U.S. patent application number 16/239822 was filed with the patent office on 2019-05-09 for magnetic downhole tool and related subassemblies having mu-metallic shielding.
The applicant listed for this patent is Halliburton Energy Services, Inc.. Invention is credited to Christopher Michael McMillon, Robert Mitchell Neely.
Application Number | 20190136668 16/239822 |
Document ID | / |
Family ID | 53479379 |
Filed Date | 2019-05-09 |
![](/patent/app/20190136668/US20190136668A1-20190509-D00000.png)
![](/patent/app/20190136668/US20190136668A1-20190509-D00001.png)
![](/patent/app/20190136668/US20190136668A1-20190509-D00002.png)
![](/patent/app/20190136668/US20190136668A1-20190509-D00003.png)
![](/patent/app/20190136668/US20190136668A1-20190509-D00004.png)
![](/patent/app/20190136668/US20190136668A1-20190509-D00005.png)
![](/patent/app/20190136668/US20190136668A1-20190509-D00006.png)
United States Patent
Application |
20190136668 |
Kind Code |
A1 |
McMillon; Christopher Michael ;
et al. |
May 9, 2019 |
Magnetic Downhole Tool And Related Subassemblies Having Mu-Metallic
Shielding
Abstract
Systems and related methods are disclosed that involve the use
of a magnetic downhole assembly or a magnetic downhole tool. The
assembly and tool include a mu-metal sleeve that is operable to
isolate a magnetic field and a permanent magnet disposed within the
mu-metal sleeve. The assembly and tool also include an actuator
that is operable to selectively extend and retract the sleeve to
alternatingly expose and shield the permanent magnet. A conveyance
is operable to deploy the magnetic downhole assembly and tool to a
selected location within a wellbore and a controller is
communicatively coupled to the actuator and operable to generate a
control signal that causes the actuator to extend or retract the
permanent magnet from the mu-metal sleeve.
Inventors: |
McMillon; Christopher Michael;
(Wylie, TX) ; Neely; Robert Mitchell; (Carrollton,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Halliburton Energy Services, Inc. |
Houston |
TX |
US |
|
|
Family ID: |
53479379 |
Appl. No.: |
16/239822 |
Filed: |
January 4, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15039014 |
May 24, 2016 |
|
|
|
PCT/US2013/077700 |
Dec 24, 2013 |
|
|
|
16239822 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 43/08 20130101;
E21B 33/1208 20130101; E21B 23/00 20130101; E21B 33/12 20130101;
E21B 33/10 20130101; E21B 31/06 20130101; E21B 41/00 20130101 |
International
Class: |
E21B 41/00 20060101
E21B041/00; E21B 43/08 20060101 E21B043/08; E21B 33/12 20060101
E21B033/12; E21B 23/00 20060101 E21B023/00; E21B 33/10 20060101
E21B033/10; E21B 31/06 20060101 E21B031/06 |
Claims
1. A system of operating a magnetic downhole assembly comprising: a
magnetic downhole assembly having: a shielding sleeve operable to
isolate a magnetic field; a permanent magnet disposed within the
shielding sleeve, the permanent magnet being coupled to a piston;
and an actuator operable to selectively extend and retract the
piston from the shielding sleeve so as to selectively expose and
shield the permanent magnet; a conveyance operable to deploy the
magnetic downhole assembly to a selected location within a
wellbore; and a controller communicatively coupled to the actuator
and operable to generate a control signal.
2. The system of claim 1, wherein the shielding sleeve comprises a
mu-metal.
3. The system of claim 1, wherein the actuator is selected from the
group consisting of a hydraulic actuator, an electric actuator, and
a mechanical actuator.
4. The system of claim 1, further comprising: a tubing segment
having a fluid flow path therethrough; a reservoir coupled to the
controller and having a magnetorheological fluid disposed therein,
the reservoir being operable to disperse the magnetorheological
fluid into the fluid flow path in response to the control
signal.
5. The system of claim 4, further comprising a pressure sensor
coupled to the controller, wherein the magnetic downhole assembly
is operable to extend the permanent magnet adjacent the fluid flow
path to generate a magnetic field across the fluid flow path in
response to the control signal, and wherein the controller is
operable to generate the control signal in response to determining
that a pressure at the pressure sensor is increasing at a rate that
is greater than a predetermined rate.
6. The system of claim 1, further comprising a tubing segment and a
reservoir coupled to the controller, wherein the reservoir
comprises a magnetorheological fluid disposed therein, and wherein
the reservoir is operable to disperse the magnetorheological fluid
adjacent the magnetic downhole assembly between an exterior surface
of the tubing segment and a wellbore wall in response to the
control signal.
7. The system of claim 6, wherein the magnetic downhole assembly is
operable to extend the permanent magnet to generate a magnetic
field about the external exterior surface of the tubing segment in
response to the control signal.
8. A magnetic downhole tool comprising: a mu-metal sleeve operable
to isolate a magnetic field; a permanent magnet disposed within the
mu-metal sleeve, the permanent magnet coupled to a piston; and an
actuator, the actuator being operable to selectively extend and
retract the piston from the mu-metal sleeve so as to selectively
expose and shield the permanent magnet.
9. The magnetic downhole tool of claim 8, wherein the mu-metal
sleeve comprises a plurality of layers of mu-metal.
10. The magnetic downhole tool of claim 9, wherein the layers of
mu-metal are separated by at least one insulating layer.
11. The magnetic downhole tool of claim 8, wherein the actuator is
selected from the group consisting of a hydraulic actuator, a
solenoid, and a mechanical actuator.
12. A method of operating a magnetic downhole tool, the method
comprising: providing a magnetic downhole tool comprising a
mu-metal sleeve operable to isolate a magnetic field, a permanent
magnet disposed within the mu-metal sleeve, the permanent magnet
coupled to a piston, and an actuator, the actuator being operable
to selectively extend and retract the piston from the mu-metal
sleeve so as to selectively expose and shield the permanent magnet;
providing a controller, the controller being communicatively
coupled to the actuator; and generating a control signal to cause
the actuator to extend or retract the metal sleeve.
13. The method of claim 12, wherein the mu-metal comprises a
nickel-iron alloy.
