U.S. patent application number 11/859861 was filed with the patent office on 2008-04-03 for blowout preventer and pump rod clamp.
This patent application is currently assigned to WEATHERFORD/LAMB, INC.. Invention is credited to Andrew J. Hanson, WILLIAM C. LANE.
Application Number | 20080078965 11/859861 |
Document ID | / |
Family ID | 39260230 |
Filed Date | 2008-04-03 |
United States Patent
Application |
20080078965 |
Kind Code |
A1 |
LANE; WILLIAM C. ; et
al. |
April 3, 2008 |
BLOWOUT PREVENTER AND PUMP ROD CLAMP
Abstract
Disclosed herein is a combined pump rod clamp/BOP for use in a
wellbore. The pump rod clamp/BOP is capable of supporting the
weight of the pump rod, preventing axial or rotational movement of
the rod, and simultaneous preventing fluids from escaping from the
well, while maintaining electrical conductivity between the BOP and
the polish rod. The pump rod clamp/BOP features rams having an
arcuate channel for clamping a pump rod. The rams include a
gripping non-metallic material non-releasably disposed on the
engaging face of the ram. The non-metallic material can coat the
entire engaging face of the ram, the arcuate channel only, or part
of the arcuate channel. The non-metallic gripping material prevents
the rams from damaging the pump rod when they engage the rod.
Inventors: |
LANE; WILLIAM C.; (The
Woodlands, TX) ; Hanson; Andrew J.; (Edmonton,
CA) |
Correspondence
Address: |
WONG, CABELLO, LUTSCH, RUTHERFORD & BRUCCULERI,;L.L.P.
20333 SH 249
SUITE 600
HOUSTON
TX
77070
US
|
Assignee: |
WEATHERFORD/LAMB, INC.
HOUSTON
TX
|
Family ID: |
39260230 |
Appl. No.: |
11/859861 |
Filed: |
September 24, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60827319 |
Sep 28, 2006 |
|
|
|
Current U.S.
Class: |
251/1.3 |
Current CPC
Class: |
E21B 19/12 20130101;
E21B 33/062 20130101 |
Class at
Publication: |
251/001.3 |
International
Class: |
E21B 7/00 20060101
E21B007/00 |
Claims
1. A pump rod clamp/blowout preventer for use in a well,
comprising: a housing having a bore for receiving a pump rod; rams
situated in the housing and movable between an activated position
wherein the rams grippingly engage the pump rod with adequate force
to support the pump rod and to prevent axial or rotational movement
of the pump rod and prevent fluids from escaping from the well
through the bore; the rams comprising: an engaging face having an
arcuate channel situated to receive the pump rod when the ram is
the activated position, and a non-metallic material non-releasably
disposed on at least a portion of the engaging face for contacting
the pump rod.
2. The pump rod clamp/blowout preventer of claim 1, wherein the
non-metallic material covers the entire engaging face.
3. The pump rod clamp/blowout preventer of claim 1, wherein the
non-metallic material is disposed substantially only in the arcuate
channel.
4. The pump rod clamp/blowout preventer of claim 1, wherein the
non-metallic material is disposed as one or more bands in the
arcuate channel.
5. The pump rod clamp/blowout preventer of claim 1, wherein the
non-metallic material is selected from the group consisting of
elastomers, rubbers, polymers, ceramics, carbides, nitrides, metal
oxides, chrysotile materials, metal oxides, and composites
containing metal oxides.
6. The pump rod clamp/blowout preventer of claim 5, wherein the
non-metallic material is aluminum oxide.
7. The pump rod clamp/blowout preventer of claim 1, wherein the
non-metallic material is non-releasably affixed to the engaging
face by gluing, brazing, form fitting, press fitting, molding,
interference fitting, spray coating, or direct chemical
deposition.
8. The pump rod clamp/blowout preventer of claim 1, wherein the
arcuate channel includes one or more pockets for non-releasably
receiving a band of the non-metallic material.
