METHOD OF FABRICATING A ROD GUIDE AND A ROD GUIDE/SUCKER COMBINATION

METHODE DE FABRICATION D'UN GUIDE DE TIGE ET D'UNE COMBINAISON GUIDE DE TIGE ET TIGE DE POMPAGE

English Abstract

A method of fabricating a rod guide. The first step
involves providing a sucker rod having an exterior surface with
a raised profile. The second step involves providing a split
sleeve having at least one segment. The split sleeve has an
interior surface with a recessed profile that mates with the
raised profile of the sucker rod thereby securing the sleeve
against axial movement relative to the sucker rod. The third
step involves providing an overlying sleeve that overlies the
split sleeve to maintain the split sleeve in mating engagement
with the sucker rod.

French Abstract

Méthode de fabrication d'un guide de tige. La première étape est de fournir une tige de pompage ayant une surface extérieure à profil surélevé. La deuxième étape consiste à fournir un manchon fendu ayant au moins un segment. Ce manchon comprend une surface intérieure munie d'un profil à rainures qui épouse le profil à saillies de la tige de pompage, évitant ainsi un déplacement axial du manchon par rapport à la tige de pompage. La troisième étape est de fournir un manchon sus-jacent qui recouvre le manchon fendu de façon à maintenir ce dernier engagé avec la tige de pompage.

Claims

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THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of fabricating a rod guide, comprising the steps
of:
firstly, providing a sucker rod having an exterior surface
with a raised profile;
secondly, providing a split sleeve having at least one
segment, the split sleeve having an interior surface with a
recessed profile that mates with the raised profile of the
sucker rod thereby securing the sleeve against axial movement
relative to the sucker rod; and
thirdly, providing an overlying sleeve that overlies the
split sleeve to maintain the split sleeve in mating engagement
with the sucker rod, the overlying sleeve being secured to the
split sleeve.
2. The method as defined in Claim 1, further comprising the
step of moulding the raised profile onto the exterior surface
of the sucker rod.
3. The method as defined in Claim 1, further comprising the
step of moulding the overlying sleeve onto the split sleeve.
4. A rod guide/sucker rod combination, comprising:
a sucker rod having an exterior surface with a raised
profile;
a split sleeve having at least one segment, the split
sleeve having an interior surface with a recessed profile that
mates with the raised profile of the sucker rod thereby
securing the sleeve against axial movement relative to the
sucker rod; and
an overlying sleeve that overlies the split sleeve to
maintain the split sleeve in mating engagement with the sucker
rod, the overlying sleeve being secured to the split sleeve.

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5. A method of fabricating a rod guide, comprising the steps
of:
providing a sucker rod having an exterior surface;
moulding onto the exterior surface of the sucker rod a
raised profile of polymer plastic;
providing a split sleeve having at least one segment, the
split sleeve having an interior surface with a recessed profile
that mates with the raised profile of the sucker rod thereby
securing the sleeve against axial movement relative to the
sucker rod while accommodating rotation of split sleeve
relative to the sucker rod; and
moulding, directly onto the split sleeve, an overlying
sleeve of polymer plastic that overlies the split sleeve to
maintain the split sleeve in mating engagement with the sucker
rod, the overlying sleeve being secured to and rotatable with
the split sleeve, the overlying sleeve having a plurality of
axially extending vanes.
6. The rod guide/sucker rod combination as defined in Claim
4, wherein the raised profile is made of polymer plastic.
7. The rod guide/sucker rod combination as defined in Claim
4, wherein the overlying sleeve is made of polymer plastic.
8. The rod guide/sucker rod combination as defined in Claim
4, wherein the split sleeve is rotatably secured to the sucker
rod and the overlying sleeve is non-rotatably secured to the
split sleeve.
9. The rod guide/sucker rod combination as defined in Claim
4, wherein the overlying sleeve has a plurality of axially
extending vanes.
10. The rod guide/sucker rod combination as defined in Claim
4, wherein at least one lubrication port is provided through
each of the overlying sleeve and the split sleeve.

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11. The rod guide/sucker rod combination as defined in Claim
10, wherein a filter element is positioned in the lubrication
port to preclude the entry of particulate matter.

Description

CA 02214230 1997-08-27
TITLE OF THE lNV~.llON:
method of fabricating a rod guide, and a rod guide/sucker
rod combination.
NAME OF lNVlSN'l'OR:
Thomas Hubert Vermeeren
FIELD OF THE lNV~ ON
The present invention relates to a method of fabricating
a rod guide and a rod guide/sucker rod combination suited, in
particular, for use with a progressive cavity pump.
RA~K~ROUND OF THE lNV~L.llON
Rod guides are intended to prevent a sucker rod which
drives a downhole pump from rubbing against interior walls of
the production tubing. United States Patent 5,339,896 which
issued to J.M. Huber Corporation in 1994 is representative of
the type of rod guide currently in widespread use. The rod
guide has a flexible body that is generally "C" shaped in
cross-section. An elongate slot extends the length of the body,
by means of which the guide is installed on a sucker rod. The
width of the slot is less that the outer diameter of the sucker
rod. During installation, the slot is expanded by flexing the
flexible body to snap the body around the sucker rod. The body
has a plurality of radial vanes which serve to centralize the
sucker rod, while minimizing flow resistance around the guide.
The body rides on the sucker rod between two stops which
maintain axial positioning. Canadian Patent 2,101,677 by Sable
which was published in 1994 discloses a rod guide with a more
complex slot configuration. There is provided a body with two

