U.S. patent application number 13/399204 was filed with the patent office on 2012-08-23 for scuttle for the monitoring and inspection of a flexible riser.
This patent application is currently assigned to PETROLEO BRASILEIRO S.A.- PETROBRAS. Invention is credited to George Carneiro CAMPELLO, Sergio Ricardo Kokay Morikawa.
Application Number | 20120211233 13/399204 |
Document ID | / |
Family ID | 45656110 |
Filed Date | 2012-08-23 |
United States Patent
Application |
20120211233 |
Kind Code |
A1 |
CAMPELLO; George Carneiro ;
et al. |
August 23, 2012 |
SCUTTLE FOR THE MONITORING AND INSPECTION OF A FLEXIBLE RISER
Abstract
The present invention relates to an apparatus for inspecting and
monitoring flexible collection and production lines in real time,
rendering possible constant tracking of the condition of the
internal structures of a flexible riser, specifically of the
tensile armour thereof. The device may be provided at any point
along the riser ensuring the establishment of an area of physical
and visual contact directly over the surface of the tensile armour
of the riser for the installation of equipment for analysis, which
area permits further accesses without destroying the sealing of the
chamber there formed.
Inventors: |
CAMPELLO; George Carneiro;
(Rio de Janeiro, BR) ; Morikawa; Sergio Ricardo
Kokay; (Rio de Janeiro, BR) |
Assignee: |
PETROLEO BRASILEIRO S.A.-
PETROBRAS
Rio de Janeiro
BR
|
Family ID: |
45656110 |
Appl. No.: |
13/399204 |
Filed: |
February 17, 2012 |
Current U.S.
Class: |
166/344 |
Current CPC
Class: |
E21B 17/00 20130101;
E21B 41/0007 20130101; E21B 47/001 20200501; F16L 33/01 20130101;
E21B 17/01 20130101; E21B 47/002 20200501 |
Class at
Publication: |
166/344 |
International
Class: |
E21B 43/01 20060101
E21B043/01 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 18, 2011 |
BR |
PI 1100228-0 |
Claims
1. A scuttle for the monitoring and inspection of a flexible riser
(150), the scuttle comprising: an inspection chamber (210)
comprising at least two structural cells (223); an inspection
window (230) being attached over at least one of said structural
cells (223); means of affixing and sealing (300) the scuttle to a
riser (150) and/or to a riser accessory, the means of affixing and
sealing (300) being configured to interact with extremities of the
inspection chamber (210) and thereby establish a watertight
connection between the inspection chamber (210) and riser (150)
and/or the riser accessory.
2. The scuttle for the monitoring and inspection of a flexible
riser according to claim 1, wherein the means of affixing and
sealing (300) comprises an expansion sleeve (400) located at an
extremity of inspection chamber (210), for supporting and
separating an external layer (156) of riser (150) from the
remaining layers.
3. The scuttle for the monitoring and inspection of a flexible
riser according to claim 2, wherein said means of affixing and
sealing comprises a sealing ring (270), and the means of affixing
and sealing is further configured so that the sealing ring is made
to compress, in use, an external layer (156) of the riser against
the expansion sleeve (400).
4. The scuttle for the monitoring and inspection of a flexible
riser according to claim 3, wherein said means of affixing and
sealing (300) further comprises an activation flange (280)
superimposed on said sealing ring (270), to compress the sealing
ring (270).
5. The scuttle for the monitoring and inspection of a flexible
riser according to claim 4, wherein the extremity of inspection
chamber (210) is provided with an internal bevel that receives the
sealing ring (270).
6. The scuttle for the monitoring and inspection of a flexible
riser according to claim 2, wherein said means for affixing and
sealing (300) is provided at both extremities of inspection chamber
(210).
7. The scuttle for the monitoring and inspection of a flexible
riser according to claim 1, wherein said means of affixing and
sealing (300) comprises an extremity of inspection chamber (210)
configured to seal against a riser end fitting (500).
8. The scuttle for the monitoring and inspection of a flexible
riser according to claim 7, further comprising said riser end
fitting (500), wherein an internal bevel is provided in said end
fitting (500), the bevel being configured to receive said sealing
ring (270).
9. The scuttle according to claim 8, wherein a outer casing (510)
of the connector interacts with said sealing ring (270) to
establishing a seal.
