Note: Descriptions are shown in the official language in which they were submitted.
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DEFORMABLE DOWNHOLE STRUCTURES INCLUDING
CARBON NANOTUBE MATERIALS, AND METHODS
OF FORMING AND USING SUCH STRUCTURES
PRIORITY CLAIM
This application claims the benefit of the filing date of United States Patent
Application Serial No. 15/063,034, filed March 7, 2016, for "DEFORMABLE
DOWNHOLE STRUCTURES INCLUDING CARBON NANOTUBE MATERIALS,
AND METHODS OF FORMING AND USING SUCH STRUCTURES."
TECHNICAL FIELD
The disclosure, in various embodiments, relates generally to materials for
monitoring the expansion of deformable downhole structures disposed in a
wellbore. More
particularly, embodiments of the disclosure relate to downhole structures
including a
carbon nanotube material incorporated into a deformable material and methods
of forming
and using carbon nanotube materials and a deformable material.
BACKGROUND
The drilling of wells for oil and gas production conventionally employs
longitudinally
extending sections or so-called "strings" of drill pipe to which, at one end,
is secured a drill bit
of a larger diameter. After a selected portion of a wellbore has been drilled,
and in some
instances reamed to a larger diameter than that initially drilled with a drill
bit (which is such
instances is termed a "pilot" bit), the wellbore is usually lined or cased
with a string or section
of casing or liner. Such a casing or liner exhibits a larger diameter than the
drill pipe used to
drill the wellbore, and a smaller diameter than the drill bit or diameter of a
reamer used to
enlarge the wellbore. Conventionally, after the casing or liner string is
placed in the wellbore,
the casing or liner string is cemented into place to seal between the exterior
of the casing or
liner string and the wellbore wall.
Tubular strings, such as drill pipe, casing, or liner, may be surrounded by an
annular
space between the exterior wall of the pipe and the interior wall of the well
casing or the
wellbore wall, for example. Frequently, it is desirable to seal such an
annular space between
upper and lower portions of the well depth. The annular space may be sealed or
filled with a
downhole article, such as a conformable device. Conformable devices include
packers, bridge
plugs, sand screens, and seals. Swellable packers and bridge plugs are
particularly useful for
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sealing an annular space because they swell (e.g., expand) upon exposure to
wellbore fluids,
wellbore temperatures, and the like and fill the cross-sectional area of the
annular space.
DISCLOSURE
In some embodiments of the present disclosure, a deformable downhole article
for use
in a wellbore includes a tubular component configured for placement in a
wellbore, a
deformable material disposed around an outer surface of the tubular component,
and an
electrically conductive element comprising a carbon nanotube (CNT) material
bonded to the
deformable material.
Additional embodiments of the present disclosure include methods of forming
such a
deformable downhole article. For example, a deformable material may be
disposed around an
outer surface of a tubular component, and an electrically conductive element
comprising a
carbon nanotube (CNT) material may be bonded to the deformable material.
Yet further embodiments of the present disclosure include methods of using
such a
deformable downhole article in a wellbore. A deformable downhole article may
be positioned
within a wellbore. The deformable downhole article may include a tubular
component, a
deformable material disposed around an outer surface of the tubular component,
and an
electrically conductive element comprising a carbon nanotube (CNT) material
bonded to the
deformable material. The deformable material may be expanded to an expanded
state in the
wellbore. Expansion of the deformable material may strain the carbon nanotube
(CNT)
material of the electrically conductive element, and an electrical property of
the electrically
conductive element may be measured. The measurement of the electrical property
may be
used to deduce information about the state of the deformable material.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and
distinctly
claiming what are regarded as embodiments of the present disclosure, various
features and
advantages of embodiments of the disclosure may be more readily ascertained
from the
following description of example embodiments of the disclosure when read in
conjunction
with the accompanying drawings, in which:
FIG. 1 illustrates an example of a wellbore including at least one deformable
downhole article disposed therein;
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FIG. 2A is a simplified and schematically illustrated cross-sectional side
view of a
deformable downhole article like that of FIG. 1 including a deformable
material in a
compressed state and having coiled fibers of CNT material disposed therein in
a first strain
state;
FIG. 2B is a simplified and schematically illustrated cross-sectional side
view of the
deformable downhole article of FIG. 2A illustrating the deformable material in
an expanded
state within a wellbore, and wherein the coiled fibers of CNT material
disposed therein are in
a second strain state that is different from the first strain state;
FIG. 2C is a simplified and schematically illustrated expanded view of the
deformable
downhole article of FIG. 2B;
FIGS. 3A-3C are simplified and schematically illustrated circuit diagrams of a
circuit
including the coiled fibers of FIG. 2A-2C;
FIG. 4A is a simplified and schematically illustrated cross-sectional side
view of
another embodiment of a deformable downhole article including a deformable
material in a
compressed state and having a coiled fiber of CNT material disposed therein in
a first strain
state;
FIG. 4B is a simplified and schematically illustrated cross-sectional side
view of the
deformable downhole article of FIG. 3A illustrating the deformable material in
an expanded
state within a wellbore, and wherein the coiled fiber of CNT material disposed
therein is in a
second strain state that is different from the first strain state;
FIG. 4C is a simplified and schematically illustrated expanded view of the
deformable
downhole article of FIG. 4B;
FIGS. 5A-5C are simplified and schematically illustrated circuit diagrams of a
circuit
including the coiled fibers of FIG. 4A-4C;
FIG. 6 is a simplified and schematically illustrated expanded view of CNT
materials
disposed in a deformable material according to another embodiment;
FIGS. 7A-7C are simplified cross-sectional side views illustrating the
formation of a
deformable downhole article as described herein using a reaction injection
molding process;
FIG. 8A is a perspective view of a deformable downhole article like that of
FIG. 1
according to another embodiment;
FIG. 8B is a simplified and schematically illustrated view of the deformable
downhole
article of FIG. 8A;
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FIG. 8C illustrates an operation of disposing a deformable material on a
tubular
component of the deformable downhole article of FIG. 8A;
FIG. 9A is a simplified and schematically illustrated view of a deformable
downhole
article like that of FIG. 1 according to another embodiment;
FIG. 9B is a simplified and schematically illustrated cross-sectional view of
the
deformable downhole article of FIG. 9A; and
FIG. 9C illustrates an operation of disposing a deformable material on a
tubular
component of the deformable downhole article of FIG. 9A.
