U.S. patent application number 16/425253 was filed with the patent office on 2019-11-21 for methods of forming modified thermoplastic structures for down-hole applications, and related down-hole tools.
The applicant listed for this patent is Baker Hughes, a GE company, LLC. Invention is credited to Michal Benes, Jiaxiang Ren.
Application Number | 20190352480 16/425253 |
Document ID | / |
Family ID | 51528245 |
Filed Date | 2019-11-21 |
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United States Patent
Application |
20190352480 |
Kind Code |
A1 |
Benes; Michal ; et
al. |
November 21, 2019 |
METHODS OF FORMING MODIFIED THERMOPLASTIC STRUCTURES FOR DOWN-HOLE
APPLICATIONS, AND RELATED DOWN-HOLE TOOLS
Abstract
A method of forming a modified thermoplastic structure for a
down-hole application comprises forming a thermoplastic structure
comprising at least one thermoplastic material formulated for
crosslinking using an electron beam process. The thermoplastic
structure is exposed to at least one electron beam to crosslink
polymer chains of the thermoplastic structure. Other methods of
forming a modified thermoplastic structure, and a down-hole tool
are also described.
Inventors: |
Benes; Michal; (The
Woodlands, TX) ; Ren; Jiaxiang; (Houston,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Baker Hughes, a GE company, LLC |
Houston |
TX |
US |
|
|
Family ID: |
51528245 |
Appl. No.: |
16/425253 |
Filed: |
May 29, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13798886 |
Mar 13, 2013 |
10351686 |
|
|
16425253 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08J 2379/08 20130101;
C08J 3/243 20130101; C08J 2381/06 20130101; C08J 3/28 20130101;
C08J 3/244 20130101; C08J 3/245 20130101; C08J 7/123 20130101; C08J
2365/02 20130101; C08J 2381/04 20130101; C08J 2371/12 20130101;
C08J 2371/00 20130101 |
International
Class: |
C08J 7/12 20060101
C08J007/12; C08J 3/24 20060101 C08J003/24; C08J 3/28 20060101
C08J003/28 |
Claims
1. A method of forming a modified thermoplastic structure for a
down-hole application, comprising: depositing a thermoplastic film
over a structure, the thermoplastic film comprising at least one
thermoplastic material comprising polymer chains that at least
partially crosslink upon exposure to an electron beam; and
subjecting the thermoplastic film to an electron beam process to
crosslink at least a portion of the polymer chains of the
thermoplastic film.
2. (canceled)
3. The method of claim 1, wherein subjecting the thermoplastic film
to an electron beam process to crosslink at least a portion of the
polymer chains of the thermoplastic film comprises crosslinking the
polymer chains of the thermoplastic film to a depth less than a
thickness of the thermoplastic film.
4. The method of claim 1, wherein subjecting the thermoplastic film
to an electron beam process to crosslink at least a portion of the
polymer chains of the thermoplastic film comprises substantially
uniformly crosslinking the at least a portion of the polymer chains
of the thermoplastic film.
5. A down-hole tool comprising at least one modified thermoplastic
structure comprising an electron beam irradiated material
comprising one or more of polyetherketone, polyetheretherketone,
polyetherketoneketone, polyetherketoneetherketoneketone,
polyphenylene sulfide, polyphenylsulfone, self-reinforced
polyphenylene, a polyimide, and a polyamideimide.
6. The down-hole tool of claim 5, wherein the at least one modified
thermoplastic structure exhibits non-uniform crosslinking of
polymer chains throughout a thickness thereof.
7. The down-hole tool of claim 5, wherein the electron beam
irradiated material further comprises at least one of a filler
material and another polymeric material.
8. The down-hole tool of claim 5, wherein the at least one modified
thermoplastic structure comprises a film over another
structure.
9. The down-hole tool of claim 8, wherein the film only partially
covers the another structure.
10. The down-hole tool of claim 5, wherein the electron beam
irradiated material comprises: polymer chains of the one or more of
polyetherketone, polyetheretherketone, polyetherketoneketone,
polyetherketoneetherketoneketone, polyphenylene sulfide,
polyphenylsulfone, self-reinforced polyphenylene, a polyimide, and
a polyamideimide; and functional groups of one of more crosslinking
agents intervening between and crosslinking the polymer chains of
the one or more of polyetherketone, polyetheretherketone,
polyetherketoneketone, polyetherketoneetherketoneketone,
polyphenylene sulfide, polyphenylsulfone, self-reinforced
polyphenylene, a polyimide, and a polyamideimide.
11. The down-hole tool of claim 10, wherein the one of more
crosslinking agents comprise one or more of an organic peroxide, an
inorganic peroxide, sulfur, diallyl maleate, triallyl cyanurate,
triallyl isocyanurate, n,n'-m-phenylene bismaleimide, a
polyacrylate, a polymethacrylate, a trifunctional acrylate, a
trifunctional methacrylate, pentaerythritol tetraacrylate,
dipentaerythritol pentaacrylate, trimethylolpropane
trimethacrylate, ethylene glycol dimethacrylate, polyethylene
glycol dimethacrylate, allyl methacrylate, a liquid butadiene, and
methacrylated polybutadiene.
12. A method of forming a modified thermoplastic structure for a
down-hole application, comprising: forming a material comprising a
thermoplastic powder comprising thermoplastic particles comprising
one or more of polyetherketone particles, polyetheretherketone
particles, polyetherketoneketone particles,
polyetherketoneetherketoneketone particles, polyphenylene sulfide
particles, polyphenylsulfone particles, self-reinforced
polyphenylene particles, and polyamideimide particles; treating the
material with at least one electron beam to crosslink at least a
portion of polymer chains of at least a portion of the
thermoplastic particles of the thermoplastic powder to form a
modified material comprising a modified thermoplastic powder;
combining the modified material with at least one crosslinking
agent to form a further modified material, the at least one
crosslinking agent formulated for crosslinking polymer chains of
the modified thermoplastic powder upon exposure to at least one
additional electron beam; depositing a film of the further modified
material over another structure; and treating the film of the
further modified material with at least one additional electron
beam to crosslink the polymer chains of the further modified
material.
