U.S. patent application number 16/520046 was filed with the patent office on 2021-01-28 for roller coupling apparatus and method therefor.
The applicant listed for this patent is MICHAEL BRENT FORD. Invention is credited to MICHAEL BRENT FORD.
Application Number | 20210025246 16/520046 |
Document ID | / |
Family ID | 1000004242019 |
Filed Date | 2021-01-28 |
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United States Patent
Application |
20210025246 |
Kind Code |
A1 |
FORD; MICHAEL BRENT |
January 28, 2021 |
ROLLER COUPLING APPARATUS AND METHOD THEREFOR
Abstract
A roller coupling apparatus for securing rods and other threaded
components together in a pumping system. The roller coupling
apparatus can include a body with a plurality of
radially-positioned wheels rotatably coupled to the body. The
arrangement of the wheels can uniformly spread the rod load within
the interior diameter of the tubing. In operation, the wheels
contact and roll along the interior diameter of the tubing,
preventing surface-to-surface wear of the coupling body exterior
and tubing interior, thereby prolonging coupling and tubing life.
In one embodiment, the wheels can include wear grooves that can
indicate wear areas in the wellbore. Multiple apparatuses can be
utilized to form rod strings of various lengths.
Inventors: |
FORD; MICHAEL BRENT; (ST.
GEORGE, UT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FORD; MICHAEL BRENT |
ST. GEORGE |
UT |
US |
|
|
Family ID: |
1000004242019 |
Appl. No.: |
16/520046 |
Filed: |
July 23, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 17/042 20130101;
E21B 17/1057 20130101; E21B 43/126 20130101 |
International
Class: |
E21B 17/10 20060101
E21B017/10; E21B 17/042 20060101 E21B017/042 |
Claims
1. A roller coupling apparatus comprising, in combination: a body
comprising: a threaded upper end; a threaded lower end; and a
plurality of wheel wells positioned between the upper end and the
lower end; and a plurality of wheels rotatably coupled to the body,
wherein each wheel of the plurality of wheels comprises: a convex
outer wall having only one circumferential wear groove, the
circumferential wear groove centrally positioned on the outer wall;
a pair of sidewalls having a plurality of wear grooves positioned
on the sidewalls; and an opening wall defining a central opening,
wherein the opening wall is configured to receive an insert;
wherein each wheel well of the plurality of wheel wells is
configured to receive one of the plurality of wheels; wherein each
wheel well of the plurality of wheel wells is semi-circularly
shaped and comprises a concave wall configured to correspond to the
convex outer wall of each wheel; wherein the plurality of wheels
are positioned radially around the body; wherein the plurality of
wheels are horizontally coplanar with each other; and wherein the
plurality of wheels are spaced-apart equidistantly from each
other.
2. (canceled)
3. The roller coupling apparatus of claim 1 further comprising: a
plurality of aligned pairs of openings in the body; a plurality of
inserts, each insert having an opening configured to receive an
axle, and wherein each insert is configured to be positioned in an
opening in one of the plurality of wheels; a plurality of axles,
wherein each axle is configured to be positioned through one of the
plurality of aligned pairs of openings in the body and in one of
the plurality of inserts.
4. The roller coupling apparatus of claim 3 wherein each axle of
the plurality of axles includes ridges on an outer surface
thereof.
5. (canceled)
6. (canceled)
7. The roller coupling apparatus of claim 1 wherein the wear
grooves on the sidewalls are concentric and spaced apart
equidistantly from each other.
8. The roller coupling apparatus of claim 1 wherein the plurality
of wheels comprises three wheels.
9. The roller coupling apparatus of claim 1 wherein the plurality
of wheels comprises a first plurality of wheels and the plurality
of wheel wells comprises a first plurality of wheel wells, the
roller coupling apparatus further comprising: a second plurality of
wheel wells positioned between the upper end and the lower end of
the body; a second plurality of wheels rotatably coupled to the
body, wherein each wheel of the second plurality of wheels
comprises: a convex outer wall having only one circumferential wear
groove, the circumferential wear groove centrally positioned on the
outer wall; a pair of sidewalls having a plurality of wear grooves
positioned on the sidewalls; and an opening wall defining a central
opening, wherein the opening wall is configured to receive an
insert; wherein each wheel well of the second plurality of wheel
wells is configured to receive one of the second plurality of
wheels; wherein each wheel well of the second plurality of wheel
wells is semi-circularly shaped and comprises a concave wall
configured to correspond to the convex outer wall of each wheel of
the second plurality of wheels; wherein the second plurality of
wheels are positioned radially around the body; wherein the second
plurality of wheels are horizontally coplanar with each other;
wherein the second plurality of wheels are spaced-apart
equidistantly from each other; and wherein the second plurality of
wheels comprises three wheels.
10. The roller coupling apparatus of claim 9 wherein the first
plurality of wheels are positioned in an upper wheel region
proximate the upper end of the body and the second plurality of
wheels are positioned in a lower wheel region proximate the lower
end of the body.