MODE(S) FOR CARRYING OUT THE INVENTION
The illustrations presented herein are not meant to be actual views of any
particular
component, device, or system, but are merely idealized representations which
are employed to
describe embodiments of the disclosure. Elements common between figures may
retain the
same numerical designation.
Deformable downhole articles, such as expandable (e.g., conformable) packers,
bridge
plugs and sandscreens, may include a deformable material that expands upon
exposure to
wellbore fluids, wellbore temperatures, activation fluids provided from a
surface of a
subterranean formation, and the like and may fill the cross-sectional area of
an annular space
between an outer surface of a tubular member and an interior wall of a
wellbore, such as the
exposed surface of the formation within the wellbore. In some instances, it
may be desirable
to verify expansion of the deformable material so as to ensure proper function
of the
deformable downhole article. Embodiments of the present disclosure may enable
a user of the
deformable downhole articles to confirm that the deformable material of the
deformable
downhole article has swelled (i.e., expanded) so as to ensure that the
deformable downhole
article will function as intended.
Carbon nanotubes (CNTs) may exhibit high electrical conductivity. In
accordance
with embodiments of the present disclosure, an electrically conductive element
comprising a
carbon nanotube (CNT) material may be bonded to the deformable material of a
deformable
downhole article, and, in use, expansion of the deformable material may strain
the carbon
nanotube (CNT) material of the electrically conductive element. Straining of
the CNT
material may result in a change of at least one electrical property of the CNT
material. For
example, CNTs may exhibit a measurable change in electrical conductivity and
resistivity
when strained. An electrical property of the electrically conductive element
may be
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measured, and the measurement of the electrical property may be used to deduce
information
about the state of the deformable material.
FIG. 1 illustrates a non-limiting example of a wellbore system 100 including a
wellbore 110 that has been drilled through a subterranean formation 112 and
into a pair of
production formations or reservoirs 114, 116 from which it is desired to
produce hydrocarbons
or otherwise extract minerals, oil and gas, and the like. The wellbore 110 may
be lined with a
metal casing in some embodiments. A number of perforations 118 may penetrate
and extend
into the formation 114, 116 such that production fluids 121 may flow from the
formations 114, 116 into the wellbore 110. The wellbore 110 may have a
substantially
vertical leg 117 and a deviated or substantially horizontal leg 119. The
wellbore 110 may
include a production string or assembly, generally indicated at 120, disposed
therein by a
tubular component 122 that extends downwardly from a drill rig 124 at the
surface 126. The
production assembly 120 defines an internal axial flow bore 128 along its
length. An
annulus 130 may be defined between the production assembly 120 and the
wellbore casing, if
present, or a wellbore wall 132. Production zones 134 are shown positioned at
selected
locations along the production assembly 120. Each production zone 134 may be
isolated
within the wellbore 110 by a pair of packer devices 136. Although only three
production
zones 134 are shown in FIG. 1, there may be a large number of such zones
arranges in serial
fashion along the vertical leg 117 and horizontal leg 119.
Each production zone 134 may include a flow control or production flow control
device 138 to govern one or more aspects of a flow of one or more fluids into
the production
assembly 120. As used herein, the term "fluid" or "fluids" includes liquids,
gases,
hydrocarbons, multi-phase fluids, mixtures of two or more fluids, water,
brine, engineered
fluids such as drilling mud, fluids injected from the surface such as water,
and naturally
occurring fluids such as oil and gas.
FIG. 2A illustrates a packer device 136 of the wellbore system 100 shown in
FIG. 1.
The packer device 136 is a deformable downhole article that includes a
deformable
material 150 disposed around an outer surface of a tubular component 122. FIG.
2A
illustrates the deformable material 150 in an initial un-swollen or compressed
state in which
the deformable material 150 has a smaller diameter than the diameter of wall
132 of the
wellbore 110. The deformable material 150 may surround a section of the
tubular
component 122 within the wellbore 110. The tubular component 122 may be a
portion of a
downhole casing or liner string, production pipe or tubing, or other tubular
component within
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the wellbore 110. The tubular component 122 may comprise a plurality of
orifices 123
configured to provide a flow of production fluids 121 from the formations 114,
116 through
the production assembly 120. The deformable material 150 may be caused to
swell (e.g.
expand) after the tubular component 122 is positioned within the wellbore 110
at a selected
location. The packer device 136 is positioned in the wellbore 110 while the
deformable
material 150 is in the initial un-swollen state in which the deformable
material 150 has a
smaller diameter than the diameter of wall 132 of wellbore 110 (FIG. 1).
As shown in FIG. 2B, after the packer device 136 is positioned at a selected
location
within the wellbore 110, the deformable material swells (e.g., expands) in the
radial direction.
In some embodiments, exposure to a wellbore fluid causes the deformable
material 150 to
expand and contact the wall 132 of the wellbore 110 to form a compressive,
fluid-tight seal
between the tubular component 122 and the wall 132. Thus, the outer diameter
of the
deformable material 150 may increase until it contacts the wall 132 of the
wellbore 110 within
subterranean formation 112. In other embodiments, an inner wall of tubing,
casing, liner, or
other surface may be disposed concentrically around the packer device 136, and
the
deformable material 150 may form a compressive, fluid-tight seal between the
tubular
component 122 and the inner wall of the tubing, casing, liner, or other
surface. Thus,
longitudinal flow of fluids (e.g., from formation 114, 116) through the
annulus 130 past the
exterior of packer device 136 (in the vertical directions from the perspective
of FIG. 2B) is
substantially prevented once the deformable material 150 is expanded.
The deformable material 150 may be formulated to expand until it fills the
annular
space 130. In some embodiments, the diameter of the wellbore 110 may be
insufficient to
allow the deformable material 150 to return fully to the expanded state.