10. The scuttle according to claim 1, wherein each structural cell
(223) comprises at least two spars (221) aligned with the axis of
riser (150), and each of the extremities of said spars (221) are
connected to a structural ring (222) so as to form said structural
cells (223).
11. The scuttle according to claim 10, wherein a sealing ring (290)
is provided on the internal face of a structural ring (222).
12. The scuttle according to claim 11, wherein the structural ring
(222) is configured to be connected directly to a outer casing
(510) of the end fitting (500), optionally by the structural ring
being threaded.
13. The scuttle according to claim 12, wherein the sealing ring
also seals a zone filled with resin of the end fitting (500).
14. The scuttle according to claim 1, wherein the scuttle is
configured such that, in use, on connecting inspection window (230)
over structural cell (223) empty space (201) is formed over the
surface of the riser.
15. The scuttle according to claim 1, further comprising said
riser, and wherein the scuttle is configured to allow inspection of
internal layers of said riser via said inspection window (230).
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an apparatus for inspecting
and monitoring flexible risers in real time. The apparatus renders
possible constant tracking of the conditions of the internal
structures of a riser, specifically of the tensile armour. The
technology proposed reduces the risk of failure by virtue of it
permitting the installation of diverse means of integrity
monitoring directly on the structure of a riser, in addition to
rendering possible local or remote visual inspections of the
tensile armour wires.
FIELD OF THE INVENTION
[0002] In subsea production systems the petroleum produced in wells
located on the bottom of the ocean is transported to a stationary
production unit (SPU) by pipes. This assembly of electrohydraulic
umbilical lines, water injection and oil and gas pumping pipes is
conventionally denominated: collection and production line.
[0003] This assembly of pipes constituting the collection and
production lines is basically subdivided into two distinct
portions: [0004] The first portion, preponderantly horizontal,
denominated: the horizontal segment. This portion is conventionally
static and also specifically known in the technical terminology as
"the flowline". [0005] The second portion, constituted by a
preponderantly vertical pipe connected to the extremity of the
horizontal segment and which ascends from the sea floor to the
platform whereat it is connected, denominated: the vertical
segment. The second portion is also known, and hereinafter
denominated, by the technical terminology of "the riser".
[0006] The term vertical employed herein shall not have a strict
interpretation by virtue of the fact that the distance between the
platform and the point of connection to the flowline, allied with
the weight of the riser itself, obliges this segment to assume a
substantially curved configuration known as a catenary.
[0007] In the market there basically exist two types of riser:
rigid and flexible, being affixed to the platform by support
structures especially designed to support and resist the stresses
thereof, which may result from both the weight and the movements
thereof.
[0008] Illustratively, some of the more obvious factors acting on a
riser are: action of internal pressure of the fluids and external
pressure of the environment, internal friction between the diverse
constituent layers thereof in the case of flexible risers,
corrosion and fatigue. In addition to these factors there may be
highlighted all types of influence from the environment wherein the
structure is installed, such as marine currents, salinity, tidal
variations, waves, infestation of live organisms.
[0009] Tides act specifically on the preponderantly vertical
portion of the riser, subjecting it to considerable forces arising
from displacement of the platform, which moves continuously in the
vertical and horizontal directions.
[0010] In summary, the riser may be subjected to diverse loads such
as: axial tension, weight of the structure itself, load resulting
from waves, drag force due to currents, and corrosive effects of
the environment and of the internal fluid. The majority of these
stresses are cyclic and induce fatigue in the structure and it is
for this reason that it requires to be periodically inspected.
[0011] Consequent upon the adoption of the system of flexible
risers, further difficulties occur requiring solutions in relation
to anchoring. This is by virtue of the fact that risers of the
flexible type, resulting from the constructional configuration
thereof, are much more sensitive than those which are rigid in
terms of the diverse stresses whereto a riser is subjected.
[0012] These types of flexible riser are constituted by overlaying
at least six interdependent layers having different compositions.
The first and most internal is the internal carcass, followed by a
polymer pressure layer. In sequence there follow the pressure
armour, the internal tensile armour layer and external tensile
armour layer composed of steel wires. Overlaid upon all the
foregoing there is in addition an external polymer layer.
[0013] Currently, in order to affix the upper extremity of a
flexible riser to the respective support thereof on the SPU, the
extremity of the riser requires to be affixed to a device which
will be the means of coupling and supporting between the riser
itself and the support. This device is known in the technical
environment as end fitting.