11. A roller coupling apparatus comprising, in combination: a body
comprising: a threaded upper end; a threaded lower end; a plurality
of wheel wells positioned between the upper end and the lower end;
and a plurality of aligned pairs of openings; a plurality of wheels
rotatably coupled to the body, wherein each wheel of the plurality
of wheels comprises: a convex outer wall having only one
circumferential wear groove, the circumferential wear groove
centrally positioned on the outer wall; a pair of sidewalls having
a plurality of wear grooves positioned on the sidewalls; and an
opening wall defining a central opening, wherein the opening wall
is configured to receive an insert; a plurality of inserts, each
insert having an opening configured to receive an axle, and wherein
each insert is configured to be positioned in an opening in one of
the plurality of wheels; a plurality of axles, wherein each axle is
configured to be positioned through one of the plurality of aligned
pairs of openings in the body and in one of the plurality of
inserts, and wherein each axle of the plurality of axles includes
longitudinal ridges on an outer surface thereof; wherein each wheel
well of the plurality of wheel wells is configured to receive one
of the plurality of wheels; wherein each wheel well of the
plurality of wheel wells is semi-circularly shaped and comprises a
concave wall configured to correspond to the convex outer wall of
each wheel; wherein the plurality of wheels are positioned radially
around the body; wherein the plurality of wheels are horizontally
coplanar with each other; and wherein the plurality of wheels are
spaced-apart equidistantly from each other.
12. (canceled)
13. (canceled)
14. (canceled)
15. The roller coupling apparatus of claim 11 wherein the wear
grooves on the sidewalls are concentric and spaced apart
equidistantly from each other.
16. The roller coupling apparatus of claim 11 wherein the plurality
of wheels comprises three wheels.
17. The roller coupling apparatus of claim 11 wherein the plurality
of wheels comprises a first plurality of wheels and the plurality
of wheel wells comprises a first plurality of wheel wells, the
roller coupling apparatus further comprising: a second plurality of
wheel wells positioned between the upper end and the lower end of
the body; a second plurality of wheels rotatably coupled to the
body, wherein each wheel of the second plurality of wheels
comprises: a convex outer wall having only one circumferential wear
groove, the circumferential wear groove centrally positioned on the
outer wall; a pair of sidewalls having a plurality of wear grooves
positioned on the sidewalls; and an opening wall defining a central
opening, wherein the opening wall is configured to receive an
insert; wherein each wheel well of the second plurality of wheel
wells is configured to receive one of the second plurality of
wheels; wherein each wheel well of the second plurality of wheel
wells is semi-circularly shaped and comprises a concave wall
configured to correspond to the convex outer wall of each wheel of
the second plurality of wheels; wherein the second plurality of
wheels are positioned radially around the body; wherein the second
plurality of wheels are horizontally coplanar with each other;
wherein the second plurality of wheels are spaced-apart
equidistantly from each other; and wherein the second plurality of
wheels comprises three wheels.
18. The roller coupling apparatus of claim 17 wherein the first
plurality of wheels are positioned in an upper wheel region
proximate the upper end of the body and the second plurality of
wheels are positioned in a lower wheel region proximate the lower
end of the body.
19. A method for protecting pumping system components from wear
during pumping operations, comprising the steps of: providing a
pumping unit; providing a roller coupling apparatus comprising, in
combination: a body comprising: a threaded upper end; a threaded
lower end; and a plurality of wheel wells positioned between the
upper end and the lower end; and a plurality of wheels rotatably
coupled to the body, wherein each wheel of the plurality of wheels
comprises: a convex outer wall having only one circumferential wear
groove, the circumferential wear groove centrally positioned on the
outer wall; a pair of sidewalls having a plurality of wear grooves
positioned on the sidewalls; and an opening wall defining a central
opening, wherein the opening wall is configured to receive an
insert; wherein each wheel well of the plurality of wheel wells is
configured to receive one of the plurality of wheels; wherein each
wheel well of the plurality of wheel wells is semi-circularly
shaped and comprises a concave wall configured to correspond to the
convex outer wall of each wheel; wherein the plurality of wheels
are positioned radially around the body; wherein the plurality of
wheels are horizontally coplanar with each other; and wherein the
plurality of wheels are spaced-apart equidistantly from each other;
providing a first threaded component; providing a second threaded
component; securing together the first and second threaded
components by threadably coupling the upper end of the roller
coupling apparatus to a lower end of the first threaded component
and threadably coupling the lower end of the roller coupling
apparatus to an upper end of the second threaded component to form
an assembly; positioning the assembly within tubing of a wellbore;
causing the assembly to move up with an upstroke of the pumping
unit and down with a downstroke of the pumping unit; and during the
movement with the upstroke and the downstroke, causing the wheels
of the roller coupling apparatus to contact and roll along an
interior diameter surface of the tubing.
20. The method of claim 19 wherein: the first threaded component is
one of a sucker rod and pony rod; and the second threaded component
is one of a sucker rod, pony rod, and sinker bar.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to oil pumps and
couplings used therein and, more specifically, to a roller coupling
apparatus and related method therefor.
BACKGROUND OF THE INVENTION
[0002] In general terms, an oil well pumping system begins with an
above-ground pumping unit, which creates the up and down pumping
action that moves the oil (or other substance being pumped) out of
the ground and into a flow line, from which the oil is taken to a
storage tank or other such structure.