Further, the
deformable material 150 may not swell (e.g., expand) uniformly as the diameter
of the
wellbore 110 may not be uniform. Swelling may result in an increase in the
radius (measured
from the tubular component 122 to an outer surface of the deformable material
150) of the
deformable material 150 by between about 20% and about 300% of the initial
radius of the
deformable material 150. In some embodiments, the initial radius of the
deformable
material 150 may be in a range from about 0.5 inch (1.27 cm) to about 2 inches
(5.08 cm),
and, more particularly, about 1 inch (2.54 cm).
The deformable material 150 may comprise any suitable type of deformable
material.
As used herein, the term "deformable material" means and includes any material
that may
swell, expand, or otherwise increase in size in at least one dimension upon
exposure to a
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downhole environment. By way of non-limiting examples, the deformable material
150 may
comprise a conformable material as described in any of U.S. Patent 9,090,012,
titled "Process
for the Preparation of Conformable Materials for Downhole Screens," issued
July 28, 2015
(hereinafter the '012 Patent); U.S. Patent 8,684,075, titled "Sand Screen,
Expandable Screen
and Method of Making," issued April 1, 2014; U.S. Patent 9,228,420, titled
"Conformable
Materials Containing Heat Transfer Nanoparticles and Devices Made Using Same,"
issued
January 5, 2016; and U.S. Patent Publication No. 2015/0176363, titled
"Swellable Downhole
Structures Including Carbon Nitride Materials, and Methods of Forming and
Using Such
Structures," filed December 24, 2013, the entire disclosure of each of which
is hereby
incorporated herein by this reference. Such conformable materials may be used
in
conformable sand screens, such as the GEOFORMO conformable sand management
system
commercially available from Baker Hughes Inc. of Houston, TX. By way of
further
non-limiting examples, the deformable material 150 may comprise a swellable
material as
described in any of U.S. Patent 8,118,092, titled "Swelling Delay Cover for a
Packer," issued
February 21, 2012; U.S. Patent 8,225,861, titled "Sealing Feed Through Lines
for Downhole
Swelling Packers," issued July 24, 2012, U.S. Patent Publication No.
2009/0084550, titled
"Water Swelling Rubber Compound for Use in Reactive Packers and Other Downhole
Tools," filed September 30, 2008; U.S. Patent Publication No. 2015/0210825,
titled
"Enhanced Water Swellable Compositions," filed March 13, 2014; U.S. Patent
Publication
No. 2009/0139708, titled "Wrap-On Reactive Element Barrier Packer and Method
of Creating
Same," filed June 6, 2008; and U.S. Patent 8,181,708, titled "Water Swelling
Rubber
Compound for Use in Reactive Packers and Other Downhole Tools," issued May 22,
2012
(hereinafter "the '708 Patent"), the entire disclosure of each of which is
hereby incorporated
herein by this reference.
As a non-limiting example, the deformable material 150 may be an open-celled
foam
material. The open-celled foam material may comprise a viscoelastic shape
memory
polymeric material. Such viscoelastic shape memory polymer materials may
exhibit a
one-way shape memory effect. In other words, viscoelastic shape memory
materials may be
restored to an original shape and/or size when triggered by, for example,
changing the
temperature of the material, exposing the material to wellbore fluids, or
exposing the material
to electrical stimulus, a chemical stimulus, or another stimulus.
Open-celled foam materials that can expand (e.g., exhibit a shape memory
effect)
comprise a wide variety of polymers. Such polymers may include a polyurethane,
a
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polyamide, a polyurea, a polyvinyl alcohol, a vinyl alcohol-vinyl ester
copolymer, a phenolic
polymer, a polybenzimidazole, a copolymer comprising polyethylene oxide units,
and
combinations thereof For example, copolymers comprising polyethylene oxide
units include
polyethylene oxide/acrylic acid/methacrylic acid copolymer crosslinked with
N,N1-methylene-bis-acrylamide, polyethylene oxide/methacrylic acid/N-vinyl-2-
pyrrolidone
copolymer crosslinked with ethylene glycol dimethacrylate, and polyethylene
oxide/poly(methyl methacrylate)/N-vinyl-2-pyrrolidone copolymer crosslinked
with ethylene
glycol dimethacrylate. In some embodiments, the foamed conformable material
may
comprise a polyurethane made by reacting a polycarbonate polyol with a
polyisocyanate.
Such polymers may be chemically or at least physically crosslinked in order to
exhibit shape
memory properties.
In accordance with embodiments of the present disclosure, the tubular
component 122
may be formed of a high strength material. In some embodiments, the tubular
component 122
comprises a metal. A portion of the tubular component 122 may comprise a
dielectric
material. For example, the portion of tubular component 122 over which the
deformable
material 150 is formed may comprise the dielectric material.
In accordance with embodiments of the present disclosure, the packer device
136
further includes at least one electrically conductive element 152 comprising a
carbon nanotube
(CNT) material bonded to the deformable material 150. As discussed in further
detail below,
the electrically conductive element 152 is located and configured such that
stress, responsive
to which the electrically conductive element 152 is strained, will be applied
to the electrically
conductive element 152 upon swelling of the deformable material 150.
In the embodiment shown in FIGS. 2A and 2B, the electrically conductive
element 152 comprises a plurality of fibers arranged in a coil. The fibers
include crosslinked
carbon nanotubes. FIGS. 2A and 2B are cross-sectional side views of the packer
device 136
taken in a plane parallel to a longitudinal axis of the tubular component 122.
As shown in
FIGS. 2A and 2B, the coil may be oriented in the deformable material 150 such
that an
axis 154 of the coil extends perpendicular to the longitudinal axis of the
tubular
component 122 and radially outward from the tubular component 122 within the
deformable
material 150. In other words, the coil may be oriented in the deformable
material 150 such
that the axis 154 of the coil extends along a radius of the deformable
material 150. Although
only two coiled fibers are illustrated in FIGS. 2A and 2B, any number of
coiled fibers of CNT
material may be employed in embodiments of the present disclosure. In
embodiments in
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which a plurality of fibers of CNT material are employed, the coiled fibers
may be dispersed
in the deformable material 150 concentrically about the tubular component 122
and along a
length of the tubular component 122.