14. The method of claim 12, wherein the step of generating the
control signal is selected from the group consisting of generating
a hydraulic control signal, generating an electric control signal,
and generating a mechanical control signal.
15. The method of claim 12, further comprising coupling the
magnetic downhole tool to a conveyance and positioning the downhole
tool at a selected location in a wellbore, wherein the conveyance
is selected from the group consisting of a slickline, a wireline,
and a tool string.
16. The method of claim 12, further comprising exposing the
permanent magnet to control the viscosity of a magnetorheological
fluid.
17. The method of claim 12, further comprising exposing the
permanent magnet to remove a plug from a wellbore casing.
18. The method of claim 12, further comprising exposing the
permanent magnet and manipulating the magnetic downhole tool to
adjust the position of a screen.
19. The method of claim 12, further comprising exposing the
permanent magnet and manipulating the magnetic downhole tool to
adjust the position of a second downhole tool.
20. The method of claim 12, further comprising exposing the
permanent magnet to couple permanent magnet to a second downhole
tool, delivering the second downhole tool to a selected location,
and retracting the permanent magnet.
Description
FIELD OF THE INVENTION
[0001] The disclosure relates to oil and gas exploration and
production, and more particularly, but not by way of limitation to
systems that employ magnetic shielding formed from a mu-metal to
selectively shield a permanent magnet to control downhole
systems.
DESCRIPTION OF RELATED ART
[0002] Hydrocarbons occur naturally in subterranean deposits and
their extraction includes drilling a well. The well provides access
to a production fluid that often contains crude oil and natural
gas. Generally, drilling of the well involves deploying a drill
string into a formation. The drill string includes a drill bit that
removes material from the formation as the drill string is lowered
to remove material from the formation and form a wellbore. After
drilling and prior to production, a casing may be deployed in the
wellbore to isolate portions of the wellbore wall and prevent the
ingress of fluids from parts of the formation that are not likely
to produce desirable fluids. After completion, a production string
may be deployed into the well to facilitate the flow of desirable
fluids from producing areas of the formation to the surface for
collection and processing. Both the drill string and production
string may include a variety of downhole tools. Such downhole tools
may also be deployed by slickline or wireline conveyances that
mechanically lower tools into a wellbore for testing and other
tasks after the well has been formed.
[0003] A number of additional mechanisms may he included in drill
strings and production strings to protect equipment within the
wellbore and ensure consistent operation of such equipment. For
example, valves and blow-out preventers may be installed to prevent
rapid, excessive increases in pressure and to prevent backflow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 illustrates a schematic view of a producing well in
which a magnetic downhole tool is deployed;
[0005] FIG. 2 illustrates a schematic view of a subterranean well
in which a magnetic downhole tool is deployed from a slickline
conveyance;
[0006] FIG. 3A is a side, cross-section of a magnetic tool in an
un-actuated state;
[0007] FIG. 3B is a side, cross-section of the magnetic tool of
FIG. 3A in an actuated state;
[0008] FIG. 3C is a perspective view of the magnetic tool of FIG.
3A in an actuated state;
[0009] FIG. 4A is a side, cross-section view of a blowout inhibitor
that includes a magnetorheological fluid and a magnet actuator in
an un-actuated state;
[0010] FIG. 4B is a side, cross-section view of the blowout
inhibitor of FIG. 4A in an actuated state.
[0011] FIG. 5A is a side, cross-section view of a zone isolator
that includes a magnetorheological fluid and a magnet actuator in
an un-actuated state; and
[0012] FIG. 5B is a side, cross-section view of the zone isolator
of FIG. 5A in an actuated state.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0013] In the following detailed description of the illustrative
embodiments, reference is made to the accompanying drawings that
form a part hereof. These embodiments are described in sufficient
detail to enable those skilled in the art to practice the
invention, and it is understood that other embodiments may be
utilized and that logical structural, mechanical, electrical, and
chemical changes may be made without departing from the scope of
the invention. To avoid detail not necessary to enable those
skilled in the art to practice the embodiments described herein,
the description may omit certain information known to those skilled
in the art. The following detailed description is, therefore, not
to be taken in a limiting sense, and the scope of the illustrative
embodiments is defined only by the appended claims.
[0014] In the drawings and description that follow, like parts are
typically marked throughout the specification and drawings with the
same reference numerals, respectively. The drawing figures are not
necessarily to scale. Certain features of the invention may be
shown exaggerated in scale or in somewhat schematic form and some
details of conventional elements may not be shown in the interest
of clarity and conciseness.
[0015] The embodiments described herein relate to the systems,
tools, and methods that include the use of a downhole tool that
includes a permanent magnet and a mu-metallic shield. In an
illustrative embodiment, a system for deploying such a downhole
tool includes a downhole tool having a shielding sleeve operable to
isolate a magnetic field, a permanent magnet disposed within the
shielding sleeve, and an actuator. As referenced herein, the
shielding sleeve is a sleeve that is operable to prevent the
transmittance of a magnetic field. The actuator is operable to
selectively extend and retract the magnet from the sleeve to expose
and shield the magnet, respectively. The system also includes a
conveyance to deploy the downhole tool to a selected location
within a wellbore and a controller communicatively coupled to the
actuator and operable to generate a control signal to the actuator
to extend or retract the magnet.
[0016] The shielding sleeve may include one or more layers of a
mu-metal. For example, the shielding sleeve may be a single layer
of mu-metal or a plurality of layers. The layers may be arranged
adjacent to one another or separated by an insulating layer. As
referenced herein, a mu-metal is a metal selected from a range of
nickel-iron alloys having relatively high magnetic permeability. An
example of a mu-metal is an alloy composed of, for example,
approximately 77% nickel, 16% iron, 5% copper and 2% chromium or
molybdenum. Mu-metals are useful for shielding against static or
low-frequency magnetic fields because of their high
permeability--having typical relative permeability values of
80,000-100,000.
[0017] In an illustrative system, the actuator may be a hydraulic
actuator and the control signal may be a hydraulic control signal,
or the actuator may be a solenoid and the control signal may be an
electric control signal. In another embodiment, the actuator may be
a mechanical actuator actuated by a mechanical control signal, such
as a tension applied to the conveyance. The conveyance may he a
slickline, a wireline, a production tool string, a drilling tool
string, an umbilical cable, or any other suitable conveyance.
