Note: Descriptions are shown in the official language in which they were submitted.
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COLLAR SWAGING OF SINGLE-PIECE CENTRALIZERS
Cross-Reference to Related Applications
[0001] This application claims priority to U.S. Provisional Patent Application
having Serial No.
61/989,699, which was filed on May 7, 2014. This application also claims
priority to U.S.
Provisional Patent Application having Serial No. 62/012,129, which was filed
on June 13, 2014.
The entirety of these provisional applications is incorporated herein by
reference.
Background
[0002] A centralizer may be installed on a tubular (e.g., a drill string or
casing string) in an
oilfield context, to provide an annular standoff between the tubular and a
surrounding tubular
(e.g., a wellbore wall). The centralizers may provide this standoff using
blades or ribs that
extend radially-outward from the tubular and axially between two end collars.
One type of
centralizer employs flexible, bow-shaped ribs or "bow springs," which
resiliently engage the
surrounding tubular. Such bow-spring centralizers may be capable of providing
a standoff across
a range of diameters in the wellbore, and may collapse radially to pass
through restrictions or
obstructions (i.e., areas of reduced diameter in the wellbore). Other types of
centralizers may use
rigid or semi-rigid ribs, or may define shapes that are not bowed.
[0003] Centralizers may be formed using a variety of manufacturing processes.
For example,
the end collars of the centralizers may be formed from rolled sheet metal. The
rolled sheet metal
may, for example, form the end collars, and strips of metal may be attached to
the end collars to
form the ribs. Another way to manufacturer the centralizers is a "one-piece"
process, which may
start with a sheet or a segment of pipe. When starting with a sheet, the sheet
may be cut to
length, and material may be cut away from sheet to yield the appropriate
geometries for the end
collars and ribs. Before or after such cutting, the sheet may be rolled and
seam welded. The
process for forming from a segment of pipe may involve cutting the material
from the pipe to
result in the appropriate geometries. In either case, portions of the
centralizer may be heat-
treated, etc. to yield the desired characteristics.
[0004] One-piece centralizer manufacturing processes may reduce the number of
steps needed to
form the centralizer; however, a challenge in the one-piece centralizer
manufacturing processes
is seen in the tolerance requirements of the pipe from which the centralizer
is made and the
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tubular (e.g., drill string or casing string) over which the centralizer is
installed. In particular,
sizing the inner diameter of the centralizer such that it may slide over the
tubular during
installation without binding, while minimizing the total outer diameter of the
finished assembly,
may be a challenge in view of such tolerances.
[0005] Accordingly, the rolled, one-piece embodiment may be more readily
implemented, since
it allows for custom sizing of the sheet, whereas the pipe may come in
standard sizes, subject to
relatively wide tolerances. On the other hand, the rolling process may be more
expensive and
may exhibit wide variations in wall thickness, whereas beginning with already-
formed pipe may
obviate some of these challenges.
Summary
[0006] Embodiments of the present disclosure may provide a method for
manufacturing a
centralizer. The method may include selecting a tubular having a first inner
diameter. The
tubular may be cut to form a blank including at least one end collar and ribs
integrally-formed
therewith. The at least one end collar may be swaged such that the first inner
diameter is
modified to a second inner diameter.
[0007] Embodiments of the present disclosure may also provide a centralizer.
The centralizer
may include a rolled tubular having a seam. At least one rib may be formed in
the rolled tubular.
At least one end collar may also be formed in the rolled tubular. The at least
one end collar has a
first inner diameter prior to a swaging process and a second inner diameter
after the swaging
process.
[0008] Embodiments of the present disclosure may further provide a swaging
device for a
centralizer. The swaging device may include a body having a tapered surface
and a plurality of
dies. The dies may include a reverse-tapered surface that is reverse tapered
with respect to the
tapered surface of the body. The dies may also include an engagement surface
that is opposite to
the reverse-tapered surface. The body is configured to slide relative to the
plurality of dies so as
to swage an end collar of the centralizer.
[0009] It is to be understood that both the foregoing general description and
the following
detailed description are exemplary and explanatory only and are not
restrictive of the present
teachings, as claimed.
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Brief Description of the Drawings
[0010] The accompanying drawing, which is incorporated in and constitutes a
part of this
specification, illustrates an embodiment of the present teachings and together
with the
description, serves to explain the principles of the present teachings. In the
figures:
[0011] Figure 1 illustrates a perspective view of a forming blank, according
to an embodiment.
[0012] Figure 2 illustrates a perspective view of a portion of the forming
blank, depicting an end
collar of the forming blank undergoing a diameter-reducing swaging process,
according to an
embodiment.
[0013] Figure 3 illustrates a side, cross-sectional view of the portion of the
forming blank of
Figure 2.
[0014] Figure 4 illustrates a perspective view of a portion of the forming
blank, depicting the end
collar thereof undergoing a diameter-increasing swaging process, according to
an embodiment.
[0015] Figure 5 illustrates a side, cross-sectional view of the portion of the
forming blank of
Figure 4.
[0016] Figure 6 illustrates a side, cross-sectional view of a portion of the
forming blank
undergoing another embodiment of the diameter-increasing swaging process.
