Milling system for abandoning a wellbore

Patent metadata

Field	Value
Publication number	US-9938781-B2
Application number	US-201414496936-A
Country	US
Kind code	B2
Filing date	Sep 25, 2014
Priority date	Oct 11, 2013
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A mill for use in a wellbore includes a tubular housing having a bore therethrough and a plurality of eccentrically arranged pockets formed in a wall thereof and an arm disposed in each pocket. Each arm has a body portion and a blade portion extending from an outer surface of the body portion and is movable between an extended position and a retracted position. The mill further includes cutters disposed along each blade portion and a block disposed in each pocket and connected to the housing. Each block has a guide engaged with a mating guide of the respective body portion and an inner passage for providing fluid communication between the housing bore and the respective pocket. The mill further includes an actuator for extending the arms.

First claim

The invention claimed is:

1. A mill for use in a wellbore, comprising:
a tubular housing having a bore therethrough and a plurality of eccentrically arranged pockets formed in a wall thereof;
an arm disposed in each pocket, each arm:
having a body portion and a blade portion extending from an outer surface of the body portion, and
movable between an extended position and a retracted position;

cutters disposed along each blade portion;
a block disposed in each pocket and connected to the housing, each block having:
a guide engaged with a mating guide of the respective body portion;
a body and a stop connected thereto for receiving the respective arm in the extended position; and
an outer passage for providing fluid communication between the housing bore and the respective stop; and

wherein each arm is operable to close the respective outer passage in the extended position.

2. The mill of claim 1 , wherein:
each block further has an inner passage for providing fluid communication between the housing bore and the respective pocket; and
the mill further comprises an actuator for extending the arms.

3. The mill of claim 2 , wherein each block further comprises a jet disposed in each inner passage.

4. The mill of claim 2 , wherein:
each block has a port formed therethrough for providing fluid communication with the respective inner passage,
the housing has a port for each pocket, each port extending from the bore thereof to an outer surface thereof and intersecting the respective pocket, and
the mill further comprises a plug disposed in each housing port for diverting flow from the respective housing port to the respective block port.

5. The mill of claim 1 , wherein:
each stop has a valve operable to close the respective outer passage in response to extension of the respective arm.

6. The mill of claim 1 , wherein the actuator comprises:
a piston disposed in a chamber formed in the housing,
a pusher for each pocket, each pusher connected to the piston and extending through a respective slot formed in the housing and into the respective pocket.

7. The mill of claim 6 , further comprising a plurality of shearable fasteners, each shearable fastener connecting the respective pusher to the housing with the arms in the retracted position.

8. The mill of claim 6 , further comprising a mandrel in sealing engagement with the housing and having one or more ports formed through a wall thereof for providing fluid communication between a bore thereof and the chamber.

9. The mill of claim 8 , further comprising a nozzle connected to the mandrel below the one or more ports of the mandrel.

10. The mill of claim 8 , wherein the mandrel has a receiver formed in an inner surface thereof below the one or more ports of the mandrel for receiving a pump down plug.

11. The mill of claim 1 , further comprising a pad formed or disposed on an exposed portion of the outer surface of each body portion.

12. The mill of claim 1 , wherein:
an outer surface of each blade portion tapers outwardly, and
each blade portion has a length substantially less than a length of the body portion.

13. The mill of claim 1 , wherein:
each blade portion has a length corresponding to a length of the body portion, and
an outer surface of each blade portion is straight.

14. The mill of claim 1 , wherein:
the cutters are a first row of cutters,
the mill further comprises a second row of cutters, and
the first row of cutters and second row of cutters are offset.

15. The mill of claim 1 , wherein:
an outer diameter of the housing corresponds to a drift diameter of an inner casing string, and
a sweep of the blade portion of the arm in the extended position corresponds to a coupling diameter of the inner casing string.

16. A bottomhole assembly (BHA) for use in a wellbore, comprising:
a window mill, comprising the mill of claim 15 , wherein each blade portion has a length substantially less than a length of the body portion; and
a section mill, comprising the mill of claim 15 , wherein each blade portion has a length corresponding to a length of the body portion.

17. A method of using the BHA of claim 16 , comprising:
deploying the BHA into the wellbore through the inner casing string,
extending arms of the window mill and radially cutting through the inner casing string, thereby forming a window through the inner casing string;
longitudinally advancing the BHA while longitudinally milling the inner casing string using the extended arms of the window mill, thereby opening the window; and
extending arms of the section mill through the window and longitudinally milling a section of the inner casing string.

18. The mill of claim 1 , wherein:
an outer diameter of the housing corresponds to a drift diameter of an inner casing string;
a sweep of the blade portion of the arm in the extended position corresponds to a coupling diameter of an outer casing string.

19. A bottomhole assembly (BHA) for use in a wellbore, comprising:
a window mill, comprising the mill of claim 18 , wherein each blade portion has a length substantially less than a length of the body portion; and
a section mill, comprising the mill of claim 18 , wherein each blade portion has a length corresponding to a length of the body portion.

20. The BHA of claim 19 , further comprising a stabilizer, comprising:
a tubular housing having a bore therethrough and a plurality of eccentrically arranged pockets formed in a wall thereof;
an arm disposed in each pocket, each arm movable between an extended position and a retracted position;
a pad formed or disposed on an outer surface of each arm;
a block disposed in each pocket and connected to the housing, each block having:
a guide engaged with a mating guide of the respective body portion; and
an inner passage for providing fluid communication between the housing bore and the respective pocket; and
a hydraulic actuator for extending the arms.

21. A method of using the BHA of claim 19 , comprising:
deploying the BHA into the wellbore through the inner casing string,
extending arms of the window mill through a previously milled window or section of the inner casing string and radially cutting through the outer casing string, thereby forming a window through the outer casing string;
longitudinally advancing the BHA while longitudinally milling the outer casing string using the extended arms of the window mill, thereby opening the outer window; and
extending arms of the section mill through the outer window and longitudinally milling a section of the outer casing string.

22. A milling system for use in a wellbore, comprising:
a first BHA, comprising:
a first window mill, comprising the mill of claim 1 ; and
a first section mill, comprising the mill of claim 1 ,

a second BHA, comprising:
a second window mill, comprising the mill of claim 1 ; and
a second section mill, comprising the mill of claim 1 ,

wherein:
an outer diameter of each housing corresponds to a drift diameter of an inner casing string,
each block comprises a stop for receiving the respective arm in the extended position, and
a sweep of the first window mill and first section mill blade portions of the arms in the extended position corresponds to a coupling diameter of the inner casing string,
a sweep of the second window mill and second section mill blade portions of the arms in the extended position corresponds to a coupling diameter of an outer casing string,

Assignees

• Weatherford Tech Holdings Llc

Inventors

• Bansal Ram K
• Haq Mohammed Aleemul
• Bailey Thomas F
• Segura Richard J
• Smith Ian

Classifications

• E21B47/095

  by detecting an acoustic anomalies, e.g. using mud-pressure pulses · CPC title

• E21B33/13

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

• E21B17/1014 Primary

  Flexible or expansible centering means, e.g. with pistons pressing against the wall of the well (E21B17/1042 takes precedence) · CPC title

• E21B29/002

  Cutting, e.g. milling, a pipe with a cutter rotating along the circumference of the pipe · CPC title

• E21B47/091

  Fixed Constructions · mapped topic