Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to thermal
blankets and in particular to a thermal blanket adapted
for use with well-heads, blow-out preventors and the
like.
Thermal coverings for devices exposed to the
~xternal environment are known in the art. In
particular, in the past, it has been attempted to shield
well-heads and blow-out preventors (BOP's) from the
environment by wrapping the well-heads and BOP's with
insulation and securing the insulation thereto using
tape. However, problems exist in that the insulation is
not shielded from the environment and thus, is not prone
to exhlblt long llfe due to the types of chemlcals
comlng lnto contact wlth the lnsulatlon. Accordlngly,
the lnsulatlon mu~t be replaced often thereby inoreasing
costs. Furthermore, another problem exlsts in that once
the insulation i8 wrapped around the well-head or BOP
and secured thereto using tape, access to the covered
devlce i9 inhibited. If access i8 required, the tape
must be cut and the insulation removed. This process ls
time consumlng and also often ruins the insulation
thereby further lncreaslng costs since new insulatlon
must be used to re-cover the device.
It is therefore an ob~ect of the present
lnventlon to obvlate or mltigate the above
dlsadvantages.
Accordlng to the present lnventlon, there i8
provlded a thermal blanket adapted to cover well-heads,
blow-out preventors and the llke comprlslng:
a body of materlal capable of covering a
devlce in use, sald body of materlal lncludlng a layer
of lnsulatlng materlal dlsposed between lnner and outer
layers of environment proof material: and
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fastening means provided on said body of
material, said fastening means being operable to
maintain said body of material over said device in use.
Preferably, the outer and inner layers of
environment material are formed from polypropylene which
is water-proof, oil-resistant and chemical-resistant.
It is also preferred that the insulation layer is formed
f rom asbestos.
Preferably the fastening means includes a tie
line passing through eyelets formed along the length of
one slde of the blanket and straps and clasps located at
opposed ends of the blanket.
In one embodlment, it ls preferable that the
thermal blanket includes sleeves formed on the inner
layer of envlronment proof materlal for holdlng heat
radlating means in the form of heat traclng or steam
llnes.
The present lnvention provldes advantages ln
that a well-head or blow-out preventor shlelded from the
envlronment using the present thermal blanket ls
lnhlblted from freezing. Furthermore, acce~s to the
covered device 18 not prohlblted. Moreover, due to the
durablllty of the materlal shleldlng the lnsulatlon, the
llfetlme of the blanket 18 lncreased as compared wlth
conventlonal technlque~ used to shleld suah devlces from
the envlronment.
Embodlments of the present lnventlon wlll be
now be described by way of example only with reference
to the accompanylng drawlngs ln whlch:
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Figure 1 is a perspectlve view of a thermal
blanket in use surrounding a blow-out preventor;
Figure 2 is a bottom plan view of the blanket
illustrated in Figure 1;
Figure 3 is a top plan view of the blanket
illustrated in Figure l;
Figure 4 is a sectional view of the blanket
illustrated in Figure 3 taken along line 4-4;
Figure 5 is a perspactive view of a thermal
blanket in use surrounding a well head;
Figure 6 is a bottom plan view of the blanket
illustrated in Figure 5;
Figure 7 is a top plan view of the blanket
lllustrated ln Figure 5;
Figure 8 is a seational view of a the blanket
illustrated in Flgure 5 taken along line 6-6.
Referring to Figures 1 to 4, a thermal blanket
for use with blow-out preventors (BOP's) and the llke ~s
shown and generally lndlcated by reference numeral 10.
As can be seen, the blanket 10 i8 generally rectangular
ln plan and lncludes a body of material 11 formed from
three layers, namely an outer layer 12, a mlddle
lnsulation layer 14 and an lnner layer 16. The outer
and lnner layers 12 and 16 respectlvely are formed from
polypropylene and are water-proof, oil-reslstant and
chemlcal-reslstant. The lnsulatlon layer 14 i.s
surrounded by the polypropylene layers 12 and 16 and is
formed from asbestos. As can be seen, the asbestos
insulatlon layer 14 i~ substantially thlcker than the
layers 12 and 16.
The layers 12 and 16 extend sllghtly beyond
one slde 18 of the asbestos layer 14 along the length of
the thermal blanket 10 and are stltched together to
define a band 20. A plurallty of spaced eyelets 22
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extending along the length of the blanket 10 pass
through the two interconnected layers 12 and 16 and
receive a tie line 23.
The layers 12 and 16 also extend beyond the
opposite side 24 of the asbestos layer 14 to define a
flap 26. A seam 28 interconnecting the layers 12 and 16
extends along the length of the blanket 10 ad;acent the
side 24 of the layer 14 to prevent the layer 14 from
moving relative to the layers 12 and 16 and to secure
the layers 12 and 16 together.
Three spaced straps 30 are stltched to the
layer 12 at one end 32 of the blanket and engage with
three spaced alasps 34 secured to the layer 12 at the
other end 36 of the blanket 10 when the blanket is being
used. Patches of additional materlal 38,40 are secured
to the layer 16 at the ends 32,36 of the blanket 10 to
provlde lncreased support for the stltchlng securlng the
straps and clasps to the blanket.
A centrally located cut-out 42 extendlng
transverse to the longltudlnal axls X of the blanket 18
provlded. The cut-out 42 18 formed through
approxlmately one-half of the wldth of the blanket and
18 surrounded by eyelets 44. A layer of supportlng
materlal 46 secured to the layer 16 surrounds the cut-
out 42 to lnhlblt tearlng of the blanket 10 from
occurrlng about the cut-out. A second tle llne 48
passes through the eyelets 44 to allow the cut-out 42 to
be closed when deslred. An second smaller aut-out 43
spaced from but ln llne wlth the cut-out 42 is also
provlded. The smaller cut-out 43 18 also surrounded by
a layer of supportlng materlal 47 whlch ls secured to
layer 16 to prevent tearlng of the blanket occurring
about ths cut-out. A thlrd tle llne 49 is passed through
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eyelets 45 surrounding the cut-out 43 to allow the cut-
out 43 to be closed when desired.