[0014] Consequently, there is a second scenario wherein the
stresses resulting from the weight and movement of a riser are
concentrated in this region. This region is represented by three
components of a collection and production line, that is to say: a
support, end fitting and the free extremity of a flexible riser.
The three components interact with one another differently.
[0015] Whilst the support presents restricted freedom of movement
in relation to the respective end fitting, it must interact in a
fixed manner in relation to the six components forming the flexible
riser. By virtue of the riser being such a critical element for
production continuity and for the safety of the SPU itself and the
environment, and at the same time being an element subjected to the
most diverse stresses which may act simultaneously on the structure
thereof, it is necessary that the riser be subjected to periodic
meticulous inspection and if possible to continuous monitoring. The
objective of this inspection and monitoring is to render it
possible to detect early signs of fatigue and consequently take
measures to mitigate or eliminate the stresses causing the
problem.
[0016] Flexible risers are usually monitored by visual inspection.
Such verifications are realised by divers and/or remotely operated
vehicles. More recently, internal and external inspection robots
have been adopted. These robots can be furnished with the most
varied devices of non-destructive inspection commonly applied, such
as: ultrasound apparatus or techniques based on induced magnetic
fields or X-rays.
[0017] However, currently a new method permits the remote
realisation of more intrinsic monitoring work through the use of
optical fibres. This is one of the most recent technologies,
disclosed by Brazilian patent document PI 0801011-0 of 30 Nov.
2010, for realising the monitoring of a riser, specifically of the
tensile armour thereof.
[0018] The aforementioned method consists of furnishing fibre optic
sensors adhered to the wires composing said tensile armour layer of
risers. As a consequence of being a technique disposing the sensors
intimately connected to the steel wire, and the former being
extremely thin, it becomes possible to track all structural
alterations of the steel wire and reveal the smallest degree of
alteration which may be considered as a deformation.
[0019] In spite of being efficient in terms of results, this method
however imposes certain restrictions representing a cost to be
considered, by virtue of the quantity of risers in operation
requiring monitoring.
[0020] Therefore, it is presented as a method which, depending on
the data collection point, requires the execution of a cut in the
external protective layer of the riser, which at the end of the
procedure is restored by taping. This type of finishing represents
a rupture of the integrity of the original external sealing without
offering a reliable mechanical solution for the reinstatement of
said sealing. Furthermore, there is the difficulty of it being a
method which can only be applied offshore, which presents
limitations. Finally, moreover there is the difficulty of carrying
out maintenance on the fibres should it be necessary.
[0021] Patent documents such as U.S. Pat. No. 7,107,863 of 19 Sep.
2006 and PI 0801011-0 of Jul. 4, 2008 reveal examples of devices
and/or apparatus designed to realise inspections from a position
internal and external to the riser. However, to date there is no
means available in the art to undertake a visual analysis of one of
the components most subjected to fatigue: the tensile armour of the
riser, whilst maintaining the integrity of its external
sealing.
[0022] The history of the dissection of end fittings of risers
which had been in operation or which were subjected to
specification testing demonstrates that there is a critical section
of failure of risers, principally located within the end fitting.
It further demonstrates that this is precisely the section wherein
the tensile armours suffer their greatest loads from cyclic fatigue
stresses.
[0023] The concentration of tension occurring in this region
accelerates the process of fatigue of the wires.
[0024] The present invention was developed in order to accommodate
the monitoring systems and to enable a visual check of the flexible
riser, preferably in the inner area of the end fitting.
[0025] In this respect, apparatus has been developed capable of
rendering inspection of the tensile armour possible, preferentially
in this critical area, whilst also maintaining the monitoring
systems in a protected state.
[0026] The invention described below flows from continual research
in this sector, the focus whereof being the objective of making
available a further means of instantaneous detection and inspection
of faults in risers. Additionally, it renders possible that the
installation of the monitoring system on the risers be also
realised onshore.
[0027] Moreover, it has the purpose of furnishing a new concept of
inspection which may be adopted as a basis for new parameters.