[0017] Figure 7 illustrates a side, cross-sectional view of a portion of the
forming blank
undergoing another embodiment of the diameter-reducing swaging process.
[0018] Figure 8 illustrates a flowchart of a method for manufacturing a
centralizer, according to
an embodiment.
[0019] Figure 9 illustrates a perspective view of a centralizer, according to
an embodiment.
[0020] Figure 10 illustrates a side, cross-sectional view of a swaging
assembly for a centralizer,
according to an embodiment.
[0021] Figure 11A illustrates a side, cross-sectional view of another
embodiment of the swaging
assembly.
[0022] Figure 11B illustrates a perspective view of a roller die of the
swaging assembly of
Figure 11A.
[0023] Figure 12 illustrates a side, cross-sectional view of yet another
embodiment of the
swaging assembly.
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[0024] Figure 13 illustrates a conceptual view of a mobile unit including the
swaging assembly,
according to an embodiment.
[0025] Figure 14 illustrates a flowchart of a method for providing a
centralizer at a wellsite,
according to an embodiment
[0026] It should be noted that some details of the figure have been simplified
and are drawn to
facilitate understanding of the embodiments rather than to maintain strict
structural accuracy,
detail, and scale.
Detailed Description
[0027] Reference will now be made in detail to embodiments of the present
teachings, examples
of which are illustrated in the accompanying drawing. In the drawings, like
reference numerals
have been used throughout to designate identical elements, where convenient.
In the following
description, reference is made to the accompanying drawing that forms a part
thereof, and in
which is shown by way of illustration a specific exemplary embodiment in which
the present
teachings may be practiced. The following description is, therefore, merely
exemplary.
[0028] Notwithstanding that the numerical ranges and parameters setting forth
the broad scope
of the disclosure are approximations, the numerical values set forth in the
specific examples are
reported as precisely as possible. Any numerical value, however, inherently
contains certain
errors necessarily resulting from the standard deviation found in their
respective testing
measurements. Moreover, all ranges disclosed herein are to be understood to
encompass any and
all sub-ranges subsumed therein.
[0029] Figure 1 illustrates a perspective view of a forming blank 100, which
may be formed into
a centralizer, according to an embodiment. It will be appreciated that, in at
least one
embodiment, the forming blank 100 may not require further operations to be
performed thereon
to result in the centralizer; that is, the forming blank 100 itself may be a
centralizer, e.g., for
relatively small clearance applications.
[0030] The forming blank 100 may be formed from a segment of a tubular, such
as casing pipe,
drill pipe, etc. The tubular for the forming blank may be fabricated in any
suitable manner, such
as roll forming and seam welding in a pipe production facility or mill. The
tubular may be
selected based on its inner diameter being near (e.g., nearest of a set of
available stock sizes) to a
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target inner diameter, as will be discussed in greater detail below. Further,
the forming blank
100 may include cut-out windows 102, which may represent areas of the tubular
that have been
removed via a cutting process applied to the segment of tubing. The cut-out
windows 102 may
be cut using water-jet cutting, laser cutting, milling, or any other suitable
process. Further, the
cut-out windows 102 may be positioned so as to define end collars 104, 106 and
ribs 108
extending axially-between the end collars 104, 106. Accordingly, the cut-out
windows 102 may
be generally elongated rectangular shapes, leaving sections defining the two,
axially-offset end
collars 104, 106 and the relatively thin ribs 108 extending axially-
therebetween. Moreover, any
number of cut-out windows 102 may be created, e.g., according to the desired
number of ribs
108. Further, the cut-out windows 102 (and thus the ribs 108) may be defined
at generally
uniform angular intervals and sizes, but, in other cases, may be non-uniform
in terms of location,
size, etc. The ribs 108 may be heat-treated, expanded, and/or otherwise formed
to provide an
appropriate shape and resiliency (e.g., to provide bow-springs), but in other
embodiments may be
rigid, semi-rigid, etc. Examples of a one-piece centralizer may be found in
U.S. Patent No.
7,845,061 and U.S. Patent Publication No. 2014/0096888, the contents of which
are incorporated
herein.
[0031] Figure 2 illustrates a perspective view of a portion of the forming
blank 100, showing the
end collar 104 undergoing a diameter-reducing swaging process, according to an
embodiment.
The end collar 106 may be generally similar to the end collar 104, and similar
processes, as will
be described below, may be applied thereto. Accordingly, a duplicative
description of the
structure and formation of the end collar 106 is omitted. With continuing
reference to Figure 2,
Figure 3 illustrates a side, cross-sectional view of the portion of the
forming blank 100 shown in
Figure 2, according to an embodiment.
[0032] In some cases, the tubular from which the forming blank 100 is cut may
have an inner
diameter ID that is larger than a target inner diameter. Thus, the end collar
104 may also have
the inner diameter ID larger than a target inner diameter, and a swaging
process may be applied
to reduce the inner diameter ID to a predefined tolerance of the target inner
diameter.
[0033] Briefly, swaging is a process by which the dimensions of a part are
altered by forcing the
part into a set of forming dies, or (additionally) by progressively engaging
rolling dies with the
part to form it into a new shape. Die swaging, for example, may be performed
using a crimping
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die set 114, which may include arcuate die segments 116 that are arranged
around the outer
diameter surface 112 of the end collar 104. The die segments 116 may be forced
radially-
inwards (compressed), as indicated by arrows 118, to reduce the outer diameter
OD (and the
inner diameter ID) of the end collar 104 to the desired size or range of
sizes.