9. A pump rod clamp/blowout preventer for use in a well,
comprising: a housing comprising: a longitudinal bore for receiving
a pump rod; at least one of an upper or lower flange for securing
the housing to wellhead equipment; and a pair of opposed radial
bores generally perpendicular to, and terminating at, the
longitudinal bore; rams and a actuators received in each of the
opposed radial bores, the actuators configured to move the rams
between an activated and a non-activated position wherein in the
activated position the rams grippingly engage the pump rod with
adequate force to support the pump rod and to prevent axial or
rotational movement of the pump rod and simultaneously prevent
fluids from escaping from the well through the longitudinal bore,
the rams comprising: an engaging face having an arcuate channel
situated to receive the pump rod when the ram is the activated
position, and a non-metallic material non-releasably disposed on at
least a portion of the engaging face for contacting the pump
rod.
10. The pump rod clamp/blowout preventer of claim 9, wherein the
actuators comprise stems threadably received within the actuators
such that rotation of the stems moves the rams between the
activated and non-activated positions.
11. The pump rod clamp/blowout preventer of claim 9, wherein the
non-metallic material covers the entire engaging face.
12. The pump rod clamp/blowout preventer of claim 9, wherein the
non-metallic material is disposed substantially only in the arcuate
channel.
13. The pump rod clamp/blowout preventer of claim 9, wherein the
non-metallic material is disposed as one or more bands in the
arcuate channel.
14. The pump rod clamp/blowout preventer of claim 9, wherein the
non-metallic material is selected from the group consisting of
elastomers, rubbers, polymers, ceramics, carbides, nitrides, metal
oxides, chrysotile materials, metal oxides, and composites
containing metal oxides.
15. The pump rod clamp/blowout preventer of claim 14, wherein the
non-metallic material is aluminum oxide.
16. The pump rod clamp/blowout preventer of claim 9, wherein the
non-metallic material does not provide an electrically insulating
barrier between the pump rod and the ram.
17. The pump rod clamp/blowout preventer of claim 16, further
comprising an electrical contact for maintaining electrical
equilibrium between the housing and the pump rod.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Provisional Application
Ser. No. 60/827,319, filed Sep. 28, 2006, the entire contents of
which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to oil and/or gas
production and more specifically to a combination pump rod clamp
and blowout preventer (BOP) for oil, gas, or water wells, and in
particular to a pump rod clamp/blowout preventer having a pump rod
clamping or gripping capability sufficient to support a pump rod
and providing enhanced safety from static charge buildup.
BACKGROUND
[0003] Blowout preventers (BOPs) and pump rod clamps (aka polished
rod clamps) have been generally known in the art for some time.
Pump rod clamps are used to suspend the rod within the well, and/or
to prevent rotational movement of the pump rod. Many types of pump
rod clamps are known. Some rod clamps use a pair of rams that are
driven radially inward to contact the pump rod and hold it in
place. Others use wedges inserted around the rod. Still others use
a pair of rams that can be bolted around the exterior surface of
the rod and hung from a mandrel or other support member.
[0004] BOPs are used to seal off the well and contain its contents
under a variety of different situations. For example, during the
servicing of a wellhead one or more blowout preventers are often
used to seal against the pump or polished rod to contain the
contents of the well when downstream equipment is removed or
disassembled for servicing. In other instances blowout preventers
may be used to seal off a well where the pump rod is removed, or in
the event of a failure of the pump rod. Blowout preventers
typically include a pair of rams that are received within cylinders
extending through a BOP housing and situated generally
perpendicular to the longitudinal axis of the well casing.
Typically the end of each ram has a semi-circular channel on its
face to allow it to seal against the exterior surface of the pump
rod when the BOP is actuated by driving the rams inward. The faces
of the rams may include an elastomer or other sealing mechanism to
ensure that a fluid tight seal is created when the rams fully
engage the pump rod.
[0005] Generally, BOPs and pump rod clamps are separate pieces of
equipment. The BOP is typically capable of sealingly engaging the
pump rod to prevent blow out, but does not engage the rod
forcefully enough to suspend the rod or prevent the rod from
rotating. Thus a rod clamp is required for this duty. Likewise,
though rod clamps grip the rod forcefully enough to suspend the rod
or prevent its rotation, the engagement between the rod clamp and
the rod is not typically a sealing engagement and thus does not
prevent the contents of the well from escaping. Thus, there is a
need for a single piece of equipment that can serve double-duty as
both a pump rod clamp and a BOP.
[0006] Recent disclosures have purported to describe particular
embodiments of combination BOP/well rod clamp devices. One example
is U.S. Pat. No. 7,000,888, by Wright et al., ("the '888 patent")
the entire contents of which are incorporated herein by reference.