The coils of crosslinked carbon nanotubes that may be employed in embodiments
of
the present disclosure may be formed by rolling mats of carbon nanotube mats,
such as those
commercially available from MER Corporation, of Tucson, Arizona.
In some embodiments, the CNTs may be generally aligned with one another in at
least
one direction within the coiled fiber. In some embodiments, the CNTs may be
generally
aligned with one another along the length of the coiled fiber of CNT material,
and/or aligned
with one another in the direction of anticipated strain of the electrically
conductive
element 172 upon expansion of the deformable material 150. In other
embodiments, the
CNTs may be randomly oriented and dispersed in the coiled fiber of CNT
material.
Furthermore, the CNTs in the CNT material of the electrically conductive
element 152 may
comprise single-walled CNTs, double-walled CNTs, or multi-walled CNTs.
In some embodiments, the electrically conductive element 152 may be disposed
within the deformable material 150. In such embodiments, the electrically
conductive
element 152 may be at least substantially surrounded (e.g., entirely
surrounded) by the
deformable material 150.
The electrically conductive element 152 may be covalently bonded to the
deformable
material 150. In other words, covalent atomic bonds may be provided directly
between the
electrically conductive element 152 and the deformable material 150. In this
configuration, as
the deformable material 150 expands from the state of FIG. 2A to the state of
FIG. 2B, the
expansion of the deformable material 150 may impart a stress, responsive to
which the
electrically conductive element 152 is strained, without extensive relative
displacement of the
electrically conductive element 152 relative to the adjacent deformable
material 150 along the
interface therebetween. In some embodiments, the CNTs of the CNT material of
the
conductive element 152 may be covalently bonded to the deformable material
150.
The packer device 136 may further include at least one electronic component
155.
FIG. 2C is an enlarged view of a portion of the packer device 136 outlined in
FIG. 2B
including the electronic component 155. In some embodiments, the at least one
electronic
component 155 may be a capacitor C coupled to the electrically conductive
element 152,
which may serve as an inductor L, to form a LC (e.g., resonant) circuit,
illustrated in FIG. 3A.
In other embodiments, the electronic device 156 may comprise a resistor R
coupled to the
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electrically conductive element 152, which may serve as an inductor L, to form
a RL (e.g.,
resistor-inductor) circuit, illustrated in FIG. 3B. In yet further
embodiments, the electrically
conductive element 152 may be coupled to a capacitor C and a resistor R to
form a RLC
circuit, as illustrated in FIG. 3C. In additional embodiments, the
electrically conductive
element 152 may be coupled to any combination of resistors and capacitors in
parallel or in
series. Electrical conductors (e.g., wires) may operably couple the
electronically conductive
element 152 and the electronic component 155 (e.g., the capacitor or
resistor).
With continued reference to FIGS. 2A-2C, the packer device 136 may further
comprise an induction logging tool 140. The induction logging tool 140 may be
provided in
and separated from the deformable material 150 by the tubular component 122.
The induction
logging tool 140 may comprise a wireline 141 extending from the induction
logging tool 140
to the surface 126. Surface equipment 142 (FIG. 1) may include an electric
power supply to
provide electric power to one or more transmitter coils 143 and one or more
receiver coils 144
in the induction logging tool 140. In other embodiments, the power supply
and/or transmitter
signal drivers and receiver processors may be located in the induction logging
tool 140. The
induction logging tool 140 may be configured to measure at least one
electrical property (e.g.,
conductivity, resistivity, inductance, etc.) of the electrically conductive
element 152. For
example, the induction logging tool 140 may measure a change in electrical
inductance of the
electrically conductive element 152 when the electrically conductive element
is strained.
With reference to FIG. 2C, an axis 145 of the transmitter coil 143 may be
coaxial with
the axis 154 of the electrically conductive element 142 in some embodiments.
The transmitter
coil 143 and electrically conductive element 142 may further be aligned with
the orifice 123
of the tubular component 122. In other embodiments, the transmitter coil 143
and the
electrically conductive element 142 may not be coaxial and/or may not be
aligned with the
orifice 123. A diameter of the electrically conductive element 142 and/or the
transmitter
coil 143 may be less than a diameter of the orifice 123. By way of example,
the diameter of
the orifice 123 may be in a range from about 0.5 inch (1.27 cm) to about 2
inches (5.08 cm)
and, more particularly, about 1 inch (2.54 cm). In other embodiments, the
diameter of the
electrically conductive element 142 and/or the transmitter coil 143 may be
greater than a
diameter of the orifice 123
The physical principles of the induction logging tool 140 are described, for
example,
in Doll, Introduction to Induction Logging and Application to Logging of Wells
Drilled with
Oil Based Mud, Vol. 1, Issue 6 (June 1949), pp. 148-162, the disclosure of
which is
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incorporated herein its entirety by this reference. By way of non-limiting
example, the
induction logging tool 140 may be an induction logging tool as described in
U.S. Patent
7,190,169, titled "Method and Apparatus for Internal Calibration in Induction
Logging
Instruments," issued March 13, 2007; U.S. Patent 8,487,625, titled "Performing
Downhole
Measurement Using Tuned Transmitters and Untuned Receivers," issued July 16,
2013; and
U.S. Patent 9,223,046, titled "Apparatus and Method for Capacitive Measuring
of Sensor
Standoff in Boreholes Filled with Oil Based Drilling Fluid," issued December
29, 2015, the
entire disclosure of each of which is incorporated herein by this reference.
Strain on the
electrically conductive element 152 may result in a measurable change in the
induction or
electromagnetic field emitted about the electrically conductive element 152,
which may be
measured as a function of power loss or resonant frequency measured in the
induction logging
tool 140.
