U.S. patent application number 11/180150 was filed with the patent office on 2007-01-18 for hydrostatic-set open hole packer with electric, hydraulic and/or optical feed throughs.
This patent application is currently assigned to Baker Hughes Incorporated. Invention is credited to Martin P. Coronado.
Application Number | 20070012460 11/180150 |
Document ID | / |
Family ID | 37106474 |
Filed Date | 2007-01-18 |
United States Patent
Application |
20070012460 |
Kind Code |
A1 |
Coronado; Martin P. |
January 18, 2007 |
Hydrostatic-set open hole packer with electric, hydraulic and/or
optical feed throughs
Abstract
Devices and methods are described for disposing electric,
hydraulic and/or optical cables or conduits axially through a
hydrostatically-set packer mechanism. Radial fluid communication is
also provided through the inner mandrel so that the packer
mechanism may be set using hydrostatic pressure within the
flowbore. Feed-through paths for the cables or conduits isolate the
cables/conduits from fluid pressure as well as axial or torsional
tensile forces.
Inventors: |
Coronado; Martin P.;
(Cypress, TX) |
Correspondence
Address: |
SHAWN HUNTER
P.O Box 270110
HOUSTON
TX
77277-0110
US
|
Assignee: |
Baker Hughes Incorporated
Houston
TX
|
Family ID: |
37106474 |
Appl. No.: |
11/180150 |
Filed: |
July 13, 2005 |
Current U.S.
Class: |
166/387 ;
166/121; 166/65.1 |
Current CPC
Class: |
E21B 33/1285 20130101;
E21B 17/18 20130101 |
Class at
Publication: |
166/387 ;
166/065.1; 166/121 |
International
Class: |
E21B 33/12 20060101
E21B033/12 |
Claims
1. A packer assembly for creating a fluid seal within a wellbore
comprising: a tubular central mandrel having an upper end and a
lower end, defining a central flowbore and having an outer radial
surface; a packer element surrounding the tubular mandrel, the
packer element being moveable between a radially reduced unset
position and a radially expanded set position; a hydrostatic
setting assembly for selectively causing the packer element to be
set in its expanded position, the hydrostatic setting assembly
comprising: a) a radial fluid communication port for communicating
hydraulic fluid pressure within the central flowbore through the
tubular mandrel to its outer radial surface; b) a piston element
for receiving fluid pressure from the central flowbore and applying
said fluid pressure to urge the packer element toward its set
position; and a cable feed-through path defined within the tubular
mandrel to allow a cable to pass from the upper end of the mandrel
to the lower end of the mandrel.
2. The packer assembly of claim 1 wherein the cable feed-through
path comprises a longitudinal drilled hole in the mandrel.
3. The packer assembly of claim 1 wherein the setting piston is
releasably secured to the central mandrel by a locking dog.
4. The packer assembly of claim 1 wherein the fluid communication
port is angularly offset from the feed-through path about the
circumference of the central mandrel.
5. The packer assembly of claim 1 wherein the setting assembly
further comprises an actuating sleeve that lies within the central
flowbore and is moveable between a first position, wherein fluid
communication through the radial fluid communication port is
blocked, and a second position, wherein the actuating sleeve does
not block the port.
6. The packer assembly of claim 5 wherein the actuating sleeve
presents an engagement shoulder that is shaped and sized to be
contacted by a suitable shifting tool for movement of the actuating
sleeve from its first to its second position.
7. The packer assembly of claim 5 wherein: the setting piston is
releasably secured to the central mandrel by a locking dog; and
wherein movement of the actuating sleeve from the first to the
second position releases the setting piston from the central
mandrel.
8. The packer assembly of claim 1 wherein the packer element
comprises a composite packer element for use in creating a fluid
seal within an uncased borehole.
9. A system for disposing a cable axially through a packer device
that is set hydrostatically, the system comprising: a central
tubular mandrel defining a flowbore to contain hydrostatic
pressure; a packer element carried by the central mandrel, the
packer element being moveable between an unset position and an
axially compressed set position; a setting mechanism for moving the
packer element to its set position in response to hydrostatic
pressure within the flowbore; and a feed-through path defined
axially through the mandrel, the feed-through path retaining a
cable in isolation from external fluid pressures.
