Note: Descriptions are shown in the official language in which they were submitted.
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A PUNCHING TOOL
Field of the invention
The present invention relates to a punching tool for providing a hole or a
dimple
in a metal casing in a borehole. The present invention further relates to a
method
for providing a hole or a dimple in a metal casing downhole and to a method
for
installing a plug in an existing hole in the casing downhole.
Background art
When producing hydrocarbons from a well, the casing is most often perforated
by
means of detonations to provide holes in the casing for letting the formation
fluid
into the casing. However, using detonations for perforating is risky, and
there is
therefore an increasing demand for alternative methods for making such holes.
Perforations or holes in a casing may be used for various purposes, such as
for
injection purposes, for insertion of completion elements, e.g. valves after
making
the completion, or for allowing fluid to flow from the formation into the
casing.
There is thus a need for an apparatus and a method for providing perforations
or
holes without using detonation of charges.
Further, when a hole or perforations are to be used for injection purposes,
e.g.
for providing an annular seal in an annulus, determination of the exact
position of
the hole in relation to an injection apparatus is a difficult task. If the
exact
position cannot be established, a large section of the casing has to be sealed
off
to perform the injection. In this regard, one applied solution is to provide a
seal
downhole well below the injection hole and simply pressurise the entire well
down
to the seal to inject the fluid. Such an operation is cumbersome and requires
a
great amount of injection fluid, making it a cost-intensive operation.
Summary of the invention
It is an object of the present invention to wholly or partly overcome the
above
disadvantages and drawbacks of the prior art. More specifically, it is an
object to
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provide a solution for providing holes in a casing without using detonation of
charges.
The above objects, together with numerous other objects, advantages, and
features, which will become evident from the below description, are
accomplished
by a solution in accordance with the present invention by a punching tool for
providing a hole or a dimple in a metal casing in a borehole, comprising:
- a tool body having an axial extension, and
- a punching unit connected with the tool body, comprising:
- a bore provided in the tool body, extending substantially radially in
relation to the axial extension,
- a fluid inlet in fluid communication with the bore, and
- a hydraulically activated punch arranged in the bore, being movable
between a retracted and a projected position,
wherein the hydraulically activated punch is moved into the projected position
by
injecting a fluid into the bore through the fluid inlet.
The punching tool described above may further comprise two isolation devices
circumferenting the tool body and arranged spaced apart in the axial extension
on opposite sides of the punching unit, the isolation devices being expandable
from the tool body in a radial direction, thereby providing zonal isolation of
a
section of the casing downhole, wherein the punching tool further comprises
one
or more injection nozzles for injecting a fluid into the section of the casing
being
isolated by the isolation devices, the injection nozzle being arranged between
the
isolation devices.
Hereby, when a section of the casing downhole has been isolated and a hole in
the casing has been punched, a fluid may be injected into the section inside
the
casing isolated by the isolation devices to inflate an annular barrier
arranged in
fluid communication with the isolated section via the punched hole. The
punching
tool may thus be used for providing a hole in the casing downhole and
subsequently for injecting a fluid though the hole. By using a tool having a
punching unit arranged between a set of isolation devices, it is guaranteed
that
the hole in the casing is provided in the isolated section. Had the hole been
punched by a first punching tool and the section of the casing been isolated
by a
second isolation and injection tool, great care would have to be taken to
position
the isolation and injection tools to secure that the hole punched was in fact
in the
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isolated section of the casing. The punching tool may also be used for other
injection purposes, such as for inflating a packer, for stimulating the
pressure in
inflatable packers or other types of annular barriers, for acid treatment of a
formation outside a casing or for fracking purposes.
In one embodiment, the hydraulically activated punch may have a punching edge
for providing a hole in a metal casing.
The punching tool described above may further comprise a pump arranged in
association with the tool body, the pump being connected to the fluid inlet
for
supplying a hydraulic fluid to the bore to move the hydraulically activated
punch
into the projected position.
