U.S. patent application number 15/999055 was filed with the patent office on 2019-10-31 for wear indicator for a joint between a riser and a floating platform.
This patent application is currently assigned to Oil States Industries (UK) Limited. The applicant listed for this patent is OIL STATES INDUSTRIES (UK) LIMITED. Invention is credited to John GALLAGHER, Richard JOHNSTON, Craig ROBERTSON.
Application Number | 20190330954 15/999055 |
Document ID | / |
Family ID | 55752921 |
Filed Date | 2019-10-31 |
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United States Patent
Application |
20190330954 |
Kind Code |
A1 |
JOHNSTON; Richard ; et
al. |
October 31, 2019 |
WEAR INDICATOR FOR A JOINT BETWEEN A RISER AND A FLOATING
PLATFORM
Abstract
The invention relates to a packer assembly comprising an inner
packer element and an outer concentric packer element, an actuator
which is slidable over the outer packer element to deflect the
outer packer element inwards against the inner packer element and a
sensor for detecting linear movement of the actuator relative to
the outer packer element.
Inventors: |
JOHNSTON; Richard;
(Broxburn, GB) ; ROBERTSON; Craig; (Wishaw,
GB) ; GALLAGHER; John; (Aberdeen, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
OIL STATES INDUSTRIES (UK) LIMITED |
Aberdeen |
|
GB |
|
|
Assignee: |
Oil States Industries (UK)
Limited
Aberdeen
GB
|
Family ID: |
55752921 |
Appl. No.: |
15/999055 |
Filed: |
February 20, 2017 |
PCT Filed: |
February 20, 2017 |
PCT NO: |
PCT/GB2017/050429 |
371 Date: |
August 17, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 43/0107 20130101;
E21B 17/07 20130101; E21B 19/006 20130101; E21B 33/038 20130101;
E21B 17/085 20130101 |
International
Class: |
E21B 33/038 20060101
E21B033/038; E21B 17/07 20060101 E21B017/07; E21B 17/08 20060101
E21B017/08; E21B 19/00 20060101 E21B019/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 19, 2016 |
GB |
1602949.8 |
Jun 30, 2016 |
GB |
1611438.1 |
Claims
1. A packer assembly comprising an inner packer element and an
outer concentric packer element, an actuator which is slidable over
the outer packer element to deflect the outer packer element
inwards against the inner packer element and a sensor for detecting
linear movement of the actuator relative to the outer packer
element.
2. A packer assembly according to claim 1, wherein the outer packer
element comprises a profiled outer surface.
3. A packer assembly according to claim 1, wherein a setting
component is provided between the actuator and the outer packer
element.
4. A packer assembly according to claim 3, wherein the setting
component comprises a profiled outer surface.
5. A packer assembly according to claim 3, wherein the setting
component comprises a plurality of bodies mounted between the
actuator and the packer assembly.
6. A packer assembly according to claim 3, wherein the plurality of
bodies form a segmented ring between the actuator and the packer
assembly.
7. A packer assembly according to claim 6 wherein the plurality of
bodies are radially moveable relative to the packer elements.
8. A packer assembly according to claim 5, wherein each body is
substantially C-shaped.
9. A packer assembly according to claim 5, wherein each body of the
setting component comprises a spine with a profiled outer
surface.
10-11. (canceled)
12. A packer assembly according to claim 11, wherein a connector
bar or strap is provided between adjacent bodies of the setting
component, and is slidably mounted between the adjacent bodies.
13. A packer assembly according to claim 2, wherein the actuator
comprises a cam surface which cooperates with the profiled outer
surface of the outer packer element.
14. (canceled)
15. A packer assembly according to claim 14, wherein the actuator
comprises a substantially tubular sleeve slidably mounted over the
outer surface of the outer packer element or the setting
component.
16. A packer assembly according to claim 13, wherein the cam
surface of the actuator is provided on an internal surface of the
sleeve.
17-19. (canceled)
20. A packer assembly according to claim 2, wherein the profiled
outer surface of the outer packer element comprises a plurality of
polyurethane blocks, elements or forms, wherein the plurality of
polyurethane blocks, elements or forms on the outer surface of the
outer packer element have a tapered surface which cooperates with
the tapered surface on the cam profile on the actuator sleeve.
21. (canceled)
22. A packer assembly according to claim 14, wherein one or more
pistons are mounted to the outer surface of the sleeve.
23. (canceled)
24. A packer assembly according to claim 2, wherein the sensor
comprises a body which is moveable through a secondary chamber.
25. A packer assembly according to claim 24, wherein one or more
apertures are provided between the piston chamber and the secondary
chamber to provide a pathway for hydraulic fluid from the chamber
within which the piston is provided and the secondary chamber.
26. A packer assembly according to claim 24, wherein the secondary
chamber comprises a first portion having a first diameter and a
second portion having a second diameter, the second diameter being
smaller than the first diameter.