13. The method of claim 12, wherein the material consist of the
thermoplastic powder, the thermoplastic powder consists of the
thermoplastic particles, and the thermoplastic particles are
selected from the group consisting of the polyetherketone
particles, the polyetheretherketone particles, the
polyetherketoneketone particles, the
polyetherketoneetherketoneketone particles, the polyphenylene
sulfide particles, the polyphenylsulfone particles, the
self-reinforced polyphenylene particles, and the polyamideimide
particles.
14. The method of claim 12, wherein combining the modified material
with at least one crosslinking agent comprises combining the
modified material with one or more of an organic peroxide, an
inorganic peroxide, sulfur, diallyl maleate, triallyl cyanurate,
triallyl isocyanurate, n,n'-m-phenylene bismaleimide, a
polyacrylate, a polymethacrylate, a trifunctional acrylate, a
trifunctional methacrylate, pentaerythritol tetraacrylate,
dipentaerythritol pentaacrylate, trimethylolpropane
trimethacrylate, ethylene glycol dimethacrylate, polyethylene
glycol dimethacrylate, allyl methacrylate, a liquid butadiene, and
methacrylated polybutadiene.
15. The method of claim 12, wherein forming a film of the further
modified material over another structure comprises only partially
coating the another structure with the film of the further modified
material.
16. The method of claim 12, further comprising selecting the
another structure from the group consisting of a sensor, a ring, a
seal, wiring, and cable.
17. The method of claim 12, wherein combining the modified material
with at least one crosslinking agent comprises combining the
modified material with the crosslinking agent at a ratio within a
range of from about 0.05 parts to about 50 parts of the
crosslinking agent per 100 parts of the modified material.
18. The method of claim 12, further comprising adding at least one
filler material to the further modified material prior to forming
the film of the further modified material over the another
structure.
19. The method of claim 18, wherein adding at least one filler
material to the further modified material comprises adding one or
more of carbon black, graphene, carbon nanofibers, single-walled
carbon nanotubes, multi-walled carbon nanotubes,
polytetrafluoroethene, an aromatic polyamide, a magnesium calcium
aluminum silicate, cellulose, clay, glass, and silica.
20. The method of claim 12, further comprising adding polymeric
particles to the further modified material prior to forming the
film of the further modified material over the another
structure.
21. The method of claim 20, further comprising selecting the
polymeric particles to comprise non-crosslinked polymer chains of
one or more polymers.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 13/798,886, filed Mar. 13, 2013, pending, the disclosure
of which is hereby incorporated herein in its entirety by this
reference.
TECHNICAL FIELD
[0002] Embodiments of the disclosure relate generally to methods of
forming structures for down-hole applications, and to related
down-hole tools. More particularly, embodiments of the disclosure
relate to methods of forming modified thermoplastic structures for
down-hole applications, and to related down-hole tools.
BACKGROUND
[0003] Wellbores are formed in subterranean formations for various
purposes including, for example, extraction of oil and gas from the
subterranean formations and extraction of geothermal heat from the
subterranean formations. Wellbores can exhibit extremely aggressive
environments. For example, wellbores can exhibit abrasive surfaces,
can be filled with corrosive chemicals (e.g., caustic drilling
muds; well fluids, such as salt water, crude oil, carbon dioxide,
and hydrogen sulfide; etc.), and can exhibit increasing high
temperatures and pressures at progressively "down-hole" locations.
For example, bottom-hole temperatures and pressures at depths of
from about 5,000 to about 8,000 meters are often greater than
250.degree. C. and 150 megapascals (MPa), respectively.
[0004] The extremely aggressive environments of wellbores can
rapidly degrade the materials of assemblies, tools, and structures
used in various down-hole applications (e.g., drilling
applications, conditioning applications, logging applications,
measurement applications, monitoring applications, exploring
applications, etc.). Such degradation limits operational
efficiency, and results in undesirable repair and replacement
costs. Accordingly, there is a continuing need for structures
having material configurations capable of withstanding such
extremely aggressive environments, as well as for methods of
forming such structures.
BRIEF SUMMARY
[0005] Embodiments described herein include methods of forming
modified thermoplastic structures for down-hole applications, and
down-hole tools. For example, in accordance with one embodiment
described herein, a method of forming a modified thermoplastic
structure for a down-hole application comprises forming a
thermoplastic structure comprising at least one thermoplastic
material formulated for crosslinking using an electron beam
process. The thermoplastic structure is exposed to at least one
electron beam to crosslink polymer chains of the thermoplastic
structure.
[0006] In additional embodiments, a method of forming a modified
thermoplastic structure for a down-hole application comprises
forming a thermoplastic powder comprising thermoplastic particles
each comprising at least one thermoplastic material formulated for
crosslinking using an electron beam process. Polymer chains of at
least a portion of the thermoplastic particles are crosslinked to
form a modified thermoplastic powder. The modified thermoplastic
powder is formed into a thermoplastic structure.
[0007] In yet additional embodiments, a down-hole tool comprises at
least one modified thermoplastic structure comprising an electron
beam irradiated material comprising at least one of
polyetherketone, polyetheretherketone, polyetherketoneketone,
polyetherketoneetherketoneketone, polyphenylene sulfide,
polyphenylsulfone, self-reinforced polyphenylene, a polyimide, and
a polyamideimide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a longitudinal schematic view of an assembly for
use in down-hole applications, in accordance with an embodiment of
the disclosure;
[0009] FIG. 2 is a simplified flow diagram illustrating a method of
forming a modified thermoplastic structure for use in down-hole
applications, in accordance with embodiments of the disclosure;
[0010] FIGS. 3A and 3B are simplified perspective views
illustrating different process stages and structures for the method
illustrated in FIG. 2, in accordance with embodiments of the
disclosure;
[0011] FIG. 4 is a simplified flow diagram illustrating another
method of forming a modified thermoplastic structure, in accordance
with an embodiment of the disclosure; and
[0012] FIGS. 5A through 5D are simplified perspective views
illustrating different process stages and structures for the method
illustrated in FIG. 4, in accordance with an embodiment of the
disclosure.