In an embodiment, the isolation devices may be constituted by inflatable
packers
being inflated and expanded from the tool body by the pump supplying a fluid
to
the inflatable packers.
Furthermore, the isolation devices may be inflatable packers, swellable
packers,
compression or cup packers, other downhole packers, retrieval packers or
combinations thereof.
Additionally, the pump may be in fluid communication with the one or more
injection nozzles, and the pump may be adapted to inject a fluid into the
section
of the casing being isolated by the isolation devices through the one or more
injection nozzles.
The punching tool described above may further comprise an inlet fluidly
connecting the pump with an annulus surrounding the punching tool, wherein the
pump is adapted to draw fluid from the annulus and inject the fluid from the
annulus through the one or more injection nozzles into the section of the
casing
being isolated by the isolation devices.
Moreover, the punching unit may comprise an abutment arranged
circumferentially opposite the hydraulically activated punch around the tool
body.
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In addition, part of the hydraulically activated punch may engage part of the
abutment to control the radial movement between the retracted and the
projected position of the hydraulically activated punch.
Furthermore, one of the hydraulically activated punch and the abutment may
comprise one or more radially extending guide elements, and the other of the
hydraulically activated punch and the abutment may comprise one or more
radially extending tracks being adapted to engage with the guide elements to
control the radial movement between the retracted and the projected position
of
the hydraulically activated punch.
Also, the hydraulically activated punch and the abutment may define an
expandable space.
The punching unit may further comprise a piston and a spring which is
compressed when the hydraulically activated punch is moved into the projected
position.
Moreover, the hydraulically activated punch and the abutment may be arranged
in a through-bore in the tool body.
In addition, sealing means may be arranged in grooves in the through-bore of
the tool body to seal against the hydraulically activated punch, and/or the
abutment may be arranged in the through-bore.
Such sealing means may be arranged in grooves in the hydraulically activated
punch, the punch base part and/or the abutment to seal against the through-
bore and the tool body.
In an embodiment, the tool may comprise a plurality of punching units.
In another embodiment, the tool may comprise a plurality of punching units and
a plurality of abutments.
Furthermore, the piston may be movable in a hollow space defined by the
hydraulically activated punch or a base part of the hydraulically activated
punch,
and the piston may be connected with the abutment through a piston rod.
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Additionally, the piston may be movable in a hollow space defined by the
abutment, and the piston may be connected with the hydraulically activated
punch through a piston rod.
5 Also, one of the hydraulically activated punch and the abutment may be
connected with the piston through a piston rod, and the other of the
hydraulically
activated punch and the abutment may have an end arranged inside the tool
body, the end comprising a flange, and a spring may be arranged between the
piston and the flange.
Further, a stop element may be arranged in connection with the hydraulically
activated punch and the abutment to avoid separation of the hydraulically
activated punch and the abutment.
Also, the abutment may be fixedly connected with the tool body.
The abutment may project radially from the tool body.
In an embodiment, the stop element may be arranged in connection with the
fluid inlet.
Furthermore, the fluid inlet may be connected with one or more fluid channels
being in fluid communication with a pressure side of the piston.
A distance between the retracted and a projected position of the punch may be
3
mm, preferably above 10 mm, most preferably above 20 mm, and more
preferably above 100 mm.
Moreover, the punch may comprise a pointed surface adapted to rupture the
metal casing during the movement of the hydraulically activated punch from the
retracted to the projected position.
Additionally, the abutment may comprise a "curved" (convex) face which is
adapted to abut an inner surface of a tubular metal casing during the
punching.
Further, the abutment may comprise attachment elements so that the face of the
abutment can be changed in relation to the inner surface of the metal casing.
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In an embodiment, the tool may comprise an electrical motor driving the pump.
In addition, the tool may comprise a fluid reservoir for containing a fluid
for being
injected into the bore to move the hydraulically activated punch into the
projected position, a fluid reservoir for containing a fluid for being
injected into
the inflatable packers to inflate and expand the inflatable packers from the
tool
body, and/or a fluid reservoir for containing a fluid for being injected into
the
isolated section of the casing through the one or more injection nozzles.