[0034] The axial length of one, some, or all of the die segments 116 may be
smaller, equal to, or
larger than the axial length of the end collar 104. For illustrative purposes
only, the die set 114 is
illustrated as being slightly larger in axial dimension than the end collar
104. In some
embodiments, the diameter-reducing swaging process may affect the shape of the
ribs 108
proximal to the end collar 104, since the ribs 108 may be integrally-formed
with the end collar
104. This change in the shape of the ribs 108 may be mitigated or removed
during subsequent
working or treating of the ribs 108, but in other embodiments, it may be
ignored.
[0035] The extent to which the inner diameter ID and/or outer diameter OD may
be decreased
may depend at least partially on the strain capacity of the material and the
desired final structural
properties of the centralizer. To name a specific example, thin-walled tubes
made from steel
with elongations of 10% or more may be decreased by 10% of their diameter or
more, which
may be an amount that bridges the range between standard mill size tubulars
and standard
centralizer sizes. Moreover, the arcuate die segments 116 may be forced
radially-inwards using
any suitable device, such as, to name just a few examples, a crimping device,
clamp, hydraulics,
or by moving a tapered sleeve across the radial die set 114.
[0036] Figure 4 illustrates another perspective view of a portion of the
forming blank 100,
depicting the end collar 104 undergoing a diameter-increasing swaging process,
according to an
embodiment. Figure 5 illustrates a side, cross-sectional view of the portion
of the forming blank
100 shown in Figure 4, according to an embodiment. Referring to Figures 4 and
5, the inner
diameter ID (and/or the outer diameter OD) of the end collar 104 may be
expanded to achieve a
target size and/or tolerance.
[0037] In an embodiment, a set of expandable dies 117 may be employed. The set
of expandable
dies 117 may include a plurality of arcuate die segments 119. Outer surfaces
120 of the die
segments 119 may be configured to engage the inner diameter surface 110 of the
end collar 104
and expand, as indicated by arrows 122, so as to increase the inner diameter
ID of the end collar
104. For example, a tapered body may be progressively received through the set
of expandable
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dies 117, thereby forcing the individual die segments 119 radially-outwards.
In various
embodiments, the arcuate die segments 119 may have an axial dimension that is
shorter, equal to,
or longer than the axial dimension of the end collar 104. The illustrated
embodiment of Figure 5,
with the axial dimension of the die segments 119 being greater than the axial
dimension of the
end collar 104, is thus merely one example among several contemplated. As with
the diameter-
reducing swaging process, the diameter-increasing swaging process may alter
the geometry of
the ribs 108 proximal to the end collar 104, since the ribs 108 are connected
thereto (e.g.,
integrally formed therewith). Such alterations may be mitigated or removed
during subsequent
working or treatment of the ribs 108 or, in some embodiments, may be
acceptable in the
centralizer.
[0038] As with the diameter-reducing swaging operation discussed above, the
extent to which
the inner diameter ID may be increased may depend at least partially on the
strain capacity of the
material and the desired final structural properties of the centralizer. To
name a specific
example, thin-walled tubes made from steel with elongations of 10% or more may
be increased
by 10% of their diameter or more, which may be an amount that bridges the
range between
standard mill size tubular goods and standard centralizer sizes.
[0039] Instead of, or in addition to, using the set of expandable dies 117 to
expand the end collar
104, the diameter-increasing swaging process may include roller forming. In
this process, a
series of tapered rollers may be rotated inside the tube, and a tapered body
may be pulled against
the rollers, forcing them gradually outwards. A similar process may also be
employed as a
diameter-reducing swaging process. Roller forming may be a relatively gentle
swaging process,
compared with die swaging, and may deliver precise inner diameter ID
tolerances, circularity,
and a good surface finish; accordingly, this process may be used as a second
swaging process, so
as to finish the end collar 104, or may be used in lieu of the die-swaging
process.
[0040] Figure 6 illustrates a schematic, side, cross-sectional view of the end
collar 104 and a
portion of the ribs 108 of the forming blank 100 undergoing another diameter-
increasing
swaging process, according to an embodiment. In this embodiment, a die 202
with a tapered
outer diameter surface 204 may be employed. The die 202 may be formed from a
single piece,
or may include several segments that are connected together, either movably or
not. The die 202
may be received into the end collar 104 and may be pulled therethrough, or the
forming blank
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100 may be pushed or pulled across the die 202, or both, such that the die 202
is drawn through
the end collar 104. The die 202 may have a maximum outer diameter that exceeds
the inner
diameter ID of the un-swaged end collar 104, and thus moving (pulling,
pushing, etc.) the die
202 through the end collar 104 may cause the end collar 104 (e.g., at least
the inner diameter ID
thereof) to expand.
