U.S. patent application number 13/897541 was filed with the patent office on 2014-07-03 for reinforced variable ram packer using fabric.
This patent application is currently assigned to Hydril USA Manufacturing LLC. The applicant listed for this patent is Hydril USA Manufacturing LLC. Invention is credited to Arturo Caballero, William L. Carbaugh, Joseph Alan Incavo.
Application Number | 20140183381 13/897541 |
Document ID | / |
Family ID | 51016059 |
Filed Date | 2014-07-03 |
United States Patent
Application |
20140183381 |
Kind Code |
A1 |
Carbaugh; William L. ; et
al. |
July 3, 2014 |
REINFORCED VARIABLE RAM PACKER USING FABRIC
Abstract
A variable ram assembly for use in a blowout preventer (BOP)
stack includes a packer element. The packer element includes an
elastomeric body having a contact surface configured with a curved
recess for sealing engaging a tubular. Fibers are included in the
body adjacent the contact surface that exert a restraining force to
prevent extrusion of the elastomeric body when it is forced against
the tubular. The fibers are integrally formed in the body and may
be woven into a fabric, which is disposed into a packer element
mold along with uncured elastomer before forming the body. The
fabric can be coated with an elastomer to bond with the body during
the forming process.
Inventors: |
Carbaugh; William L.;
(Humble, TX) ; Incavo; Joseph Alan; (The
Woodlands, TX) ; Caballero; Arturo; (Humble,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hydril USA Manufacturing LLC |
Houston |
TX |
US |
|
|
Assignee: |
Hydril USA Manufacturing
LLC
Houston
TX
|
Family ID: |
51016059 |
Appl. No.: |
13/897541 |
Filed: |
May 20, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61747576 |
Dec 31, 2012 |
|
|
|
Current U.S.
Class: |
251/1.1 ;
137/15.18 |
Current CPC
Class: |
Y10T 137/0491 20150401;
E21B 33/062 20130101 |
Class at
Publication: |
251/1.1 ;
137/15.18 |
International
Class: |
E21B 33/06 20060101
E21B033/06 |
Claims
1. A variable ram comprising: a ram block selectively moveable
within a blowout preventer (BOP); and a ram packer disposed in the
ram block comprising an elastomer body, a contact surface along a
lateral side of the body, a recess portion on a mid-portion of the
contact surface that projects radially into the body and that is in
selective sealing engagement with a tubular in the BOP, and fibers
in the body adjacent the contact surface, so that when the ram
block is moved radially inward into sealing contact with the
tubular, the fibers exert a force that oppose extrusion of the
body.
2. The variable ram of claim 1, wherein the fibers comprise a
material selected from the group consisting of a polyester, a
polyamide, a cellulose fiber, cotton, para-aramid synthetic fiber,
neoprene, nitrile rubber, hydrogenated nitrile rubber, carboxylated
nitrile rubber, and combinations thereof.
3. The variable ram of claim 1, wherein the contact surface
adjacent an end of the recess portion is at an angle with respect
to the recessed portion to define an edge on the contact surface,
and wherein the fibers extend adjacent the edge.
4. The variable ram of claim 1, wherein the fibers comprise lateral
fibers that extend laterally along the body.
5. The variable ram of claim 1, wherein the fibers comprise axial
fibers that extend axially in the body.
6. The variable ram of claim 1, wherein the fibers comprise lateral
fibers that extend laterally along the body and axial fibers in the
body adjacent the contact surface that are generally coplanar with
the lateral fibers and oriented at an angle with the lateral
fibers.
7. The variable ram of claim 1, wherein the fibers are woven into a
planar fabric and rubber coated to define a rubberized fabric.
8. The variable ram of claim 1, wherein at least some of the fibers
extend adjacent to one of an upper surface and a lower surface of
the body that respectively adjoin opposing upper and lower ends of
the contact surface.
9. The variable ram of claim 1, wherein the elastomer body is more
elastic than the fibers.
10. The variable ram of claim 1, wherein the elastomer body is
substantially solid.
11. A ram packer assembly for use in a blowout preventer (BOP)
comprising: a body comprising an elastomeric material and
selectively disposed in a ram block; a contact surface on the body
having a curved recess that selectively seals against a tubular in
the BOP; and a fabric integral in the body and disposed adjacent
the contact surface, so that when the body is forced against the
tubular, the fabric exerts a force on that opposes extrusion of the
body.