Moreover, the fluid reservoir may be one common fluid reservoir.
Furthermore, the hydraulically activated punch may be a punch adapted to
provide a dimple in a metal casing.
Additionally, the hydraulically activated punch may be a punch having rounded
edges.
Also, the hydraulically activated punch may be a pin punch, a centre punch, a
taper punch, a flat chisel, a cape chisel, a half-round nose chisel or a
combination
thereof.
Further, the hydraulically activated punch may be a punch adapted to install a
plug in an existing hole in the casing downhole to seal the existing hole.
Hereby, if an annular barrier or packer bursts, an inlet to such annular
barrier or
packer may be sealed off to avoid fluid from flowing from the casing and into
the
formation through the defect annular barrier or packer. Thus, by installing a
plug
in an inlet of the defect annular barrier or packer, the remaining annular
barriers
or packers may still be inflated by pressurising the well from the top or by
pressurising a section of the well containing the defect annular barrier or
packer.
Moreover, the punch may have a cavity in which the plug can be arranged.
In an embodiment, the hydraulically activated punch may be further adapted to
hold on to the plug prior to installing the plug in the existing hole, to
place the
plug in the existing hole when the hydraulically activated punch is moved into
a
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projected position, and to deform the plug when the hydraulically activated
punch
is moved into a fully projected position.
In addition, the cavity of the punch may have a circumferential projection or
a
plurality of projections matching a circumferential groove in the plug.
By having a projection matching the groove of the plug, the plug can be held
in
place before being inserted, and when the hole has been plugged, the plug is
secured in the hole so that the force securing the plug in the hole is greater
than
a force enabling detachment of the plug from the punch. The plug is thus
easily
detached from the punch when the plug has been punched in the hole.
The present invention furthermore relates to a method for providing a hole or
a
dimple in a metal casing downhole, comprising the steps of:
- providing a punching tool as described above in the metal casing downhole,
- positioning the punching unit of the punching tool at a location where a
hole or
dimple is to be provided,
- positioning the abutment arranged circumferentially opposite the
hydraulically
activated punch around the tool body so that it abuts a casing wall at a
position
circumferentially opposite the hydraulically activated punch, and
- moving the hydraulically activated punch radially from a retracted
position to a
projected position so that a hole or dimple is provided in the metal casing by
the
hydraulically activated punch in its projected position.
Furthermore, the hydraulically activated punch may be moved radially to
provide
a hole in the metal casing, the method further comprising the steps of
expanding
the isolation devices from the tool body in a radial direction, thereby
providing
zonal isolation of a section of the casing downhole, and injecting a fluid
into the
section of the casing being isolated by the isolation devices, thereby forcing
a
fluid through the hole provided in the casing.
Moreover, the hydraulically activated punch may be moved radially to provide a
dimple in the metal casing, the method further comprising the step of
arranging
an electronic device in the dimple or hole, the electronic device comprising a
radio-frequency identification (RFID) chip, a radio-frequency tag (RFT) and/or
one or more sensors, such as a temperature sensor.
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Finally, the present invention relates to a method for installing a plug, such
as a
Lee-plug, in an existing hole in the casing downhole, the method comprising
the
steps of:
- providing a punching tool as described above in the casing downhole,
- positioning the punching unit of the punching tool at a location opposite
the
existing hole,
- positioning the abutment arranged circumferentially opposite the
hydraulically
activated punch around the tool body so that it abuts a casing wall at a
position
circumferentially opposite the hydraulically activated punch,
- moving the hydraulically activated punch radially from a retracted position
to a
projected position to place the plug in the existing hole, and
- moving the hydraulically activated punch to a fully projected position,
thereby
deforming the plug to secure the plug and seal the existing hole.
In one embodiment, part of the plug may be plastically deformed.