DETAILED DESCRIPTION
[0013] Methods of forming modified thermoplastic structures for use
in down-hole applications are described, as are thermoplastic
structures for down-hole tools. In some embodiments a method of
forming a modified thermoplastic structure for a down-hole
application comprises forming a thermoplastic structure including
at least one thermoplastic material formulated for crosslinking
using an electron beam process. The thermoplastic structure is
exposed to at least one electron beam to crosslink at least some
polymer chains of the thermoplastic structure. In additional
embodiments, a method of forming a modified thermoplastic structure
for a down-hole application comprises forming a thermoplastic
powder including thermoplastic particles each comprising at least
one thermoplastic material formulated for crosslinking using an
electron beam process. Polymer chains of at least a portion of the
thermoplastic particles are crosslinked to form a modified
thermoplastic powder including modified thermoplastic particles.
The modified thermoplastic powder, and optionally, one or more
additives, is formed into a thermoplastic structure. The modified
thermoplastic structures of the disclosure may exhibit enhanced
properties (e.g., enhanced mechanical strength, wear resistance,
thermal resistance, chemical resistance, etc.) favorable to the use
of the modified thermoplastic structure in a down-hole application.
The methods and structures of the disclosure may increase the
efficiency of down-hole applications and reduce costs as compared
to corresponding conventional methods and structures.
[0014] The following description provides specific details, such as
material types, material thicknesses, and processing conditions in
order to provide a thorough description of embodiments of the
disclosure. However, a person of ordinary skill in the art will
understand that the embodiments of the disclosure may be practiced
without employing these specific details. Indeed, the embodiments
of the disclosure may be practiced in conjunction with conventional
fabrication techniques employed in the industry. In addition, the
description provided below does not form a complete process flow
for manufacturing a structure, tool, or assembly. The structures
described below do not form a complete tool or a complete assembly.
Only those process acts and structures necessary to understand the
embodiments of the disclosure are described in detail below.
Additional acts to form the complete tool or the complete assembly
from various structures may be performed by conventional
fabrication techniques. Also note, any drawings accompanying the
present application are for illustrative purposes only, and are
thus not drawn to scale. Additionally, elements common between
figures may retain the same numerical designation.
[0015] As used herein, the terms "comprising," "including,"
"containing," "characterized by," and grammatical equivalents
thereof are inclusive or open-ended terms that do not exclude
additional, unrecited elements or method steps, but also include
the more restrictive terms "consisting of" and "consisting
essentially of" and grammatical equivalents thereof. As used
herein, the term "may" with respect to a material, structure,
feature or method act indicates that such is contemplated for use
in implementation of an embodiment of the disclosure and such term
is used in preference to the more restrictive term "is" so as to
avoid any implication that other, compatible materials, structures,
features and methods usable in combination therewith should or must
be, excluded.
[0016] As used herein, the singular forms "a," "an," and "the" are
intended to include the plural forms as well, unless the context
clearly indicates otherwise.
[0017] As used herein, the term "and/or" includes any and all
combinations of one or more of the associated listed items.
[0018] As used herein, the term "substantially," in reference to a
given parameter, property, or condition, means to a degree that one
of ordinary skill in the art would understand that the given
parameter, property, or condition is met with a small degree of
variance, such as within acceptable manufacturing tolerances.
[0019] FIG. 1 is a longitudinal schematic view of an assembly 100
for use in a down-hole application (e.g., a drilling application, a
conditioning application, a logging application, a measurement
application, a monitoring application, etc.). As shown in FIG. 1,
the assembly 100 may be provided into a wellbore 102 within a
subterranean formation 104. The assembly 100 may include at least
one modified thermoplastic structure 106 formed in accordance with
methods described hereinbelow. The modified thermoplastic structure
106 may be a component of a down-hole tool 108 of the assembly 100.
The down-hole tool 108 may, for example, include the modified
thermoplastic structure 106 and at least one other component 110
(e.g., a device, such as a sensor; a ring, such as an O-ring; a
seal, such as a lip seal; wiring; cable; etc.). The modified
thermoplastic structure 106 may at least partially surround (e.g.,
contain, hold, shield, etc.) the other component 110. In additional
embodiments, the modified thermoplastic structure 106 may comprise
a stand-alone structure of the assembly 100 (e.g., a valve, such as
a ball valve).
[0020] FIG. 2 is a simplified flow diagram illustrating a method of
forming a modified thermoplastic structure (e.g., such as the
modified thermoplastic structure 106 previously described with
reference to FIG. 1) for a down-hole application, in accordance
with embodiments of the disclosure. The method includes forming a
thermoplastic structure, and subjecting the thermoplastic structure
to an electron beam process. The method illustrated in FIG. 2 is
described in further detail below in relation to FIGS. 3A and 3B,
which are simplified perspective views of the different process
stages and structures for the method depicted in FIG. 2. With the
description as provided below, it will be readily apparent to one
of ordinary skill in the art that the method described herein may
be used in various applications. In other words, the method may be
used whenever it is desired to form a modified thermoplastic
structure.