27. (canceled)
28. A packer assembly according to claim 26, wherein the diameter
of the second portion is around 1/4 the diameter of the first
portion.
29. A packer assembly according to claim 1, wherein when the
actuator slides over the outer surface of the outer packer element,
hydraulic fluid is forced from the piston chamber into the sensor
chamber through the apertures to force the sensor body to move
through the sensor chamber.
30. A packer assembly according to claim 1, wherein a window or
slot is provided in the sensor chamber for viewing the position of
the sensor within the chamber.
31-34. (canceled)
35. A packer assembly according to claim 1, wherein the assembly
further comprises an outer housing.
36-38. (canceled)
39. A packer assembly according to claim 38, wherein the outer
housing surrounds the packer element and comprises flanged covers
at each end, which have angled detents provided therein into which
a profiled locking member of a latch for securing the flanked
covers to the outer housing can be driven.
40. A packer assembly according to claim 36, further comprising one
or more spacers mounted between the packer elements and the flanged
covers of the housing.
41. (canceled)
42. A telescopic joint comprising and outer tubular member and a
concentric inner tubular member, the inner member being slidably
received within the outer member and a packer assembly according to
any of the preceding claims provided between the inner wall of the
outer tubular member and the outer wall of the inner tubular
member.
43. (canceled)
Description
FIELD OF THE INVENTION
[0001] This invention relates to a packer and more particularly to
a packer for providing a seal between two joints and more
particularly still to a packer for providing a seal between two
concentric tubular members of a telescopic joint and further to a
system for monitoring wear or said packer as the tubular members
move relative to each other.
BACKGROUND
[0002] When recovering hydrocarbons such as oil and gas from
reservoirs which are located subsea, it is necessary to provide a
stable pathway for the recovered fluids from the reservoir to the
surface. This may involve the use of a fixed platform or rig which
extends from the sea bed to the surface with a string of pipes or
risers extending between the infrastructure permanently installed
subsea and the platform. The infrastructure may be for example a
subsea christmas tree providing an assembly of valves, spools and
fittings for intervention into the well below.
[0003] However, in deeper water it is not always practical to
provide fixed moorings between the surface platform and the seabed.
In these cases, a floating platform such as an FPSO may be used
with the top side processing equipment provided on the deck of the
FPSO and a casing or riser string provided between the FPSO and the
subsea infrastructure.
[0004] Movement of the FPSO due to heave, surge or sway caused by
localised swells and weather conditions must be accommodated as any
such movement at the surface will be transferred into the casing
string connected between the FPSO and the subsea infrastructure
which can lead to damage to FPSO, the top side equipment, the
subsea infrastructure or the casing string itself
[0005] Movement of the FPSO can be accommodated by providing a
telescopic joint in the casing string. Such a joint comprises two
concentric tubular members or pipes, forming an outer element and
an inner element of the joint. The inner element can slide
longitudinally or stroke within the outer element and extends out
of the end of the outer element. Typically, the telescopic joint
will be formed with an inner pipe section and an outer pipe
section. The outer pipe section is typically connected to the upper
most riser joint of the casing string and the inner pipe section is
typically connected to the rig floor of the FPSO. The telescopic
joint is designed to prevent damage to the riser and control
umbilicals by compensating for the vertical movement from heave,
surge sway or offset of the drilling vessel. As the position of the
vessel moves during these conditions, the length of the telescopic
joint changes to compensate for the movement of the vessel thereby
maintaining the integrity of the riser.
[0006] Tension in the riser is maintained during operation through
an SDL tension ring or equivalent such as for example an SDL or KT
ring. This maintains tension in the riser whilst the telescopic
joint strokes in and out providing compensation for vertical
movement of the offshore drilling vessel or FPSO.
[0007] When the telescopic joint is being handled it can be locked
in the fully retracted position via a latch mechanism which secures
the inner pipe section to the outer pipe section and prevents
relative movement and thus stroking of the joint.
[0008] A seal is provided between the inner and outer pipe sections
to maintain a seal between fluids flowing through the telescopic
joint and the atmosphere. As the inner and outer pipe sections move
relative to one another, friction causes the seal to wear over
time. The rate of wear is dependent upon various factors such as
operation conditions, local weather patterns and the material
characteristics of the seal and can be difficult to predict.
Therefore, regular monitoring of the integrity of the seal is
essential to ensure that remedial action can be taken to replace
the seal before the wear becomes so severe that the seal is
compromised as this could lead to a leakage of fluids from the
joint into the surrounding sea water.
[0009] In order to inspect the seal, the telescopic joint has to be
recovered to surface and stripped down to gain access to the seal
and, if necessary, to replace the seal. As this requires shutting
down of production through the telescopic joint and therefore
through the riser, this is a very costly process both in terms of
time and lost operating revenue.