Brief description of the drawings
The invention and its many advantages will be described in more detail below
with reference to the accompanying schematic drawings, which for the purpose
of
illustration show some non-limiting embodiments and in which
Fig. 1 shows a punching tool in a casing,
Fig. 2 shows a partly cross-sectional view of the punching tool,
Fig. 3 shows a partly cross-sectional view of another embodiment of the
punching
tool,
Fig. 4 shows another embodiment of the punching tool in a casing,
Fig. 5 shows yet another embodiment of the punching tool in a casing,
Fig. 6 shows yet another embodiment of the punching tool in a casing,
Fig. 7 shows a partly cross-sectional view of another embodiment of the
punching
tool along the axial extension of the tool,
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Fig. 8 shows a partly cross-sectional view of another embodiment of the
punching
tool along a radial extension of the tool perpendicular to the axial extension
of
the tool,
Fig. 9 shows a partly cross-sectional view of a punching tool for providing a
dimple in a casing downhole,
Fig. 10 shows a cross-sectional view of a casing in which an electronic device
has
been secured in a dimple,
Fig. 11 shows a partly cross-sectional view of the punching tool comprising
isolation devices for providing zonal isolation of a section of the casing,
Fig. 12 shows a partly cross-sectional view of the punching tool comprising an
injection nozzle for injecting a fluid into the isolated section of the
casing, and
Fig. 13 shows a partly cross-sectional view of a punching tool comprising a
hydraulically activated punch adapted to install a plug in an existing hole in
a
casing downhole.
All the figures are highly schematic and not necessarily to scale, and they
show
only those parts which are necessary in order to elucidate the invention,
other
parts being omitted or merely suggested.
Detailed description of the invention
Fig. 1 shows a punching tool 1 having just punched a hole 2a in a casing 3 in
a
borehole 4. The punching tool 1 comprises a tool body 5 having an axial
extension 6, a punching unit 11 comprising a bore 27a provided in the tool
body,
and a hydraulically activated punch 9 which is movable between a retracted and
a projected position to be able to punch out a piece 12 of a wall 13 of the
casing
3 or to provide a dimple in a wall 13 of the casing 3. The hydraulically
activated
punch may also be used for applying a force to an object, such as a plug,
downhole, e.g. to plug a hole in the casing. The hydraulically activated punch
9 is
arranged in a bore 27a extending in a direction substantially radial in
relation to
the axial extension of the tool body, and a fluid inlet 26 in fluid
communication
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with the bore is provided to enable injection of a fluid into the bore to
activate
the hydraulically activated punch. The punching unit further comprises an
abutment 10 arranged circumferentially opposite the hydraulically activated
punch around the tool body to abut the wall of the casing so that the force
5 generated by injection of the fluid into the bore is applied to the
hydraulically
activated punch and exploited to move the hydraulically activated punch in the
radial direction. The abutment is fixedly connected with the tool body.
In one embodiment, the punching tool further comprises two isolation devices
70
10 for providing zonal isolation of a section 75 of the casing and a
plurality of
injection nozzles 80 for injecting a fluid into the isolated section of the
casing, as
shown in Figs. 11-12. The isolation devices 70 circumferent the tool body and
are
positioned along the tool body on opposite sides of the punching unit, and are
expandable from the tool body in a radial direction. When the isolation
devices 70
are expanded, they isolate a section 75 of the casing, thereby providing zonal
isolation. The isolation devices 70 may be constituted by inflatable packers,
swellable packers, compression or cup packers, other down hole packers,
retrieval
packers, combinations thereof or any other means known to the skilled person
for providing a seal between the inner wall of the casing and the tool body.
The
injection nozzles 80 are arranged between the isolation devices 70, allowing a
fluid to be injected into the isolated section 75 of the casing through the
injection
nozzles.
The punching tool 1 is submerged into the well and is powered through a
wireline
14 and connected with the tool through a cable head 15. The punching tool 1
comprises a motor 17 connected with the cable head 15 through an electronic
section 16 and a pump 18 driven by the motor, which pump supplies a fluid
under pressure to the bore 27a via the fluid inlet 26 to activate the
hydraulically
activated punch 9. In one embodiment, the pump is further in fluid
communication with the isolation devices 70 constituted by inflatable packers.