[0041] Similarly, Figure 7 illustrates a schematic, side, cross-sectional view
of the end collar 104
and a portion of the ribs 108 of the forming blank 100, undergoing another
diameter-decreasing
swaging process, according to an embodiment. In this embodiment, a die 300
with a tapered
inner diameter surface 302 may be employed. The die 300 may be a single-piece,
but in other
embodiments, may include two or more pieces, which may be movably secured
together or fixed
together. The end collar 104 may be received into the die 300, e.g., pulled or
pushed
therethrough, or the end collar 104 may be held stationary as the die 300 is
pushed or pulled
therethrough. The die 300 may thus be drawn across the end collar 104. The
minimum inner
diameter defined by the tapered inner diameter surface 302 may be less than
the outer diameter
OD of the end collar 104, and thus the end collar 104 may be reduced in outer
diameter OD and,
in at least some embodiments, in inner diameter ID, by the end collar 104
passing over the end
collar 104. The tapered inner diameter surface 302 may be conical in profile,
curved, etc.
Moreover, in an embodiment, the die 300 may include or be replaced with
rollers, hydraulics,
pneumatics, may include multiple pieces fixedly or movably secured together,
etc.
[0042] The swaging processes, whether diameter-increasing or diameter-
reducing, may be
performed as cold-forming processes, or may be practiced on hot material
(e.g., one or more
steel alloys). Swaging the hot material may lower the forces required, but may
also reduce the
accuracy of the final ID tolerance as the material (e.g., steel) cools and
transforms its
microstructure. Additionally, the swaging processes may use hydraulic dies or
any other tools
suitable for increasing or decreasing the diameter of the end collar 104.
[0043] Figure 8 illustrates a flowchart of a method 400 for manufacturing a
single-piece
centralizer, according to an embodiment. The method 400 may include selecting
a tubular, e.g.,
of a standard size from a mill, having an inner diameter ID, an outer diameter
OD, or both that
are near to, but outside of a determined, acceptable tolerance of a determined
target inner
diameter or outer diameter, as at 402. In an embodiment, the tubular may be a
heat-treatable
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alloy steel tube of the nearest mill size to (e.g., under or over) the desired
inner diameter ID of
the finished centralizer. Example casing sizes over which the centralizer may
be installed and/or
fabricated from range from about 4 1/2" to about 13 5/8".
[0044] The method 400 may then include cutting the tubular to a specified
axial length, as at
404. Before, after, or while cutting the tubular to the specified axial length
at 404, the method
400 may also include cutting windows 102 out of the tubular, thereby defining
ribs 108
circumferentially between the windows 102, and end collars 104, 106 on
opposite axial ends of
the windows 102 and ribs 108, as at 406. Such cutting may be accomplished
using a variety of
machines configured to cut cylindrical structures, e.g., by water-jet cutting,
laser cutting, milling,
etc. It will be appreciated that two or more such machines may be employed,
e.g., one to cut the
tubular to the axial length at 404 and one to cut out the windows 102 at 406,
and in other cases, a
single machine may perform both operations.
[0045] The cutting operations may yield a starting or "forming" blank 100 with
continuous
sections at either end (the end collars 104, 106) connected by ribs 108, which
may, in some
embodiments, be formed into a bowed, spring profile. The method 400 may then
proceed to
swaging the end collars 104, 106 of the blank 100, as at 408. When starting
with a tubular with
an inner diameter ID smaller than the desired final collar inner diameter ID,
the two end collars
104, 106 may be expanded (e.g., using a die or rollers as part of the swaging
operation). When
starting with a tubular with an inner diameter that is larger than the desired
final collar outer
diameter OD, the end collar 104, 106 may be compressed (e.g., using a die or
rollers as part of a
swaging operation).
[0046] In addition to changing the inner and/or outer diameter ID, OD, the
swaging process may
also reduce ellipticity (i.e., make more circular or "circularize") in the end
collars 104, 106.
Accordingly, the shape of starting tubulars that have a slight ovality may be
corrected in the
swaging operation, at the same time the inner diameter ID thereof is being
adjusted. Further, in
some embodiments, one or both of the end collars 104, 106 may include a peak,
e.g., along the
seam where the tubular is welded together. The swaging process may be employed
to remove
this peak, while also increasing or decreasing the diameter, and increasing
the circularity of the
end collar 104.
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[0047] Figure 9 illustrates a perspective view of a centralizer 500, according
to an embodiment.
The centralizer 500 may be formed as a single piece (e.g., from a sheet of
metal that is rolled and
welded along a seam 502). The rolling and/or welding may be conducted at a
pipe mill (e.g., to
standard size and tolerance specifications). The centralizer 500 may have one
or more first
windows 504 cut (or otherwise formed or defined) therein, which are spaced
apart
circumferentially so as to define ribs 506 therebetween. The first windows 504
may be
rectangular, ovular, or any other suitable shape. Further, the first windows
504 may generally be
centered at the axial center of the centralizer 500, and may have an axial
dimension that is
shorter than the overall axial dimension of the centralizer 500. Accordingly,
the centralizer 500
may include one or more end collars 508, 510 at either or both axial ends of
the centralizer 500,
with the ribs 506 and the first windows 504 extending therebetween.
[0048] The ribs 506 may be integrally-formed with the end collars 508, 510.
Further, the ribs
506 may be radially-extended and/or heat-treated (e.g., to provide resilient
bow-springs). In
other embodiments, the ribs 506 may be otherwise shaped and/or formed as rigid
or semi-rigid
ribs or blades.