[0018] According to another illustrative embodiment, a downhole
tool includes a mu-metal sleeve operable to isolate a magnetic
field and a permanent magnet disposed within the mu-metal sleeve.
The tool also includes an actuator operable to extend and retract
the mu-metal sleeve to selectively shield and expose the permanent
magnet, respectively. The mu-metal sleeve may be formed from one or
more layers of a nickel-iron alloy or a similar nickel alloy. In an
embodiment in which the tool has multiple mu-metal layers, the
layers may be disposed adjacent one another or separated by a
non-magnetic insulating layer. The insulating layer may be air, a
cloth layer, a plastic layer, a dielectric layer, or a layer of any
other suitable material. The actuator may be a hydraulic actuator,
a solenoid, or a mechanical actuator.
[0019] According to another illustrative embodiment, a method for
deploying a permanent magnet in a wellbore includes providing a
downhole tool having a mu-metal sleeve that is operable to isolate
a magnetic field and a permanent magnet disposed within the
mu-metal sleeve. The downhole tool also includes an actuator, which
is operable to selectively extend and retract the permanent magnet
to alternatingly expose and shield the permanent magnet using the
mu-metal sleeve.
[0020] The method also includes coupling the downhole tool to a
conveyance, providing a controller that is communicatively coupled
to the actuator, and generating a control signal to cause the
actuator to extend or retract the permanent magnet. The actuator
may be a hydraulic actuator, an electrical actuator, and a
mechanical actuator, and, correspondingly, the control signal may
be a hydraulic control signal, an electric control signal, or a
mechanical control signal. The conveyance that is coupled to the
actuator may be a slickline, a wireline, a production tool string,
a drill string, a production tool string or any other suitable
conveyance. The method may further include exposing the permanent
magnet to control the viscosity of a magnetorheological fluid or
exposing the permanent magnet to orient a second tool within a
wellbore.
[0021] As referenced herein, a magnetorheological fluid is a type
of fluid whose properties, including, for example, viscosity,
change in the presence of a magnetic field. For example, when a
magnetorheological fluid is exposed to a magnetic field, the
viscosity of the fluid may increase to the extent that it becomes a
viscoelastic solid. Examples of magnetorheological fluids include a
first composition including 20 wt. % carbonyl iron (CI) and fumed
silica stabilizer ("Aerosil 200") in silicone oil (OKS 1050); a
second composition including 40 wt. % carbonyl iron (CI) and fumed
silica stabilizer ("Aerosil 200") in silicone oil (OKS 1050); a
third composition including 20 wt. % carbonyl iron (CI) in silicone
oil (OKS 1050); and a fourth composition including 40 wt. %
carbonyl iron (CI) in silicone oil (OKS 1050).
[0022] Unless otherwise specified, any use of any form of the terms
"connect," "engage," "couple," "attach," or any other term
describing an interaction between elements is not meant to limit
the interaction to direct interaction between the elements and may
also include indirect interaction between the elements described.
In the following discussion and in the claims, the terms
"including" and "comprising" are used in an open-ended fashion, and
thus should be interpreted to mean "including, but not limited to".
Unless otherwise indicated, as used throughout this document, "or"
does not require mutual exclusivity.
[0023] The various characteristics mentioned above, as well as
other features and characteristics described in more detail below,
will he readily apparent to those skilled in the art with the aid
of this disclosure upon reading the following detailed description
of the embodiments, and by referring to the accompanying drawings.
Other means may be used as well.
[0024] The representative systems, methods, and tools may be used
in any number of well and tool string configurations, including,
for example, the configurations described below. Referring now to
the figures, FIG. 1 shows an example of a production system 100
that includes a blowout inhibitor 124 and a plurality of isolators
104. The production system 100 includes a rig 116 atop the surface
132 of a well 101. Beneath the rig 116, the wellbore 108 is formed
within the geological formation 106, which is expected to produce
hydrocarbons. The wellbore 108 may be formed in the geological
formation 106 using a drill string that includes a drill bit to
remove material from the geological formation 106. The wellbore 108
in FIG. 1 is shown as being near-vertical, but may be formed at any
suitable angle to reach a hydrocarbon-rich portion of the
geological formation 106. As such, in an embodiment, the wellbore
108 may follow a vertical, partially vertical, angled, or even a
partially horizontal path through the geological formation 106.
[0025] Following or during formation of the wellbore 108, a
production tool string 112 may be deployed that includes tools for
use in the wellbore 108 to operate and maintain the well. Such
tools may be referred to as downhole tools. For example, the
production tool string 112 optionally includes an artificial lift
system to assist fluids from the geological formation to reach the
surface 132 of the well 101. Such an artificial lift system may
include an electric submersible pump 102, sucker rods, a gas lift
system, or any other suitable system for generating a pressure
differential. The pump 102 receives power from the surface 132 from
a power transmission cable 110, which may also be referred to as an
"umbilical cable." In the embodiment of FIG. 1, the umbilical cable
may also serve as a conveyance for other items within the
production tool string 112, such as a magnetic downhole tool as
described below with regard to FIGS. 3A-3C.
[0026] In a production environment, as shown in FIG, 1, production
fluids 146 are extracted from the formation 106 and delivered to
the surface 132 via the wellbore 108. As fluid 146 is transported
to the surface 132, the fluid passes through a blowout preventer
142 and a fluid diverter 144 that diverts fluid 146 to a collection
tank 140 for subsequent processing and refinement.
[0027] In such systems, a well operator may monitor the condition
of the well 101 and components of the production tool string 112 to
ensure that the well operates efficiently and to determine whether
the production fluid 146 has desired properties. For example, an
operator may want to determine that the production fluid 146 has a
high hydrocarbon content and a low water content. In some cases, a
well operator may determine that a portion of the formation 106
produces desirable fluids while another portion of the foundation
produces undesirable fluids, each such portion of the formation may
be referred to as a zone. An operator may similarly determine that
different zones within a formation produce fluid at different
rates, or that different zones have higher or lower hydrostatic
pressure relative to one another. For example, the formation 106
may have a first zone 156 that interacts with the wellbore 108
downhole from a second zone 158. To account for such differing
characteristics, an operator may include an isolator 104 for
separating the first zone 156 from the second zone to allow for
different rates of production or to allow, for example, production
of fluid from the first zone 156 without allowing production from
the second zone 158. Similarly, to prevent the ingress of fluids
from a zone in the formation 106, the system 100 may include a
casing 114 that restricts the communication of fluids between the
formation 106 and wellbore 108.