Accordingly, the inflatable packers are inflated and expanded from the tool
body
by the pump supplying a fluid to the inflatable packers. In a further
embodiment,
the pump is in fluid communication with the injection nozzle 80 via a conduit
83
extending in the axial extension of the punching tool, as indicated by the
dotted
lines in Fig. 11. The pump is further fluidly connected to an inlet 81
provided in
the punching tool, whereby fluid may be drawn in by the pump from an annulus
82 surrounding the punching tool. The fluid drawn in from the annulus may
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subsequently be supplied to the injections nozzles 80 via the conduit 83 and
injected into the isolated section of the casing. When a hole 2a is provided
in the
wall of the isolated section of the casing and fluid is continuously injected
into
that section, the fluid in the section will be displaced through the hole 2a,
as
shown in Fig. 12. The hole 2a, 2c may be an existing hole 2c or a hole 2a
provided by the punching tool, and the casing may also have a plurality of
holes
through which the fluid can be injected.
In Fig. 2, the hydraulically activated punch 9 defines a hollow space 19a in
which
a piston 20 is arranged, enabling the hydraulically activated punch 9 to move
from its retracted position to its projected position, thus functioning as a
hydraulic punch cylinder. The hydraulically activated punch 9 moves inside an
expandable space 31 primarily defined by the bore 27a. In one end, the
hydraulically activated punch 9 has a punching edge 21a for providing a hole
in a
metal casing, and in the opposite end, a flange 22 extending towards a piston
rod
23 of the piston is provided. Between the flange 22 and the piston, a spring
24 is
arranged which is compressed when the hydraulically activated punch is in its
projected position. In another embodiment, the end of the hydraulically
activated
punch extending from the tool body may alternatively be adapted to provide a
dimple in a metal casing, as illustrated in Fig. 9. The hydraulically
activated
punch for providing a dimple in the metal casing may have a shape
substantially
similar to that of a pin punch, a centre punch, a taper punch, a flat chisel,
a cape
chisel, a half-round nose chisel, a combination thereof, or any other shape
for
providing a dimple known to the skilled person.
Further, in another embodiment, the hydraulically activated punch is adapted
to
install a plug 61 in an existing hole 2c in the casing, as shown in Fig. 13.
The
hydraulically activated punch is adapted to hold on to the plug prior to
installation
and to place the plug in the existing hole by moving the hydraulically
activated
punch into a projected position. After having placed the plug in the hole 2c,
the
plug may be deformed by further moving the hydraulically activated punch into
a
fully projected position, whereby the plug is secured in the hole and the hole
is
sealed. The plug may be any kind of plug suitable for sealing a hole in a
casing
downhole, such as a plug sold under the trade name Lee Plug by The Lee
Company. What is special about the Lee Plug is that only a radial force is
required
to install the plug, and such a plug may thus be installed by the punching
tool
according to the present invention.
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After having plugged the hole, the hydraulically activated punch may be moved
further radially from the tool body in an even further projected position,
forcing
the plug further outwards and deforming the casing wall so that the plug does
not diminish the inner diameter of the casing. In this way, the plug plugs the
hole
and is used to provide a dimple in the casing wall.
The pump 18 illustrated by dotted lines in Fig. 2 provides fluid through fluid
channels 25 into the expandable space 31 through inlets 26 in order to force
the
hydraulically activated punch radially outwards from the tool body 5. When the
punching process is completed, the pump stops pumping fluid into the
expandable space 31, and the fluid is forced back into the fluid channel 25 by
the
decompressing force of the spring 24. Sealing means 28 is arranged in grooves
29 in the bore 27a of the tool body to seal against the hydraulically
activated
punch 9.
By having a hydraulically activated punching tool, the punching force can be
substantially increased compared to prior art mechanically operated solutions.