12. The ram packer assembly of claim 11, further comprising a
series of interlocking plates that selectively slide with respect
to one another on a radial surface of the body when the body is
radially compressed.
13. The ram packer assembly of claim 11, wherein the fabric
comprises fibers made of a material selected from the group
consisting of a polyester, a polyamide, a cellulose fiber, cotton,
para-aramid synthetic fiber, neoprene, nitrile rubber, hydrogenated
nitrile rubber, carboxylated nitrile rubber, and combinations
thereof.
14. The ram packer assembly of claim 11, wherein the fabric is
provided along an interface between an end of the curved recess and
an adjacent planar portion of the contact surface.
15. The ram packer assembly of claim 11, wherein a portion of the
body adjacent the fabric is stiffer than a portion of the body
distal from the fabric.
16. A method of forming a ram packer assembly having a contact
surface and that is for use in a blowout preventer (BOP), the
method comprising: a. providing an uncured elastomer; b. disposing
the uncured elastomer into a ram packer assembly mold; c. inserting
the uncured elastomer into the mold; d. strategically disposing
fibers in the mold to be adjacent the contact surface; and e.
curing the uncured elastomer to form a body with the fibers
integrally set in the body.
17. The method of claim 16, further comprising providing sliding
plates in the mold that mount on opposing surfaces of the body.
18. The method of claim 16, wherein the fibers comprise a material
selected from the group consisting of a polyester, a polyamide, a
cellulose fiber, cotton, para-aramid synthetic fiber, neoprene,
nitrile rubber, hydrogenated nitrile rubber, and combinations
thereof.
19. The method of claim 16, wherein the fibers are woven into a
fabric and coated with an elastomer that adheres with the body.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of
co-pending U.S. Provisional Application Ser. No. 61/747,576 filed
on Dec. 31, 2012, the full disclosure of which is hereby
incorporated by reference herein for all purposes.
BACKGROUND
[0002] 1. Field of Invention
[0003] The present disclosure relates in general to a variable ram
packer for use with a blowout preventer (BOP) mounted on a
wellhead. More specifically, the present disclosure relates to a
variable ram packer with a packer element having a reinforcement
material on its contact surface.
[0004] 2. Description of Prior Art
[0005] Wellbores in hydrocarbon bearing subterranean formations are
formed by rotating a drill bit mounted on a lower end of a drill
string. Typically, a wellhead housing is installed at the earth's
surface and through which bit and string are inserted. A blow out
preventer (BOP) stack usually mounts on top of the wellhead housing
that provides pressure control of the wellbore, and often includes
rams to shut in the wellbore should pressure in the wellbore become
uncontrollable. Additional rams are often included with BOP stacks
that are for shearing the string within the BOP stack, and also for
pressure testing within the BOP. Further typically included with
BOP stacks are flow lines and valves to allow fluid flow through
the BOP stack for remediating overpressure in the wellbore.
[0006] One type of BOP ram for pressure testing within a BOP stack
is a variable ram packer. Variable ram packers usually include a
pair of hydraulically powered rams on opposing lateral sides of the
BOP stack, which are selectively forced radially inward into
compressive engagement with the tubular. An elastomer packer
element is typically provided with the variable ram packers for
engaging the tubular, and has a curved recess on its engaging
surface for receiving the tubular. The curved recesses on the pair
of packers form a seal in the bore and around the tubular so
pressure in the wellbore can be verified. Adjacent the curved
recess, each packer element often has a planar surface that defines
an edge at the interface between the recess and planar surface.
During operation of the variable ram packers, compressive stresses
in the recess transfer to the unsupported edge portion and extrude
it outward. Over time, the edge portion is susceptible to damage
from these multiple extrusion cycles, especially during exposure to
varying low and high temperatures.