10. The system of claim 9 further comprising: a radial fluid
communication port for transmitting hydrostatic fluid pressure from
the flowbore to an actuation chamber located radially outside of
the central mandrel; and wherein the fluid communication port is
angularly offset from the feed-through path about the circumference
of the central mandrel.
11. The system of claim 9 wherein the feed-through path comprises a
longitudinal drilled hole in the central mandrel.
12. The system of claim 10 wherein the setting mechanism further
comprises a piston element retained within the actuation chamber
for receiving fluid pressure from the central flowbore and applying
said fluid pressure to urge the packer element toward its set
position.
13. The system of claim 12 wherein the piston element is releasably
secured to the central mandrel.
14. The system of claim 13 wherein the piston element is releasably
secured to the central mandrel by a locking dog.
15. The system of claim 9 wherein the setting mechanism further
comprises an actuating sleeve that lies within the flowbore and is
moveable between a first position, wherein fluid communication
through the radial fluid communication port is blocked, and a
second position, wherein the actuating sleeve does not block the
port.
16. The system of claim 15 wherein the actuating sleeve is
releasably retained in the first position by a shear pin.
17. A method of disposing a cable axially through a
hydrostatically-set packer device, the method comprising the steps
of: forming a cable pass-through path within a central mandrel of
the packer device; disposing a cable along the cable pass-through
path; and securing an end nut upon the cable to secure the cable to
the central mandrel.
18. The method of claim 17 wherein the step of forming a
pass-through path within the central mandrel comprises drilling a
longitudinal hole within the central mandrel that is shaped and
sized to accommodate the cable.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to the design of downhole
packers and to mechanisms for passing cables and conduits through a
packer. In particular aspects, the invention relates to the design
of packers that are set using hydrostatic wellbore fluid
pressure.
[0003] 2. Description of the Related Art
[0004] When installing a production string within a wellbore, it is
often necessary to form a fluid seal within a large diameter
opening, such as an open (uncased) hole. To accomplish this, a
packer assembly is needed that can provide large radial expansion
of the sealing element. Unfortunately, conventional large expansion
packer systems generally lack the ability to pass electrical or
fiber optic cables or fluid conduits axially through the packer
assembly so that other devices may be used below the packer
device.
[0005] The desirable requirements for a large diameter packer
system are typically at odds with those for a conduit pass-through
system. U.S. Pat. No. 6,220,362, issued to Roth et al. describes a
pass-through conduit arrangement for a packer assembly or other
tool. The Roth patent is owned by the assignee of the present
invention and is incorporated herein by reference. Roth describes a
system wherein one or more axial conduit passages are formed
through an interior portion of a packer or other tool. Roth teaches
that there be complete pressure isolation between the conduit and
both the tubing and the annulus. However, Roth describes the use of
a separate carrier 60 that lies radially within the tool mandrel 24
and is used to define the longitudinal passages for the conduits or
cables. The potential exists for improper sealing between the
carrier and mandrel during fabrication of the tool, leading to
undesirable fluid entry into the longitudinal passages.
Additionally, this design does not offer any means for radial
communication of fluid outwardly from the flowbore of the tool to
the radial exterior of the tool. In fact, the requirement that the
longitudinal passages remain isolated from fluid pressure from the
flowbore, as well as the annulus, dictates against penetration of
the carrier and/or mandrel by a radial fluid communication passage.
If the carrier and mandrel of this tool were perforated to allow
radial fluid communication, the passages defined therebetween would
undesirably become exposed to external wellbore fluid
pressures.
[0006] To the inventor's knowledge, conduit feed through systems
have not been successfully integrated into hydrostatically-set
packer assemblies. It is believed that this failure is due to the
complexity of a hydrostatic setting mechanism and the need for such
a device to communicate hydrostatic fluid pressure through the
inner mandrel of the packer assembly and into a chamber within the
exterior portion of the packer assembly. The use of multiple
interior pieces, such as a separate carrier and mandrel, to define
a longitudinal cable/conduit pass-through, and the attendant
assembly requirements, also adds to the difficulty of incorporating
a cable feed-through feature into a hydrostatically-set device.