Furthermore, tests have shown that the hole in the casing can be made with a
higher degree of accuracy and that this cut is cleaner, leaving almost no
burrs on
the edges. The prior art solutions leave substantial burrs on the edges,
hindering
the insertion of a valve in the hole in a subsequent process. If the hole is
made to
open the casing to an inflow of well fluid, such as hydrocarbons, also called
oil
and/or gas, the burrs hinder an optimal inflow, causing a more turbulent flow
before the hole at the burring side.
In Fig. 3, also the abutment 10 projects radially from the tool body 5, and it
is
therefore slidably arranged in a second bore 32 provided in the tool body. The
abutment 10 is activated by injecting a fluid into the second bore 32, whereby
the abutment 10 moves radially in relation to the axial extension. The
abutment
has a hollow space 33 in which a second piston 34 moves, thereby compressing a
second spring 35 between the piston and a second flange 36 provided in one end
of the abutment opposite an outer face of the abutment abutting the inner wall
of
the casing. The fluid is injected into the second bore 32 by the pump pumping
a
fluid into the expandable space 38 via second fluid channels 37 and through
second inlets 39. One pump may thus supply fluid to move both the
hydraulically
activated punch 9 and the abutment 10, and the fluid channels 25, 37 supplying
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fluid to the hydraulically activated punch 9 and the abutment 10 may be one
channel.
The punching tool 1 may comprise several punching units 11 punching holes in
the casing in a predetermined pattern, as shown in Fig. 4. Thus, the punching
tool can be used instead of a perforation gun, thereby avoiding the risky
detonations downhole. As can be seen in Fig. 5, the punching tool 1 comprises
second punching units 11b also arranged circumferentially opposite the first
punching units 7 around the tool body 5. The second punching units have the
same design as the first punching units 7 and function as abutments in
relation to
the first punching units 7. Similarly, the first punching units function as
abutments to the second punching units 11b. The punching units shown in Fig. 5
are arranged with an angular spacing of 180 .
As shown in Fig. 6, the punching tool 1 may further comprise third punching
units
11c and fourth punching units (not shown) arranged opposite each other and
between the first and second punching units. The third and fourth punching
units
have a design similar to that of the previously described punching units and
function as abutments in relation to one another. Each of the punching units
is
thus arranged with an angular displacement of 90 along the circumference of
the punching tool. Further, the third and fourth punching units are displaced
in an
axial direction of the punching tool in relation to the first and second
punching
units. The punching tool shown in Fig. 5 thus comprises 10 punching units
spaced
apart to optimise the tool length, and all the punching units may be supplied
with
fluid from the same pump through the same channel or through several
channels.
In another embodiment shown in Fig. 7, the hydraulically activated punch and
the abutment are arranged in a through-bore 27b. As shown, the abutment 10
and the hydraulically activated punch 9 engage one another, forming two
common fluidly connected expandable spaces 31. The radial movement of the
abutment and the hydraulically activated punch thus occurs by the abutment and
the hydraulically activated punch moving radially away from each other. A
piston
20 provided on a piston rod 23 is arranged in each of the expandable spaces
31,
and the piston rods 23 are connected with the abutment 10 by screws 41. The
hydraulically activated punch 9 is connected with a punch base part 42
defining
part of each of the expandable spaces 31, and the punch base part 42 is again
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threadedly connected with two inserts 40. The pistons are movable within each
of
the expandable spaces 31. The inserts 40 each have a flange 22 which together
with the piston compresses a spring 24 when the hydraulically activated punch
and the abutment are projected from the tool body. The hydraulically activated
punch 9 and the abutment 10 are forced away from each other by means of fluid
pumped into the expandable space 31 through fluid channels 25 and is led into
the expandable space through a circumferential groove 43 leading the fluid in
through the inlet 26 and into a cylinder bore 44. Sealing means 28 are
arranged
in grooves 29 in the through-bore 27b in which the hydraulically activated
punch
and the abutment are arranged, preventing the fluid from escaping into the
annulus 82 surrounding the tool.