[0003] Below ground, a shaft or "wellbore" is lined with piping
known as "casing." Into the casing is inserted piping known as
"tubing." A string of sucker rods is inserted into the tubing. The
string of sucker rods typically includes multiple individual sucker
rods, which are typically 25-28 feet in length each. In addition,
the rod string can include pony rods (also known as shooter rods,
pups, and rod subs), which are sucker rods that are less than 25
feet in length. Pony rods can be of different lengths, such as two,
four, six, or eight feet in length. The individual sucker rods are
joined together with couplings to form the sucker rod string.
According to American Petroleum Institute (API) specifications,
such couplings are 4.5 to 5 inches in length. Standard couplings
may typically be 4-6 inches in length. The sucker rod string can be
up to or more than one mile in length and is ultimately, indirectly
coupled at its north end to the above-ground pumping unit. The
string of sucker rods is coupled at its south end indirectly to the
subsurface oil pump itself, which is also located within the
tubing, which is sealed at its base to the tubing. The sucker rod
string couples to the oil pump at a coupling known as a 3-wing
cage. A sinker bar, which is heavily-weighted to help maintain the
tension in the sucker rod string particularly on the downstroke,
can be positioned directly above the subsurface oil pump.
[0004] The subsurface oil pump has a number of basic components,
including a barrel and a plunger. The plunger operates within the
barrel, and the barrel, in turn, is positioned within the tubing.
The north end of the plunger is typically connected to a valve rod
or hollow valve rod, which moves up and down to actuate the pump
plunger. The valve rod or hollow valve rod typically passes through
a valve rod guide.
[0005] Beginning at the south end, subsurface oil pumps generally
include a standing valve, which has a ball therein, the purpose of
which is to regulate the passage of oil (or other substance being
pumped) from downhole into the pump, allowing the pumped matter to
be moved northward out of the system and into the flow line, while
preventing the pumped matter from dropping back southward into the
hole. Oil is permitted to pass through the standing valve and into
the pump by the movement of the ball off of its seat, and oil is
prevented from dropping back into the hole by the seating of the
ball.
[0006] North of the standing valve, coupled to the sucker rod, is a
traveling valve. The purpose of a conventional traveling valve is
to regulate the passage of oil from within the pump northward in
the direction of the flow line, while preventing the pumped oil
from slipping back down in the direction of the standing valve and
hole.
[0007] In use, oil is pumped from a hole through a series of
"downstrokes" and "upstrokes" of the oil pump, wherein these
motions are imparted by the above-ground pumping unit. During the
upstroke, formation pressure causes the ball in the standing valve
to move upward, allowing the oil to pass through the standing valve
and into the barrel of the oil pump. This oil will be held in place
between the standing valve and the traveling valve. In the
conventional traveling valve, the ball is located in the seated
position. It is held there by the pressure from the oil that has
been previously pumped. The oil located above the traveling valve
is moved northward in the direction of the 3-wing cage at the end
of the oil pump.
[0008] During the downstroke, the ball in the conventional
traveling valve unseats, permitting the oil that has passed through
the standing valve to pass therethrough. Also during the
downstroke, the ball in the standing valve seats, preventing the
pumped oil from slipping back down into the hole.
[0009] The process repeats itself again and again, with oil
essentially being moved in stages from the hole, to above the
standing valve and in the oil pump, to above the traveling valve
and out of the oil pump. As the oil pump fills, the oil passes
through the 3-wing cage and into the tubing. As the tubing is
filled, the oil passes into the flow line, from which the oil is
taken to a storage tank or other such structure.
[0010] Unlike typical wellbores of the past, which are typically
drilled in relatively straight vertical lines, a current drilling
trend is for wellbores to be drilled vertically in part and then
horizontally in part, resulting in wellbores that have some
curvature or "deviation." Such wells may commonly be referred to as
"deviated" wells. When drilling deviated wells, drillers typically
drill vertically for some distance (e.g. one mile), through the
upper zone and down to the bedrock, and then transition to drilling
horizontally. One advantage to drilling wellbores in this
configuration is that the horizontal area of the well typically has
many more perforations in the casing, which allows for more well
fluid to enter the wellbore than with typical vertical casing
wells. This, in turn, allows for more well fluid to be pumped to
the surface. It should be understood that while conventional wells
are typically drilled vertically, conventional wells can also have
some moderate curvature or deviation in the wellbore.
[0011] Horizontal wells may typically be drilled at an angle of
roughly ten to twelve degrees over roughly 1000 feet to allow for a
gradual slope. This results in approximately one degree of
deviation for every 100 feet. A problem that occurs when drilling
such wells, particularly when they are drilled relatively fast, is
that the wells are not drilled perfectly, resulting in crooked
wellbores. Such wells may have many slight to extreme deviations in
the drill hole, which would create a non-linear configuration. When
the deviated well is completed to depth, the drill pattern is
positioned horizontally to drill. The pump, coupled to the sucker
rod string, then must be lowered from the surface through all of
the deviations of the wellbore down to the horizontal section of
the well where it would be placed in service.