[0007] U.S. Pat. No. 6,842,315 issued to Coronado et al., describes
a hydrostatically-set packer device having a composite sealing
element with large radial expansion capabilities for use in through
tubing and open hole applications. This patent is owned by the
assignee of the present invention and is, therefore, incorporated
by reference. The device of the '315 patent provides no
feed-through arrangement for cables or conduits to be passed
longitudinally through the packer device.
[0008] The present invention addresses the problems of the prior
art.
SUMMARY OF THE INVENTION
[0009] The invention provides devices and methods for axially
disposing electric, hydraulic and/or optical cables or conduits
through the inner mandrel of a hydrostatically-set packer
mechanism. In accordance with the devices and methods of the
present invention, radial fluid communication is also provided
through the inner mandrel so that the packer mechanism may be set
using hydrostatic pressure within the flowbore. The axial
feed-through path(s) for the cables or conduits are isolated from
flowbore and annular fluid pressure. Additionally, the
cables/conduits are protected from axial tensile forces and
torsional forces that might damage them.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIGS. 1A-1C present a side, cross-sectional view of an
exemplary packer assembly with conduit feed through system
constructed in accordance with the present invention.
[0011] FIG. 2 is an axial cross-section taken along lines 2-2 in
FIG. 1C.
[0012] FIG. 3 is an axial cross-section taken along lines 3-3 in
FIG. 1C.
[0013] FIGS. 4A-4C present a side, cross-sectional view of the
packer assembly shown in FIGS. 1A-1C, now with the packer element
having been set.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] FIGS. 1A-1C, 2, and 3 illustrate an exemplary
hydrostatically-set packer assembly 10 that is constructed in
accordance with the present invention. The packer assembly 10
includes a central mandrel 12 having an upper threaded end 14 which
allows the packer assembly 10 to be incorporated into a production
tubing string. The central mandrel 12 defines a central axial
flowbore 16 along its length. A cable feed through path, generally
designated as 18, passes through the central mandrel 12. Beginning
at the upper end of the packer assembly 10, the central mandrel 12
features a radially enlarged upper portion 20 with outer threads
22. Below the enlarged upper portion 20 is a radially reduced
mandrel portion 24. At the lower end of the radially reduced
portion 24 is a lower radially enlarged portion 26. The enlarged
portion 26 also defines an enlarged bore portion 27 within. The
lower portion 26 presents an outwardly projecting shoulder 28 and a
threaded connection 30 to a lower end sub 32. The lower end sub 32
includes a set of interfitting longitudinal anti-rotation splines
34 and an axial cable passage 36. The splines 34 engage
complimentary splines 35 formed on the outside of the central
mandrel 12. Below the cable passage 36 is a lateral cable opening
38.
[0015] In a currently preferred embodiment, the feed-though path 18
includes an axially-oriented longitudinal central portion 40 and an
upper angled end portion 42 that extends from the upper end of the
central portion 40 radially outwardly to an axial upper end passage
44. The axial upper end passage 44 includes an enlarged bore 46
that is shaped and sized to accommodate end nut 48. The lower end
of the central portion 40 interconnects to a lower angled end
portion 50 that extends radially outwardly to an axially-oriented
lower portion 52. The lower end of the lower portion 52 also has an
enlarged bore 54 that is shaped and sized to accommodate an end nut
56. It is noted that the feed-through path 18, and all of its
individual components 40, 42, 50, 52, are preferably constructed by
drilling of suitably sized holes or passages through the central
mandrel 12. The component portions 40, 42, 50, 52 should
interconnect with one another axially to provide a continuous path.
An exemplary cable 58 is shown disposed within the feed-through
path 18 and secured therewithin by end nuts 48, 56. It can be seen
that a portion 60 of the cable 58 extends upwardly toward the entry
of the wellbore (not shown) while another portion 62 of the cable
58 extends downwardly toward a location below the packer assembly
10. Thus, the cable feed-through path 18 allows communication
through the packer assembly 10 to a device (not shown) that is
located below the packer assembly 10. It is noted that the term
"cable," is used herein to refer to an electrical cable, a
hydraulic fluid conduit, a fiber optic cable, or any other type of
tubular structure that is used to transmit fluid, power or
communications into or out of a wellbore.