FIGS. 4A-4C are similar to FIGS. 2A-2C and illustrate another embodiment of a
packer device 170 that may be employed in a wellbore system, such as the
wellbore
system 100 of FIG. 1. The packer device 170 is a deformable downhole article
that, like the
packer device of 136, includes a tubular component 122 and a deformable
material 150
disposed around the tubular component 122 as previously described herein with
reference to
FIGS. 2A-2C. The packer device 170 also includes electrically conductive
element 152
comprising a carbon nanotube (CNT) material bonded to the deformable material
150, and the
electrically conductive element 152 is located and configured such that strain
will be applied
to the electrically conductive element 152 upon swelling of the deformable
material 150.
FIG. 4C is an enlarged view of a portion of the packer device 170 outlined in
FIG. 4B.
With continued reference to FIGS. 4A through 4C, the packer device 170 may
further include
an electronic device 156 in lieu of the induction logging tool 140. The
electronic device 156
may be operably coupled to the electrically conductive element 152 and
configured to
measure at least one electrical property (e.g., conductivity, resistivity,
inductance, etc.) of the
electrically conductive element 152. In some embodiments, the electronic
device 156 may be
located within the packer device 170, such as within a recess or other
receptacle within the
tubular component 122. In other embodiments, the electronic device 156 may be
located in
another component of the production assembly 120, such as in another sub in
the production
assembly 120. In yet further embodiments, the electronic device 156 may be
located at the
surface.
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The electronic device 156 may comprise an electronic signal processor 158, a
memory
device 160, and a communication device 162. The packer device 170 may also
comprise a
battery or other power supply 164. The power supply 164 may be located in the
electronic
device 156 or in the deformable material 150. The packer device 170 may
comprise at least
one electrical component 174 coupled to the electrically conductive element
152 and the
power supply 164. In some embodiments, the at least one electronic component
174
comprises a capacitor C coupled to the electrically conductive element 152,
which may serve
as an inductor L, to form a LC (e.g., resonant) circuit, as illustrated in
FIG. 5A. In other
embodiments, the electronic component 174 may comprise a resistor R coupled to
the
electrically conductive element 152, which may serve as an inductor L, to form
a RL (e.g.,
resistor-inductor) circuit, as illustrated in FIG. 5B. In yet other
embodiments, the electrically
conductive element 152 may be coupled to a capacitor C and a resistor R to
form a RLC
circuit, as illustrated in FIG. 5C. Electrical conductors (e.g., wires) may
operably couple the
electronic component 174, the electrically conductive element 152, and the
power supply 164.
The wires may contact the electrically conductive element 152 at two or more
locations, such
that the power supply 164 may provide an electrical current through the
electrically
conductive element 152 via the wires. Electrical conductors may further couple
the electronic
component 174 and/or the electrically conductive element 152 to the electronic
device 156.
The electronic device 156 may comprise a multimeter or voltmeter that allows
the
electronic device 156 to measure an electrical property of the electrically
conductive
element 152 during use of the packer device 136 and expansion of the
deformable
material 150. For example, the electronic device 156 may measure a change in
inductance or
resistivity of the electrically conductive element 152 by measuring a change
in resonant
frequency of the LC circuit, RL circuit, or RLC circuit. The communication
device 162 may
comprise a transmitter and/or a receiver that is used to transmit information
relating to the
measured electrical property of the electrically conductive element 152 to the
surface 126 for
analysis, and/or to receive information such as operational commands from the
surface 126.
The communication device 162 may comprise, for example, a mud-pulse telemetry
system.
FIG. 6 illustrates another configuration of an electrically conductive element
172
disposed in the deformable material 150. The electrically conductive element
172 may have a
zig-zag shape oscillating about an axis 176 of the electrically conductive
element 172. The
electrically conductive element 172 may be oriented in the deformable material
150 such that
the axis 176 of the zig-zag shape extends perpendicular to the longitudinal
axis of the tubular
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component 122 and radially outward from the tubular component 122 within the
deformable
material 150. In other words, the electrically conductive element 172 may be
oriented in the
deformable material 150 such that the axis 154 of the coil extends along a
radius of the
deformable material 150. The electrically conductive element 172 is located
and configured
such that strain will be applied to the electrically conductive element 172
upon swelling of the
deformable material 150. Strain on the electrically conductive element 172 may
result in a
measurable change in the induction or electromagnetic field emitted about the
electrically
conductive element 172, which may be measured as a function of power loss or
resonant
frequency measured in the induction logging tool 140, as described previously
herein with
reference to FIGS. 2A through 2C. Strain on the electrically conductive
element 172 may also
be measured by coupling the electrically conductive element 172 to an
electrical
component 174, a power supply 164, and an electronic device 156, as described
previously
herein with reference to FIGS. 4A through 4C. In yet other embodiments,
electrically
conductive elements disposed in the deformable material 150 may have any other
shape
configured such that strain will be applied to the electrically conductive
element 172 upon
swelling of the deformable material 150.
As previously mentioned, the CNTs in the CNT material of the electrically
conductive
elements 152, 172 may be crosslinked, such that direct covalent atomic bonds
join adjacent
CNTs directly together in the conductive elements 152, 172. Such crosslinking
of the CNTs
in the CNT material of the electrically conductive elements 152, 172 may cause
the CNT
material to exhibit increased mechanical strength (e.g., higher tensile
strength or yield
strength) compared to CNT materials having CNTs that are not crosslinked.
Methods for
crosslinking CNTs are known in the art and disclosed in, for example, D.N.
Ventura et al., A
Flexible Cross-Linked Multi-Walled Carbon Nanotube Paper for Sensing Hydrogen,
Carbon 50 (2012), pp. 2672-2674, the contents of which are incorporated herein
in their
entirety by this reference. For example, as disclosed therein, CNTs may be
functionalized
with amine groups to form aminated CNTs, and the aminated CNTs may be
crosslinked with
benzoquinone.
Additionally, the CNTs in the CNT material of the electrically conductive
elements 152, 172 may be impregnated with metal nanoparticles. In other words,
metal
nanoparticles may be attached to outer walls of the CNTs. In some embodiments,
the CNTs
may be impregnated with at least one of platinum, copper, silver, gold,
ruthenium, rhodium,
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tin, or palladium nanoparticles and combinations thereof The attachment of
metal
nanoparticles to the CNTs may increase the electrical conductivity of the
CNTs.