[0012] There are a number of problems that are regularly
encountered during oil pumping operations. Oil that is pumped from
the ground is generally impure, and includes water, gas, and solid
impurities such as sand and other debris. The presence of solids
can cause major damage to the pump components, thus reducing the
run cycle of the pump, reducing revenue to the operator, and
increasing expenses. For example, during pumping operations, scale,
paraffin, or other solids buildup can accumulate in various areas
of the tubing. This can create a very narrow tolerance between the
pumping system's various subsurface components (including, for
example, rods, rod couplings, and sinker bars) and the tubing
which, in turn, can cause wear and damage to these subsurface
components and tubing during pumping operations, especially when
they are dragged across the interior diameter surface of the
tubing. Further, particularly where deviations are present (whether
in conventional or horizontal wells), the rod couplings can make
contact with the tubing, also causing wear and damage to the
couplings and tubing during pumping operations. In such situations,
the rod couplings and tubing must then be repaired or replaced,
which is both time consuming and expensive and, further, can result
in loss of revenue to the well operators while the well is
non-operational.
[0013] One solution to address these problems has been to provide
wheeled couplings/rod guides. However, presently known wheeled
couplings/rod guides suffer from several shortcomings in various
areas of the design. For example, such wheeled couplings/rod guides
are typically around 28 inches in length, which falls outside of
the API specification range for rod couplings. Such wheeled
couplings/rod guides require manual installation with hand wrenches
or other hand tools. This method of installation is time consuming
and can result in inconsistent torque application during coupling
installation. This can cause loosening of the couplings and rod
parts during pumping operations, leading to coupling failure and
expensive well downtime. As a further example, the wheels of
presently known wheeled couplings/rod guides are typically fitted
through openings in the body of the coupling/rod guide and centered
vertically in the body, such that portions of each wheel protrude
from opposing sides of the body. This configuration can be
problematic. For example, in the event that the wheel encounters a
high spot in the tubing due to scale or paraffin or other solids
buildup, the wheel will seize and drag through the high spot,
causing damage to the wheel by flattening its protruding
portions.
[0014] The present invention addresses these problems encountered
in prior art pumping systems, and provides other, related,
advantages.
SUMMARY
[0015] In accordance with one embodiment of the present invention,
a roller coupling apparatus is disclosed. The roller coupling
apparatus comprises, in combination: a body having a threaded north
end and a threaded south end; and a plurality of wheels rotatably
coupled to the body; wherein the wheels are positioned radially
around the body; and wherein the wheels are spaced-apart
equidistantly from each other.
[0016] In accordance with another embodiment of the present
invention, a roller coupling apparatus is disclosed. The roller
coupling apparatus comprises, in combination: a body comprising: a
threaded north end; a threaded south end; a plurality of wheel
wells positioned between the north end and the south end; and a
plurality of aligned pairs of openings; a plurality of wheels
rotatably coupled to the body, a plurality of inserts, each insert
having an opening configured to receive an axle, and wherein each
insert is configured to be positioned in an opening in one of the
plurality of wheels; a plurality of axles, wherein each axle is
configured to be positioned through one of the plurality of aligned
pairs of openings in the body and in one of the plurality of
inserts; wherein each wheel well of the plurality of wheel wells is
configured to receive one of the plurality of wheels; wherein the
wheels are positioned radially around the body; and wherein the
wheels are spaced-apart equidistantly from each other.
[0017] In accordance with another embodiment of the present
invention, a method for protecting pumping system components from
wear during pumping operations is disclosed. The method comprises
the steps of: providing a pumping unit; providing a roller coupling
apparatus comprising, in combination: a body having a threaded
north end and a threaded south end; and a plurality of wheels
rotatably coupled to the body; wherein the wheels are positioned
radially around the body; and wherein the wheels are spaced-apart
equidistantly from each other, providing a first threaded
component; providing a second threaded component; securing together
the first and second threaded components by threadably coupling the
north end of the roller coupling apparatus to a south end of the
first threaded component and threadably coupling the south end of
the roller coupling apparatus to a north end of the second threaded
component to form an assembly; positioning the assembly within
tubing of a wellbore; causing the assembly to move up with an
upstroke of the pumping unit and down with a downstroke of the
pumping unit; and during the movement with the upstroke and the
downstroke, causing the wheels of the roller coupling apparatus to
contact and roll along an interior diameter surface of the
tubing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present application is further detailed with respect to
the following drawings. These figures are not intended to limit the
scope of the present application, but rather, illustrate certain
attributes thereof.