[0028] In addition, the well operator may take steps to ensure that
the pressure in the well does not increase beyond a predetermined
threshold, and that pressure within the well or production string
112 does not increase at a rate that is faster than a predetermined
rate. Rapid increases in pressure, which may be referred to herein
as "pressure spikes" may damage equipment in the production string
112 that is subject to the pressure spike or stress other sealing
elements that are designed to contain the well. To account for such
pressure spikes and prevent damage to wellbore equipment, the
production system 100 may include a blowout inhibitor 124 that
prevents such pressure spikes from being transmitted to parts of
the production string that are up-hole from, or closer to the
surface than, the blowout inhibitor 124. The system 100 may also
include a pressure sensor 148 to monitor pressure in the wellbore
at or near the blowout inhibitor 124.
[0029] In an embodiment, a surface controller 120 may be
communicatively coupled to the isolator 104 or blowout inhibitor
124 (either of which may be referred to as a "downhole component")
by the cable 110 or by a wireless communication protocol, such as
mud-pulse telemetry or a similar communications protocol. The cable
110 may supply power to the downhole component and facilitate the
transmission of data between the surface controller 120 and
downhole component. In some embodiments, one or more of the
downhole components may be permanently or semi-permanently deployed
in the wellbore 108, and may include an on-board controller that
functions autonomously or that communicates with the surface
controller 120 via a wired or wireless communications protocol.
[0030] The production system 100 of FIG. 1 is deployed from the rig
116, which may be a drilling rig, a completion rig, a workover rig,
or another type of rig. The rig 116 includes a derrick 109 and a
rig floor 111. The production tool string 112 extends downward
through the rig floor, through a fluid diverter 144 and blowout
preventer 142 that provide a fluidly sealed interface between the
wellbore 108 and external environment. The rig 116 may also include
a motorized winch 130 and other equipment for extending the tool
string 112 into the wellbore 108, retrieving the tool string 112
from the wellbore 108, and positioning the tool string 112 at a
selected depth within the wellbore 108.
[0031] While the operating environment shown in FIG. 1 relates to a
stationary, land-based rig 116 for raising, lowering and setting
the tool string 112, in alternative embodiments, mobile rigs,
wellbore servicing units (such as coiled tubing units, slickline
units, or wireline units), and the like may be used to lower the
tool string 112. Further, while the operating environment is
generally discussed as relating to a land-based well, the systems
and methods described herein may instead be operated in subsea well
configurations accessed by a fixed or floating platform. Further,
while the downhole components are shown as being deployed in a
production environment, the downhole components may be similarly
deployed in a drilling environment during the formation of the
wellbore 108 and in slickline operations.
[0032] Referring now to FIG. 2, a magnetic downhole tool 270 that
is analogous to the magnetic downhole tool of the illustrative
embodiments described above is shown deployed in a slickline system
200. The deployment of the slickline tool string 215 is analogous
in many respects to the deployment of the production tool string
112 of FIG. 1. For example, the slickline tool string 215 is
deployed into a wellbore 208 formed in a formation 206. The tool
string 215 is lowered into the wellbore 208 from a slickline
conveyance 210 from a rig 216 that includes a platform 211 and
derrick 209. The depth to which the tool string 215 is lowered is
controlled by a motorized winch 230 mounted at the surface 232 and
controlled by a surface controller 220, which may also be
communicatively coupled to the tool 270. As described in more
detail below, the magnetic downhole tool 270 may include a
permanent magnet that can be selectively exposed and shielded.
[0033] The magnetic downhole tool 270 may therefore be lowered into
the wellbore 208 in a shielded state and actuated to an exposed
state to accomplish a number of downhole tasks. For example, the
permanent magnet may be exposed to retrieve a stuck tool, a
fragment thereof, or any other magnetic object from the wellbore.
In another embodiment, the magnetic downhole tool 270 may be
actuated and the magnet exposed to retrieve a plug 272 from a
casing 214 in the wellbore 208, or to orient or otherwise position
a second tool in the wellbore 208 relative to the magnet of the
magnetic downhole tool 270. For example, the magnetic downhole tool
270 may be used to deliver and orient a second tool downhole, to
orient a plug in a casing in the wellbore 208, or to move or shift
a screen in a downhole environment.
[0034] FIGS. 3A-3C show an embodiment of a downhole tool 300 that
is analogous to the magnetic downhole tool 270 described above with
regard to FIG. 2. The tool 300 includes coupling 312 for coupling
the downhole tool 300 to a conveyance, such as slickline cable, a
wireline cable, or a tool string, and a shielding sleeve 304, which
may be a mu-metal sleeve, as described above. The shielding sleeve
304 may be formed from a single layer of the mu-metal or by
plurality of layers. In an embodiment, the shielding sleeve 304
includes a first layer 320 and a second layer 322 separated by an
optional insulator 324 or insulating layer. In an embodiment that
includes the insulator 324, the insulator 324 is formed from a
material that is magnetically inert, such as a foam, cloth, a
vacuum, air, a non-magnetic solid material, or a non-magnetic
liquid layer. The shielding sleeve encloses a permanent magnet 302.
The permanent magnet 302 includes a magnetized material that
generates a persistent magnetic field. The magnetized material may
he a ferromagnetic material, such as iron, nickel, cobalt, and
alloys thereof. In an embodiment, the magnetized material is a
magnetically processed alnico or ferrite.
[0035] The permanent magnet 302 is housed within the shielding
sleeve 304 and is coupled to a piston 310 of an actuator 306 that
is operable to extend the permanent magnet 302 from the shielding
sleeve 304 in response to receiving an actuation signal from a
controller, which may be a surface controller or an onboard
controller. FIGS. 3B and 3C show the magnetic downhole tool 300 in
an extended state in which the permanent magnet 302 protrudes from
the shielding sleeve 304 to magnetically engage objects that are
outside of the shielding sleeve 304.