SUMMARY
[0010] It is an aim of the present invention to provide a sealing
member particularly for use in maintaining a seal between the inner
and outer elements of a telescopic joint, in which wear on the seal
can be monitored without the need to remove the telescopic joint
from the riser.
[0011] It is also an aim of the present invention to provide a
sealing member which facilitates real time, remote monitoring of
the wear on the sealing member and therefore of the integrity of
the seal between the inner and outer elements of the telescopic
joint to allow remedial action to be taken when necessary before
the integrity of the seal is compromised.
[0012] According to one aspect of the present invention there is
provided a packer assembly comprising an inner packer element and
an outer concentric packer element, an actuator which is slidable
over the outer packer element to deflect the outer packer element
inwards against the inner packer element and a sensor for detecting
linear movement of the actuator relative to the outer packer
element.
[0013] Preferably the outer packer element comprises a profiled
outer surface.
[0014] Alternatively, a setting component is provided between the
actuator and the outer packer element. Advantageously the setting
component comprises a profiled outer surface.
[0015] Preferably the setting component comprises a plurality of
bodies mounted between the actuator and the packer assembly.
Preferably the plurality of bodies form a segmented ring around
between the actuator and the packer assembly. Advantageously the
plurality of bodies are radially moveable relative to the packer
elements. Preferably each body is substantially C-shaped. More
preferably each body of the setting component comprises a spine
with a profiled outer surface. Conveniently each body of the
setting component further comprises upper and lower arms which
extend from the spine inwardly towards the packer assembly.
Advantageously a connector strap or bar is provided between
adjacent bodies of the setting component. Preferably the connector
bar or strap is slidably mounted between adjacent bodies.
[0016] Advantageously the actuator comprises a cam surface which
cooperates with the profiled outer surface of the outer packer
element. Preferably the actuator comprises a substantially tubular
sleeve. Advantageously the sleeve is slidably mounted over the
outer surface of the outer packer element or the setting
component.
[0017] Preferably also the cam surface of the actuator is provided
on an internal surface of the sleeve.
[0018] Advantageously the cam surface of the actuator comprises a
tapered surface which cooperates with the profiled outer surface of
the outer packer element or the setting component to force the
outer element radially inwards against the inner packer
element.
[0019] Preferably the profiled outer surface of the outer packer
element comprises a plurality of polyurethane blocks, elements or
forms. Preferably the blocks are mounted to a rubber component
which forms the inner surface of the outer packer element.
[0020] Advantageously the blocks on the outer surface of the outer
packer element have a tapered surface which cooperates with the
tapered surface on the cam profile on the actuator sleeve.
[0021] Advantageously the sleeve is mounted within a chamber
containing hydraulic fluid.
[0022] Alternatively, one or more pistons are mounted to the outer
surface of the sleeve.
[0023] The or each piston is provided within a piston chamber such
that the piston(s) move(s) through the chamber(s) as the sleeve
moves vertically.
[0024] Preferably the sensor comprises a body which is moveable
through a secondary chamber. The body may act as an indicator to
provide information to the operator of the status or condition of
the packer assembly.
[0025] Conveniently one or more apertures are provided between the
piston chamber and the secondary chamber to provide a pathway for
hydraulic fluid from the chamber within which the piston is
provided and the secondary chamber. Preferably the secondary
chamber comprises a first portion having a first diameter and a
second portion having a second diameter. Preferably also the
diameter of the second portion may be smaller than the diameter of
the first portion. Advantageously the diameter of the second
portion may be around 1/4 the diameter of the first portion. As the
actuator slides over the outer surface of the outer packer element,
hydraulic fluid is forced from the piston chamber into the sensor
chamber through the apertures to force the sensor body to move
through the sensor chamber.
[0026] Advantageously means are provided in the sensor chamber for
viewing the position of the sensor within the chamber.
[0027] Conveniently a window or slot is provided in the sensor
chamber through which the piston can be viewed.
[0028] Advantageously a scale may be provided adjacent to or on the
window slot or alternatively on the sensor. This enables the
position of the sensor within or adjacent to the viewing window to
provide a simple and accurate indication of the position of the
sensor within the chamber and thus the position of the actuator
relative to the outer packer element which is affected by wear on
the inner packer element. Therefore, the operator is able to
monitor the position of the sensor in order to provide a real time
indication of the extent of travel of the actuator and thus show
the extent of wear on the inner packer element.
[0029] Conveniently the packer assembly further comprises a linear
potentiometer. The linear potentiometer comprises a contact slider
and a ground terminal. Preferably the contact slider is connected
to the sensor piston and is mechanically moved by the piston. As
the contact slider is moved thus the distance between the slider
and the ground terminal changes thus changing the resistance of the
potentiometer.