[0019] FIG. 1 is a side view of an embodiment of a roller coupling
apparatus in accordance with one or more aspects of the present
invention, with portions thereof shown in phantom;
[0020] FIG. 2 is a side, cross-sectional view of the roller
coupling apparatus of FIG. 1, with portions thereof shown in
phantom;
[0021] FIG. 3 is a bottom perspective view of the roller coupling
apparatus of FIG. 1, with portions thereof shown in phantom;
[0022] FIG. 4 is an end view of the roller coupling apparatus of
FIG. 1, with portions thereof shown in phantom;
[0023] FIG. 5A is a perspective view of an illustrative wheel of
the roller coupling apparatus of the present invention;
[0024] FIG. 5B is a perspective view of an illustrative wheel of
the roller coupling apparatus of the present invention;
[0025] FIG. 6 is a perspective view of an illustrative insert of
the roller coupling apparatus of the present invention;
[0026] FIG. 7 is a perspective view of an illustrative axle of the
roller coupling apparatus of the present invention;
[0027] FIG. 8 is a side view of an embodiment of a roller coupling
apparatus in accordance with one or more aspects of the present
invention;
[0028] FIG. 9 is a side view of another embodiment of a roller
coupling apparatus in accordance with one or more aspects of the
present invention; and
[0029] FIG. 10 is another side view of the roller coupling
apparatus of FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The description set forth below in connection with the
appended drawings is intended as a description of presently
preferred embodiments of the disclosure and is not intended to
represent the only forms in which the present disclosure may be
constructed and/or utilized. The drawing figures are not
necessarily drawn to scale and certain figures can be shown in
exaggerated or generalized form in the interest of clarity and
conciseness. The description sets forth the functions and the
sequence of steps for constructing and operating the disclosure in
connection with the illustrated embodiments. It is to be
understood, however, that the same or equivalent functions and
sequences may be accomplished by different embodiments that are
also intended to be encompassed within the spirit and scope of this
disclosure.
[0031] FIGS. 1-10, together, disclose embodiments of a roller
coupling apparatus 10 of the present invention. The roller coupling
apparatus 10 is adapted to be used with a pumping system, such as
an oil pumping system, that is positioned within a pump barrel. The
roller coupling apparatus 10 is configured to securely couple two
various threaded components that are placed within the tubing, such
as rods, including sucker rods and pony rods, and sinker bars. The
roller coupling apparatus 10 provides rolling capability at the
threaded connections and thereby prevents subsurface components
such as couplings, rods, and sinker bars from being dragged across
the interior diameter surface of the tubing during pumping
operations, which would cause damage to both the subsurface
components and tubing. Although the term "oil" is used herein, it
should be understood that the roller coupling apparatus 10 of the
present invention may be used in pumping systems that pump fluids
other than oil, such as debris-containing water. In describing the
structure of the roller coupling apparatus 10 and its operation,
the terms "north" and "south" are utilized. The term "north" is
intended to refer to that end of the pumping system that is more
proximate the pumping unit, while the term "south" refers to that
end of the system that is more distal the pumping unit, or
"downhole."
[0032] Referring first to FIGS. 1-3, an embodiment of the roller
coupling apparatus 10 of the present invention is shown. The roller
coupling apparatus 10, which has a substantially cylindrical
external configuration, can be divided into the following principal
components: a body 12 and a plurality of rollers or wheels 30
(hereinafter wheels 30) which are rotatably coupled to the body
12.
[0033] Beginning at the top portion of FIGS. 1-3, the components of
the roller coupling apparatus 10 will be described in further
detail. In this embodiment, the body 12 comprises a north end 14
having an inlet 16, which is configured to receive a southern end
of a rod (not shown). Inlet 16 includes a threaded region 18.
Threaded region 18 is configured to permit the roller coupling
apparatus 10 to be coupled to a southern end of a rod. As seen in
this embodiment, threaded region 18 can originate southward of
north end 14 and terminate northward of a plurality of wheel wells
20. While in this embodiment threaded region 18 is shown as
comprising female threading, in order to correspond to male pin
threading present on the ends of conventional rods, it should be
understood that threaded region 18 may comprise either male or
female threading, as long as it engages corresponding male or
female threading present on the rod to which it may be coupled.
[0034] Continuing southward in the drawing figures, as seen in this
embodiment, the body 12 further includes a plurality of wheel wells
20, each of which is configured to house one of a plurality of
wheels 30, as described further herein. Each wheel well 20 can be
substantially semi-circularly shaped and can comprise a concave
wall configured to correspond to the shape of each wheel 30. With
this configuration, a portion of each wheel 30 can be positioned
within each wheel well 20. This configuration helps to protect the
wheels 30 from damage that could otherwise be caused by the narrow
tolerance between the roller coupling apparatus 10 exterior and
tubing interior due to buildup of scale, paraffin or other solids,
since the wheels 30 will continue to roll in such solids buildup
areas. This is in contrast to presently known wheeled couplings/rod
guides, in that the wheels of such couplings/rod guides can seize
and become dragged through areas of the tubing having solids
buildup, flattening the wheels. Each wheel well 20 can have an
overall diameter that is greater than an exterior diameter of each
wheel 30. In this way, each wheel 30 can be suspended when
positioned in each wheel well 20 without contacting the interior
surface of the wheel well 20. As best seen in FIG. 4, in this
embodiment, the roller coupling apparatus 10 utilizes a set of
three wheel wells 20 (corresponding to three wheels 30) that are
positioned in the same horizontal plane. The wheel wells 20 are
positioned radially around the body 12 and are spaced-apart
equidistantly from each other. In this embodiment, the wheel wells
20 are spaced 120 degrees apart. While in this embodiment three
wheel wells 20 are shown, it should be understood that more than
three wheel wells 20 (corresponding to more than three wheels 30)
may be provided as may be needed for particular well conditions and
configurations and depending upon the dimensions of the body 12 of
the roller coupling apparatus 10.