In order to fasten the hydraulically activated punch 9 and the abutment 10 to
each other, a hollow rod 45 functioning as a stop element is arranged
penetrating
both the hydraulically activated punch and the abutment. Both comprise an
elongated opening allowing the hydraulically activated punch 9 and the
abutment
10 to move in relation to the rod and each other. The rod is hollow to be able
to
lead the fluid and has openings for the fluid to enter, thus leading the fluid
into
the expandable space 31. The fluid inlet 26 is thus positioned in the centre
of the
punching unit.
In another embodiment shown in Fig. 8, the punching unit 11 is rotated 90
degrees compared to the punching unit shown in Fig. 8. Otherwise, the punching
unit shown in Fig. 8 has substantially the same design as the punching unit of
Fig. 7. In Fig. 8, the punching unit, however, has a fluid channel 46 in the
punch
base part 42 to lead the fluid from the hollow rod 45 to one end of each of
the
expandable spaces 31 so that the fluid is injected into the expandable spaces
acting directly on the pistons. Hereby, the initial movement of the
hydraulically
activated punch 9 and the abutment 10 requires less fluid power.
In Figs. 7 and 8, part of the hydraulically activated punch 9 engages part of
the
abutment 10 to control the radial movement between the retracted and the
projected position of the hydraulically activated punch 9. The abutment 10 has
radially extending guide elements 50 engaging radially extending tracks 51 of
the
hydraulically activated punch 9. Hereby, the hydraulically activated punch 9
engages the abutment 10 on an outside thereof or vice versa so as to control
the
radial movement between the retracted and the projected position of the
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hydraulically activated punch 9. In Fig. 8, the sealing means 28 are arranged
in
grooves in the punch base part 42 and in the abutment to seal against the
through-bore 27b and the tool body 5.
5 The punching tool 1 is designed so that the distance between the
retracted and
the projected position of the hydraulically activated punch is above 5 mm,
preferably above 10 mm, more preferably above 20 mm, and most preferably
above 50 mm. However, this depends on the completion and the restrictions
already present in the completion.
The punching tool may be used to punch only a small hole having a diameter
smaller than that of the hydraulically activated punch, and thus, the hole is
made
by the tip of the hydraulically activated punch. When having a double-cased
casing and when the inner casing is blocked in the bottom, it may be necessary
to make small relief holes and even pump gas down through the outer casing in
through the inner casing to force the fluid upwards. Such relief holes may
also be
necessary to even out the pressure between the casing and the annulus. When
making relief holes, the piece of the casing is not separate from the rest of
the
casing and does not flow freely in the annulus.
The punching tool may have several abutments and one hydraulically activated
punch, all of which are hydraulically activated so that the abutments are
positioned on both sides of the hydraulically activated punch and are
projected
radially until the hydraulically activated punch presses against the inner
wall of
the casing. Subsequently, the hydraulically activated punch is activated and
cuts
its way into the casing wall without having to travel a certain length before
reaching the inner casing wall. In this way, the hydraulically activated punch
is
capable of penetrating thicker casings than if it had to travel a certain
length
before reaching the inner casing wall.
The hydraulically activated punch may be any kind of punch, e.g. a punch
comprising a pointed surface adapted to rupture the metal casing during the
movement of the hydraulically activated punch from the retracted to the
projected position.
As shown, the abutment has a curved and convex face which is adapted to abut
an inner surface of a tubular metal casing during the punching. The abutment
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may comprise attachment elements so that the face of the abutment can be
changed in relation to the inner surface of the metal casing. The abutment
face
may then change to a teethed surface or a similar design to better be able to
fasten the tool while punching the hole.
The pump of the tool takes fluid in from the well through a filter, but the
tool
may instead comprise a fluid reservoir, or the fluid may be led from the
surface
through the wireline which is thus also a supply line.
In the following, the use of the punching tool will be described in further
detail.