[0028] Other objectives which the scuttle for the monitoring and
inspection of a flexible riser, object of the present invention,
proposes to achieve are listed below: [0029] 1. to permit direct
visual inspection of the tensile armour of a riser; [0030] 2. to
permit the application thereof onshore or offshore; [0031] 3. to
permit not solely visual inspection but the installation of diverse
means of inspection on the tensile armour in a hermetic manner;
[0032] 4. to render possible total access for maintenance; [0033]
5. to render possible exchange of the means of inspection at any
moment; [0034] 6. to maintain the integrity of the external
sealing; [0035] 7. to be applicable to any segment of riser,
whether new or in operation.
SUMMARY OF THE INVENTION
[0036] According to the present invention, there is provided a
scuttle for the monitoring and inspection of a flexible riser, the
scuttle comprising: an inspection chamber comprising at least two
structural cells; an inspection window being attached over at least
one of said structural cells; means of affixing and sealing the
scuttle to a riser and/or to a riser accessory, the means of
affixing and sealing being configured to interact with extremities
of the inspection chamber and thereby establish a watertight
connection between the inspection chamber and riser (150) and/or
the riser accessory.
[0037] According to this aspect of the invention, it is possible to
inspect a riser via the window, whilst simultaneously establishing
a water-tight seal. This protects the section of the riser under
inspection, which allows for the external layer of the riser (for
example) to be removed to aid inspection of the riser.
[0038] The means of affixing and sealing can comprise an expansion
sleeve located at an extremity of inspection chamber, for
supporting and separating an external layer of riser from the
remaining layers. The expansion sleeve assists in the exposure of
an area of a riser that is under investigation.
[0039] The means of affixing and sealing can comprise a sealing
ring, and the means of affixing and sealing can be further
configured so that the sealing ring is made to compress, in use, an
external layer of the riser against the expansion sleeve. By
compressing the sealing ring against the riser, a water-tight seal
can be formed.
[0040] The means of affixing and sealing can further comprise an
activation flange superimposed on said sealing ring, to compress
the sealing ring. The activation flange can be used to assist in
the compression of the seal, thereby energising it and making it as
water-tight as possible.
[0041] The extremity of inspection chamber can be provided with an
internal bevel that receives the sealing ring. This allows for the
seal between the ring and inspection member to be as tight as
possible.
[0042] The means for affixing and sealing can be provided at both
extremities of inspection chamber. That is, each end of the
inspection chamber may be provided with an expansion sleeve,
sealing ring, activation flange and bevel. This allows each end of
the sealing chamber to be sealed against a riser. However, it may
also be desirable for only one end of the inspection chamber to
have such a seal, whilst the other end is configured to seal
against a connector, for example. In that case, the means of
affixing may comprise another seal at the end configured to seal
against the connector.
[0043] Said means of affixing and sealing can comprise an extremity
of inspection chamber configured to seal against a riser connector.
This can be in in combination with another sealing ring arrangement
as discussed above.
[0044] The scuttle can further comprise said riser connector,
wherein an internal bevel is provided in said connector, the bevel
being configured to receive said sealing ring. This provides a
tight seal between the sealing ring and the connector.
[0045] An outer casing of the connector can interact with said
sealing ring to establishing a seal.
[0046] Each structural cell can comprise at least two spars aligned
with the axis of riser, and each of the extremities of said spars
can be connected to a structural ring so as to form said structural
cells. This provides a strong frame for the structural cells, which
can then support the window and attaching means.
[0047] The sealing ring can be provided on the internal face of a
structural ring. That is, for example at one end of the scuttle,
the seal can be made between the structural ring and riser, rather
than between the extremity of the inspection chamber and the
riser.
[0048] The structural ring can be configured to be connected
directly to an outer casing of a/the connector, optionally by the
structural ring being threaded.
[0049] The sealing ring can also seal a zone filled with resin of
the connector.
[0050] The scuttle can be configured such that, in use, on
connecting inspection window over structural cell empty space is
formed over the surface of the riser.
[0051] The scuttle can be configured, in combination with the
riser, to allow inspection of internal layers of said riser via
said inspection window (230).
[0052] The present invention relates to apparatus capable of
housing monitoring and inspection devices installed directly on the
tensile armour of a riser, comprising two principal and distinct
parts, that is to say: an inspection chamber as such and means of
affixing and sealing to the riser or to another riser
accessory.