[0036] In an embodiment, the actuator 306 may he actuated in a
binary mode in which the piston 310 is either fully extended or
fully retracted or in a continuously variable mode in which the
piston 310 is extended only a specified distance. The actuator 306
may be a mechanical actuator, an electrical actuator, or a
hydraulic actuator. In an embodiment in which the actuator 306 is a
mechanical actuator, the actuator 306 may include a lever arm,
gearing, ratchet extension, biasing spring, or some combination
thereof to render the actuator 306 operable to extend the piston
310 in response to receiving a first mechanical actuation signal
and to retract the piston 310 in response to receiving a second
mechanical actuation signal. The first and second mechanical
actuation signal may be an applied tension, a relaxed tension, a
tension of a preselected magnitude, a series of applied tensions,
or a combination thereof. In an embodiment, the first mechanical
actuation signal and second mechanical actuation signal may be
applied to the actuator 306 from a slickline conveyance.
[0037] In another embodiment, the actuator 306 may be a hydraulic
actuator, such as a hydraulic chamber coupled to a hydraulic
control line. The hydraulic chamber may receive a hydraulic control
signal from a remote hydraulic controller or from a hydraulic
control line that causes the piston 310 to extend and retract from
the actuator 306. In another embodiment, the actuator 306 may be an
electronic actuator, such as a solenoid, which may be coupled to an
onboard controller or a surface-based controller that generates an
actuation signal to cause the actuator 306 to extend and retract
the piston 310 from the shielding sleeve 304.
[0038] In the actuated state shown in FIGS. 3B and 3C, the magnetic
downhole tool 300 may be used for a number of downhole functions.
For example, the magnetic downhole tool 300 may be deployed to
retrieve a lost tool, broken equipment, or other magnetic debris
from a wellbore. In another embodiment, the magnetic downhole tool
300 may be deployed to remove a plug from a wellbore casing, to
shift a screen, or to assist with the delivery and orientation and
installation of a second tool or other downhole equipment by
attracting or repelling a magnetized surface toward or away front
the magnetic downhole tool 300. For example, in an embodiment, the
magnetic downhole tool 300 may be magnetically coupled to a second
tool in an extended state, lowered into a wellbore to deliver the
second tool to its intended location, actuated to transition the
magnetic downhole tool 300 to a retracted state to decouple the
second tool from the permanent magnet 302, and retrieved from the
wellbore.
[0039] FIG. 4A shows a blowout inhibitor 400 that includes an
actuator 406 that operates similar to actuator 306 of the magnetic
downhole tool 300 described with regard to FIGS. 3A-3C. The blowout
inhibitor 400 occupies a tubing segment 436 of the tool string and
may also be referred to as a blowout inhibitor subassembly. The
tool string may be a production string or any other type of tool
string or conduit that delivers fluid from a formation to the
surface. In the embodiment of FIG. 4A, the blowout inhibitor 400 is
a magnetorheological blowout inhibitor that includes a reservoir
430. The reservoir 430 may be a cylindrical, or ring-shaped
reservoir that is coupled to the interior of the tubing segment
436. A magnetorheological fluid 432 may be stored within the
reservoir and released or forced into a flow path through the
tubing segment 436. As referenced herein, the flow path refers to
the path from a downhole opening of the tubing segment 436 upward
to an upper opening of the tubing segment 436.
[0040] In an embodiment, the blowout inhibitor 400 also includes a
controller 420 that is coupled to the reservoir 430 via a control
line 422 and operable to actuate the release of magnetorheological
fluid 432 from the reservoir 430. In an embodiment, the controller
420 includes or is coupled to a pressure sensor that monitors the
pressure of fluid in the tool string and the rate of change of
pressure in the tool string. The pressure sensors and controller
420 may be operable to monitor the static pressure at or below the
sensor location to determine if the static pressure exceeds a
predetermined pressure of if the static pressure is increasing at a
rate that is faster than a predetermined rate of change. As
referenced herein, either an increase in the static pressure beyond
the predetermined pressure or an increase in the rate of change of
the static pressure beyond the predetermined rate of change may be
referred to as a "pressure spike." The predetermined pressure and
predetermined rate of change of pressure may be selected to
correspond to pressure changes or rates of pressure change that are
likely to increase the risk of equipment in the tool string that is
upstream from the blowout inhibitor 400.
[0041] In an embodiment, the controller 420 is configured to detect
a pressure spike and to cause the magnetorheological fluid 432 to
be released from the reservoir 430 into the flow path in response
to detection of a pressure spike. The detection of the pressure
spike may also result in the transmission of an actuation signal
from the controller 420 to a permanent magnet assembly 401 that is
coupled to the controller 420 via the control line 422. The
permanent magnet assembly 401 includes an enclosure 404 that
includes a metallic shield. Like the metallic shields discussed
above, the metallic shield may be formed from one or more layers of
a mu-metal. One or more permanent magnets 402 are selectively
extendable and retractable from the enclosure 404 by one or more
synchronized actuators 406, each having a piston 410 that is
coupled to the permanent magnet 402 and operable to extend and
retract the permanent magnet 402. Each actuator 406 may therefore
cause a piston 410 to extend and retract the permanent magnet 402
in response to an actuation signal received from the controller
420.
[0042] In an embodiment, the controller 420 may be replaced by a
surface controller or other controller that is operable to monitor
pressure within the tool string. As discussed above with regard to
the actuator of the downhole tool of FIGS. 3A-3C, the actuator 406
may be a mechanical actuator, a hydraulic actuator, or an
electronic actuator, and the actuation signal may be transmitted to
the actuator 406 using any of the types of control lines and
control signals discussed above. In the embodiment of FIGS. 4A and
4B, however, the actuator 406 is considered to be an electronic
actuator, such as a solenoid, that receives an actuation signal
from the controller 420 via an electronic control line 422. To
generate a magnetic field across the flow path upon extension of
the permanent magnet 402, a ferromagnetic member 408 may be placed
at the center of the tubing segment 436 to facilitate the formation
of a magnetic field between the permanent magnet 402 and the
ferromagnetic member 408.