SUMMARY OF THE INVENTION
[0007] Provided herein are embodiments of a variable ram for use
with a blowout preventer (BOP) and a method of making In one
example, a variable ram is disclosed that includes a ram block
selectively moveable within a BOP, and a ram packer disposed in the
ram block. In this example, the ram packer is made of an elastomer
body with a contact surface along one of its lateral sides. A
recess portion is provided on a mid-portion of the contact surface,
and which projects radially into the body. The recess portion is in
selective sealing engagement with a tubular in the BOP, and fibers
in the body adjacent the contact surface, so that when the ram
block is moved radially inward into sealing contact with the
tubular, the fibers exert a force that oppose extrusion of the
body. The fibers can be made from a polyester, a polyamide, a
cellulose fiber, cotton, para-aramid synthetic fiber, neoprene,
nitrile rubber, hydrogenated nitrile rubber, carboxylated nitrile
rubber, and combinations thereof. In one example, a portion of the
contact surface, adjacent an end of the recess portion, is at an
angle with respect to the recessed portion; where the angle defines
an edge on the contact surface, and wherein the fibers extend
adjacent the edge. The fibers comprise can be lateral fibers that
extend laterally along the body. Optionally, the fibers can be
axial fibers that extend axially in the body. In another example,
the fibers are lateral fibers that extend laterally along the body
and axial fibers in the body adjacent the contact surface that are
generally coplanar with the lateral fibers and oriented at an angle
with the lateral fibers. The fibers can be woven into a planar
fabric and rubber coated to define a rubberized fabric. In an
example, at least some of the fibers extend adjacent to one of an
upper surface and a lower surface of the body that respectively
adjoin opposing upper and lower ends of the contact surface. The
elastomer body can be more elastic than the fibers. The elastomer
body can be substantially solid.
[0008] Also disclosed herein is an example of a ram packer assembly
for use in a BOP and which includes an elastomeric body selectively
disposed in a ram block. The body has a contact surface with a
curved recess that selectively seals against a tubular in the BOP.
A fabric is integral in the body and adjacent the contact surface.
Thus when the body is forced against the tubular, the fabric exerts
a force that opposes extrusion of the body. A series of
interlocking inserts can be included that selectively slide with
respect to one another on a radial surface of the body when the
body is radially compressed. The fabric can include fibers made of
one or more of a polyester, a polyamide, a cellulose fiber, cotton,
para-aramid synthetic fiber, neoprene, nitrile rubber, hydrogenated
nitrile rubber, and a carboxylated nitrile rubber. In an example,
the fabric is provided along an interface between an end of the
curved recess and an adjacent planar portion of the contact
surface. The portion of the body adjacent the fabric can be stiffer
than a portion of the body distal from the fabric.
[0009] A method of forming a ram packer assembly is provided
herein, where the ram packer assembly has a contact surface and
that is for use in a BOP. One example of the method includes
providing an uncured elastomer and disposing it into a ram packer
assembly mold. Fibers are strategically disposed in the mold to be
adjacent the contact surface. The uncured elastomer is cured to
form a body with the fibers integrally set in the body. Sliding
plates are optionally provided in the mold that mount on opposing
surfaces of the body. In one example, the fibers are made from one
of a polyester, a polyamide, a cellulose fiber, cotton, para-aramid
synthetic fiber, neoprene, nitrile rubber, hydrogenated nitrile
rubber, and combinations thereof The fibers can be woven into a
fabric and coated with an elastomer that adheres with the body.
BRIEF DESCRIPTION OF DRAWINGS
[0010] Some of the features and benefits of the present invention
having been stated, others will become apparent as the description
proceeds when taken in conjunction with the accompanying drawings,
in which:
[0011] FIG. 1 is a perspective view of an example of a variable ram
having an embodiment of a packer element in accordance with an
embodiment of the present invention.
[0012] FIG. 2 is a side partial sectional view of an example of the
variable ram of FIG. 1 included in a blowout preventer stack in
accordance with an embodiment of the present invention.
[0013] FIG. 3 is a perspective view of an example of a packer
element of FIG. 1 in accordance with an embodiment of the present
invention.
[0014] FIG. 4 is a plan view of an alternate embodiment of the
packer element of FIG. 1 in accordance with an embodiment of the
present invention.
[0015] FIG. 5 is a plan view of an example of molding an embodiment
of the packer element of FIG. 1 in accordance with an embodiment of
the present invention.