[0030] Conveniently the packer assembly further comprises a
wireless transmitter which sends a signal to a wireless receiver
indicative of the position of the piston within the packer
assembly. Preferably the wireless transmitter reacts to the change
in resistance of the potentiometer.
[0031] This allows the operator not only to monitor the integrity
of the seal provided by the inner and outer packer elements, but to
do this from a remote location without having to visually inspect
the components that the packer assembly is built into. This is
especially convenient where the packer assembly is built into a
component which is deployed subsea for example or positioned in
difficult to view areas of a platform or vessel as it allows the
operator to monitor the integrity of the seal from a suitable
location on the surface platform or vessel.
[0032] Preferably also the assembly further comprises an outer
housing. Conveniently the outer housing surrounds the packer
elements and may comprise flanged covers at each end of the
housing. Advantageously a latch is provided for securing the
flanged covers to the outer housing. Conveniently the latch
comprises a profiled locking member and the flanged covers may have
angled detents provided therein into which the profiled locking
member can be driven. This provides a quick release mechanism to
allow the flanged covers to be mounted to or removed from the outer
housing which saves time and effort compared to conventional bolted
arrangements.
[0033] Preferably also one or more spacers may be mounted between
the packer elements and the flanged covers of the outer housing.
This provides a means of adjusting the wear point on the packer by
the setting component which can prolong the life of the packer
elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Embodiments of the present invention will now be described
with reference to the accompanying figures in which:
[0035] FIG. 1 is a schematic cross sectional view through part of a
telescopic joint fitted with a packer according to one aspect of
the present invention;
[0036] FIG. 2 is a perspective view of the packer assembly of the
telescopic joint of FIG. 1;
[0037] FIG. 3 is a top view of the outer packer element of the
packer assembly of FIG. 2;
[0038] FIG. 4 is a cross sectional view of the outer packer element
of FIG. 3;
[0039] FIG. 5 is a perspective view of an inner packer element of
the packer assembly of FIG. 2;
[0040] FIG. 6 is a top view of the outer packer element of FIG.
5;
[0041] FIG. 7A is a schematic cross sectional view of a packer
assembly according to a second embodiment of the invention;
[0042] FIG. 7B is a schematic view of the setting component of the
second embodiment of the present invention;
[0043] FIG. 8 is a cross sectional view through the housing of the
second embodiment;
[0044] FIG. 9 is a schematic view of the second embodiment with the
outer housing removed;
[0045] FIG. 10 is a schematic view of the outer housing of the
second embodiment of the invention,
[0046] FIGS. 11-13 are schematic views of the latch mechanism
between the packer housing and the top and bottom covers, and
[0047] FIG. 14 is a schematic view of a further embodiment of the
present invention.
DETAILED DESCRIPTION
[0048] Turning now to the figures, FIG. 1 shows a schematic view of
one embodiment of the present invention incorporated into an outer
tubular element 1 of a telescopic joint which is intended to
prevent damage to a riser and control umbilicals extending from a
subsea location by compensating for vertical movement due to heave,
surge or say or offset of a floating drilling platform or vessel.
The inner tubular element of the telescopic joint is not shown for
clarity.
[0049] The outer tubular element 1 of the telescopic joint
comprises a generally cylindrical hollow body 2 with a bore 3
extending from one end of the body to the other. In use the inner
tubular element of the telescopic joint will be received within the
upper end of the bore of the outer tubular element. A substantially
tubular housing 4 surrounds the upper end (in use) of the outer
tubular element. In the embodiment shown, the housing is integrally
formed with the upper end of the outer tubular element.
Alternatively, it may be mounted on top of the upper end of the
outer tubular element. The housing provides support for and seating
for sealing elements which act between the inner and outer tubular
members and also associated actuating and control components as
will be explained in more detail below.
[0050] A packer assembly 5 is provided to form a seal between the
inner surface of the outer tubular element 1 and the outer surface
of the inner tubular member (when inserted) of the telescopic
joint. In the embodiment shown a dual set of packer assemblies is
provided comprising an upper packer assembly 6 and a lower packer
assembly 7 although in practice only a single packer assembly may
be used.
[0051] Each of the upper and lower packer assemblies 5, 5'
comprises an inner and an outer packer element 8, 9. In use the
inner packer element 8 is mounted concentrically within the outer
packer element 9.
[0052] The packer assemblies 6, 7 are each mounted within
respective annular recesses 10 in the inner surface of the housing
surrounding the upper end (in use) of the outer tubular component
1. A corresponding aperture may be provided in the outer wall of
the outer tubular element through which the packer assembly can
project into the recess in the housing.