[0043] In another embodiment, the ferromagnetic member 408 may be
omitted and two permanent magnets of opposing polarity may be
placed across from each other in the enclosure 404, which may be
separate enclosures, with each enclosure 404 and permanent magnet
402 occupying opposing sides of the tubing segment 436. In such an
embodiment, extension of the permanent magnets 402 of opposing
polarity will generate a magnetic field between the permanent
magnets 402 across the flow path of the tubing segment 436.
[0044] FIG. 4B shows the blowout inhibitor 400 in an actuated state
in which the system has been actuated in response to, for example,
a pressure spike. In the actuated state, the controller 420 has
transmitted actuation signals to the reservoir 430 and actuator
406. In response to receiving the actuation signal, the reservoir
has released the magnetorheological fluid 432 into the flow path of
the tubing segment 436. The magnetorheological fluid 432 may be
released by any suitable release method. For example, the
magnetorheological fluid 432 may be forced through a valve 440 into
the flow path by a pump, by a collapse of the of reservoir 430, by
a piston or other mechanism that forces the magnetorheological
fluid 432 into the flow path, or by releasing a pressurized fluid
into the reservoir 430 that displaces the magnetorheological fluid
432 into the flow path.
[0045] In the embodiment of FIG. 4B, the actuation signal has also
caused the actuator 406 to extend the permanent magnet 402 from the
enclosure 404. To prevent propagation of the pressure spike up-hole
from the tubing segment 436, a magnetic field 438 is generated
between the ferromagnetic member 408 and the extended permanent
magnets 402. In an embodiment that does not include the
ferromagnetic member 408, the magnetic field 438 may be generated
between permanent magnets 402 of opposing polarity. As the
magnetorheological fluid 432 flows into the magnetic field 438,
interaction between the magnetic field and magnetorheological fluid
432 causes the magnetic fluid to form a visco-elastic solid, which
effectively clogs the fluid flow path and forms a seal 434 that
prevents the pressure spike from propagating upward and inhibits
blowout. In an embodiment, a support structure that does not
generally inhibit flow along the flow path in the absence of a
pressure spike may be included in the tubing segment 436 to assist
with formation of the seal 434. For example, a lattice, web,
netting, or combination thereof may be deployed at the intended
location of the seal 434 to provide additional anchor points for
the magnetorheological fluid 432 as it begins to interact with the
magnetic field 438 and solidify.
[0046] FIG. 5A shows a zone isolator 500 that includes an actuator
506 that operates similar to actuator 306 of the magnetic downhole
tool 300 described with regard to FIGS. 3A-3C. The zone isolator
500 occupies a tubing segment 536 of the tool string and may also
be referred to as a zone isolations subassembly. The tool string
may be a production string or any other type of tool string that
delivers fluid from a formation to the surface. In the embodiment
of FIG. 5A, the zone isolator 500 is a magnetorheological zone
isolator that includes a reservoir 530. The reservoir 530 may be a
cylindrical, or ring-shaped reservoir that is coupled to the tubing
segment 536 and operable to emit fluid to the exterior of the
tubing segment 536. A magnetorheological fluid 532 may be stored
within the reservoir 530 and released or forced into the fluid that
is adjacent a permanent magnet assembly 501. As such, the reservoir
530 may be located above, below, or coincident with the permanent
magnet assembly 501 depending on the direction of fluid flow.
[0047] In an embodiment, the zone isolator 500 also includes a
controller 520 that is coupled to the reservoir 530 via a control
line 522 and operable to actuate the release of magnetorheological
fluid 532 from the reservoir 530 at the direction of a well
operator. The controller 520 may be coupled to a surface controller
via a wired or wireless communication interface to receive an
actuation instruction from a well operator. In an embodiment, the
controller 520 is configured to cause the magnetorheological fluid
532 to be released from the reservoir 530 adjacent to the permanent
magnet assembly in response to an actuation instruction. The
receipt of the actuation instruction may also result in the
transmission of an actuation signal from the controller 520 to the
permanent magnet assembly 501.
[0048] The permanent magnet assembly 501 includes an enclosure 504
that includes a metallic shield. Like the metallic shields
discussed above, the metallic shield may be formed from one or more
layers of a mu-metal. One or more permanent magnets 502 are
selectively extendable and retractable from the enclosure 504 by
one or more synchronized actuators 506, each having a piston 510
that is coupled to the permanent magnet 502 and operable to extend
and retract the permanent magnet 502. Each actuator 506 may
therefore cause a piston 510 to extend and retract the permanent
magnet 502 in response to an actuation signal received from the
controller 520.
[0049] In an embodiment, the controller 520 may be replaced by a
surface controller or other controller that is operable to transmit
an actuation instruction to the permanent magnet assembly 501 and
reservoir 530. As discussed above with regard to the actuator of
the downhole tool of FIGS. 3A-3C, the actuator 506 may be a
mechanical actuator, a hydraulic actuator, or an electronic
actuator, and the actuation signal may be transmitted to the
actuator 506 using any of the types of control lines and control
signals discussed above. In the embodiment of FIGS. 5A and 5B,
however, the actuator 506 is considered to be an electronic
actuator, such as a solenoid, that receives an actuation signal
from the controller 520 via an electronic control line 522.
[0050] FIG. 5B shows the zone isolator 500 in an actuated state in
Which the system has been actuated in response to an actuation
instruction. In the actuated state, the controller 520 has
transmitted actuation signals to the reservoir 530 and actuator
506. In response to receiving the actuation signal, the reservoir
has released the magnetorheological fluid 532 adjacent the
permanent magnet assembly 501. The magnetorheological fluid 532 may
be released by any suitable release method, as described above with
regard to FIG. 4B.
[0051] In the embodiment of FIG. 5B, the actuation signal has also
caused the actuator 506 to extend the permanent magnet 502 from the
enclosure 504. To prevent fluid communication between the wellbore
zone above the tubing segment 536 and the wellbore zone below the
tubing segment 536, a magnetic field 538 is generated between the
wellbore wall 508 and the extended permanent magnets 502. As the
magnetorheological fluid 532 flows through one or more valves 542
into the magnetic field 538 in the wellbore 508, interaction
between the magnetic field 538 and magnetorheological fluid 532
causes the magnetic fluid to form a visco-elastic solid, which
effectively forms a zone isolator 540 that prevents fluid
interaction between the two wellbore zones. In an embodiment, a
support structure that does not generally inhibit flow along the
exterior of the tubing segment 536 may be included to assist with
formation of the zone isolator 540. For example, a magnetically
conductive lattice, web, netting, or combination thereof may be
deployed at the intended location of the zone isolator 540 to
strengthen the zone isolator and extend the magnetic field 538 by
providing an anchor structure for the magnetorheological fluid 532
as it begins to interact with the magnetic field 538 and
solidifies.