[0049] One or more second windows 512 may optionally be cut from (or otherwise
formed or
defined in) the centralizer 500, e.g., in the end collars 508, 510. The second
windows 512 may
be spaced circumferentially apart, defining axial bridges 513 therebetween,
which may maintain
the integrity of the end collars 508, 510. Further, the second windows 512 may
be sized and
configured to engage a stop-feature 514 coupled with a tubular (e.g., casing
or drill pipe) 516 on
which the centralizer 500 may be installed. In a specific embodiment, the stop-
feature 514 may
be a spray-deposited metal, such as WEARSOX (commercially-available from
Antelope Oil
Tool & Mfg. Co., LLC). In other embodiments, the stop-feature 514 may be any
structure that is
welded, adhered, fastened, or otherwise attached to the tubular 516. In still
other embodiments,
the stop-feature 514 may be integrally-formed with the tubular 516. Further,
the stop-features
514 may have an axial length that is less than an axial length of the second
windows 512, thereby
providing an axial range of motion for the end collars 508, 510, e.g.,
allowing the ribs 506, in a
bow-spring embodiment, to flex.
[0050] The end collars 508, 510 may have an inner diameter ID and an outer
diameter OD. As
described above with respect to the forming blank 100 of Figures 1-7, the
inner and/or outer
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diameters may be larger or smaller than desired. For example, it may be
advantageous for the
end collars 508, 510 to have an inner diameter ID that is slightly larger than
the outer diameter
OD of the tubular 516 around which the centralizer 500 is to be installed.
Accordingly, and as
also discussed above with respect to the end collars 104, 106, the end collars
508, 510 may be
swaged, either to increase or decrease the inner and/or outer diameter
thereof, to thereby modify
the inner and/or outer diameter to a target dimension within a target
tolerance.
[0051] The first and second windows 504, 512 may be formed in the centralizer
500 at the same
time or at different times, using the same or different machines, processes,
etc. Further, the first
and/or second windows 504, 512 may be formed before or after welding the sheet
of metal
together to form the seam 502 and/or before or after swaging one or both of
the end collars 508,
510.
[0052] Accordingly, it will be seen that a single-piece centralizer with a
precise inner diameter
ID and circularity tolerance may be formed from an inexpensive, high-volume
starting tubular
stock of arbitrary intermediate diameter near, but outside of a tolerance for,
the desired final
product dimensions and tolerances. This may obviate the process of rolling
individual tube
sections or accounting for variable-wall thickness tolerances of seamless
tubulars as the starting
point for the production process.
[0053] Figure 10 illustrates a side, cross-sectional view of a swaging device
1000, according to
an embodiment, which may be employed for swaging end collars 1002, 1004 of a
centralizer
1006. The centralizer 1006 may be formed and/or otherwise share a similar
structure as an
embodiment of the centralizer 100 or 500. Accordingly, ribs 1008 may extend
between the end
collars 1002, 1004.
[0054] The swaging device 1000 may include a plurality of dies 1010, which may
be arcuate
segments that are disposed circumferentially-around a central axis 1012 (e.g.,
as described above
with reference to the arcuate die segments 119 shown in Figure 4). Any number
of dies 1010
may be employed. Further, the dies 1010 may be held together using one or more
elastic bands
(two shown: 1014, 1016), which may be disposed in one or more grooves (two
shown: 1018,
1020). In a specific embodiment, the elastic bands 1014, 1016 may be 0-rings;
however, in
other embodiments, other types of elastic bands or springs may be employed.
Moreover, in some
cases, the elastic bands 1014, 1016 may not be disposed in a groove, but may
ride freely on an
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outer surface 1021 of the dies 1010 or may be otherwise positionally-
constrained with respect
thereto. Further, in some cases, the bands 1014, 1016 may be segmented, with
each segment
extending between two of the dies 1010, either along the outer surface 1021 of
the dies 1010, or
at a radial position inwards therefrom.
[0055] The dies 1010 may be received within the end collar 1002 of the
centralizer 1006, such
that the outer surfaces 1021 of the dies 1010 are generally at about the same
distance from the
central axis 1012 as the inner surface of the end collar 1002 (i.e., the outer
surface 1021 of the
dies 1010 touches the end collar 1002, or nearly does). In some embodiments,
however, the dies
1010 may be substantially smaller than the end collar 1002 and spaced radially-
apart therefrom,
at least initially. In either example, the outer surface 1021 may be
configured to bear upon the
end collar 1002 and may thus be considered to provide an engagement surface of
the dies 1010.
[0056] The swaging device 1000 may also include a body 1022 and a shaft 1024.
The body
1022 may be a mandrel, which may be coupled with the shaft 1024 (e.g., by
meshing threads
1026, 1028 thereof, respectively, as shown). In other embodiments, any
connection capable of
providing a least a linear transmission of force along the central axis 1012
in at least one of a
first axial direction Di and a second axial direction D2, from the shaft 1024
to the body 1022,
may be employed.