The '888 patent describes a pump rod clamp having rams featuring
arcuate channels to sealingly engage a pump rod. The rams include
one or more gripping inserts releasably secured to the rams, or a
non-metallic coating applied to the rams, providing an electrically
insulating barrier between the pump rod clamp and the pump rod.
[0007] U.S. Pat. No. 6,843,313, by Hult ("the '313 patent") and
related U.S. Patent Application Publication No. 2005/0045323 A1,
describe a pump drive head for a progressing cavity pump that
includes a pump rod lock-out clamp that is integral with or
adjacent to a blow-out-preventer. One embodiment described in these
references includes a BOP that serves as a lock out clamp for well
servicing. The BOP/lock-out clamp includes metal pistons that are
forced against the pump rod to grippingly engage in metal-to-metal
contact. The inner end of the pistons includes an arcuate recess
with curvature corresponding to the pump rod. The pistons also
include a narrow elastomeric seal running across the vertical flat
face of the piston, along the arcuate recess, along the mid height
of the piston and then circumferentially around the piston. The
elastomeric seals seal between the pistons, between the pistons and
the pump rod, and between the pistons and the piston bores, thereby
preventing fluid from escaping up the well bore when the pistons
are engaged with the pump rod. The entire contents of the '313
patent and U.S. Patent Application Publication No. 2005/0045323 A1
are incorporated herein by reference.
SUMMARY
[0008] Disclosed herein is a combination pump rod clamp/BOP. The
pump rod clamp/BOP has a housing having a lateral bore for
receiving a pump rod. Rams are contained in the housing for
engaging the pump rod with strength capable of supporting the
weight of the pump rod and preventing axial or rotational movement
of the rod. When the pump rod clamp/BOP is activated, i.e., when
the rams are engaged with the pump rod, the rams also seal off the
lateral bore, preventing fluids from escaping from the well through
the bore.
[0009] The rams have an arcuate channel for clamping the pump rod
and also include a gripping non-metallic material non-releasably
disposed on the face of the ram. The non-metallic material can coat
the entire leading face of the ram, the arcuate channel only, or
part of the arcuate channel. These and other features will be
apparent in view of the below description and the attached
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A illustrates a pump rod clamp/BOP in a deactivated
position.
[0011] FIG. 1B illustrates a pump rod clamp/BOP in an engaged
(activated) position.
[0012] FIG. 2 illustrates a ram for a pump rod clamp/BOP, the ram
having a non-metallic gripping material non-releasably disposed
thereon.
[0013] FIG. 3 illustrates a top-down view of rams engaging a pump
rod, as when a pump rod clamp/BOP is in an activated position.
[0014] FIG. 4 illustrates a ram for pump rod clamp/BOP having a
non-metallic non-releasable insert.
DESCRIPTION
[0015] In the FIGS. like numbers represent like elements. FIGS. 1A
and 1B illustrate a BOP/pump rod clamp according to the present
disclosure. Pump rod clamp/BOP 1 includes a central housing 2
having a longitudinal bore 3 extending through the central housing
2 for receiving a pump rod 4. Central housing 2 may contain upper
and lower flanges or threaded connections, 5 and 6 respectively,
for mounting the housing to wellhead equipment. As is common with
most blowout preventers, central housing 2 further includes a pair
of opposed radial bores 7 and 8 that are generally perpendicular
to, and that terminate at, longitudinal bore 3. Rams 9 and 10 are
slidably received within bores 7 and 8. One or more actuators 11
are used to move rams 9 and 10 between a deactivated position FIG.
1A wherein rams 9 and 10 do not engage the exterior surface of the
pump rod and an activated position wherein rams 9 and 10 extend
into longitudinal bore 7 and 8 and grippingly engage the exterior
surface of the pump rod 4. Any of a variety of actuators may be
used to move the rams between their activated and deactivated
positions. Such mechanisms include manual, hydraulic, pneumatic, or
electric actuators. In the embodiment shown, actuators 11 include
stems 12 that can be threadably received within the actuators. The
inner most ends of the stems 12 are attached to rams 9 and 10 and
are free to rotate with respect to the rams. Stems 12 can be
rotated manually, electrically, pneumatically, or the like to move
rams 9 and 10 between engaged and disengaged positions.