Embodiments of the present disclosure also include methods of forming
deformable
downhole articles as described herein, such as the packer devices 136, 170.
For example, in
accordance with such methods, a deformable material 150 may be disposed around
an outer
surface of a tubular component 122 configured for placement in a wellbore, and
an electrically
conductive element 152, 172 comprising a carbon nanotube (CNT) material may be
bonded to
the deformable material 150.
In some embodiments, the deformable material 150 may be disposed around the
outer
surface of the tubular component 122 by using a molding process, such as a
reaction injection
molding process, to mold the deformable material 150 around the tubular
component 122, as
illustrated in FIGS. 7A-7C.
As shown in FIG. 7A, a tubular component 122 may be positioned at least
partially
within a mold 180 having a mold cavity 182 therein. The mold cavity 182 may
have a size
and shape corresponding to the deformable material 150 to be formed therein
around the
tubular component 122. In some embodiments, the mold cavity 182 may have a
size and
shape corresponding to the size and shape of the deformable material 150 in
the expanded
state shown in FIG. 2B and FIG. 3B. Referring to FIG. 7B, the electrically
conductive
element 152 (or the electrically conductive element 172 of FIGS. 4A-4C) may be
positioned
within the mold cavity 182 at a selected position. The electrically conductive
element 152
may be positioned within the mold cavity 182 before or after positioning the
tubular
component 122 at least partially within the mold 180. The electrically
conductive
element 152 may be disposed within the mold cavity 182 in the expanded state
shown in
FIGS. 2B and 4B. As shown in FIG. 7C, the deformable material 150 may be
provided within
the mold cavity 182 around the tubular component 122.
In some embodiments, the molding process used to form the deformable material
150
may comprise a reaction injection molding process. In such a process, a liquid
precursor may
be injected into the mold cavity 182 of the mold 180 as a liquid or paste. A
chemical reaction
may result in crosslinking between molecules (e.g., polymer chains or monomer
units) so as to
result in the formation of a non-flowable polymer material. The polymer
material may be as
previously described herein with reference to FIGS. 2A-2C. As previously
mentioned, the
deformable material 150 may comprise a shape memory polymeric material. In
some
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embodiments, the deformable material 150 may be formed as described in the
aforementioned
'012 Patent, previously incorporated herein by reference.
During the molding process, the electrically conductive element 152 may be
bonded to
the deformable material 150 as previously described herein. In particular, the
CNTs in the
carbon nanotube (CNT) material of the electrically conductive element 152 may
be covalently
bonded to the deformable material 150 as the deformable material 150 is formed
around the
tubular component 122.
For example, in some embodiments, the deformable material 150 may comprise
polyurethane. In such embodiments, the polyurethane may be formed by, for
example,
reacting alcohols having two or more reactive hydroxyl groups per molecule
(e.g., polyols)
and isocyanates having more than one reactive isocyanate group per molecule
within the mold
cavity 182 of the mold 180. In some embodiments, the CNTs in the carbon
nanotube (CNT)
material of the electrically conductive element 152, 172 may be functionalized
with amine
groups prior to forming the deformable material 150 around or adjacent the
electrically
conductive element 152, 172. During the formation of the deformable material
150, the
aminated carbon nanotubes may react with the isocyanates during the reaction
injection
molding process, resulting in the formation of covalent bonds between the CNTs
of the CNT
material and the polyurethane of the deformable material 150.
The deformable material 150 may be allowed to cure in the mold cavity 182 of
the
mold 180. As the deformable material 150 and the electrically conductive
element 152, 172
may be formed in the expanded state, the deformable material 150 and the
electrically
conductive element 152, 172 are compressed. The deformable material 150 may be
compressed until a diameter of the deformable material 150 has a diameter less
than the
diameter of the wall 132 of the wellbore 110 (FIG. 1), as previously described
herein with
reference to FIGS. 2A and 2B. As the deformable material 150 is compressed,
the
electrically conductive element 152, 172 may also be compressed to a
compressed state, in
which the length of the electrically conductive element 152, 172 is reduced as
illustrated in
FIGS. 2A and 4A.
FIGS. 8A-8C illustrate another embodiment of a packer device 200 that may be
employed in a wellbore system, such as the wellbore system 100 of FIG. 1. The
packer
device 200 is a deformable downhole article that, like the packer device 136,
includes a
tubular component 122. The deformable material 202 disposed around the tubular
component 122 may comprise a rubber or elastomer. In some embodiments, the
elastomer of
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the deformable material 202 may comprise the deformable material 150 as
previously
described herein with reference to FIGS. 2A-2C. For example, the deformable
material 202
may be a rubber or elastomer as described in U.S. Patent Publication No.
2009/0139708, and
the '708 Patent, each of which was previously incorporated by reference
herein.
FIG. 8B illustrates a partial cross-sectional view of the deformable material
202
having the electrically conductive element 152 disposed therein. As previously
described
herein with reference to FIGS. 2A-2C, the electrically conductive element 152
may be
oriented in the deformable material 202 such that the axis 154 of the coil
extends
perpendicular to the longitudinal axis of the tubular component 122 and
radially outward from
the tubular component 122 within the deformable material 150. In other words,
the coils may
be oriented in the deformable material 202 such that the axis 154 of the coil
extends along a
radius of the deformable material 202.
The electrically conductive element 152 is located and configured such that
stress will
be applied to the electrically conductive element 152 upon swelling of the
deformable
material 202. The electrically conductive element 152 may be strained
responsive to the
imparted stress without extensive relative displacement of the electrically
conductive
element 152 relative to the adjacent deformable material 202 along the
interface therebetween.
Strain on the electrically conductive element 152 may result in a measurable
change in the
induction or electromagnetic field emitted about the electrically conductive
element 152,
which may be measured as a function of power loss or resonant frequency
measured in the
induction logging tool 140, as described previously herein with reference to
FIGS. 2A through
2C. Strain on the electrically conductive element 152 may also be measured by
coupling the
electrically conductive element 152 to an electrical component 174, a power
supply 164, and
an electronic device 156, as described previously herein with reference to
FIGS. 4A through
4C. In yet other embodiments, electrically conductive elements disposed in the
deformable
material 202 may have any other shape configured such that strain will be
applied to the
electrically conductive element 152 upon swelling of the deformable material
202.