[0057] Further, the body 1022 may have a tapered outer surface 1030, which may
be configured
to slide along a reverse-tapered inner surface 1032 of the dies 1010. The
reverse-tapered inner
surface 1032 of the dies 1010 may be defined radially-opposite to the outer,
engaging surface
1021 thereof. Further, the tapered outer surface 1030 may be tapered (e.g.,
angled with respect
to the central axis 1012) by a taper angle a ranging from about 10, about 2 ,
about 30, about 40
,
or about 50 to about 20 , about 15 , about 10 , or about 70
.
[0058] The swaging device 1000 may also include a driver 1034, which may be a
hydraulic,
pneumatic, magnetic, mechanical, or any other type of driver 1034.
Accordingly, one or more
power sources (e.g., gas, electric, hydraulic, pneumatic) may be provided, to
operate the driver
1034. Further, the driver 1034 may be configured to move the shaft 1024 and
thus the body
1022 linearly. Moreover, the driver 1034 may be configured to support a weight
of the swaging
device 1000 against a support surface. For example, the central axis 1012 may
extend vertically,
or at an acute angle to vertical, such that the body 1022 is above the driver
1034.
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[0059] In some embodiments, a retaining plate 1031 may be provided to restrain
the position of
the dies 1010 and/or the centralizer 1006. For example, the retaining plate
1031 may be disposed
between the driver 1034 and the body 1022, with the shaft 1024 extending
movably
therethrough.
[0060] In operation, according to an example, the centralizer 1006 may be
loaded onto the
swaging device 1000, e.g., with the end collar 1002 abutting the retaining
plate 1031. The driver
1034 may then be energized, so as to move the shaft 1024 linearly in the first
axial direction Di.
Moving the shaft 1024 may also move the body 1022. The dies 1010 may be
restrained from
moving by engagement with the retaining plate 1031. Accordingly, the body 1022
may move in
the first axial direction Di with respect to the dies 1010, and thus the
tapered outer surface 1030
may slide relative to the reverse-tapered inner surface 1032. In this way, the
dies 1010 may be
forced to expand radially-outward, proportional to the distance moved by the
body 1022 and the
taper angle a. When the body 1022 is moved in the second direction D2 (e.g.,
away from the
driver 1034, as shown), the body 1022 may allow the dies 1010 to move radially-
inward, e.g., by
the elasticity of the bands 1014, 1016.
[0061] Driving the dies 1010 outwards may cause the end collar 1002 to be
expanded and thus
plastically deformed outwardly. Accordingly, the end collar 1002 may begin at
a first diameter,
which may be expanded to a second, target diameter by the dies 1010. Further,
the second,
target diameter may be within a target tolerance, and may have a target
cylindricity. Moreover,
the expansion (e.g., deformation) may be controlled in a number of ways, for
example, by
varying the size of the retaining plate 1031 so as to control the stroke of
the body 1022, by
determining a force necessary to move the body 1022 by a certain amount and
limiting the force
applied to the body 1022 to that amount, by providing a stop block for the
shaft 1024 movement,
or in any other manner. Additionally, the end collar 1002 may retain some
amount of elasticity
during the radially-outward deformation. Accordingly, the body 1022 may be
moved
sufficiently to account for the end collar 1002 springing back after the dies
1010 are disengaged
therefrom.
[0062] Once the end collar 1002 is expanded, the driver 1034 may reverse the
direction of the
force on the shaft 1024, and may drive the body 1022 in the second axial
direction D2, allowing
the dies 1010 to move radially-inwards. The centralizer 1006 may then be
removed from the
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swaging device 1000. Then, the other end collar 1004 may be swaged, or another
centralizer
1006 may be loaded onto the swaging device 1000.
[0063] Figure 11A illustrates a side, cross-sectional view of another
embodiment of the swaging
device 1000. Figure 11B illustrates a perspective view of a roller body 1100
for use with the
swaging device 1000 of Figure 11A. As shown, the roller body 1100 may be
tapered, similar to
the body 1022 (Figure 10), but may also include a plurality of rollers 1102
which may be
disposed in cutouts 1104 defined in an outer surface 1106 of the roller body
1100. Although four
rollers 1102 and four cutouts 1104 are shown, it will be appreciated that any
number of rollers
1102 and cutouts 1104 may be employed. Further, in some embodiments, the
rollers 1102 may
extend along an entirety of the roller body 1100, e.g. between a first axial
end 1108 and a second
axial end 1110 of the roller body 1100, but in other embodiments, may be
spaced apart from the
axial ends 1108, 1110 (e.g., by retaining walls configured to maintain or
assist in maintaining the
position of the rollers 1102).
[0064] In some embodiments, the cutouts 1104 may have a generally uniform
depth (e.g., the
distance from the outer surface 1106 to the bottom of the cutouts 1104).
Moreover, the rollers
1102 may be generally cylindrical, and thus the tapering of the outer surface
1106 may result in
the rollers 1102 being oriented at the taper angle a. In some embodiments, the
rollers 1102 may
be tapered, rather than cylindrical. Further, the rollers 1102 may be
restrained in the cutouts
1104 by shafts or any other suitable connectors that may allow the rollers
1102 to roll with
respect to the outer surface 1106 of the roller body 1100. In other
embodiments, the rollers 1102
may be or include one or more (e.g., rows of) spherical rolling elements
disposed in the cutouts
1104.