[0053] FIG. 2 is a perspective view of a packer assembly 5
according to one embodiment of the present invention. FIGS. 3 and 4
show the outer packer element separated from the inner packer
element. As shown in FIG. 3, the outer packer element 9 is
generally toroidal in shape and comprises an inner cylindrical
rubber component 11 and an outer cylindrical polyurethane component
12. The outer component is formed by mounting a plurality of
polyurethane elements, blocks or forms 13 onto the outer surface of
the rubber component 11. Each of the polyurethane elements 13 is
substantially rectangular and extends from one side surface 14 of
the inner rubber component 11 to the other side surface 15. The
thickness of the polyurethane elements 13 gradually increases from
each end towards the centre 16 of the polyurethane elements. Thus
the polyurethane elements 13 have tapered ends 17 with a raised
central region 16 as seen in the cross sectional view of FIG. 4.
The polyurethane elements may be individually mounted to the inner
component or may be provided as a unitary element forming a
segmented ring.
[0054] Steel rings 18 are mounted on each side 14, 15 of the inner
rubber component 11 to hold the hold the inner and outer components
together of the outer packer element together. Preferably the
elements 13 are bonded or otherwise mounted to the rubber component
11.
[0055] An O-ring 19, of a resilient material such as rubber, is
provided around the outer surface of the steel rings at either side
of the outer packer element. The O-ring may sit within a groove in
the steel rings.
[0056] The inner packer element 8 of the packer assembly 5 is shown
in FIGS. 5 and 6 and comprises a substantially annular resilient
component comprising a polyurethane element 20 with steel end rings
21 mounted on each side 23, 24 of the element 8. In the embodiment
shown, the inner packer element is a split packer with one or more
rubber strips 22 providing an integral sealing bead which extends
across the surface of the inner packer element from one side to the
other. In this embodiment, two such beads are provided at
diametrically opposite positions on the inner packer element.
[0057] FIG. 2 illustrates the inner packer element 8 mounted
concentrically within the outer packer element 9 to form a packer
assembly 5 which is mounted within the recess 10 in the housing 4
surrounding the upper portion of the outer tubular member.
[0058] An actuating system 25 is provided within the housing 4 for
mechanically applying radial pressure to the outer surface of the
outer packer element 9 of the packer assembly 5 and thus applying
pressure to the inner packer element 8 against the outer surface of
an inner tubular element when inserted into the outer tubular
element.
[0059] The actuating system 25 comprises a piston which
reciprocates within a piston chamber in the housing adjacent the
recess within which the packer assembly 5 is received. The piston
comprises a substantially tubular sleeve component 26 which is
mounted in the housing 4 in an annular chamber 27 behind the packer
assembly 5. The tubular piston sleeve has an upper portion 28 which
has a first thickness, a central portion 29 which has an enlarged
thickness with respect to the upper portion and a lower portion 30
which has a reduced thickness with respect to the upper portion of
the piston component.
[0060] The enlarged central portion 29 of the piston has a tapered
cam surface 31 provided on the interior of the central portion
which cooperates with the outer tapered surface 17 and raised
centre portion 16 of the polyurethane elements 13 mounted on the
outer component 12 of the outer packer element as will be described
further below.
[0061] Where dual packer assemblies 6, 7 are provided such as shown
in the embodiment of FIG. 1, upper and lower piston sleeve
components 26, 26' will be provided to engage with the upper and
lower packer assemblies respectively.
[0062] The piston sleeve 26 slides within the annular chamber 27
under the influence of hydraulic fluid introduced into the chamber
above the sleeve. One or more cross drilled holes 32 are provided
in the fluid chamber 27 below the piston sleeve 26 to allow
hydraulic fluid to be forced from the chamber 27 into a second
chamber 33 within the housing 4 as the piston sleeve advances
through the chamber 27. In the embodiment shown, 4 such second
chambers are provided although the number of second chambers can be
changed dependent upon the requirements of the system.
[0063] A sensor which in this embodiment is in the form of a visual
indicator 34 is mounted within each of the second chambers. The
visual indicators may comprise a piston which is actuated by the
introduction of hydraulic fluid into the second chamber 33 from
chamber 27. The outer surface of the piston may have a graded or
coloured scale or numbered scale applied to it. A window or slot is
provided in the side wall of the second chamber 33 adjacent the
outer surface of the housing 4 through which the position of the
visual indicator 34 can be inspected. Alternatively, a graded or
numbered scale may be provided on or adjacent to the window against
which the position of the visual indicator 34 can be monitored.
[0064] A linear potentiometer 35 is mounted within the housing 4 in
one of the second chambers 33. The linear potentiometer comprises a
contact slider and a ground terminal and produces a change in
resistance that is linearly proportional to the distance between
the contact slider and the ground terminal.
[0065] Springs 36 are provided in the chambers 33 to bias the
visual indicators 34 into a first position which indicates no wear
on the inner packer element. Preferably the first position is a
lower position within the chamber 33. The springs are preferably
coil springs which surround an upper portion of the visual
indicators.