[0016] While the invention will be described in connection with the
preferred embodiments, it will be understood that it is not
intended to limit the invention to that embodiment. On the
contrary, it is intended to cover all alternatives, modifications,
and equivalents, as may be included within the spirit and scope of
the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
[0017] The method and system of the present disclosure will now be
described more fully hereinafter with reference to the accompanying
drawings in which embodiments are shown. The method and system of
the present disclosure may be in many different forms and should
not be construed as limited to the illustrated embodiments set
forth herein; rather, these embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey its
scope to those skilled in the art. Like numbers refer to like
elements throughout.
[0018] It is to be further understood that the scope of the present
disclosure is not limited to the exact details of construction,
operation, exact materials, or embodiments shown and described, as
modifications and equivalents will be apparent to one skilled in
the art. In the drawings and specification, there have been
disclosed illustrative embodiments and, although specific terms are
employed, they are used in a generic and descriptive sense only and
not for the purpose of limitation.
[0019] FIG. 1 provides a perspective view of an example embodiment
of a variable ram 10, which includes a ram block 12 which houses a
ram packer assembly 14. A recess 15 in the ram block 12 is
configured to receive the ram packer assembly 14. The recess 15
intersects with a forward facing end of the ram block 12, and
extends partially across the width and length of the ram block 12.
In the example of FIG. 1, the ram block 12 is a substantially
metallic member that is generally rectangular shaped, and where its
length and width exceed its height. A packer element 16 makes up
part of the packer assembly 14, which in an example is made at
least in part from an elastomeric material. Inserts 18 shown set on
an upper radial surface of the packer element 16 and arranged in a
semi-circle with its outer radius projecting into the recess 15.
Brackets at opposing terminal ends of the semi-circle are coupled
to the forward facing end of the packer element 16, but the
individual inserts 18 are laterally moveable on the radial surface
of the packer element 16. Inserts 18 are interlocked on their
respective adjoining edges, but slideable towards one another so
the semi-circle compresses when the packer element 16 is laterally
compressed.
[0020] An example of a blowout preventer (BOP) 20 is shown in a
side sectional view in FIG. 2 and which includes an embodiment of
the variable ram 10. The BOP 20 includes a body 21 for housing a
pair of variable rams 10; the variable rams 10 can be selectively
actuated laterally in and out of body 21. BOP 20 is shown mounted
on an upper end of a wellhead housing 22 that anchors on .a surface
24, where surface 24 may be subsea or on land. A main bore 26
through wellhead assembly 22 and BOP 20 is shown registering with a
wellbore 28 that is being formed through the surface 24 by a drill
string 30. In the example, the drill string 30 extends through the
main bore 26 and the wellbore 28, and includes a drill bit (not
shown) on its lower end, that when rotated by drill string 30
excavates wellbore 28. As illustrated in the example of FIG. 2,
variable rams 10 project radially inward from opposing bodies 21
into sealing engagement with an outer surface of tubular 30. In one
example, sealingly engaging the tubular 30 with variable ram allows
a pressure test to be performed in wellbore 28.
[0021] A perspective view of an example of packer assembly 14 is
provided in FIG. 3 wherein opposing lateral ends of packer assembly
14 are shown angled upward away from an upper radial surface. A
contact surface 32 is defined on the side of the packer element 16
that projects outward from the ram block 12 (FIG. 1) and which
includes a curved recess 34, which can be shaped as semi-circular
or semi-elliptical member. The curved recess 34 is shown formed
along a mid-portion of the contact surface 32 and projects radially
inward and follows a generally curved path with its outer radius
set adjacent inner radius of the inserts 18. In an example, when
the variable ram 10 is urged radially inward as illustrated in FIG.
2, the contact surface 32 is compressed against outer surface of
drill string 30. Strategically profiling the curved recess 34 in
combination with compressing the contact surface 32 against the
drill string 30 forms a sealing surface between packer element 16
and tubular 30 to define an axial pressure barrier in the main bore
26. Adjacent opposing ends of the curved recess 34, the contact
surface 32 is disposed in a plane generally parallel within axis of
drill string 30 (FIG. 2) thereby defining flats 36 on lateral ends
of the curved recess 34.
