U.S. patent application number 13/630931 was filed with the patent office on 2013-01-24 for unibody lubricator with externally threaded nipple.
This patent application is currently assigned to MVM MACHINING. The applicant listed for this patent is MVM MACHINING. Invention is credited to STEPHEN MAERZ.
Application Number | 20130020091 13/630931 |
Document ID | / |
Family ID | 47554981 |
Filed Date | 2013-01-24 |
United States Patent
Application |
20130020091 |
Kind Code |
A1 |
MAERZ; STEPHEN |
January 24, 2013 |
UNIBODY LUBRICATOR WITH EXTERNALLY THREADED NIPPLE
Abstract
A lubricator for receiving a plunger is provided. The lubricator
has a bore, a first end having a well head connection, a second end
having a stem connection, and a plurality of ports, including a
catcher port and flow ports. The flow ports are externally threaded
nipples that extend radially beyond the outer surface of body of
the lubricator.
Inventors: |
MAERZ; STEPHEN; (Calgary,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MVM MACHINING; |
Calgary |
|
CA |
|
|
Assignee: |
MVM MACHINING
Calgary
CA
|
Family ID: |
47554981 |
Appl. No.: |
13/630931 |
Filed: |
September 28, 2012 |
Current U.S.
Class: |
166/379 ;
166/90.1 |
Current CPC
Class: |
F16L 41/04 20130101;
E21B 19/16 20130101; E21B 33/03 20130101; E21B 43/121 20130101;
E21B 33/038 20130101 |
Class at
Publication: |
166/379 ;
166/90.1 |
International
Class: |
E21B 19/16 20060101
E21B019/16 |
Claims
1. A lubricator for receiving a plunger comprising: an outer
surface; an inner surface defining a bore; a well head connection
at a first end for connecting a well head; a stem connection at a
second end for connecting a stem; at least one flow port for
connecting a flow line, the at least one flow port being an
externally threaded nipple that extends radially outwardly from the
outer surface; and a catcher port for catching a plunger.
2. The lubricator of claim 1, further comprising a supplementary
port for attaching gauges or sensors, or for injecting
chemicals.
3. The lubricator of claim 1, wherein the externally threaded
nipple is a threadolet attached to an aperture that allows fluid to
flow between the inner surface and the outer surface.
4. The lubricator of claim 3, wherein the threadolet is attached by
welding.
5. The lubricator of claim 1, wherein the lubricator is formed by
forging, machining, casting, or a combination thereof.
6. The lubricator of claim 1, further comprising lifting
eyelets.
7. A method for connecting a plunger lubricator to a flow line
fitting having external threads, comprising: providing an
externally threaded nipple that extends radially outwardly from an
outer surface of the lubricator; threadedly connecting the
externally threaded nipple to a first end of an internally threaded
collar; and threadedly connecting a second end of the internally
threaded collar to the external threads of the flow line
fitting.
8. The method of claim 7, further comprising disposing a
compressible washer inside the collar, between the externally
threaded nipple and the flow line fitting.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a plunger lubricator.
BACKGROUND
[0002] During fluid production operations, a plunger lift system is
sometimes used when pressure within a wellbore is insufficient to
cause fluid to rise naturally. In a plunger lift system, a plunger
serves as a mechanical interface between lift gas below the plunger
and produced fluid above the plunger. When sufficient lift gas from
the reservoir collects below the plunger to provide buoyant lift to
the plunger and produced fluid above the plunger, the fluid and
plunger are elevated in the wellbore to the surface. At the
surface, a lubricator is used to absorb the kinetic energy of the
plunger and to recover the plunger from the wellbore. The
lubricator has fluid flow ports where produced fluids above the
plunger maybe fed to, for instance, a pipeline or collection
system.
[0003] Canadian patent no. 2,635,993 discloses a plunger lubricator
housing, which comprises an elongated tubular body made from a
single piece of material. The body has a first end, a second end,
an outer surface, an inner surface that defines a plunger receiving
interior bore, and radial ports which provide fluid communication
between the interior bore and the outer surface. Each of the radial
ports 43 has a threaded coupling that is inset from the outer
surface of the body 40. FIG. 6 illustrates an example of a radial
port 43 having a threaded coupling 41 inset in the body 40, which
is shown to be connected to the external threads 42 of a fitting
44. As fluid flows out of port 43 (and the direction of fluid flow
is indicated by an arrow "F"), the fluid may cause erosion in an
area 42 near the junction of threaded coupling 41 and fitting 44
because the presence of the fitting 44 disrupts the flow path
within port 43 as the fluid has to change directions to flow around
the fitting.
SUMMARY OF INVENTION
[0004] The invention disclosed herein provides for a plunger
lubricator.
[0005] In accordance with one aspect of the present invention,
there is provided a lubricator for receiving a plunger comprising:
an outer surface; an inner surface defining a bore; a well head
connection at a first end for connecting a well head; a stem
connection at a second end for connecting a stem; at least one flow
port for connecting a flow line, the at least one flow port being
an externally threaded nipple that extends radially outwardly from
the outer surface; and a catcher port for catching a plunger.