Embodiments of the present disclosure also include methods of forming
deformable
downhole articles, such as the packer device 200. For example, in accordance
with such
methods, the deformable material 202 may be disposed around an outer surface
of the tubular
component 122 configured for placement in a wellbore, and an electrically
conductive
element 152 comprising a carbon nanotube (CNT) material bonded to the
deformable
material 202, as previously described herein with reference to FIGS. 2A-2C, 4A-
4C, and 6.
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In some embodiments, the electrically conductive element 152 may be disposed
in and
bonded to the rubber or elastomer of the deformable material 202 when the
deformable
material 202 is in an uncured state. The deformable material 202 may be cured
on a curing
mandrel in a manner known in the art in some embodiments. In other
embodiments, the
deformable material 202 may be cured on the tubular component 122. For
example, the
deformable material 202 may be cured by a method as described in U.S. Patent
Publication
No. 2009/0139708, previously incorporated herein by reference. The deformable
material 202 in a cured or uncured state and having the electrically
conductive element 152
disposed therein may be wrapped onto the tubular component 122, as in the
direction depicted
by arrow 206 illustrated in FIG. 8C.
FIGS. 9A-9C illustrate another embodiment of a packer device 210 that may be
employed in a wellbore system, such as the wellbore system 100 of FIG. 1. The
packer
device 210 is a deformable downhole article that, like the packer device 136,
includes a
tubular component 122. The packer device 210 further comprises a deformable
material 212,
like the deformable material 202, previously described herein with reference
to FIGS. 8A-8C.
An electrically conductive element 214 may be disposed in the deformable
material 212. The
electrically conductive element 214 may be disposed in the deformable material
212 in an
uncured state, as previously described herein with reference to FIGS. 8A-8C.
The electrically conductive element 214 comprises a fiber arranged in a coil
that
extends concentrically around the tubular component 122 within the deformable
material 212.
In some embodiments, the electrically conductive element 214 may comprise a
carbon
nanotube (CNT) material bonded to the deformable material 202, as previously
described
herein with reference to FIGS. 2A-2C, 4A-4C, and 6. In other embodiments, the
electrically
conductive element 214 may comprise a carbon nanotube (CNT) wire disposed
within the
deformable material 202. FIG. 9B is a cross-sectional view of the packer
device 210 taken in
a plane transverse to the longitudinal axis of the tubular component 122. As
shown in
FIG. 9B, the electrically conductive element 214 extends circumferentially
around at least a
portion of the tubular component 122. The electrically conductive element 214
may extend
entirely around the circumference of the tubular component 122 one or more
times in a
circular or helical manner. Although only one electrically conductive element
214 is
illustrated in FIGS. 9A-9C, any number of electrically conductive element 214
may be
employed in embodiments of the present disclosure. In embodiments in which a
plurality of
electrically conductive element 214 are employed, each electrically conductive
element 214
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may extend entirely around the circumference of the tubular component 122 one
or more
times.
In some embodiments, the ends of the electrically conductive element 214 may
be in
direct or indirect electrical contact. For example, the ends of the
electrically conductive
element 214 may be connected in an electrical circuit. In other words, the
ends of the
electrically conductive element 214 may be connected to the electrical
component 155, as
described previously herein with reference to FIGS. 2A-3C, or the electrical
component 174,
as described previously herein with reference to FIGS. 4A-5C. In other
embodiments, the
ends of the electrically conductive element 214 may be directly coupled to
each other.
The deformable material 212 having the electrically conductive element 214
disposed
therein may be formed about the tubular component 122, as previously described
herein with
reference to FIGS. 8A-8C. For example, the deformable material 212 having the
electrically
conductive element 214 disposed therein may be wrapped about the tubular
component 122 in
the direction depicted by arrow 216 illustrated in FIG. 9C.
The electrically conductive element 214 is located and configured such that
stress will
be applied to the electrically conductive element 214 upon swelling of the
deformable
material 212. The electrically conductive element 214 may be strained
responsive to the
imparted stress without extensive relative displacement of the electrically
conductive
element 152 relative to the adjacent deformable material 212 along the
interface therebetween.
Strain on the electrically conductive element 214 may result in a measurable
change in the
induction or electromagnetic field emitted about the electrically conductive
element 214,
which may be measured as a function of power loss or resonant frequency
measured in the
induction logging tool 140, as described previously herein with reference to
FIGS. 2A through
2C and as illustrated in FIG. 9B. Strain on the electrically conductive
element 214 may also
be measured by coupling the electrically conductive element 152 to an
electrical
component 174, a power supply 164, and an electronic device 156, as described
previously
herein with reference to FIGS. 4A through 4C. In yet other embodiments,
electrically
conductive elements disposed in the deformable material 212 may have any other
shape
configured such that strain will be applied to the electrically conductive
element 214 upon
swelling of the deformable material 212.
In yet additional embodiments, the present disclosure includes methods of
using a
deformable downhole article in a wellbore 110, such as the packer device 136,
the packer
device 170, the packer device 200, or the packer device 210. For example, the
packer
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device 136, 170, 200, 210 may be positioned within a wellbore 110 at a desired
location while
the deformable material 150, 202, 212 is in an unswollen or compressed state
(e.g., the states
shown in FIGS. 2A and 4A). The deformable material 150, 202, 212 then may be
caused to
swell or expand to an expanded state (e.g., the states shown in FIGS. 2B and
4B) at the
selected location in the wellbore 110. The deformable material 150, 202, 212
may be caused
to swell (e.g. expand) by application of a stimulus (e.g., exposure to the
wellbore 110
environment). The stimulus may be a thermal stimulus, a chemical stimulus, an
electrical
stimulus, etc. Swelling or expansion of the deformable material 150, 202, 212
may further
result in expansion of the electrically conductive element 152, 172, 214 as
the electrically
conductive element 152, 172, 214 is located and configured such that strain is
applied to the
electrically conductive element 152, 172, 214 by the deformable material 150,
202, 212.