[0035] Referring now to FIG. 4, the body 12 further includes a
plurality of aligned pairs of openings 28. Each opening 28 is
configured to receive an end of an axle 50, to permit the wheels 30
to be coupled to the body 12, as described further herein. While in
this embodiment three aligned pairs of openings 28 (corresponding
to three wheels 30) are shown, it should be understood that more
than three aligned pairs of openings 28 (corresponding to more than
three wheels 30) may be provided as may be needed for particular
well conditions and configurations and depending upon the
dimensions of the body 12 of the roller coupling apparatus 10.
[0036] Referring again to FIGS. 1-3 and continuing with the bottom
portion thereof, in this embodiment, the body 12 further comprises
a south end 22 having an inlet 24, which is configured to receive a
northern end of a rod (not shown). Similar to inlet 16, inlet 24
includes a threaded region 26. Threaded region 26 is configured to
permit the roller coupling apparatus 10 to be coupled to a northern
end of a rod or sinker bar. As seen in this embodiment, threaded
region 26 can originate northward of south end 22 and terminate
southward of wheel wells 20. While in this embodiment threaded
region 26 is shown as comprising female threading, in order to
correspond to male pin threading present on the ends of
conventional rods and sinker bars, it should be understood that
threaded region 26 may comprise either male or female threading, as
long as it engages corresponding male or female threading present
on the rod or sinker bar to which it may be coupled.
[0037] In one embodiment, the body 12 can be approximately five
inches in length. However, it should be understood that the length
of the body 12 may deviate from this dimension, as desired. For
example, the roller coupling apparatus 10 could have a length
longer than five inches, in order to accommodate additional sets of
three wheels 30 each, as described further herein, or as may be
required for heavier rod loads, severe deviation of the wellbore
configuration, and the like. As another example, the roller
coupling apparatus 10 could have a length slightly less than five
inches.
[0038] Referring now to FIGS. 1-5A, the wheel 30 of the roller
coupling apparatus 10 will be discussed in further detail. As seen
in this embodiment, wheel 30 includes an outer wall 32 flanked by
sidewalls 34. Outer wall 32 can be substantially convex in shape.
As best seen in FIG. 5A, each wheel 30 is provided with a central
opening 36, defined by opening wall 38, which is configured to
receive an insert 40. Wheel 30 can be fabricated from a variety of
high-density materials suitable for downhole pumping applications
including, by way of example only, various metals, such as
stainless steel or ToughMet.RTM. alloys by Materion Corporation or
high-density thermoplastics or high-density polymers. While in this
embodiment three wheels 30 are provided in the roller coupling
apparatus 10 (see FIG. 4), it should be understood that more than
three wheels 30 may be provided as may be needed for particular
well conditions and configurations and depending upon the
dimensions of the body 12 of the roller coupling apparatus 10.
[0039] Referring now to FIGS. 5B and 8, in one embodiment, wheel 30
includes wear grooves 35. In one embodiment, wear grooves 35 can be
concentric and spaced apart equidistantly from each other. In one
embodiment, each groove 35 can have a depth ranging from
approximately 0.0001 to 0.010 inch. However, it would be possible
to vary the depth of grooves 35, as may be needed for particular
well conditions and configurations. While in this embodiment seven
grooves 35 are provided (with three grooves 35 on each sidewall 34
and one groove 35 on outer wall 32), it should be understood that
more or fewer than seven grooves 35 may be provided as desired.
[0040] Referring now to FIG. 6, the insert 40 of the roller
coupling apparatus 10 will be discussed in further detail. As seen
in this embodiment, insert 40 is generally a hollow cylinder in
shape. Insert 40 includes a central opening 42 defined by opening
wall 44, which is configured to receive an axle 50. Insert 40 can
include side surfaces 46 and outer surface 48. Insert 40 can be
fabricated from a variety of high-density materials suitable for
downhole pumping applications including, by way of example only,
various metals, such as stainless steel or ToughMet.RTM. alloys.
While in this embodiment three inserts 40 are provided in the
roller coupling apparatus 10 corresponding to three wheels 30 (see
FIG. 4), it should be understood that more than three inserts 40
may be provided depending upon the number of wheels 30
utilized.
[0041] Each wheel 30 is rotatably coupled to the body 12 by axle
50, which is inserted through aligned openings 28 and 42 in the
body 12 and insert 40, respectively. Referring now to FIG. 7, the
axle 50 of the roller coupling apparatus 10 will be discussed in
further detail. As seen in this embodiment, axle 50 is generally
cylindrical in shape. In one embodiment, axle 50 can be hollow and
can include a slit 51 from end to end. When wheel 30 fitted with
insert 40 is positioned in wheel well 20, axle 50 may then be
positioned through a first opening 28 in body 12, opening 42 in
insert 40, and a second opening 28 in body 12. When so positioned,
each end of axle 50 may protrude outwardly from insert 40 into
aligned pairs of openings 28 in the body 12, thereby securing each
wheel 30 in position on the body 12. As seen in FIG. 4, in one
embodiment, the ends of each axle 50 may further protrude slightly
from an outer diameter of the body 12. Referring to FIG. 2, each
axle 50 can further include a plurality of ridges 52, which may
grip the opening wall 44 of insert 40, thereby securing axle 50 in
place. Axle 50 can be fabricated from a variety of high-density
materials suitable for downhole pumping applications including, by
way of example only, various metals, such as stainless steel,
carbon steel, or ToughMet.RTM. alloys. While in this embodiment
three axles 50 are provided in the roller coupling apparatus 10
(see FIG. 4), it should be understood that more than three axles 50
may be provided depending upon the number of wheels 30
utilized.