[0053] The inspection chamber can optionally be composed of a
structural chassis having a predominantly cylindrical format. Said
structural chassis presents at least two spars aligned with the
axis of the riser and parallel to the most external surface of said
riser. Each of the extremities of the spars interconnect with a
structural ring, each section of the structural ring
interconnecting at least two contiguous spars, forming a structural
cell.
[0054] Consequently, the structural chassis can comprise at least
two contiguous structural cells distanced from the exposed surface
of the riser.
[0055] An inspection window comprising a lamina having a channelled
format is on structural cells forming an empty watertight space on
the exposed surface of the riser.
[0056] A means of affixing and sealing constituted by at least an
arrangement of elements which, by interacting with the free
extremities of the inspection chamber, establishes a watertight
connection between the latter and the riser or other riser
accessory.
[0057] According to an aspect of the invention, there is provided a
scuttle for the monitoring and inspection of a flexible riser,
characterised in that it comprises: inspection chamber (210) as
such, composed of structural chassis (220) of predominantly
cylindrical format formed by at least two contiguous structural
cells (223) distanced from the exposed surface of riser (150) and
provided with a continuous surface of support throughout the entire
perimeter thereof, each structural cell (223) comprising at least
two spars (221) aligned with the axis of riser (150) and parallel
to the most external surface of said riser, each of the extremities
of said spars (221) being connected to structural ring (222) such
as to form said structural cell (223); inspection window (230),
constituted by a lamina having a channelled format, being attached
over structural cells (223); and means of affixing and sealing
(300) to riser (150) or to another riser accessory, constituted by
an assembly of elements which, interacting in a specific
arrangement with the free extremities of inspection chamber (210),
establish a watertight connection between the latter and riser
(150) or another riser accessory.
[0058] Optionally, the means of affixing and sealing (300) is
constituted by expansion sleeve (400) of tubular format provided
between the external layer (156) of riser (150) and overlaid
tensile armour layers (154 and 155), supporting and separating
external layer (156) of riser (150) from the remaining layers; the
free extremity of inspection chamber (210) is provided with an
internal bevel wherein it receives sealing ring (270) having the
form of a wedge, there being superimposed thereon activation flange
(280).
[0059] Optionally, spar (221) has a cross-section of varied
configuration.
[0060] Optionally, structural rings (222) are provided with means
of affixing (300) directly onto riser (150) itself or any of the
accessories of said riser.
[0061] Optionally, on connecting inspection window (230) over
structural cell (223) empty space (201) is formed over the exposed
surface of the riser.
[0062] Optionally, the external face of spar (221) is coincident
with the contact face of structural rings (222) such as to form a
continuous surface of support on the edge of structural cells (223)
along the entire perimeter of contact with inspection window
(230).
[0063] Optionally, inspection window (230) has a channelled form,
preferentially having a cylindrical section.
[0064] Optionally, inspection chamber (210) and means of affixing
and sealing (300) to riser (150) or to another riser accessory are
bipartite.
[0065] Optionally, means of affixing and sealing (300) is
alternatively constituted by a free extremity of inspection chamber
(210) turned towards the extremity of riser end fitting (500) and
directly facing activation flange (280), said end fitting (500)
being provided with an internal bevel wherein it receives sealing
ring (270) having the form of a wedge, which interacts with the
extremity of outer casing (510) of said end fitting (500)
establishing sealing and limiting the zone filled with resin (520)
of said connector.
[0066] Optionally, means of affixing and sealing (300) is moreover
alternatively constituted by monitoring and inspection scuttle
(200) threaded directly onto outer casing (510), visually exposing
tensile armours (154 and 155) at a point immediately subsequent to
zone filled with resin (520).
[0067] Optionally, structural ring (222) of inspection chamber
(210), turned towards the extremity of end fitting (500) has
provided on its internal face sealing ring (290) which establishes
contact with the exposed surface of tensile armours (154 and 155),
structural ring (222) being threaded directly onto the extremity of
outer casing (510) such that sealing ring (290) is the element
separating the zone filled with resin (520) from empty space (201)
on the exposed surface of riser (150).
BRIEF DESCRIPTION OF THE DRAWINGS
[0068] The invention will be described later in greater detail in
conjunction with the drawings listed below which, merely in terms
of example, accompany this specification of which they form an
integral part and wherein:
[0069] FIG. 1 depicts a perspective view of the device of the
present invention.
[0070] FIGS. 2 and 2A depict longitudinal cross-sectional views of
the device of the present invention.