[0066] A wireless sender unit 37 is mounted on the housing 4 and
receives an electrical signal from the potentiometer 35 and
transmits this to a hand held receiver (not shown) which can be
used by an operator in a remote location.
[0067] The operation of the present invention will now be
described. A packer assembly 5 is constructed by mounting the inner
packer element 8 concentrically within the outer packer element 9.
The packer assembly 5 is mounted within the housing 4 and piston
sleeve 26 is mounted into the annular chamber 27 of the housing
surrounding the packer assembly. As the inner tubular element of
the telescopic joint is introduced into the upper end of the bore
of the outer tubular member, the packer assembly forms a seal
between the inner and outer tubular members such that the inner
tubular member can move relative to the outer tubular member
without any fluids running through the telescopic joint leaking out
between the two tubular members.
[0068] Hydraulic fluid is forced into the upper end of the chamber
27 in which the piston sleeve 26 is mounted. As the fluid enters
the chamber, the piston sleeve 26 is pushed downwards into the
chamber. As the piston sleeve extends into the chamber, the cam
surface 31 on the interior of the central portion 29 of the piston
sleeve contacts the tapered outer surface 17 of the outer packer
element and pushes the outer packer radially inwards which in turn
deflects the inner packer element 8 and forces the inner packer
element into closer contact with the outer surface of the inner
tubular member of the telescopic joint to maintain the seal around
the inner tubular member of the joint.
[0069] As the inner tubular member of the telescopic joint strokes
within the outer tubular member, friction between the inner surface
of the inner packer element 8 and the outer surface of the inner
tubular member causes wearing of the inner PU surface 20 of the
inner packer element which affects the integrity of the seal
between the inner and outer tubular members.
[0070] As the inner packer element wears, the thickness of the
packer assembly 5 reduces and the piston sleeve can move further
into the chamber 27 under influence of the hydraulic fluid. This
causes the cam surface 31 on the piston sleeve 26 to moves further
down the outer tapered surface 17 of the outer packer element 9 to
maintain the seal around the inner tubular component.
[0071] As the piston sleeve 26 moves downwards over the outer
surface of the outer packer element 9, this energizes the hydraulic
fluid in the chamber below the piston sleeve 26. The hydraulic
fluid is forced by the piston sleeve through the cross drilled
holes 32 and into the lower portion of the fluid chamber 33 in
which the visual indicators 34 are mounted. The further the piston
sleeve 26 rides up the tapered surface 17 and moves over the outer
surface of the outer packer element 9 to maintain a seal by the
inner packer element 8, the more hydraulic fluid is forced from the
lower portion of the piston chamber 27 into the fluid chambers 33
and the visual indicators 34 are pushed against the spring bias and
move upwards relative to the viewing windows to provide a real
time, on-going indication of the position of the piston sleeve 26,
and therefore of the relative wear of the inner packer element 8 of
the packer assembly 5.
[0072] This allows the operator to monitor the wear on the inner
packer element 8, and thus the effective seal around the inner
tubular component of the telescopic joint without having to disturb
the joint or reduce or stop flow of fluids through the joint and to
take remedial action before the wear on the inner packer element
reaches a critical point where the seal is compromised.
[0073] Additionally, as the visual indicators 34 move through the
fluid chambers 33 under the influence of the hydraulic fluid
entering the chambers, the slider on the linear potentiometer
similarly moves and the movement is detected by the wireless
transmitter which sends a signal to a remote receiver. This allows
an operator working remotely from the joint to monitor the
condition of the seal between the telescopic elements of the joint
without having to disturb the joint or even be in close proximity
to it.
[0074] In the above embodiment shown the actuation assembly for the
upper and lower packer assemblies is similar, with the piston
sleeve of the lower packer assembly mounted in the opposite
orientation to the piston sleeve surrounding the upper packer
assembly.
[0075] A further and more preferred embodiment of the invention is
illustrated in FIGS. 7-10 with like numerals used to identify
similar components but increased by 100. In this embodiment the
dual packer assembly 105 comprises an inner sealing packer element
108 and an outer energising packer element 109 as before, however
the outer packer has a similar form as the inner packer in that
both inner and outer packer elements are substantially annular with
the inner packer element mounted concentrically within the outer
packer element. Rings 118 may be provided at the upper and lower
edges of the outer packer element to encase the two packers
together.
[0076] A plurality of blocks or dogs 150 are mounted between the
outer packer element and the tubular sleeve component 126 and form
a setting component which assist in forcing the packer assembly
against the inner member of a telescopic joint to prevent leakage
of fluids between the inner and outer members as they move relative
to one another.
[0077] The dogs are radially moveable towards the outer packer
element 109. The outer upper surface 151 of the dogs are tapered to
match the tapered cam surface 131 on the actuating sleeve such that
as the actuating sleeve pushes down on the dogs in this embodiment,
the dogs are pushed radially inwardly against the outer packer
element. As the inner packer element 108 wears against the barrel,
the dogs 150 are pushed inwards by the sleeve which therefore
maintains the pressure holding the inner packer onto the inner
barrel. This causes the sleeve member 126 to move downwardly within
the housing.