[0052] In addition to the illustrative embodiments described above,
many examples of specific combinations are within the scope of the
disclosure, some of which are presented below.
[0053] Example one: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal.
[0054] Example two: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
shielding sleeve is a mu-metal.
[0055] Example three: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
shielding sleeve comprises a mu-metal, and the mu-metal is a
nickel-iron alloy.
[0056] Example four: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
actuator is a hydraulic actuator and the control signal is a
hydraulic control signal.
[0057] Example five: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
actuator is a solenoid and the control signal is an electric
control signal.
[0058] Example six: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
actuator is a mechanical actuator and the control signal is a
mechanical control signal.
[0059] Example seven: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment having a fluid flow path
therethrough and a reservoir coupled to the controller and having a
magnetorheological fluid disposed therein. The reservoir is
operable to disperse the magnetorheological fluid into the fluid
flow path in response to the control signal.
[0060] Example eight: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment having a fluid flow path
therethrough and a reservoir coupled to the controller and having a
magnetorheological fluid disposed therein. The reservoir is
operable to disperse the magnetorheological fluid into the fluid
flow path in response to the control signal. The magnetic downhole
assembly is operable to extend the permanent magnet adjacent the
fluid flow path to generate a magnetic field across the fluid flow
path in response to the control signal.
[0061] Example nine: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment having a fluid flow path
therethrough and a reservoir coupled to the controller and having a
magnetorheological fluid disposed therein. The reservoir is
operable to disperse the magnetorheological fluid into the fluid
flow path in response to the control signal. The magnetic downhole
assembly is operable to extend the permanent magnet adjacent the
fluid flow path to generate a magnetic field across the fluid flow
path in response to the control signal. The system also includes a
ferromagnetic member.
[0062] Example ten: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment having a fluid flow path
therethrough and a reservoir coupled to the controller and having a
magnetorheological fluid disposed therein. The reservoir is
operable to disperse the magnetorheological fluid into the fluid
flow path in response to the control signal. The magnetic downhole
assembly is operable to extend the permanent magnet adjacent the
fluid flow path to generate a magnetic field across the fluid flow
path in response to the control signal. The system also includes a
pressure sensor coupled to the controller. The controller is
operable to generate the control signal in response to determining
that a pressure at the pressure sensor is greater than a
predetermined pressure.
[0063] Example eleven: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment having a fluid flow path
therethrough and a reservoir coupled to the controller and having a
magnetorheological fluid disposed therein. The reservoir is
operable to disperse the magnetorheological fluid into the fluid
flow path in response to the control signal. The magnetic downhole
assembly is operable to extend the permanent magnet adjacent the
fluid flow path to generate a magnetic field across the fluid flow
path in response to the control signal. The system also includes a
pressure sensor coupled to the controller. The controller is
operable to generate the control signal in response to determining
that a pressure at the pressure sensor is increasing at a rate that
is greater than a predetermined rate.
[0064] Example twelve: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment having a fluid flow path
therethrough and a reservoir coupled to the controller and having a
magnetorheological fluid disposed therein. The reservoir is
operable to disperse the magnetorheological fluid into the fluid
flow path in response to the control signal. The magnetic downhole
assembly is operable to extend the permanent magnet adjacent the
fluid flow path to generate a magnetic field across the fluid flow
path in response to the control signal. The system also includes a
lattice disposed in the fluid flow path proximate the magnetic
downhole assembly.
[0065] Example thirteen: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment having a fluid flow path
therethrough and a reservoir coupled to the controller and having a
magnetorheological fluid disposed therein. The reservoir is
operable to disperse the magnetorheological fluid into the fluid
flow path in response to the control signal. The magnetic downhole
assembly is operable to extend the permanent magnet adjacent the
fluid flow path to generate a magnetic field across the fluid flow
path in response to the control signal. The system also includes a
web disposed in the fluid flow path proximate the magnetic downhole
assembly.
[0066] Example fourteen: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment having a fluid flow path
therethrough and a reservoir coupled to the controller and having a
magnetorheological fluid disposed therein. The reservoir is
operable to disperse the magnetorheological fluid into the fluid
flow path in response to the control signal. The magnetic downhole
assembly is operable to extend the permanent magnet adjacent the
fluid flow path to generate a magnetic field across the fluid flow
path in response to the control signal. The system also includes
netting in the fluid flow path proximate the magnetic downhole
assembly.
[0067] Example fifteen: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment and a reservoir coupled to
the controller. The reservoir includes a magnetorheological fluid
disposed therein, and is operable to disperse the
magnetorheological fluid adjacent the magnetic downhole assembly
between an exterior surface of the tubing segment and a wellbore
wall in response to the control signal.
[0068] Example sixteen: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment and a reservoir coupled to
the controller. The reservoir includes a magnetorheological fluid
disposed therein, and is operable to disperse the
magnetorheological fluid adjacent the magnetic downhole assembly
between an exterior surface of the tubing segment and a wellbore
wall in response to the control signal. The magnetic downhole
assembly is operable to extend the permanent magnet to generate a
magnetic field about the external exterior surface of the tubing
segment in response to the control signal.
[0069] Example seventeen: A system for operating a magnetic
downhole assembly including a magnetic downhole assembly having a
shielding sleeve that is operable to isolate a magnetic field. The
system also includes a permanent magnet disposed within the
shielding sleeve and an actuator. The actuator is operable to
selectively extend and retract the sleeve to selectively expose and
shield the permanent magnet. In addition, the system includes a
conveyance operable to deploy the magnetic downhole assembly to a
selected location within a wellbore and a controller
communicatively coupled to the actuator and operable to generate a
control signal. The system further includes a tubing segment and a
reservoir coupled to the controller. The reservoir includes a
magnetorheological fluid disposed therein, and is operable to
disperse the magnetorheological fluid adjacent the magnetic
downhole assembly between an exterior surface of the tubing segment
and a wellbore wall in response to the control signal. The
controller is operable to generate the control signal in response
to receiving an actuation instruction from an operator.