[0016] The enlarged bore portion 27 of the central mandrel 12
accommodates an actuating sleeve 62 and an internal guide sleeve
64. The guide sleeve 64 provides a radially exterior surface 66
that defines the inner boundary of the lateral cable opening 38.
Additionally, the guide sleeve 64 presents an inner surface 68 with
an upper radially is enlarged bore portion 70. The actuating sleeve
62 presents an inner surface 72 that extends radially inwardly of
the enlarged bore 70, thereby creating an engagement shoulder 74 at
the lower end of the sleeve 62. The outer radial surface 76 of the
actuating sleeve 62 carries a number of annular fluid seals 78, a
dog recess 80 and a locking ring 79. It is noted that the actuating
sleeve 62 is axially moveable between a lower position, shown in
FIG. 1, wherein the lower end of the sleeve 62 contacts the guide
sleeve 64, and an upper position, shown in FIG. 2, wherein the
upper end 82 of the actuating sleeve 62 contacts an internal stop
shoulder 84 of the central mandrel 12. Frangible shear screws 82
pass through the body of the central mandrel 12 and into the
actuating sleeve 62 to initially secure the actuating sleeve 62 in
its lower position.
[0017] A plurality of radial fluid communication ports 88 also pass
through the central mandrel 12 to provide fluid communication
between the internal flowbore 16 of the mandrel 12 and its radial
exterior. As FIG. 2 illustrates, the shear screws 82 are angularly
offset from each of the fluid ports 88 about the circumference of
the central mandrel 12. Fluid flow through the fluid ports 88 is
initially blocked by the presence of the actuating sleeve 62 and
fluid seals 78.
[0018] Beginning once again proximate the upper end of the packer
assembly 10, a second set of longitudinal anti-rotation splines 90
are defined upon the central mandrel body 12. Splines 90 interfit
with complimentary anti-rotation splines 92 on the central mandrel
12. The interfitting of the splines 90, 92 prevents rotation of the
central mandrel 12 components with respect to one another.
[0019] The ring 98 is retained in place upon the outer surface of
the central mandrel 12 by a housing sub 100 that is secured to the
central mandrel 12 by threaded connection 22. An annular space 102
is defined between the lower end of the housing sub 100 and the
outer surface of the central mandrel 12. Ring 104 is secured to the
lower end of the housing sub 100 at threaded connection 106. The
ring 104 provides tensioning portions 105, of a type known in the
art, for exerting a tensioning force upon the packer element
110.
[0020] An upper end setting sleeve 108 also surrounds the central
mandrel 12 below the ring 104. The setting sleeve 108 is used to
help set the packer element 110 that lies immediately below it on
the radial exterior of the central mandrel 12. During setting of
the packer assembly 10, the upper end setting sleeve 108 remains
stationary with respect to the central mandrel 12. The upper end
setting sleeve 108 has a retainer portion 112 that extends over a
portion of the packer element 110. A lower end setting sleeve 114
is located at the lower end of the packer element 110 and also
presents a retainer portion 116 that extends over a portion of the
packer element 110.
[0021] The packer element 110 is preferably a composite packer
element as described in U.S. Pat. No. 6,843,315, issued to Coronado
et al. This patent is owned by the assignee of the present
invention and is herein incorporated by reference. This type of
packer element is suitable for use in creating a fluid seal in
larger bores and even uncased borehole sections. Below the lower
end setting sleeve 114 is a setting, or actuating, assembly,
generally shown at 118, having an upper sub 120 with fluid fill
port 122, a setting assembly housing 124 and a lower sub 126. The
setting assembly housing 124 encases an atmospheric chamber 128.
The atmospheric chamber 128 is bounded at axial ends by the upper
and lower subs 120, 126. When the piston assembly 10 is in the
unset position (shown in FIG. 1), the atmospheric chamber 128 is at
atmospheric pressure.