[0021] Referring to FIG. 3A, a thermoplastic structure 302 may be
formed from at least one thermoplastic material, and, optionally,
at least one additive. As used herein, the term "thermoplastic
material" means and includes a polymeric material that may be
softened (e.g., melted) by heat and hardened by cooling in a
reversible physical process. The thermoplastic material may be
formulated to undergo crosslinking when subjected to an electron
beam process, as described in further detail below. The
thermoplastic material may, for example, be at least partially
converted into a thermoset material upon being subjected to the
electron beam process. As used herein, the term "thermoset
material" means and includes a solid polymeric material that, due
to crosslinking, will not melt upon heating. Suitable thermoplastic
materials include, but are not limited to, polyaryletherketones
(PAEK), such as polyetherketone (PEK), polyetheretherketone (PEEK),
polyetherketoneketone (PEKK), and polyetherketoneetherketoneketone
(PEKEKK); polyphenylene sulfide (PPS); polyphenylsulfone (PPSU);
self-reinforced polyphenylene (SRP); polyimides (PI); and
polyamideimides (PAI). In some embodiments, the thermoplastic
material of the thermoplastic structure 302 comprises PEEK. If
included, the additive may be at least one of a filler material, an
extender material, a cross-linking agent, a lubricant, a pigment, a
plasticizer, an anti-oxidant, and another polymeric material.
Non-limiting examples of suitable additives are described in
further detail below with reference to FIG. 5C. The thermoplastic
structure 302 may be substantially homogeneous (e.g., the
thermoplastic material may consist of the thermoplastic material,
or the thermoplastic material and the additive may be uniformly
distributed throughout the thermoplastic structure 302), or may be
heterogeneous (e.g., the thermoplastic material and the additive
may be non-uniformly distributed throughout the thermoplastic
structure 302).
[0022] The thermoplastic structure 302 may comprise a bulk
structure, may comprise a film (e.g., layer, coating, etc.) at
least partially covering another structure, or may comprise a
combination thereof. In addition, the thermoplastic structure 302
may exhibit a desired shape and a desired size. For example, as
depicted in FIG. 3A, the thermoplastic structure 302 may exhibit a
tubular shape. In additional embodiments, the thermoplastic
structure 302 may exhibit a different shape, such as a conical
shape, a pyramidal shape, a cubic shape, a cuboidal shape, a
spherical shape, a hemispherical shape, a cylindrical shape, a
semicylindrical shape, truncated versions thereof, or an irregular
shape. Irregular shapes include complex shapes, such as shapes
associated with down-hole structures and devices (e.g., tools). In
some embodiments, the thermoplastic structure 302 may exhibit
substantially uniform properties (e.g., thermal resistance,
hardness, elastic modulus, bulk modulus, toughness, chemical
resistance, abrasion resistance, friction coefficient, mechanical
strength, etc.) throughout a thickness T.sub.1 thereof.
[0023] The thermoplastic structure 302 may be formed using at least
one conventional process, such as at least one of a conventional
molding process (e.g., an injection molding process, a compression
molding process, a transfer molding process, etc.), and a
conventional deposition process (e.g., a flame spray process). Such
processes are well known in the art, and are therefore not
described in detail herein.
[0024] Referring next to FIG. 3B, the thermoplastic structure 302
(FIG. 3A) may be subjected to an electron beam process to crosslink
polymer chains thereof and form a modified thermoplastic structure
306. As used herein, the terms "crosslink" and "crosslinking" refer
to a process in which more than one polymer chain, or more than one
portion of a long polymer chain, are joined together by at least
one chemical bond (e.g., a covalent bond, a hydrogen bond, etc.).
As shown in FIG. 3B, at least a portion of the thermoplastic
structure 302 may be exposed to at least one electron beam 308. The
electron beam 308 may crosslink non-crosslinked polymer chains of
the thermoplastic structure 302, and/or may further crosslink
previously crosslinked polymer chains of the thermoplastic
structure 302 (e.g., crosslinked polymer chains formed during the
formation of the thermoplastic structure 302). The electron beam
process may at least partially convert the thermoplastic material
of the thermoplastic structure 302 into a thermoset material. The
electron beam process may be performed without previously
performing another process (e.g., a post-formation thermal anneal
process, etc.) to crosslink polymer chains of the thermoplastic
structure 302, or may be performed after at least partially
crosslinking polymer chains of the thermoplastic structure 302
using another process. The crosslinking facilitated by the electron
beam process may enhance one or more properties (e.g., thermal
resistance, hardness, tensile strength, tear strength, abrasion
resistance, chemical resistance, extrusion resistance, elongation,
elastic modulus, bulk modulus, etc.) of the modified thermoplastic
structure 306 relative to the thermoplastic structure 302.
[0025] The electron beam process may crosslink polymer chains of
the thermoplastic structure 302 (FIG. 3A) up to the thickness
T.sub.1 thereof. In some embodiments, the electron beam process
crosslinks polymer chains of the thermoplastic structure 302 to the
thickness T.sub.1 thereof. In additional embodiments, the electron
beam process crosslinks polymer chains of the thermoplastic
structure 302 to a depth less than the thickness T.sub.1 thereof.
For example, referring to FIG. 3A, the electron beam process may
crosslink polymer chains of the thermoplastic structure 302
proximate a surface 304 thereof, but may not crosslink polymer
chains of the thermoplastic structure 302 distal from the surface
304. Furthermore, referring again to FIG. 3B, the degree of
crosslinking (e.g., crosslinking density) may be substantially
uniform (e.g., may not vary), or may be non-uniform (e.g., may
vary) throughout the thickness T.sub.1 of the modified
thermoplastic structure 306. For example, the degree of
crosslinking may not increase or decrease, may decrease, may
increase, may decrease and then increase, or may increase and then
decrease in a direction extending away from a surface 310 of the
modified thermoplastic structure 306. If the degree of crosslinking
is non-uniform, the degree of crosslinking may vary linearly, may
vary stepwise, or may vary in a Gaussian manner throughout the
thickness of the thermoplastic structure. In addition, different
regions of the surface 310 of the modified thermoplastic structure
306 may exhibit substantially the same degree of crosslinking, or
at least one region of the surface 310 of the modified
thermoplastic structure 306 may exhibit a greater degree of
crosslinking than at least one other region of the surface 310 of
the modified thermoplastic structure 306. Varying at least one of
the depth, degree, and location of crosslinking throughout the
modified thermoplastic structure 306 may enable the modified
thermoplastic structure 306 to exhibit different properties (e.g.,
thermal resistance, hardness, tensile strength, tear strength,
abrasion resistance, chemical resistance, extrusion resistance,
elongation, elastic modulus, bulk modulus, etc.) in desired regions
without changing the chemical composition of the modified
thermoplastic structure 306.
