, Well Wall Friction is a friction force between cuttings and a well wall, Aarea is a wellbore cross section area, and {dot over (V)}des is a rate of change of Vdes;
- and
- operating a pump to move drilling fluid through the fluid circulation system based on the desired pressure for a pump segment of the fluid circulation system.
Dependencies are inferred from the claim text.