[0042] As best seen in FIG. 4, in this embodiment, the roller
coupling apparatus 10 utilizes a set of three wheels 30 that are
positioned in the same horizontal plane. The wheels 30 are
positioned radially around the body 12 and are spaced-apart
equidistantly from each other. In this embodiment, the wheels 30
are spaced 120 degrees apart. This configuration spreads the rod
load more uniformly within the interior diameter of the tubing. In
this regard, this configuration allows for 360-degree load weight
carrying of the rod to transfer to the wheels 30 which roll inside
the tubing, thereby eliminating the surface-to-surface wear of the
sucker rod coupling and tubing that can occur during pumping
operations, especially in deviated areas of the wellbore. While in
this embodiment three wheels 30 are provided in the roller coupling
apparatus 10, it should be understood that more than three wheels
30 may be provided as may be needed for particular well conditions
and configurations and depending upon the dimensions of the body 12
of the roller coupling apparatus 10. For example, where the body 12
has relatively larger dimensions, it may be desired to provide
additional radially-positioned wheels 30. Further, while in this
embodiment the wheels 30 are shown positioned inline vertically on
the body 12, it should be understood that the wheels 30 can be
positioned at various degrees from vertical on the body 12. Such a
configuration allows for slight rod rotation during pumping
operations which, in turn, allows for more even wear, helping to
eliminate premature pumping operation failures related to rod and
tubing wear issues.
[0043] Referring now to FIGS. 9-10, reference number 100 refers
generally to another embodiment of the roller coupling apparatus of
the present invention. The roller coupling apparatus 100 is similar
to the roller coupling apparatus 10, but includes a body 12 of a
length longer than the roller coupling apparatus 10 in order to
accommodate an additional set of wheels 30. For this reason, the
same reference numbers used in describing the features of the
roller coupling apparatus 10 will be used when describing the
identical features of the roller coupling apparatus 100.
[0044] In this embodiment, the body 12 includes six wheel wells 20,
corresponding to six wheels 30 (see FIGS. 9-10, which show opposing
sides of the roller coupling apparatus 100). However, it should be
understood that more or less than six wheel wells 20, corresponding
to more or less than six wheels 30, may be provided as desired. As
can be seen from a review of FIGS. 9-10, a first set of three wheel
wells 20 is provided proximate the north end 14 of the body 12,
while a second set of three wheel wells 20 is provided proximate
the south end 22 of the body 12. In one embodiment, the body 12 of
the roller coupling apparatus 100 can be approximately seven inches
in length. This longer length, compared to the length of the roller
coupling apparatus 10 (which, as described above, is approximately
five inches in length), is configured to accommodate the second set
of three wheel wells 20 and wheels 30. However, it should be
understood that the length of the body 12 may deviate from this
dimension, as desired. For example, the roller coupling apparatus
100 could have a length longer than twenty-four inches, in order to
accommodate yet additional sets of wheels 30. It should be noted
that for each additional set of wheels incorporated into the roller
coupling apparatus 100, approximately two inches are added to the
length of the body 12 in order to accommodate the additional wheel
set(s). For example, a roller coupling apparatus 100 with three
sets of wheels would have a body 12 length of approximately nine
inches, a roller coupling apparatus 100 with four sets of wheels
would have a body 12 length of approximately eleven inches, and so
on.
[0045] As seen from a review of FIGS. 9-10, in this embodiment, the
roller coupling apparatus 100 utilizes two sets of three wheels 30
each, including three wheels 30 positioned in a northern wheel
region 54, proximate the northern end 14 of the body 12, and three
wheels 30 positioned in a southern wheel region 56, proximate the
southern end 22 of the body 12, for a total of six wheels 30. The
wheels 30 of the northern wheel region 54 are positioned in a first
horizontal plane. Further, the wheels 30 of the northern wheel
region 54 are positioned radially around the body 12 and are
spaced-apart equidistantly from each other. In this embodiment, the
wheels 30 of the northern wheel region 54 are spaced 120 degrees
apart. Similarly, the wheels 30 of the southern wheel region 56 are
positioned in a second horizontal plane that is located southward
of the first horizontal plane. Further, the wheels 30 of the
southern wheel region 56 are positioned radially around the body 12
and are spaced-apart equidistantly from each other. In this
embodiment, the wheels 30 of the southern wheel region 56 are
spaced 120 degrees apart. As seen from a review of FIGS. 9-10, the
wheels 30 of the northern wheel region 54 are staggered relative to
the wheels 30 of the southern wheel region 56, and vice versa, such
that each wheel 30 of the northern wheel region 54 is positioned
diagonally from each wheel 30 of the southern wheel region 56, and
vice versa. As with the roller coupling apparatus 10, the
configuration of the wheels 30 in the roller coupling apparatus 100
spreads the rod load more uniformly within the interior diameter of
the tubing. In this regard, this configuration allows for
360-degree load weight carrying of the rod to transfer to the
wheels 30 which roll inside the tubing, thereby eliminating the
surface-to-surface wear of the sucker rod coupling and tubing that
can occur during pumping operations, especially in deviated areas
of the wellbore. As with the roller coupling apparatus 10, while in
this embodiment the wheels 30 are shown positioned inline
vertically on the body 12, it should be understood that the wheels
30 can be positioned at various degrees from vertical on the body
12. Such a configuration allows for slight rod rotation during
pumping operations which, in turn, allows for more even wear,
helping to eliminate premature pumping operation failures related
to rod and tubing wear issues.