[0026] The depth and degree of crosslinking throughout the
thickness T.sub.1 of the modified thermoplastic structure 306 may
be controlled as a function of the acceleration voltage of the
electron beam 308 and a dosage of the electron beam 308. For
example, an increase in the acceleration voltage of the electron
beam 308 may increase the depth of crosslinking, and an increase in
the dosage of the electron beam may increase the degree of
crosslinking throughout the depth. As a non-limiting example, the
acceleration voltage may be within a range of from about 50
kilovolts (kV) to about 9.0 megavolts (MV) or greater, such as from
about 100 KV to about 8.0 MV, from about 100 KV to about 4.0 MV, or
from about 100 KV to about 2.0 MV. A single acceleration voltage
may be utilized, or multiple acceleration voltage may be utilized
(e.g., such as when multiple electron beams are utilized in the
electron beam process). In addition, the dosage may be greater than
or equal to about 1 megagray (MGy), such as greater than or equal
to about 10 MGy, greater than or equal to about 20 MGy, greater
than or equal to about 30 MGy, greater than or equal to about 50
MGy, greater than or equal to about 100 MGy, or greater than or
equal to about 120 MGy. In some embodiments, the dosage is greater
than or equal to about 30 MGy. A single dosage may be utilized, or
multiple dosages may be utilized. In addition, the surface 304
(FIG. 3A) of the thermoplastic structure 302 (FIG. 3A) may be
substantially evenly exposed to the electron beam 308, or at least
one region of the surface 304 of the thermoplastic structure 302
may be exposed to a greater dosage of the electron beam 308 than at
least one other region of the surface 304 of the thermoplastic
structure 302 (e.g., through use of a mask). The thermoplastic
structure 302 may be exposed to the electron beam 308 in an inert
atmosphere (e.g., an atmosphere substantially free of oxygen, such
as under vacuum, within a nitrogen atmosphere, within a noble gas
atmosphere, etc.).
[0027] FIG. 4 is a simplified flow diagram illustrating another
method of forming a modified thermoplastic structure (e.g., such as
the modified thermoplastic structure 106 previously described with
reference to FIG. 1) for a down-hole application, in accordance
with additional embodiments of the disclosure. The method includes
forming a thermoplastic powder, crosslinking polymer chains of the
thermoplastic powder to form a modified thermoplastic powder,
optionally combining the modified thermoplastic powder with at
least one additive to form a mixture, forming a thermoplastic
structure from the modified thermoplastic powder (or, optionally,
the mixture), and optionally subjecting the thermoplastic structure
to an electron beam process. The method illustrated in FIG. 4 is
described in further detail below in relation to FIGS. 5A through
5D, which depict simplified perspective views of the different
process stages and structures of the method depicted in FIG. 4.
With the description as provided below, it will be readily apparent
to one of ordinary skill in the art that the method described
herein may be used in various applications. In other words, the
method may be used whenever it is desired to form a modified
thermoplastic structure.
[0028] Referring to FIG. 5A, a thermoplastic powder 500 may be
formed to include thermoplastic particles 502. Each of the
thermoplastic particles 502 may independently be formed of and
include at least one thermoplastic material formulated to undergo
crosslinking when subjected to an electron beam process, as
described in further detail below. The thermoplastic material may,
for example, be at least partially converted into a thermoset
material upon when subjected to the electron beam process. Suitable
thermoplastic materials include, but are not limited to, a PAEK
(e.g., PEK, PEEK, PEKK, PEKEKK, etc.), PPS, PPSU, SRP, PI, and PAI.
In some embodiments, the thermoplastic material of each of the
thermoplastic particles 502 comprises PEEK.
[0029] Each of the thermoplastic particles 502 may independently be
of a desired size. The thermoplastic particles 502 may comprise,
for example, at least one of micro-sized thermoplastic particles
and nano-sized thermoplastic particles. As used herein the term
"micro-sized" means and includes a size (e.g., width or diameter)
of greater than or equal to about one (1) micrometer (.mu.m), such
as from about 1 .mu.m to about 500 .mu.m. As used herein the term
"nano-sized" means and includes a size (e.g., width or diameter) of
less than 1 .mu.m. In some embodiments, the nano-sized
thermoplastic particles may be less than or equal to about 500
nanometers (nm) in size, or less than or equal to about 250 nm in
size. In addition, each of the thermoplastic particles may
independently be of a desired shape, such as at least one of a
spherical shape, a hexahedral shape, an ellipsoidal shape, a
cylindrical shape, a conical shape, or an irregular shape. In some
embodiments, each of the thermoplastic particles has a
substantially spherical shape. The thermoplastic particles may be
monodisperse, wherein each of thermoplastic particles has
substantially the same material composition (e.g., PEK, PEEK, PEKK,
PEKEKK, PPS, PPSU, SRP, PI, PAI, etc.), particle size, and particle
shape, or may be polydisperse, wherein the thermoplastic particles
include a range of material compositions, particle sizes, and/or
particle shapes. Each of the thermoplastic particles may be
discrete, or at least two of the thermoplastic particles may be
agglomerated into at least one larger structure (e.g., a
thermoplastic pellet formed of and including multiple thermoplastic
particles). The thermoplastic powder 500 may be formed using
conventional methods and equipment, which are not described in
detail herein.