CA 02214230 1997-08-27
diametrically opposed longitudinal slots each of which extend
half the length of the rod guide. A transverse slot connects
the two longitudinal slots, by manipulating the body the rod
guide can be snapped onto a sucker rod.
The rod guides, as described above, are experiencing
problems with wear due to abrasion. Fine grains of sand and
like particulate matter are working their way past the stops
and getting between the rod guide and the sucker rod.
SUMMARY OE THE lNv~NllON
What is required is an alternate rod guide construction.
According to one aspect of the present invention there is
provided a method of fabricating a rod guide. The first step
involves providing a sucker rod having an exterior surface with
a raised profile. The second step involves providing a split
sleeve having at least one segment. The split sleeve has an
interior surface with a recessed profile that mates with the
raised profile of the sucker rod thereby securing the sleeve
against axial movement relative to the sucker rod. The third
step involves providing an overlying sleeve that overlies the
split sleeve to maintain the split sleeve in mating engagement
with the sucker rod. The overlying sleeve is secured to the
split sleeve.
According to another aspect of the present invention there
is provided a rod guide/sucker rod combination which includes
a sucker rod having an exterior surface with a raised profile.
A split sleeve is provided having at least one segment. The
split sleeve has an interior surface with a recessed profile
that mates with the raised profile of the sucker rod thereby
securing the sleeve against axial movement relative to the
sucker rod. An overlying sleeve overlies the split sleeve to
maintain the split sleeve in mating engagement with the sucker

CA 02214230 1997-08-27
rod. The overlying sleeve is secured to the split sleeve.
The rod guide/sucker rod combination, as described
provides a number of advantages. Wear due to abrasion has been
reduced, if not completely eliminated, by internalizing the
axial stops. The rod guide/sucker rod combination is,
therefore, much less likely to have fine grains of sand and
like particulate matter work its way between the rod guide and
the sucker rod. The rod guide is much less prone to separating
from the sucker rod and falling down the well tubing. Fewer
maintenance checks on the sucker rod and the rod guide are
required.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more
apparent from the following description in which reference is
made to the appended drawings, wherein:
FIGURE 1 is a perspective view of a rod guide/sucker rod
combination fabricated in accordance with the teachings of the
present invention.
FIGURE 2 is an exploded perspective view of a rod
guide/sucker rod combination fabricated in accordance with the
teachings of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment, a rod guide/sucker rod
combination generally identified by reference numeral 10, will
now be described with reference to FIGURES 1 and 2.
Referring to FIGURE 1, completed rod guide/sucker rod
combination 10 has as components a sucker rod 12, split sleeve
14 and an overlying sleeve 16.

CA 02214230 1997-08-27
Referring to FIGURE 2, the method of fabricating rod
guide/sucker rod combination 10 involves the following steps.
The first step involves providing a sucker rod 12 having an
exterior surface 18 with a raised profile 20. As sucker rod
12 does not come with such a raised profile, raised profile 20
is, preferably, injection molded onto exterior surface 18 of
sucker rod 12. The configuration illustrated shows injected
molded portion 22, which forms raised annular profile 20. The
second step involves providing split sleeve 14. Split sleeve
14, as illustrated consists of two segments 14a and 14b. Split
sleeve 14 has an interior surface 24 with a recessed annular
profile 26 that mates with raised annular profile 20 of sucker
rod 12. As long as segments 14a and 14b are held together to
maintain recessed annular profile 26 in engagement with raised
annular profile 20, split sleeve 14 is secured against axial
movement relative to sucker rod 12. Split sleeve 14 is
preferably formed through an injection molding process. The
third step involves providing an overlying sleeve 16 that
overlies split sleeve 14 to maintain segments 14a and 14b of
split sleeve 14 in mating engagement with sucker rod 12.
Overlying sleeve 16 must be secured to split sleeve 14. It is
preferred that overlying sleeve 16 be injection molded over
split sleeve 14, in situ. Preferably overlying sleeve 16 has
a plurality of exterior vanes 28. Once this step is completed
rod guide/sucker rod combination 10 is ready to be taken and
installed at a field location. Referring to FIGURE 1, in order
to promote improved fluid flow, it is preferred that injection
moulded portion 22, split sleeve 14 and overlying sleeve 16 be
staggered to give the ends a stepped or generally conical
shape. If the materials used for moulded portion 22 and split
sleeve 14 are not self lubricating, it may be advisable to
provide a lubrication port 30 which extends through both
overlying sleeve 16 and split sleeve 14. In order to prevent
silt, sand and other abrasives from entering lubrication port
30, it may be advisable to position a filter element 32 in
lubrication port 30.

CA 02214230 1997-08-27
It will be apparent to one skilled in the art that the
component parts of rod guide/sucker rod combination 10 can be
fabricated from any suitable material, such as nylon,
polyethylene, polyphenylene sulfide, or polyphthalamide. It
will also be apparent to one skilled in the art that any
desired configuration of vanes 28. It will finally be apparent
to one skilled in the art that modifications may be made to the
illustrated embodiment without departing from the spirit and
scope of the invention as hereinafter defined in the Claims.

Representative Drawing