[0022] Further illustrated in the example of FIG. 3 is a
reinforcing compound 38 embedded within the body of the packer
element 16 and adjacent the contact surface 32. The reinforcing
compound 38 is shown made up of individual fibers 39 that extend
laterally along at least a portion of the length of the contact
surface 32. Optional fibers 39 are shown that extend axially
between opposing upper and lower radial surfaces of the packer
element 16. Alternate embodiments exist, wherein reinforcing
compound 38 includes only fibers that run either laterally, or
vertically, but not both. Further, the reinforcing compound 38 is
shown extending over an interface 40 on the contact surface 32
where curved recess 34 transitions into flat 36. In an example,
interface 40 is defined as an edge where the contact surface 32
angles in a radial direction at the boundary between flat 36 and
curved recess 34. Providing the reinforcing compound 38 across the
interface 40 further enhances and/or provides an advantage against
extrusion of the packer element 16 when set in sealing contact with
drill string 30 (FIG. 2).
[0023] In an embodiment, the reinforcing compound 38 is made up of
a fabric of the fibers 39. Example materials for the fiber 39
include polyester, nylon, rayon, cotton, polyamide, neoprene,
nitrile rubber, hydronated nitrile rubber, carboxylated nitrile
rubber, and combinations thereof. Moreover, the fiber 39 can have
an end per inch value of 10.times.10, 15.times.15, 20.times.20,
30.times.30, and all values there between. Exemplary values for a
gauge of the fibers 39 include 0.22 inch, 0.50 inch, 0.10 inch,
0.20 inch, and all values there between. Additionally, example
materials for the packer element 15 include rubber, neoprene,
nitrile rubber, hydrogenated nitrile rubber, carboxylated nitrile
rubber, natural rubber, butyl rubber, ethylene-propylene rubber,
epiclorohydrin, chlorosulfunated polyethylene, fluororelastomers,
and combinations thereof
[0024] FIG. 4 illustrates an alternate embodiment of the packer
assembly 14 shown in a plan view, wherein the reinforcing compound
38 extends onto the upper radial surface 42. More specifically, in
the example of FIG. 4, the reinforcing compound extends a distance
D from a contact surface 32 of packer assembly 14. Further, the
reinforcing compound 38 is provided along substantially all of the
curved recess 34 and approximately to a midpoint between terminal
ends of the packer assembly 14 along the flat portion 36.
Optionally however, embodiments exist wherein the reinforcing
compound 38 is concentrated at or adjacent to the interface 40
between the curved recess 34 and flat 36. In another optional
embodiment, the reinforcing compound 38 extends along the entire or
substantially entire surface of contact surface 32. Further
illustrated in FIG. 4 is a rearward surface 44 of the packer
assembly 14 that is curved and projects radially outward from the
contact surface 32.
[0025] One example of forming a packer element 16 is shown in FIG.
5. In this example, a mold 46 is provided having sidewalls 48 that
approximate the outer periphery of the packer element 16 (FIG. 3).
In this example, an amount of uncured elastomer 50 is provided
within the mold 46, and in an amount to substantially fill the mold
46 when cured in the mold. Included with the uncured elastomer 50
is an example of a reinforcing compound 38 shown set along an
inside of sidewall 48 adjacent where the contact surface 32 (FIG.
3) will be located on completion of the formation process. As is
known, the mold 46 is enclosed and subjected to increased
temperature and/or pressure for a period of time until the uncured
elastomer 50 cures and transforms into the packer element 16.
Disposing the reinforcing compound 38 along with the uncured
elastomer 50 allows the reinforcing compound 38 to be integrally
formed with the packer element 16 after the curing process is
complete. Thus in one example, the reinforcing compound 38 is
coated with a material that bonds with the elastomer making up the
packer element 16 during the curing process. An elastomer, such as
rubber, is one example of a bonding material for coating the
reinforcing compound 38. Furthermore, the process illustrated in
FIG. 5 can in one example create a substantially solid packer
element 16. Examples exist wherein the reinforcing compound 38 is
formed from a material having a greater stiffness than the material
making up packer element 16.
[0026] The present invention described herein, therefore, is well
adapted to carry out the objects and attain the ends and advantages
mentioned, as well as others inherent therein. While a presently
preferred embodiment of the invention has been given for purposes
of disclosure, numerous changes exist in the details of procedures
for accomplishing the desired results. These and other similar
modifications will readily suggest themselves to those skilled in
the art, and are intended to be encompassed within the spirit of
the present invention disclosed herein and the scope of the
appended claims.
* * * * *