[0071] FIG. 3 depicts a cross-sectional view of a constructional
alternative of the present invention.
[0072] FIG. 4 depicts a cross-sectional view of a second
constructional alternative of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0073] The scuttle for the monitoring and inspection of a flexible
riser, object of the present invention, has been developed based on
research having the objective of rendering feasible means of
monitoring a riser in real time and, at the same time, ensuring the
integrity of the annular space of the riser with the due sealing
thereof, by providing a display window and access for the
installation of a type of analysis or monitoring device on the
tensile armour.
[0074] As will become clear, the present invention can furnish
means not solely of housing various analytical and monitoring
equipments on the internal structure of the riser, but also
rendering possible the direct inspection of the tensile armour
thereof.
[0075] The scuttle for monitoring and inspection (200) of a
flexible riser, the basic configuration whereof is visualised in
FIG. 1, has been developed from the possibility of furnishing a
device (300) for affixing to and sealing the structure of a
flexible riser (150).
[0076] The constitution of a riser currently existing in the market
is basically composed of at least six interdependent layers having
different compositions: the first and most internal being the
internal carcass (151), followed by a polymer pressure layer (152).
In sequence there follow the pressure armour (153), the internal
tensile armour layer (154) and the external tensile armour layer
(155) composed of steel wires. Overlaid upon all the foregoing
there is furthermore an external polymer layer (156).
[0077] As may be observed in FIG. 1 or in FIG. 2, the scuttle for
monitoring and inspection (200) of a flexible riser, herein
proposed, comprises two principal and distinct parts, that is to
say: the inspection chamber (210) as such and means of affixing and
sealing (300) to the riser (150) or to another riser accessory.
[0078] As will be disclosed later, and easily visualised by means
of FIG. 1 and accompanied concomitantly by FIG. 2 wherein the
device is shown in cross-section, the present new concept of
inspection and monitoring can render possible the formation of a
watertight chamber directly upon tensile armours (154) and (155),
at any part of a riser, based on the activation of a means of
affixing and sealing (300) capable of being provided preferentially
on the structure of a flexible riser.
[0079] Consequently, an inspection chamber (210) is composed of a
structural chassis (220). Chassis (220) can be of predominantly
cylindrical format. Said structural chassis (220) can present at
least two spars (221). Spars (221) can be substantially aligned
with the axis of riser (150). The spars (221) can also be
substantially parallel to the most external surface of said
riser.
[0080] Each of the extremities of spars (221) can interconnect with
a structural ring (222). The structural rings (222) can each, in
turn, be provided with means of affixing (300) to the riser itself
(150) and/or to one of the accessories of said riser.
[0081] Each section of structural rings (222), interconnected to at
least two contiguous spars (221), forms a structural cell (223).
The structural cell (223) can have a continuous surface of support.
That is, a structural cell (223) can be formed by connecting at
least two contiguous spars (221) to two structural rings (222). The
structural cell (223) can be attached to the riser (150) by the
means of affixing (300).
[0082] Consequently, structural chassis (220), which may be
bipartite, comprises at least two contiguous structural cells
(223), which may be distanced from the exposed surface of riser
(150). As such, on attaching an inspection window (230) to the
respective structural cells (223) there is formed an empty space
(201) on the external, exposed, surface of the riser, represented
by tensile armours (154 and 155). This empty space (201) can be
seen in FIG. 2.
[0083] Spar (221) may have a cross-sectional profile of varied
configuration. However the external face thereof is preferentially
coincident with the contact face of structural rings (222) such as
to form a continuous surface of support at the edge of structural
cells (223), along the entire perimeter entering into contact with
inspection window (230).
[0084] Inspection window (230) can be constituted by a lamina,
being a thin layer of material. The lamina can have a channelled
format, preferentially the section of a cylinder. That is, the
lamina can be shaped to form a channel, so as to fit around the
structural chassis (220). The edge of the lamina can establish
contact with and can seal the entire perimeter of at least one
structural cell (223) and, consequently, with said structural rings
(222) and spars (221) composing it.
[0085] The means of affixing and sealing (300) to riser (150),
which may be bipartite, is better visualised and understood through
the assistance of FIG. 2A. In FIG. 2A the device is shown in
cross-section. Said means of affixing and sealing (300) is
constituted preferentially by an assembly of elements. This
assembly of elements, by interacting in a specific arrangement with
the free extremities of inspection chamber (210), establish a
watertight connection between the latter and riser (150).