[0065] Referring specifically to Figure 11A, the roller body 1100 may be
coupled with the driver
1034 via the shaft 1024. The shaft 1024 may be coupled with the roller body
1100 such that
linear and torque (rotational) forces may be applied to the roller body 1100
via the shaft 1024.
The retaining plate 1031 may remain stationary, and may serve to restrain the
position, axially
and/or rotationally, of the dies 1010. The roller body 1100 may be received
within the dies 1010,
and the end collar 1002 received therearound (e.g., as discussed above with
respect to the body
1022).
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[0066] In operation, in addition to being moved along the central axis 1012,
the driver 1034 may
rotate the shaft 1024, and thus the body 1022, about the central axis 1012.
This may cause the
rollers 1102 to roll against the dies 1010 as the body 1022 moves, which may
reduce friction
forces, and thus reduce loading forces that may be required to expand the end
collar 1002 of the
centralizer 1006. Although described above and illustrated as employing the
dies 1010, it will be
appreciated that, in some cases, the roller body 1100 may bear directly on the
end collar 1002,
with the dies 1010 being omitted.
[0067] Figure 12 illustrates a partial cross-section of another embodiment of
the swaging device
1000. In this embodiment, the swaging device 1000 includes an outer body 1200,
which may be
generally annular and received around the end collar 1002 of the centralizer
1006. The swaging
device 1000 of Figure 12 may also include an outer die 1202, which may include
a plurality of
arcuate segments. The outer body 1200 may include a tapered inner surface
1204, and the outer
dies 1202 may include a reverse-tapered outer surface 1206. The inner and
outer surfaces 1204,
1206 may engage one another, such that movement of the outer body 1200 in the
first axial
direction may cause the outer dies 1202 to be driven radially-inwards.
[0068] The outer body 1200 may be coupled with the driver 1034 via an elongate
member 1208.
The elongate member 1208 may, for example, be a cable, with the driver 1034
including a reel to
take up the cable. In another embodiment, the elongate member 1208 may be or
include a
hydraulic arm, which may be extended or retracted by energizing the driver
1034. In another
embodiment, the elongate member 1208 may be at least partially threaded, and
the driver 1034
may include a screw or pinion, so as to linearly translate the elongate member
1208.
[0069] In operation, the end collar 1002 may be loaded into the swaging device
1000, with the
end collar 1002 disposed radially-within the outer dies 1202 and the outer
body 1200. The body
1200 may then be driven (e.g., pushed and/or pulled) in the first direction Di
(e.g., toward the
driver 1034 in the illustrated embodiment), such that the tapered inner
surface 1204 slides
against the reverse-tapered outer surface 1206 of the dies 1202, thereby
driving the dies 1202
inward, so as to reduce the diameter of the end collar 1002 to a target
diameter, tolerance,
cylindricity, etc. Once the dies 1202 have reached the prescribed position,
the driver 1034 may
reverse or, at least, remove the force on the outer body 1200, allowing the
swaged, larger end
collar 1003 to be removed from the swaging device 1000.
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[0070] Figure 13 illustrates a conceptual view of a mobile swaging unit 1300,
according to an
embodiment, including one or more embodiments of the swaging device 1000. The
mobile
swaging unit 1300 may be a truck, as illustrated, such as a flat-bed truck. In
other embodiments,
however, other types of vehicles may be used. Further, the mobile swaging unit
1300 may be
deployed to or proximal to a wellsite, which may include casing-running and/or
drilling
equipment with which the centralizer 1006 may be employed and deployed into a
wellbore at the
wellsite.
[0071] The mobile swaging unit 1300 may, in some embodiments, include a
hoisting device
1302, such as a crane. The hoisting device 1302 is merely optional however,
and may be
employed, for example, when relatively large-diameter, or otherwise heavy,
centralizers 1006 are
to be swaged. For many sizes of centralizers 1006, however, one or two human
users may be
able to load the centralizer 1006 into the swaging device 1000, without
needing a hoisting device
1302.
[0072] As shown, the swaging device 1000 may be disposed in a vertical
orientation (e.g., with
the driver 1034 supported directly on the ground). In some embodiments,
however, a table,
stand, brackets, etc. may be provided. In such a vertical configuration, the
centralizer 1006 may
be carried (or hoisted) by the end collar 1004 and slid down onto the body
1022 (e.g., Figure 10).
In situations where a human worker is responsible for moving the centralizer
1006 onto the
swaging device 1000, the vertical orientation of the swaging device 1000 may
minimize or avoid
the worker having to bend to load the centralizer 1006 onto the swaging device
1000, which may
enhance ergonomics. Moreover, in still other cases, the swaging device 1000
may be
horizontally-oriented and supported (e.g., on a stand). Once the end collar
1002 of the
centralizer 1006 is loaded onto the swaging device 1000, the driver 1034 may
be energized to
swage (either expand, as shown, or contract) the end collar 1002.
[0073] The mobile swaging unit 1300 may include a lift or another device that
may facilitate
moving the swaging device 1000 to the illustrated position. For example, the
hoisting device
1302 may be employed to move the swaging device 1000 into position. In other
embodiments,
other lifting devices may be employed. In still other embodiments, however,
the swaging device
1000 may be generally fixed in position in the mobile swaging unit 1300 (e.g.,
attached to the
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truck or a moving platform thereof), or may be moved by one or more human
workers without
the assistance of a lifting device.