[0030] Referring next to FIG. 5B, the thermoplastic powder 500
(FIG. 5A) may be exposed to at least one process to crosslink
polymer chains of at least a portion of the thermoplastic particles
502 and form a modified thermoplastic powder 504 including modified
thermoplastic particles 506. The process may effectuate
intra-particle crosslinking of polymer chains (e.g., crosslinking
of polymer chains of one of thermoplastic particles 502) without
substantially effectuating inter-particle crosslinking of polymer
chains (e.g., crosslinking of polymer chains of one of the
thermoplastic particles 502 with polymer chains of another of the
thermoplastic particles 502). In additional embodiments, the
process may effectuate intra-particle crosslinking of polymer
chains and at least some inter-particle crosslinking of polymer
chains. Substantially all of the thermoplastic particles 502 may
undergo a substantially similar amount of crosslinking, or at least
one of the thermoplastic particles 502 may undergo a different
amount of intra-particle crosslinking than at least one other of
the thermoplastic particles 502. The extent of crosslinking (e.g.,
throughout the bulk of the modified thermoplastic powder 504, and
within each modified thermoplastic particle 506 thereof) may at
least partially depend on the process utilized to effectuate the
crosslinking, as described in further detail below.
[0031] In some embodiments, the thermoplastic powder 500 (FIG. 5A)
may be subjected to an electron beam process to crosslink polymer
chains of at least a portion of the thermoplastic particles 502 and
form a modified thermoplastic powder 504. For example, as depicted
in FIG. 5B, at least a portion of the thermoplastic powder 500
(FIG. 5A) may be exposed to at least one electron beam 508 to form
the modified thermoplastic powder 504. The number of modified
thermoplastic particles 506 throughout the modified thermoplastic
powder 504 and degree of crosslinking within each of the modified
thermoplastic particles 506 may be controlled by the accelerating
voltage, dosage, and location of the electron beam 508. An increase
in the acceleration voltage of the electron beam may increase a
penetration depth of the electron beam into the bulk of the
thermoplastic powder 500 (FIG. 5A), and an increase in the dosage
of the electron beam 508 may increase the degree of crosslinking
throughout the depth (e.g., in each of the thermoplastic particles
502 exposed). As a non-limiting example, the acceleration voltage
may be within a range of from about 50 kilovolts (kV) to about 9.0
megavolts (MV) or greater, such as from about 100 KV to about 8.0
MV, from about 100 KV to about 4.0 MV, or from about 100 KV to
about 2.0 MV. A single acceleration voltage may be utilized, or
multiple acceleration voltage may be utilized (e.g., such as when
multiple electron beams 104 are utilized in the electron beam
process). In addition, the dosage may be greater than or equal to
about 1 MGy, such as greater than or equal to about 10 MGy, greater
than or equal to about 20 MGy, greater than or equal to about 30
MGy, greater than or equal to about 50 MGy, greater than or equal
to about 100 MGy, or greater than or equal to about 120 MGy. A
single dosage may be utilized, or multiple dosages may be utilized.
The thermoplastic powder 500 (FIG. 5A) may be substantially evenly
laterally exposed to the electron beam 508, or at least one lateral
region of the thermoplastic powder 500 may be exposed to a greater
dosage of the electron beam 508 than at least one other lateral
region of the thermoplastic powder 500 (e.g., through use of a
mask). In some embodiments, the electron beam process is controlled
such that each thermoplastic particle 502 of the thermoplastic
powder 500 is converted to a modified thermoplastic particle 506,
and such that each of the modified thermoplastic particles 506
exhibits substantially the same degree of crosslinking as each
other of the modified thermoplastic particles 506. In additional
embodiments, the electron beam process may convert at least a
portion of the thermoplastic material of at least some of the
thermoplastic particles 502 into a thermoset material. The electron
beam process may, for example, convert at least some of the
thermoplastic particles 502 into thermoset particles. In
embodiments wherein at least a majority of the thermoplastic
particles 502 are converted into thermoset particles, at least one
at least one additive (e.g., crosslinking agent, other polymeric
material, etc.) may be utilized to effectuate forming a
thermoplastic structure including the thermoset particles. The
thermoplastic powder 500 (FIG. 5A) may be exposed to the electron
beam 508 in an inert atmosphere (e.g., under vacuum, within a
nitrogen atmosphere, within a noble gas atmosphere, etc.).
[0032] In additional embodiments, the thermoplastic powder 500 may
be exposed to an oxidation process to crosslink polymer chains of
at least some of the thermoplastic particles 502 and form the
modified thermoplastic powder 504. For example, the thermoplastic
powder 500 may be exposed to an oxygen-containing atmosphere (e.g.,
an air atmosphere) to form the modified thermoplastic particles
506. The number of modified thermoplastic particles 506 and degree
of crosslinking within each of the modified thermoplastic particles
506 may be controlled by the amount of oxygen in the
oxygen-containing atmosphere and the duration of exposure. In some
embodiments, oxidation process is controlled such that each of the
thermoplastic particles 502 is converted to a modified
thermoplastic particle 506, and such that each of the modified
thermoplastic particles 506 exhibits substantially the same degree
of crosslinking as each other of the modified thermoplastic
particles 506. In additional embodiments, the oxidation process may
convert at least a portion of the thermoplastic material of at
least some of the thermoplastic particles 502 into a thermoset
material. For example, the oxidation process may convert the
thermoplastic material proximate surfaces of at least some of the
thermoplastic particles 502 into a thermoset material.
[0033] In further embodiments, a combination of an electron beam
process and an oxidation process may be utilized to crosslink
polymer chains of at least some of the thermoplastic particles 502.
For example, the thermoplastic powder 500 may be exposed to the
electron beam process and then may be exposed to the oxidation
process, or the thermoplastic powder 500 may be exposed to the
oxidation process and then may be exposed to the electron beam
process.