[0070] Example eighteen: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment and a reservoir coupled to
the controller. The reservoir includes a magnetorheological fluid
disposed therein, and is operable to disperse the
magnetorheological fluid adjacent the magnetic downhole assembly
between an exterior surface of the tubing segment and a wellbore
wall in response to the control signal. The system also includes a
lattice disposed about the external exterior surface of the tubing
segment proximate the magnetic downhole assembly.
[0071] Example nineteen: A system for operating a magnetic downhole
assembly including a magnetic downhole assembly having a shielding
sleeve that is operable to isolate a magnetic field. The system
also includes a permanent magnet disposed within the shielding
sleeve and an actuator. The actuator is operable to selectively
extend and retract the sleeve to selectively expose and shield the
permanent magnet. In addition, the system includes a conveyance
operable to deploy the magnetic downhole assembly to a selected
location within a wellbore and a controller communicatively coupled
to the actuator and operable to generate a control signal. The
system further includes a tubing segment and a reservoir coupled to
the controller. The reservoir includes a magnetorheological fluid
disposed therein, and is operable to disperse the
magnetorheological fluid adjacent the magnetic downhole assembly
between an exterior surface of the tubing segment and a wellbore
wall in response to the control signal. The system also includes a
web disposed about the external exterior surface of the tubing
segment proximate the magnetic downhole assembly.
[0072] Example twenty: A magnetic downhole tool includes a mu-metal
sleeve operable to isolate a magnetic field, a permanent magnet
disposed within the mu-metal sleeve, and an actuator operable to
selectively extend and retract the sleeve to selectively expose and
shield the permanent magnet.
[0073] Example twenty-one: A magnetic downhole tool includes a
mu-metal sleeve operable to isolate a magnetic field, a permanent
magnet disposed within the mu-metal sleeve, and an actuator
operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The mu-metal
sleeve comprises a plurality of layers of mu-metal.
[0074] Example twenty-two: A magnetic downhole tool includes a
mu-metal sleeve operable to isolate a magnetic field, a permanent
magnet disposed within the mu-metal sleeve, and an actuator
operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The mu-metal
sleeve comprises a plurality of layers of mu-metal, and the layers
of mu-metal are separated by at least one insulating layer.
[0075] Example twenty-three: A magnetic downhole tool includes a
mu-metal sleeve operable to isolate a magnetic field, a permanent
magnet disposed within the mu-metal sleeve, and an actuator
operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The mu-metal
sleeve comprises a plurality of layers of mu-metal. The mu-metal is
a nickel-iron alloy.
[0076] Example twenty-four: A magnetic downhole tool includes a
mu-metal sleeve operable to isolate a magnetic field, a permanent
magnet disposed within the mu-metal sleeve, and an actuator
operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The actuator is
a hydraulic actuator.
[0077] Example twenty-five: A magnetic downhole tool includes a
mu-metal sleeve operable to isolate a magnetic field, a permanent
magnet disposed within the mu-metal sleeve, and an actuator
operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The actuator is
a solenoid.
[0078] Example twenty-six: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve.
[0079] Example twenty-seven: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The mu-metal comprises a
nickel-iron alloy.
[0080] Example twenty-eight: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The actuator is a
hydraulic actuator and generating the control signal comprises
generating a hydraulic control signal.
[0081] Example twenty-nine: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The actuator is a
solenoid and the control signal is an electric control signal.
[0082] Example thirty: A method for operating a magnetic downhole
tool includes providing a magnetic downhole tool comprising a
mu-metal sleeve that is operable to isolate a magnetic field. The
magnetic downhole tool also includes a permanent magnet disposed
within the mu-metal sleeve and an actuator. The actuator is
operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The actuator is a
mechanical actuator and generating the control signal includes
generating a mechanical control signal.
[0083] Example thirty-one: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The method also includes
coupling the magnetic downhole tool to a slickline conveyance and
positioning the downhole tool at a selected location in a
wellbore.
[0084] Example thirty-two: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The method further
includes coupling the magnetic downhole tool to a wireline
conveyance and positioning the downhole tool at a selected location
in a wellbore.
[0085] Example thirty-three: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The method also includes
coupling the magnetic downhole tool to a tool string and
positioning the downhole tool at a selected location in a
wellbore.
[0086] Example thirty-four: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The method also includes
exposing the permanent magnet to control the viscosity of a
magnetorheological fluid.
[0087] Example thirty-five: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The method also includes
exposing the permanent magnet to orient a second tool within a
wellbore.
[0088] Example thirty-six: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The method also includes
exposing the permanent magnet to remove a plug from a wellbore
casing.
[0089] Example thirty-seven: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The method also includes
exposing the permanent magnet and manipulating the magnetic
downhole tool to adjust the position of a screen.
[0090] Example thirty-eight: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The method also includes
exposing the permanent magnet and manipulating the magnetic
downhole tool to adjust the position of a second downhole tool.
[0091] Example thirty-nine: A method for operating a magnetic
downhole tool includes providing a magnetic downhole tool
comprising a mu-metal sleeve that is operable to isolate a magnetic
field. The magnetic downhole tool also includes a permanent magnet
disposed within the mu-metal sleeve and an actuator. The actuator
is operable to selectively extend and retract the sleeve to
selectively expose and shield the permanent magnet. The method also
includes providing a controller that is communicatively coupled to
the actuator and generating a control signal to cause the actuator
to extend or retract the mu-metal sleeve. The method also includes
exposing the permanent magnet to couple permanent magnet to a
second downhole tool, delivering the second downhole tool to a
selected location, and retracting the permanent magnet.
[0092] It will be understood that the above description of
preferred embodiments is given by way of example only and that
various modifications may be made by those skilled in the art. The
above specification, examples, and data provide a complete
description of the structure and use of exemplary embodiments of
the invention. Although various embodiments of the invention have
been described above with a certain degree of particularity, or
with reference to one or more individual embodiments, those skilled
in the art could make numerous alterations to the disclosed
embodiments without departing from the scope of the claims.
* * * * *