As previously mentioned, expansion of the deformable material 150, 202, 212
may
alter a strain state of the carbon nanotube (CNT) material of the electrically
conductive
element 152, 172, 214 which may cause the inductance and resistivity of the
electrically
conductive element 152, 172, 214 to change. As a result, the electronic device
156 or the
induction logging tool 140 of the packer device 136, 170, 200, 210 may be used
to measure
the inductance or resistivity of the electrically conductive element 152, 172,
214 either
directly or indirectly, as previously described herein, during and/or after
expansion of the
deformable material 150, 202, 212. As a result, the rate of expansion and/or
the extent of the
expansion of the deformable material 150, 202, 212 may be determined so as to
ensure that
the deformable material 150, 202, 212 has expanded as intended, and that the
packer
device 136, 170, 200, 210 will safely operate as intended.
Although the disclosure has described embodiments of a deformable downhole
article
including an electrically conductive element formed of a carbon nanotube (CNT)
material, the
invention is not so limited. For example, the electrically conductive element
incorporated in
the deformable downhole article may comprise any electrically conductive
material including,
but not limited to, electrically conductive metals. Such electrically
conductive metals may
optionally be coated with a dielectric material and embedded in the deformable
material
according to any of the embodiments of the present disclosure.
Additional non-limiting example embodiments of the present disclosure are set
forth
below.
Embodiment 1: A deformable downhole article for use in a wellbore, comprising:
a
tubular component configured for placement in a wellbore; a deformable
material disposed
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around an outer surface of the tubular component; and an electrically
conductive element
comprising a carbon nanotube (CNT) material bonded to the deformable material.
Embodiment 2: The deformable downhole article of Embodiment 1, wherein the
electrically conductive element is located and configured such that stress
will be applied to the
electrically conductive element upon swelling of the deformable material and
the electrically
conductive element is strained responsive to the applied stress.
Embodiment 3: The deformable downhole article of Embodiment 1 or
Embodiment 2, further comprising an electronic device operably coupled to the
electrically
conductive element and configured to measure at least one electrical property
of the
electrically conductive element.
Embodiment 4: The deformable downhole article of any one of Embodiments 1
through 3, wherein the CNT material extends radially outward from at least a
portion of the
tubular component.
Embodiment 5: The deformable downhole article of any one of Embodiments 1
through 3, wherein the CNT material comprises crosslinked carbon nanotubes,
and the CNT
material extends
Embodiment 6: The deformable downhole article of any one of Embodiments 1
through 5, wherein the electrically conductive element is covalently bonded to
the deformable
material.
Embodiment 7: The deformable downhole article of any one of Embodiments 1
through 6, wherein the CNT material comprises crosslinked carbon nanotubes
(CNTs), and
wherein CNTs of the CNT material are covalently bonded to the deformable
material.
Embodiment 8: The deformable downhole article of any one of Embodiments 1
through 7, wherein the electrically conductive element is disposed within the
deformable
material.
Embodiment 9: The deformable downhole article of any one of Embodiments 1
through 8, wherein CNTs of the CNT material are impregnated with metal
nanoparticles.
Embodiment 10: The deformable downhole article of Embodiment 9, wherein the
metal nanoparticles comprise palladium nanoparticles.
Embodiment 11: The deformable downhole article of Embodiment 7, wherein CNTs
of the CNT material are crosslinked with benzoquinone.
Embodiment 12: The deformable downhole article of any one of Embodiments 1
through 11, wherein the deformable material comprises a shape memory polymer.
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Embodiment 13: The deformable downhole article of Embodiment 12, wherein the
shape memory polymer comprises polyurethane.
Embodiment 14: A method of forming a deformable downhole article for use in a
wellbore, comprising: disposing a deformable material around an outer surface
of a tubular
component configured for placement in a wellbore; and bonding an electrically
conductive
element comprising a carbon nanotube (CNT) material to the deformable
material.
Embodiment 15: The method of Embodiment 14, wherein disposing the deformable
material around the outer surface of the tubular component comprises molding
the deformable
material around the tubular component.
Embodiment 16: The method of Embodiment 15, wherein molding the deformable
material around the tubular component comprises a reaction injection molding
process.
Embodiment 17: The method of any one of Embodiments 14 through 16, wherein
bonding the electrically conductive element comprising the carbon nanotube
(CNT) material
to the deformable material comprises covalently bonding the electrically
conductive element
to the deformable material.
Embodiment 18: A method of using a deformable downhole article in a wellbore,
comprising: positioning a deformable downhole article in a wellbore, the
deformable
downhole article includes a tubular component, a deformable material disposed
around an
outer surface of the tubular component, and an electrically conductive element
comprising a
carbon nanotube (CNT) material bonded to the deformable material; expanding
the
deformable material to an expanded state in the wellbore, expansion of the
deformable
material straining the carbon nanotube (CNT) material of the electrically
conductive element;
and measuring an electrical property of the electrically conductive element.
Embodiment 19: The method of Embodiment 18, wherein measuring the electrical
property of the electrically conductive element comprises measuring a
resistivity or
inductance of the electrically conductive element.
Embodiment 20: The method of Embodiment 18 or Embodiment 19, further
comprising correlating a measurement obtained by the measuring of the
electrical property of
the electrically conductive element to a degree of expansion of the deformable
material.
Embodiment 21: The method of any one of Embodiments 18 through 20, wherein the
electrically conductive element is covalently bonded to the deformable
material.
While the present disclosure has been described herein with respect to certain
illustrated embodiments, those of ordinary skill in the art will recognize and
appreciate that it
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is not so limited. Rather, many additions, deletions, and modifications to the
illustrated
embodiments may be made without departing from the scope of the disclosure as
hereinafter
claimed, including legal equivalents thereof In addition, features from one
embodiment may
be combined with features of another embodiment while still being encompassed
within the
scope of the disclosure as contemplated by the inventors.
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