A plurality of discontinuous spaced sleeves 50
extending parallel to the longitudinal axis X of the
blanket 10 are secured to the inner layer 16. The
sleeves funct~on to receive and hold heat tracing or
steam lines to allow a heat source to be applied to the
device being surrounded by the blanket 10.
The operation of the thermal blanket 10 will
now be described with partlcular reference to Figure 1.
In use, when lt ls deslred to shleld th~ blow-out
preventor 60 from the environment, the body of material
- 15 11 is wrapped around the devlce 60 so that the flap 26
folds about the seam 28 and overlies the ground G and so
that the inner layer 16 is ad~acent the device 60 being
covered. Thereafter, the straps 30 are passed through
clasps 34 and secured 80 that the blanket 10 forms an
envelope around the device 60. Once this has been done,
gravel 62 or another sultable material is placed on the
flap 26 to maintaln its posltion. The upper portion of
the two halves of the blanket 10 are then brought
together and the tie line 23 is passed thraugh the
eyelets 22 if this has not previously been done. The
tle line 23 18 then drawn taught to seal oompletely the
upper surface of the device 60 or to seal the blanket 10
about a proJeotion 64 extending from the devlce 60. The
cut-outs 42, 43 are also closed via the tie llnes 48, 49
passing through the eyelets 44, 45.
As can be seen from Figure 1, if desired,
flexible steam lines 66 or heat traaing maybe passed
through the sleeves 50 prlor to surrounding the device
60 wlth the blanket 10. If thls ls done, the steam
llnes 66 or other heat radiating means are brought into
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close quarters with the device 60 being covered when the
blanket surrounds the device. Thus, the blanket 10 can
be used to thaw devices which have frozen or used to
inhibit devices from freezing. When steam lines 66 or
the like are placed in the sleeves 50, the ends of the
lines are made accessible via the cut-outs 42, 43. This
allows the ends of the steam lines to be connected to a
suitable steam source.
If heat tracing is used, the electrical leads
pro~ecting from the blanket via the cut-outs 42, 43 can
be connected to a suitable power supply.
In Figures 5 to 8 another embodiment of the
present invention is shown surrounding a well head. In
this embodiment like reference numerals will be used to
lndicate like components with the suffix "A" appended
for clarity.
Referring now to Flgures 5 through 8, a
thermal blanket for use with well heads and the llke is
shown and generally indicated by reference numeral lOA .
Slmllar to the prevlous embodlment, the blanket lOA is
generally rectangular and i8 dlmensloned to aover a
typlcal well head. The blanket lOA includes a body of
materlal llA formed from three layers, namely an outer
layer 12A, a middle lnsulatlon layer 14A and an inner
layer 16A. ~he outer and inner layers 12A and 16A
respectively are formed from polypropylene and are
water-proof, oll-reslQtant and chemical-resistant. The
insulation layer 14A is surrounded by the polypropylene
layers 12A and 16A and is formed from asbestos. As can
be seen, the asbestos insulation layer 14A ls
substantially thlcker than the layers 12A and 16A.
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The layers 12A and 16A extend sllghtly beyond
one slde 18A of the asbestos layer 14A along the length
of the thermal blanlcet lOA and are stitched together to
define a band 20A. A plurality of spaced eyelets 22A
extending along the length of the blanket lOA pass
through the two interconnected layers 12A and 16A and
receive a tie line 23A.
The layer~ 12A and 16A also extend beyond the
opposite side 24A of the asbestos la~er 14A to define a
flap 26A. A seam 28A interconnecting the layers 12A and
16A extends along the length of the blanket lOA ad~acent
the slde 24A of the layer 14A to prevent the layer 14A
from movlng relative to the layers 12A and 16A and to
seoure the layers 12A and 16A together.
Three spaced straps 30A are stltched to the
layer 12A at one end 32A of the blanket and engage wlth
three spaaed clasps 34A secured to the layer 12A at the
other end 36A of the blanket lOA when the blanket ls
being used. Patches of additlonal materlal 38A, gOA are
secured to the layer 16A at the ends 32A, 36A of the
blanket lOA to provide inareased support for the
stitchlng securlng the straps and clasps to the blanket.
The operation of the thermal blanket lOA wlll
now be described with partlcular reference to Figure 5.
In use, when it 18 desired to shield the well head 60A
from the envlronment, the body of material llA lS
wrapped around the devlce 60A 80 that the flap 26A folds
about the seam 28 and overlles the ground GA and 80 that
the lnner layer 16A ls adJacent the devlce 60A being
covered. Thereafter, the straps 30A are passed through
clasps 34A and secured so that the blanket lOA forms an
envelope around the device 60A. Once this has been
done, gravel 62A or another suitable material is placed
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on the flap 26A to maintain its position. The upper
portion of the two halves of blanket lOA are then
brought together and the tie line 23A is passed through
the eyelets 22A if this has not been previously done.
The tie line 43A is then drawn taught to seal completely
the upper surface of the device 60A or to seal the
blanket lOA about a pro~ection 64A extending from the
device 60A.
Although not shown in Figures 5 to 8, it
should be apparent that sleeves for receiving steam
lines or heat tracing may also be provided in a manner
similar to that shown in the embodiment of Figures 1 to
4 lf desired.
It should be apparent to one of skill in the
art that the present invention can be modified wlthout
departing form the scope thereof as defined by the
depended olaims.
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