[0086] In a preferred embodiment, external layer (156) of riser
(150) is protected and separated from the remaining layers of riser
(150) by expansion sleeve (400) of tubular format furnished between
said external layer (156) and overlaid tensile armour layers (154
and 155).
[0087] The free extremity of inspection chamber (210) is provided
with an internal bevel wherein it receives a sealing ring (270).
Sealing ring (270) can have the form of a wedge. Superimposed upon
sealing ring (270) can be activation flange (280). Activation
flange (280), on being pressed against the free extremity of said
inspection chamber (210), can make sealing ring (270) compress
external layer (156) of the riser against expansion sleeve
(400).
[0088] This operating principle of means of affixing and sealing
(300) to riser (150), as revealed by the arrangement described
above, provided at both extremities of inspection chamber (210),
distinguishes the basic constructional configuration of the scuttle
for monitoring and inspection (200). The scuttle (200) may be
installed at any point of a flexible riser.
[0089] Consequently, if required for purposes of calibration and
control or even for research purposes, diverse types of monitoring
or non-destructive testing devices may be disposed directly on the
tensile armour in a watertight manner at any part of a riser,
furthermore rendering possible visual access.
[0090] FIG. 3 discloses an alternative for affixing and application
of scuttle for monitoring and inspection (200).
[0091] In application of the same operating principle of means of
affixing and sealing (300), the respective constructional elements
having however been rearranged, one of the extremities of
inspection chamber (210) may be affixed and sealed directly at the
extremity of end fitting (500) of a flexible riser. That is, the
scuttle (200) may be attached to both the riser (150) and the end
fitting (500), rather than only on the riser (150) itself.
[0092] In this manner a critical section of flexible riser, subject
to a considerable and a varied total of stresses, may be monitored
and inspected.
[0093] For this, as also visualised in FIG. 3, the free extremity
of inspection chamber (210) turned towards the extremity of end
fitting (500) directly faces activation flange (280). Activating
flange (280) is provided with an internal bevel wherein it receives
sealing ring (270), which can have the form of a wedge. The sealing
ring (270) can interact with the extremity of outer casing (510) of
said end fitting (500). On pressing inspection chamber (210)
against outer casing (510), sealing ring (270) can be made to
compress external layer (156) of the riser against expansion sleeve
(400), activating and establishing sealing.
[0094] In this constructional configuration the extremity of
expansion sleeve (400) will serve as limit for the zone filled with
resin (520) of end fitting (500), which is filled with resin.
[0095] A second constructional alternative, optimised and requiring
greater interaction with the design of end fitting (500), is
revealed by FIG. 4. The alternative proposes a monitoring and
inspection scuttle (200) threaded directly onto outer casing (510),
visually exposing tensile armours (154 and 155) at a point
immediately subsequent to the section suffering the greatest stress
in the production line: the zone filled with resin (520) and
adhesion.
[0096] From FIG. 4 it may be noted that structural ring (222) of
inspection chamber (210), at the end of the scuttle (200) towards
the extremity of end fitting (500), is provided on the internal
face thereof with a sealing ring (290). Sealing ring (290)
establishes contact with the exposed surface of tensile armours
(154 and 155). Subsequently, structural ring (222) is threaded
directly on to the extremity of outer casing (510).
[0097] Consequently, sealing ring (290) is the element separating
the zone filled with resin (520) from empty space (201) on the
exposed surface of riser (150).
[0098] It may be easily perceived that the present invention not
solely provides a watertight space around the entire perimeter of
the tensile armour of a riser, but principally renders the mounting
procedure very much more simple, rapid and realisable on lines in
operation.
[0099] Consequently, one of the unquestionable advantages of the
invention proposed is not solely having the possibility of
selecting the point of mounting, but also the assurance that, in
spite of establishing an area of physical and visual contact
directly upon the tensile armour surface of the riser, this area
renders possible new accesses without destroying the sealing
thereof.
[0100] The invention has been described herein with reference being
made to the preferred embodiments thereof. Nevertheless, it will be
clear that the invention is not limited to those embodiments and
those skilled in the art will immediately perceive that alteration
and substitution may be implemented without departing from the
inventive defined in the claims.
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