[0046] While non-grooved wheels 30 are shown in the embodiment in
FIGS. 9-10, it should be understood that the wheels 30 of the
roller coupling apparatus 100 may include wear grooves 35, as shown
in FIG. 5B and as discussed above.
[0047] As described herein, each roller coupling apparatus 10 and
100 is configured to be coupled at its north end 14 to the south
end of a rod, and at its south end 22 to the north end of another
rod or to a sinker bar, thereby connecting the two rods together,
or connecting a rod and a sinker bar together, to form an assembly.
Multiple roller coupling apparatuses 10 and 100 may be utilized to
connect multiple rods together, thereby forming a rod string of
various lengths, as may be needed depending on the depth of the
well and length of the wellbore in which the roller coupling
apparatuses 10 and 100 are employed.
[0048] The roller coupling apparatus 10 can be installed in the
same manner as a conventional rod coupling. In this regard, the
roller coupling apparatus 10 can be installed with hydraulic power
tongs on the pulling unit. Such tongs can be set so that an equal
amount of torque is applied to each roller coupling apparatus 10
utilized in a given pumping operation, which can include multiple
roller coupling apparatuses 10 as may be needed. This method of
installation is economical, efficient, and provides torque
consistency among the rod couplings. Compared to manual
installation, this method of installation is faster in that it can
require a few seconds to install rod couplings with hydraulic power
tongs, as opposed to the minutes that may be required for manual
installation.
[0049] Unlike the roller coupling apparatus 10, the roller coupling
apparatus 100, with its multiple sets of wheels 30, is not suited
for installation with hydraulic power tongs on the pulling unit,
due to its longer body length. Instead, the roller coupling
apparatus 100 can be installed manually with hand wrenches or other
hand tools.
[0050] In operation, the roller coupling apparatus 10 or 100, being
part of the rod string, will move up with the upstroke of the
pumping unit and down with the downstroke of the pumping unit. As
the roller coupling apparatus 10 or 100 moves within in the
wellbore, wheels 30 make contact with and roll along the interior
diameter surface of the tubing. This prevents the body 12 exterior
from contacting the tubing interior, preventing surface-to-surface
wear of the body 12 exterior and tubing interior, including in
deviated areas of the wellbore. In turn, with the wheels 30
contacting the tubing, this helps to keep the rods from contacting
the tubing. This prolongs the life of the rod assembly and
tubing.
[0051] The roller coupling apparatus 10 or 100 that includes one or
more wear grooves 35 on wheels 30 provides further advantages. In
this regard, wear grooves 35 allow the operator to determine the
wear undergone by the wheels 30 and provide an indication of when
the roller coupling apparatus(es) 10 or 100 should be repaired or
replaced. The operator can inspect the wheels 30 for wear when the
well experiences down-time and the downhole pumping system
components are retrieved for repair. This will enable the operator
to determine the location of the most severe wear areas in the
wellbore, by reviewing the wear patterns on the wheels 30 including
where the grooves 35 have become worn. The operator can then make
an informed decision, based on quantitative data, to place
additional roller coupling apparatuses 10 or 100 in the severe wear
areas, by replacing single sucker rods with multiple, shorter, pony
rods, which would allow for more roller coupling apparatuses 10 or
100 to be installed in wellbore locations experiencing severe wear.
Such wear may occur due to such reasons as rod loading in deviated
areas of the wellbore or rod buckling due to fluid pounding caused
by the pump barrel not completely filling with fluid in between
pump strokes. This causes the rods to buckle in the tubing,
particularly when the traveling valve passes through an empty space
in the barrel and then slams into the fluid area. This results in a
large shock throughout the rod assembly, causing damage to the rods
and tubing. Utilizing the roller coupling apparatus 10 or 100 in
the rod assembly lessens the damage to the rod assembly and
tubing.
[0052] The foregoing description is illustrative of particular
embodiments of the invention, but is not meant to be a limitation
upon the practice thereof. While embodiments of the disclosure have
been described in terms of various specific embodiments, those
skilled in the art will recognize that the embodiments of the
disclosure may be practiced with modifications without departing
from the spirit and scope of the invention.
* * * * *