[0034] Referring to FIG. 5C, upon formation, the modified
thermoplastic powder 504 (FIG. 5B) may, optionally, be combined
with at least one additive 510 to form a mixture 512. By way of
non-limiting example, the additive 510 may be at least one of a
filler material, an extender material, a cross-linking agent, a
lubricant, a pigment, a plasticizer, an anti-oxidant, and another
polymeric material. The type and amount of the additive 510 may at
least partially depend on the properties of modified thermoplastic
powder 504, and on desired properties of a thermoplastic structure
to be formed, as described in further detail below. The mixture 512
may be substantially homogeneous (e.g., the modified thermoplastic
particles 506 and the additive 510 may be uniformly dispersed
throughout the mixture 512), or may be heterogeneous (e.g., the
modified thermoplastic particles 506 and the additive 510 may be
non-uniformly dispersed throughout the mixture 512).
[0035] In some embodiments, the at least one additive 510 may
comprise at least one filler material. The filler material may be a
material formulated and configured to enhance at least one property
(e.g., thermal resistance, hardness, tensile strength, tear
strength, abrasion resistance, chemical resistance, extrusion
resistance, elongation, elastic modulus, bulk modulus, etc.) of a
thermoplastic structure to be formed. Suitable fillers materials
include, but are not limited to, carbon fillers (e.g., carbon
black; graphene; carbon fibers, such as carbon nanofibers,
single-walled carbon nanotubes, multi-walled carbon nanotubes;
etc.), polytetrafluoroethene (PTFE) fillers, aromatic polyamide
fillers, slagwool fillers (magnesium calcium aluminum silicates),
cellulose fillers, ZYLON.RTM. fillers, clay fillers, glass fillers,
and silica fillers. The filler material may be provided as at least
one of a plurality of particles and plurality of fibers. Individual
units (e.g., particles, fibers) of the filler material may range
from micro-sized (e.g., having a cross-sectional width or diameter
greater than or equal to about one micrometer) to nano-sized (e.g.,
having a cross-sectional width or diameter less than about one
micrometer, such as less than or equal to about 500 nanometers),
and may each independently have a desired shape (e.g., a spherical,
hexahedral, ellipsoidal, cylindrical, tubular, conical, or
irregular shape). The size and shape of the individual units may
facilitate different properties in the thermoplastic structure to
be formed. For example, nano-sized units (e.g., nanoparticles,
nanofibers, nanotubes, etc.) may facilitate enhanced hardness and
tensile strength in the thermoplastic structure to be formed as
compared to micro-sized units. The individual units of the filler
material may be monodisperse, wherein each of the individual units
has substantially the same material composition, size, and shape,
or may be polydisperse, wherein the individual units include a
range of material compositions, sizes, and/or shapes.
[0036] As a non-limiting example, if combined with the modified
thermoplastic powder 504, the filler material may be provided at a
ratio of within a range from about 0 parts to about 150 parts of
the filler material per 100 parts of modified thermoplastic powder
504, such as from about 0.05 parts to about 5 parts of the filler
material per 100 parts of the modified thermoplastic powder 504,
from about 5 parts to about 25 parts of the filler material per 100
parts of the modified thermoplastic powder 504, from about 25 parts
to about 50 parts of the filler material per 100 parts of the
modified thermoplastic powder 504, from about 50 parts to about 75
parts of the filler material per 100 parts of the modified
thermoplastic powder 504, from about 75 parts to about 100 parts of
the filler material per 100 parts of the modified thermoplastic
powder 504, or from about 100 parts to about 125 parts of the
filler material per 100 parts of modified thermoplastic powder
504.
[0037] In additional embodiments, the at least one additive 510 may
comprise at least one crosslinking agent. The crosslinking agent
may be a material that facilitates or enhances crosslinking of
polymer chains of the modified thermoplastic powder 504, and/or
another polymeric material in at least one subsequent process, as
described in further detail below. The cross-linking agent may, for
example, enhance crosslinking of polymer chains during or after the
formation of a thermoplastic structure, such as during an electron
beam process performed after forming the thermoplastic structure.
The cross-linking agent may effectuate crosslinking upon exposure
to at least one electron beam, or may not effectuate crosslinking
upon exposure to at least one electron beam. The type and amount of
crosslinking agent may at least partially depend on the
thermoplastic powder 500 (e.g., PEK, PEEK, PEKK, PEKEKK, PPS, PPSU,
SRP, PI, PAT, etc.) and other additives (e.g., filler material,
other polymeric material, etc.) utilized, and on the desired
properties of the thermoplastic structure to be formed. A suitable
cross-linking agent may, for example, comprise at least one of an
organic peroxide, an inorganic peroxide, sulfur, diallyl maleate,
triallyl cyanurate, triallyl isocyanurate, n,n'-m-phenylene
bismaleimide, a polyacrylate, a polymethacrylate, a trifunctional
acrylate, a trifunctional methacrylate, pentaerythritol
tetraacrylate, dipentaerythritol pentaacrylate, trimethylolpropane
trimethacrylate, ethylene glycol dimethacrylate, polyethylene
glycol dimethacrylate, allyl methacrylate, a liquid butadiene, and
methacrylated polybutadiene.
[0038] As a non-limiting example, if combined with the modified
thermoplastic powder 504, the crosslinking agent may be provided at
a ratio within a range of from about 0 parts to about 50 parts of
the crosslinking agent per 100 parts of the modified thermoplastic
powder 504, such as from about 0.05 parts to about 5 parts of the
crosslinking agent per 100 parts of the modified thermoplastic
powder 504, from about 5 parts to about 10 parts of the
crosslinking agent per 100 parts of the modified thermoplastic
powder 504, from about 10 parts to about 25 parts of the
crosslinking agent per 100 parts of the modified thermoplastic
powder 504, or from about 25 parts to about 50 parts of the
crosslinking agent per 100 parts of the modified thermoplastic
powder 504.