[0022] An actuating piston, generally shown at 130, is retained
within the atmospheric chamber 128. The actuating piston 130 is
made up of a lower piston ring 132, central ring 134, and an upper
piston ring 136, these components being affixed to one another by
threaded connections 138, 140. The lower piston ring 132 presents a
fluid pressure receiving area 142. Additionally, the lower piston
ring 132 has an annular dog recess 144 inscribed upon its inner
surface. Elastomeric O-ring seals 146 are used to provide fluid
sealing between the actuating piston 130 and the chamber 128. The
upper end of the upper piston ring 136 is secured by threaded
connection 148 to a body lock ring assembly 150. The body lock ring
assembly 150 includes a locking ring 152 with an inner ratchet
surface 154. The ratchet surface 154 is formed to interengage with
outwardly-facing ratchet surface 156 on central mandrel 12. Packer
element setting member 158 is affixed to the body lock ring
assembly 150 and presents an enlarged setting portion 160 that
abuts the lower end of the packer element 110.
[0023] A locking dog 162 initially secures the actuating piston 130
and the central mandrel 12 together. In the unset position, shown
in FIG. 1, the dog 162 resides within a dog passage 164 that is
disposed radially through the central mandrel 12. A portion of the
dog 162 extends outwardly into dog recess 144 in the actuating
piston 130. Movement of the dog 162 radially inwardly is blocked by
the presence of actuating sleeve 62. It is noted that the dog 162
and all shear screws 82 are radially offset from the cable
feed-through path(s) 18 so that the feed-through path(s) 18 remain
unexposed to fluid ingress and wellbore pressures. This arrangement
is best shown in FIGS. 2 and 3.
[0024] Hydrostatic forces are used to set the packer device 10.
FIGS. 4A-4C show the packer device 10 in a set condition. When it
is desired to set the packer assembly 10, a shifting tool (not
shown), of a type known in the art, is disposed into the flowbore
16 of the central mandrel 12. The shifting tool contacts the
engagement shoulder 74 of the actuating sleeve 62 and moves the
actuating sleeve 62 axially upwardly. This movement will shear the
shear screws 82 and unblock fluid communication ports 88. The
locking ring 79 secures into a mating recess in the central mandrel
12 (see FIG. 4C) to secure the actuating sleeve 62 in the upward
position. Additionally, upward movement of the actuating sleeve 62
will bring the dog recess 80 into general alignment with the
locking dog 162. The dog 162 is moved radially inwardly to reside
partially within the recess 80 and is thus moved out of the outer
dog recess 144. This unlocks the actuating piston 130 from
engagement with the central mandrel 12. As upward movement of the
actuating sleeve 62 unblocks the fluid ports 88, hydrostatic fluid
pressure present within the flowbore 16 will then be transmitted
through the ports 88 and enter the pressure receiving area 142.
Wellbore hydrostatic pressure will bear upon the pressure receiving
area 142 of the actuation piston 130 and urge the piston 130
axially upwardly. The packer element setting member 158 will
compress the packer element 110 axially to cause it to expand
radially and become set.
[0025] It can be seen that the arrangement of the present invention
provides a means for disposing one or more cables axially through a
hydrostatically-set packer device while also permitting radial
fluid communication through the central mandrel. The feed-through
paths 18 of the packer assembly 10 desirably isolate the cables
from fluid pressure present in either the flowbore 16 or the
annulus surrounding the packer device 10. Because the feed-through
paths 18 are angularly offset from the fluid communication ports 88
about the circumference of the central mandrel 12, fluid pressure
being communicated radially through the mandrel 12 will not enter
the feed-through paths 18.
[0026] Cables extending through the feed-through paths 18 are also
protected from axial tensional forces that would be exerted upon
the packer assembly 10 as it is being used as well as torsional
forces that might be experienced as the packer assembly 10 is being
made up or run in the well. The cables are retained in place within
the feed-through path(s) 18 by end nuts 48, 56, which secure them
to the central mandrel 12.
[0027] Those of skill in the art will recognize that numerous
modifications and changes may be made to the exemplary designs and
embodiments described herein and that the invention is limited only
by the claims that follow and any equivalents thereof.
* * * * *