[0078] The dogs have a substantially C-shape with a spine element
161 and upper and lower arms 162 which extend from the spine
element. The spine and arms define a recess or slot 163 across the
inner face of the dogs. In use elongate inserts are provided
between the slots of adjacent dogs. In the embodiment shown the
inserts are substantially rectangular but could be arcuate in some
embodiments. As the sleeve member 126 moves downwardly and pushes
the dogs radially inwardly, the inserts 164 minimize the risk of
the edges of the dogs pinching the outer surface of the outer
packer 109. The inserts ensure that the dogs move inwardly by the
same amount and maintain smooth operation of the dogs.
[0079] In this embodiment, a plurality of actuating pistons 165 are
fastened to the lower portion 166 of the outer surface sleeve. The
pistons have a cylindrical body. In this embodiment there are three
pistons but there could be one or more pistons in some embodiments.
Each piston moves vertically with the sleeve. Each piston in the
preferred embodiment is fastened to the sleeve by a screw 168 or
other fixing member which passes through a horizontal bore 169 in
the piston into a receiving aperture in the outer surface of the
sleeve.
[0080] A tube 170 is formed within the body of the housing and the
piston 165 is located within the tube. As the sleeve moves
vertically, the piston 165 moves vertically through the tube. Each
piston is housed within its own dedicated tube in the housing. Each
tube is of a diameter slightly larger than the diameter of the
piston body to ensure a close fit between the tube 170 and the
cylindrical body.
[0081] The lower end of the piston tube 171 has one or more cross
drilled apertures 172 which allow hydraulic fluid in the tube below
the piston body to communicate with a secondary tube 173 within
which a position indicator 174 is located. The indicator is a
substantially cylindrical body 175 which in the preferred
embodiment has three differently coloured sections 176. The
indicator body may have a diameter substantially similar to the
diameter of the piston body. The upper portion of the secondary
tube 173 has a diameter slightly larger than the diameter of the
indicator body to ensure a close fit between the outer surface of
the indicator body and inner surface of the tube but the lower
section of the secondary tube has a smaller diameter than the upper
section. In the preferred embodiment, the lower section of the
secondary tube is around 1/4 of the diameter of the piston tube
such that a vertical movement of the piston of 1 cm through the
piston tube will result in a vertical movement of 4 cm of the
indicator body in the secondary tube.
[0082] Each piston tube 170 in the housing has an associated
secondary tube 173 with a sensor in the form of a position
indicator 174 mounted in the secondary tube with a fluid passageway
between the lower end of the piston tube and the lower end of the
secondary tube. Each of the pistons are mounted at the same
position around the sleeve and so move vertically by the same
amount as the sleeve, and therefore each position indicator is
similarly moved by an equivalent amount.
[0083] A window 180 is provided in the outer surface of the housing
which is aligned with the secondary tube(s) 173. A grading or scale
may be provided on or adjacent to the window.
[0084] Hydraulic fluid in the piston chamber is forced through the
cross drilled holes 172 into the chamber in which the visual
indicators are mounted.
[0085] In the preferred embodiment, three actuating pistons are
fastened to the sleeve, each moving through a piston tube and three
secondary tubes are provided each with a position indicator
providing a visual indication of the wear on the.
[0086] The visual indicators preferably have graduated colours to
give an indication of wear as the rod passes the viewing window in
the chamber. In some embodiments, a spring may be connected between
the top of the indicator rod and the top of the fluid chamber
returns the indicator rod to the rest position when the sleeve
moves upwards within the housing.
[0087] In the illustrated embodiment, upper and lower packer
assemblies 105, 105' are mounted within the housing, each assembly
having inner and outer packer elements 108, 109. In some
embodiments the sleeve 126 of the upper packer assembly may be
moved vertically downward within the housing to push the locking
dogs 150 radially inwardly whilst the sleeve 126' of the lower
packer assembly is moved upwards to produce the same movement in
the locking dogs 150' of the lower packer assembly. Alternatively,
both sleeves 126 126' may be moved vertically in the same direction
to produce radial movement of the dogs 150, 150' against the outer
packer 109.
[0088] Each of the upper and lower packer assemblies have three
position indicators 174 which can be viewed through the windows 180
in the outer surface of the housing to provide a quick and simple
way for the operator to identify wear on the packers.
[0089] The operation of this embodiment is similar to the first
embodiment in that as the packer assemblies wear, the thickness of
the packer assemblies reduce and the sleeves 126, 126' can move
further vertically under the influence of hydraulic actuating
fluid. This causes the cam surface 131 on the piston sleeves to
move further down the outer tapered surface 117 of the outer packer
element 109 to maintain the seal around the inner tubular
component.