[0039] In further embodiments, the at least one additive 510 may
comprise at least one other polymeric material. The other polymeric
material may be formulated and configured, to enhance at least one
property (e.g., thermal resistance, hardness, tensile strength,
tear strength, abrasion resistance, chemical resistance, extrusion
resistance, elongation, elastic modulus, bulk modulus, etc.) of a
thermoplastic structure to be formed. The other polymeric material
may, for example, be at least one of another thermoplastic
material, a thermoset material, and an elastomeric material. In
some embodiments, the other polymeric material may be provided as a
powder of polymeric particles. The polymeric particles may range
from micro-sized (e.g., having a cross-sectional width or diameter
greater than or equal to about one micrometer) to nano-sized (e.g.,
having a cross-sectional width or diameter less than about one
micrometer, such as less than or equal to about 500 nanometers),
and may each independently have a desired shape (e.g., a spherical,
hexahedral, ellipsoidal, cylindrical, conical, or irregular shape).
Polymer chains of each of the polymeric particles may be
substantially non-crosslinked, or polymer chains of at least one of
the polymer particles may be crosslinked (e.g., at least one of the
polymer particles may exhibit intra-particle crosslinking). The
polymeric particles may be monodisperse, wherein each of the
polymeric particles has substantially the same material
composition, size, and shape, or may be polydisperse, wherein the
polymeric particles include a range of material compositions,
sizes, and/or shapes. Each of the polymeric particles may be
discrete, or at least two of the polymeric particles may be
agglomerated into at least one larger polymeric structure (e.g., a
polymeric pellet including multiple smaller polymeric
particles).
[0040] As a non-limiting example, if combined with the modified
thermoplastic powder 504, the other polymeric material may be
provided at a ratio within a range of from about 0 parts to about
150 parts of the other polymeric material per 100 parts of the
modified thermoplastic powder 504, such as from about 0.05 parts to
about 25 parts of other the polymeric material per 100 parts of the
modified thermoplastic powder 504, from about 25 parts to about 50
parts of the other polymeric material per 100 parts of the modified
thermoplastic powder 504, from about 50 parts to about 75 parts of
the other polymeric material per 100 parts of the modified
thermoplastic powder 504, from about 75 parts to about 100 parts of
the other polymeric material per 100 parts of the modified
thermoplastic powder 504, or from about 100 parts to about 125
parts of the other polymeric material per 100 parts of the modified
thermoplastic powder 504.
[0041] Referring to FIG. 5D, the modified thermoplastic powder 504
(FIG. 5B), or the mixture 512 (FIG. 5C), may be formed into a
thermoplastic structure 514 for use in down-hole applications. The
thermoplastic structure 514 may comprise a bulk structure, or may
comprise a film (e.g., layer, coating) at least partially coating
another structure. For example, a volume of the modified
thermoplastic powder 504 (or the mixture 512) may be subjected to a
conventional molding process (e.g., an injection molding process, a
compression molding process, a transfer molding process, etc.) to
form the thermoplastic structure 514 to comprise a bulk structure
of a desired shape and size. As another example, the modified
thermoplastic powder 504 (or the mixture 512) may be subjected to a
conventional deposition process (e.g., a flame spray process) to
form the thermoplastic structure 514 to comprise a film of desired
dimensions (e.g., length, width, thickness) on or over another
structure. While FIG. 5D depicts the thermoplastic structure 514 as
a tubular structure, the thermoplastic structure 514 may exhibit a
different structural configuration (e.g., shape and size). The
thermoplastic structure 514 may, for example, exhibit a conical
shape, a pyramidal shape, a cubic shape, a cuboidal shape, a
spherical shape, a hemispherical shape, a cylindrical shape, a
semicylindrical shape, truncated versions thereof, or an irregular
shape. Irregular three-dimensional shapes include complex shapes,
such as shapes associated with down-hole structures and devices
(e.g., tools). The modified thermoplastic powder 504 (and/or the
other polymeric material, if present) may undergo at least some
crosslinking during the formation of the thermoplastic structure
514 (e.g., crosslinking facilitated through a crosslinking agent
combined with the modified thermoplastic powder 504 or the other
polymeric material). The thermoplastic structure 514 may exhibit
substantially uniform properties (e.g., thermal resistance,
hardness, elastic modulus, bulk modulus, toughness, chemical
resistance, abrasion resistance, friction coefficient, mechanical
strength, and other characteristics) throughout a thickness T.sub.2
thereof.
[0042] Following formation, the thermoplastic structure 514, may,
optionally, be subjected to an electron beam process. The electron
beam process may be substantially similar to that previously
described in relation to FIG. 3B. The electron beam process may
enhance properties (e.g., thermal resistance, hardness, elastic
modulus, bulk modulus, toughness, chemical resistance, abrasion
resistance, friction coefficient, mechanical strength, and other
characteristics) of at least a portion of the thermoplastic
structure 514. In additional embodiments, such as in embodiments
where the thermoplastic structure 514 already exhibits desired
properties as a result of previous processing (e.g., processing
prior to or during the formation of the thermoplastic structure
302, such as from subjecting the thermoplastic powder 500 to the
electron beam process previously described with reference to FIG.
5B), the electron beam process may be omitted.
[0043] The methods of the disclosure facilitate the formation of
modified thermoplastic structures exhibiting enhanced properties
(e.g., enhanced mechanical strength, wear resistance, thermal
resistance, chemical resistance, etc.) enabling the modified
thermoplastic structures to withstand the aggressive environmental
conditions (e.g., abrasive materials, corrosive chemicals, high
temperatures, high pressures, etc.) frequently experienced in
down-hole applications (e.g., drilling applications, conditioning
applications, logging applications, measurement applications,
monitoring applications, etc.) better than many structures
conventionally utilized. Accordingly, the modified thermoplastic
structures formed by the methods of the disclosure may exhibit a
relatively prolonged operational life, which may reduce costs and
increase the efficiency of down-hole applications.
[0044] While the disclosure is susceptible to various modifications
and alternative forms, specific embodiments have been shown by way
of example in the drawings and have been described in detail
herein. However, the disclosure is not intended to be limited to
the particular forms disclosed. Rather, the disclosure is to cover
all modifications, equivalents, and alternatives falling within the
scope of the disclosure as defined by the following appended claims
and their legal equivalents.
* * * * *