[0074] Figure 14 illustrates a flowchart of a method 1400 for providing a
centralizer (e.g., a
single-piece centralizer) at a wellsite, according to an embodiment. For
purposes of illustration,
the method 1400 is described herein with reference to the swaging device 1000
and the
centralizer 1006 (e.g., Figure 10); however, it will be appreciated that the
method 1400 is not
limited to any particular structure, unless otherwise stated herein, and may
be employed with any
of the centralizer embodiments and/or swaging devices disclosed herein and/or
others.
[0075] The method 1400 may include selecting a tubular, as at 1402. The
tubular selected may
be fabricated in a stock size at a pipe mill, for example. In some cases, the
stock sizes may have
a tolerance range. Further, the stock size may define an inner diameter that
is smaller or larger
than a desired, second inner diameter. The desired, second inner diameter may
be selected such
that the centralizer 1008, with the end collars 1002, 1004 of the second inner
diameter, may slide
along a casing, drill pipe, or any other tubular, with little or no
interference and a minimized
outer diameter. Further, a cylindricity of the stock pipe may be outside of an
acceptable
tolerance.
[0076] The tubular may be cut to a desired axial length, as at 1404. Before,
during, or after such
cutting at 1404, windows may be cut from the tubular, so as to define the
centralizer 1006 having
the end collars 1002, 1004 and ribs 1008, as at 1406. In some embodiments,
heat treatment
operations, rib expansion, and/or any other process may be conducted, so as to
give the
centralizer 1006 any desired metallurgical or other types of properties.
[0077] Before, during, or after cutting at 1404 and/or 1406, the centralizer
1006 (or tubular, in
the case that the tubular is uncut) may be transported to a wellsite, as at
1408. The wellsite may
be an area that is proximal to a wellhead of a subterranean well, such as a
natural gas well, oil
well, and/or the like. One or more tubulars, such as, for example, base pipe,
drill pipe, casing,
lining, etc. may be configured to be run into the well. In some embodiments,
the tubulars may be
centralized within a surrounding tubular using the centralizer 1006, so as to
provide an annular
standoff between the tubulars and the surrounding tubular.
[0078] However, as noted above, in some embodiments, the tubulars may have an
outer diameter
that is larger than the inner diameter of the centralizer 1006. Accordingly,
the method 1400 may
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include swaging the end collars 1002, 1004 of the centralizer 1006 at the
wellsite, as at 1410.
This may be conducted using an embodiment of the mobile unit 1300 and/or the
swaging device
1000. For example, a user may hoist, either by hand or using a lifting device,
such as lifting
device 1302, the centralizer 1008 and load the end collar 1002 onto the
swaging device 1000.
The user may then energize the driver 1034 of swaging device 1000, causing the
swaging device
1000 to swage the end collar 1002, such that the inner diameter of the end
collar 1002 reaches a
predetermined size that exceeds the outer diameter of the tubular to be
centralized by a
predetermined amount. Thereafter, the swaging may be repeated for the other
end collar 1004.
The centralizer 1006 may then be received around (e.g., slid over the end of)
the tubular, and the
tubular may be deployed, e.g., as part of a tube string, into the well along
with the centralizer
1006.
[0079] In other embodiments, the outer diameter of the tubulars may be smaller
than the inner
diameter of the centralizer 1006, prior to swaging at 1410. For example, the
inner diameter of
the un-swaged centralizers 1006 may be larger than needed to slide the end
collars 1002, 1004
over the tubular. Accordingly, the swaging at 1410 may include reducing the
inner diameter
thereof, so as to reduce the positive outer diameter added by using the
centralizer 1006 on the
tubular. Whether increasing the diameter or decreasing the diameter of the
centralizer 1006,
swaging at 1410 may, in at least one embodiment, also increase a cylindricity
of the end collars
1002, 1004, e.g., to within a desired tolerance of a desired target
cylindricity.
[0080] While the present teachings have been illustrated with respect to one
or more
implementations, alterations and/or modifications may be made to the
illustrated examples
without departing from the spirit and scope of the appended claims. In
addition, while a
particular feature of the present teachings may have been disclosed with
respect to only one of
several implementations, such feature may be combined with one or more other
features of the
other implementations as may be desired and advantageous for any given or
particular function.
Furthermore, to the extent that the terms "including," "includes," "having,"
"has," "with," or
variants thereof are used in either the detailed description and the claims,
such terms are intended
to be inclusive in a manner similar to the term "comprising." Further, in the
discussion and
claims herein, the term "about" indicates that the value listed may be
somewhat altered, as long
as the alteration does not result in nonconformance of the process or
structure to the illustrated
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embodiment. Finally, "exemplary" indicates the description is used as an
example, rather than
implying that it is an ideal.
[0081] Other embodiments of the present teachings will be apparent to those
skilled in the art
from consideration of the specification and practice of the present teachings
disclosed herein. It
is intended that the specification and examples be considered as exemplary
only, with a true
scope and spirit of the present teachings being indicated by the following
claims.
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