[0090] As the piston sleeve 126 moves downwardly over the outer
surface of the outer packer element, this causes the pistons 165 to
move vertically with the sleeve. As the pistons 165 move through
the tubes 170, the hydraulic fluid in the tube is energised and
forced through the cross drilled holes 172 into the secondary tubes
where the fluid forces the position indicators to rise within the
tube. As noted above, the ration of the volumes of the piston tube
and the secondary tubes can be controlled to ensure that a minimum
movement of the piston body with the tube 170 causes a maximum
movement of the position indicator within the secondary tube to
allow for close maintenance and early intervention as the packer
wears. By monitoring the section of the position indicator that is
visible through the viewing window, an operator can quickly and
easily check the condition of the packer elements without having to
interrupt the operation of the telescopic joint. Any change in the
condition of the packer elements will be readily noted via ongoing
checking and monitoring of the position indicators. This allows for
early intervention to be made before the condition of the packer
elements becomes critical.
[0091] In an embodiment in which the upper and lower sleeves 126,
126' move in opposite directions, references to upwardly and
downwardly above will be understood by the skilled person to cover
the appropriate movements in that that embodiment.
[0092] In FIGS. 10-13 the housing of the packer is provided with a
latch which allows the top and bottom flanged covers of the packer
housing to be connected to and quickly released from housing of the
packer.
[0093] In this embodiment the latch comprises a dog assembly which
has a housing 200 mounted externally at the top and bottom of the
packer housing. The housing 200 of the dog assembly has an axial
bore 201 within which a latch screw 202 is mounted. The latch screw
has a thread 203 on at least a part of the external body of the
screw and a head 204 which may be integrally formed with the body
of the screw. The head is provided internally of the housing when
the screw is inserted into the housing. A corresponding thread is
provided internally within the housing of the dog assembly. The
head of the screw has a profile which is enlarged with respect to
the body of the screw and the head of the screw is inserted into a
cooperating profile in the rear face of a latch dog such that
movement of the screw through the dog assembly housing moves the
latch dog inwardly and outwardly with respect to the external
surface of the top or bottom cover of the packer housing.
[0094] The outer surface of the latch dog has a profile that in
this embodiment provides two angled teeth or pins which extend into
cooperating angled detents in the outer surface of the top or
bottom cover when the latch dog is driven into a locking position
which pulls the cover down onto the packer housing and preloads the
connection.
[0095] This holds the covers in place on the packer housing but
provides a quick release mechanism to allow the packer housing to
be quickly connected to the top and bottom covers which can replace
a more traditional bolted connection between the top and bottom
covers and the packer housing. This provides for a reduction in the
time and effort required in building the telescopic joint and also
provides for a reduction in time and therefore operating cost
required for any maintenance and repair that requires the top or
bottom cover of the joint to be removed from the packer housing to
allow access to the packer.
[0096] FIG. 14 illustrates a further embodiment in which a spacer
220 is mounted above or below the body of the packer 108 to alter
the relative position of the packer and the dogs 150 within the
packer housing. This has the effect of adjusting the wear point on
the packer by the dogs 150.
[0097] In the embodiment illustrated the spacers are shown as being
above and/or below the packer 108 but they could alternatively be
provided above and/or below the locking dog 150 in order to
vertically alter the position of the locking dog rather than the
packer.
[0098] During use and over time, the action of the dogs 150 acting
on the outer surface of the packer element may cause the packer
element to wear along the external surface. By providing a means
for altering the effective wear point on the packer external
surface, the life of the packer element may be increased which
provides a further substantial advantage in managing the life of
the packer element and thereby improving the operation and
maintenance of the telescopic joint.
[0099] Spacers may be mounted above or below the packer or the
dogs. In some embodiments spacers may be mounted both above and
below the packer and/or the dogs to provide a number of different
relative operating positions between the packer element and the
dogs.
[0100] The present invention therefore converts linear mechanical
operation of an actuation sleeve into a visual signal or an
electronic signal which is indicative of the position of the
condition of the packer assembly and therefore the integrity of the
seal between the inner and outer sections of the telescopic joint.
This provides a simple and effective way of monitoring the
integrity of the seal without having to inspect the seal or
disassemble the components into which the seal is mounted. Thus
production time is not lost due to shut down of the flow of
hydrocarbons through the telescopic joint.
[0101] Whilst the specific description relates to the use of such a
packer assembly in a telescopic joint, the invention may be
utilised in other non-telescopic joint applications.
[0102] Although the concepts disclosed herein have been described
in connection with the preferred form of practicing them and
modifications thereto, those of ordinary skill in the art will
understand that many other modifications can be made thereto.
Accordingly, it is not intended that the scope of these concepts in
any way be limited by the above embodiment descriptions.
* * * * *