[0006] In accordance with another aspect of the present invention,
there is provided a method for connecting a plunger lubricator to a
flow line fitting having external threads, comprising: providing an
externally threaded nipple that extends radially outwardly from an
outer surface of the lubricator; threadedly connecting the
externally threaded nipple to a first end of an internally threaded
collar; and threadedly connecting a second end of the internally
threaded collar to the external threads of the flow line
fitting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Drawings are included for the purpose of illustrating
certain aspects of the invention. Such drawings and the description
thereof are intended to facilitate understanding and should not be
considered limiting of the invention. Drawings are included, in
which:
[0008] FIG. 1 A is a perspective view of a first side of a
lubricator;
[0009] FIG. 1B is a perspective view of a second side of the
lubricator;
[0010] FIG. 2 is an elevation view of the second side of the
lubricator;
[0011] FIG. 3 is a cross-sectional view of the lubricator along the
line "A-A" in FIG. 2;
[0012] FIG. 4 is an elevation view of the first side of the
lubricator;
[0013] FIG. 5 is an enlarged view of the part marked "B" of the
lubricator in FIG. 3;
[0014] FIG. 6 is a cross-sectional view of a port of a prior art
lubricator; and
[0015] FIG. 7 is a cross-sectional view of a flow port of the
present lubricator.
DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS
[0016] The detailed description set forth below in connection with
the appended drawings is intended as a description of various
embodiments of the present invention and is not intended to
represent the only embodiments contemplated by the inventor. The
detailed description includes specific details for the purpose of
providing a comprehensive understanding of the present invention.
However, it will be apparent to those skilled in the art that the
present invention may be practiced without these specific
details.
[0017] Referring to FIGS. 1A, 1B, and 2 to 5, a lubricator 10
comprises an outer surface 14 and a bore 18 defined by an inner
surface 12. Bore 18 is for receiving a plunger (not shown).
Lubricator 10 also includes a well head connection 20 at a first
end for connecting to a well head (not shown), and a stem
connection 24 at a second end for connecting to a stem (not shown).
Lubricator 10 may be formed by forging, machining bar stock,
casting, or a combination of known manufacturing methods.
[0018] Lubricator 10 further includes flow ports 28 for connecting
to flow lines (not shown). In one embodiment, flow ports 28 are
externally threaded nipples 29 that extend radially beyond outer
surface 14. Lubricator 10 may also be provided with other ports 30,
which may be used for attaching gauges or sensors, or for injecting
chemicals. Lubricator 10 may also comprise a catcher port 34 to
catch a plunger at the top of its stroke. Ports 30 and 34 may be
external nipples that extend radially outwardly from outer surface
14. In one embodiment, ports 28, 30, and 34 are machined into
lubricator 10. In another embodiment, ports 28, 30, and 34 are
formed by creating apertures in the body of lubricator 10 and then
integrating separate components to the circumference of the
apertures, for example, by attaching threadolets by welding. In one
embodiment, lubricator 10 includes an equipment attachment which
may be used for attaching a sensor to indicate the arrival of a
plunger. In another embodiment, other components, such as lifting
eyelets, are welded or otherwise attached to lubricator 10.
[0019] In one embodiment, lubricator 10 is constructed from a
single piece of material as described hereinafter. A single piece
of material is machined, forged, or casted to form bore 18 and
outer surface 14. The material may be any metal meeting proper
specifications for strength, temperature rating, ductility,
durability, corrosion resistance, capability of being welded,
worked or machined, typically a steel, and preferably 4130 or 4140
carbon steel. Well head connection 20 is machined at the first end,
and stem connection 24 is machined at the second end. In one
embodiment, outer surface 14 may be machined to form ports 28, 30
and 34. In another embodiment, apertures are created in the body of
lubricator 10 and separate threadolet components may be welded to
the circumference of the apertures to form ports 28, 30, and 34. In
a further embodiment, outer surface 14 is machined to have an
increased thickness at various points along the length of the
lubricator 10 such that the lubricator 10 may have increased
thickness about ports 28, 30 and 34, or at other locations.
[0020] Referring to FIGS. 6 and 7, in contrast to the prior art
radial port 40 having an inset threaded coupling 41, flow port 28
of lubricator 10 is an externally threaded nipple 29. In one
embodiment, nipple 29 is connected to fitting 44 by a collar 46.
Collar 46 may have internal threads that allow collar 46 to mate
with the external threads of nipple 29 and fitting 44. Connecting
nipple 29 and fitting 44 using collar 46 may minimize erosion of
the inner surface of flow port 28 and fitting 44. Further, collar
46 may provide additional reinforcement by increasing the wall
thickness at the joint between nipple 29 and fitting 44. In a
further embodiment, a compressible washer 48 is disposed inside
collar 46, between the adjacent ends of nipple 29 and fitting 44.
Compressible washer 48 may act i) to protect the threads on collar
46; ii) to seal the joint between nipple 29 and fitting 44; and/or
iii) as a lock-washer, which exerts longitudinal force to increase
thread-to-thread friction between the collar's threads' side-slopes
and the mating surfaces in the threads of nipple 29 and fitting
44.
[0021] The previous description of the disclosed embodiments is
provided to enable any person skilled in the art to make or use the
present invention. Various modifications to those embodiments will
be readily apparent to those skilled in the art, and the generic
principles defined herein may be applied to other embodiments
without departing from the spirit or scope of the invention. Thus,
the present invention is not intended to be limited to the
embodiments shown herein, but is to be accorded the full scope
consistent with the claims, wherein reference to an element in the
singular, such as by use of the article "a" or "an" is not intended
to mean "one and only one" unless specifically so stated, but
rather "one or more". All structural and functional equivalents to
the elements of the various embodiments described throughout the
disclosure that are know or later come to be known to those of
ordinary skill in the art are intended to be encompassed by the
elements of the claims. Moreover, nothing disclosed herein is
intended to be dedicated to the public regardless of whether such
disclosure is explicitly recited in the claims.
* * * * *