[0016] FIG. 2 illustrates a ram 9, having a engaging face 21
directed generally toward longitudinal bore 3 (and hence toward the
exterior surface of a pump rod received within the longitudinal
bore). Leading face 21 includes an arcuate channel 22 in general
alignment with longitudinal bore 3 and a pump rod received therein.
Arcuate channel 22 is positioned in such a manner that, when the
rams are moved inwardly to their activated position, arcuate
channel 22 encompasses the pump rod and grippingly engages the
exterior surface of the rod.
[0017] Engaging face 21 includes a non-releasable non-metallic
material 23 for making contact with the pump rod to securely hold
the rod in place when the rams are moved to their activated
position. FIG. 3 illustrates a top-down cross sectional view of
rams 9 and 10 engaging a pump rod 4. Non-metallic material 23 makes
contact with pump rod 4 and holds the rod in place. Leading faces
21 sealingly engage each other, thereby preventing fluids from
escaping up bore 3. The non-metallic gripping material can be
disposed only (or substantially only) in the arcuate channel as
shown in FIG. 2 or can partially or totally coat the entire leading
face 21.
[0018] FIG. 4 illustrates an alternative embodiment of ram 9
including gripping inserts 41 disposed in arcuate channel 22.
Gripping inserts 41 can be made of any suitable non-metallic
material, as described above. Gripping inserts 41 are joined to ram
9 using any suitable non-releasable method. For example, gripping
inserts 41 can be non-releasably press-fit into receiving cavities
machined into arcuate channel 22.
[0019] The non-metallic material can be any non-metallic material
suitable for grippingly engaging a pump rod. The non-metallic
material presents a hard surface for engaging the exterior of the
pump rod without scoring or galling the rod. Traditional rod clamps
that permit metal-to-metal contact often gall the surface of the
rod and create burs, ridges, and other marks that can rip or tear
packing material when the rod is pulled from the well. The
non-metallic material reduces the likelihood of damage to the
exterior of the rod. The non-metallic material can have a slightly
roughened texture. As used herein, non-metallic material refers to
materials that are not metals or alloys.
[0020] Suitable non-metallic materials include elastomers such as
rubbers, polymers, and the like, ceramics, carbides, nitrides,
composites, metal oxides, etc. Composites commonly used for
automobile break shoes are particularly suitable. Such materials
include chrysotile materials, metal oxides, and composites
containing metal oxides. Metal oxides, such as aluminum oxide are
also particularly suitable.
[0021] The non-metallic material can be affixed to the rams by any
suitable non-releasable method. For example, the material can be
glued to the ram using a durable gluing material such as a resin,
epoxy, or the like. If the non-metallic material is amenable to
brazing, as in the case of carbides, for example, brazing can be
used. Non-releasably form fitting, press fitting, molding, or
interference fitting can also be used. The non-metallic material
can be deposited directly on the ram, spray coated onto the ram, or
deposited chemically onto the ram, etc. According to one
embodiment, the arcuate channel includes pockets for receiving a
band of the non-metallic material. The non-metallic material can be
press fit, or otherwise non-releasably disposed within the pockets,
as shown in FIG. 4. Generally the methods of applying the
non-metallic material to the rams in a non-releasable manner
provide a high degree of rigidity in the structure.
[0022] The non-metallic material may or may not provide an
insulating barrier between the rams and the pump rod and/or between
the pump rod and the pump rod clamp/BOP. According to one
embodiment, the non-metallic material does not provide such
electrical insulation. In such an embodiment, the pump rod and the
pump rod clamp/BOP may be maintained in electrical equilibrium
(i.e., electrical contact is provided between the pump rod
clamp/BOP and the pump rod) to prevent static charge buildup
between the pump rod and the pump rod clamp/BOP. Such electrical
equilibrium may be provided by a shunt wire, Conductive coatins,
conductive seals, one or more metallic tabs, non-grippingly
engaging metallic round nose spring plunger, or the like to
maintain electrical equilibrium between the pump rod and the
housing of the pump rod clamp/BOP.
[0023] It should be understood that the inventive concepts
disclosed herein are capable of many modifications. To the extent
such modifications fall within the scope of the appended claims and
their equivalents, they are intended to be covered by this
patent.
* * * * *