In Fig. 9, the punching tool comprises a hydraulically activated punch 9 for
providing a dimple 2b in the casing downhole. When the punching tool has been
inserted into the casing and the punching unit has been positioned at a
location
where a dimple is to be provided, the abutment 10 arranged circumferentially
opposite the hydraulically activated punch is positioned so that it abuts the
casing. Subsequently, the hydraulically activated punch is moved radially from
the retracted position to the projected position so that a dimple is provided
in the
metal casing. When the dimple has been provided, the hydraulically activated
punch is retracted into the tool body, and an electronic device 60 is secured
in
the dimple, as shown in Fig. 10. The electronic device may have various
functionalities and may comprise a radio-frequency identification (RFID) chip,
a
radio-frequency tag (RFT), and/or one or more sensors, such as a temperature
sensor.
In Fig. 11, the punching tool comprises a hydraulically activated punch 9 for
providing a hole 2a in the casing downhole. When the punching tool has been
inserted into the casing and the punching unit has been positioned at a
location
where a hole is to be provided, the abutment 10 arranged circumferentially
opposite the hydraulically activated punch is positioned so that it abuts the
casing. The isolation devices 70 are also expanded from the tool body, thereby
sealing off a section 75 of the casing. Subsequently, the hydraulically
activated
punch is moved radially from the retracted position to the projected position
so
that a hole 2a is provided in the metal casing. When the hole has been
provided,
the hydraulically activated punch is retracted into the tool body by the force
exerted by the spring shown in the previously mentioned figures. The isolation
devices 70 may also be expanded when the hole has been punched in the casing
to seal off the section 75 of the casing. When the hole has been punched and
the
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section of the casing has been isolated, a fluid is injected into the section
of the
casing being isolated by the isolation devices, as shown in Fig. 12. Thereby,
the
fluid present in the isolated section is forced through the hole 2a in the
casing
and into an annular barrier 90. The punching tool may thus be used for
expanding the annular barrier or stimulating the pressure in the annular
barrier,
e.g. to expand the annular barrier even further. The punching tool may also be
used for other injection purposes envisaged by the skilled person, such for
inflating inflatable packers or other types of annular barriers, for flushing
the
annulus after insertion of the casing, for acid treatment of a formation
outside a
casing or for fracking purposes.
In Fig. 13, the punching tool comprises a hydraulically activated punch 9 for
installing a plug 61 in an existing hole 2c in the casing. This functionality
may be
relevant if an annular barrier forming part of a series of annular barriers is
defect.
An annular barrier may be defect if for example the annular barrier have burst
during inflation as shown in Fig. 13, or if the annular barrier is leaking for
other
reasons, and fluid injected into the well to inflate the series of annular
barriers
will thus flow through the defect annular barrier into the formation. Hereby,
the
series of annular barriers cannot be inflated as the required pressure cannot
be
reached by pressurising the well from the top or by pressurising a section of
the
well containing the defect annular barrier. However, by installing the plug 61
in
the existing hole 2c constituting an inlet to the defect annular barrier, the
defect
annular barrier is sealed off and the remaining annular barriers may still be
inflated.
In order to be able to install a plug in an existing hole 2c, the exact
position of
the existing hole must be known and the operator must be able to position the
punching tool in the correct position to install the punch. To facilitate
positioning
of the punching tool, the casing in the vicinity of the annular barrier and
the
punching tool may be provided with associated marker tags 91 and marker tag
identifications means 92. The marker tag 91 may be arranged on the casing and
the marker tag identification means 92 may be arranged on the punching tool,
or
the other way around. The marker tag 91 may be a radio-frequency
identification
(RFID) chip, a radio-frequency tag (RFT) or any other device adapted to send
or
receive a signal known to the skilled person, and the marker tag
identification
means 92 may be any kind of sensor or receiver known to the skilled person for
detecting the position of the marker tag 91 in relation to the punching tool.
In
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one embodiment, the marker tag 91 and the marker tag identification means 92
may be replaced by mechanical positioning means, whereby the punching tool
may latch onto the casing to ensure the correct position of the punching tool
in
relation to the existing hole 2c.
When the punching tool has been inserted into the casing and the punching unit
has been positioned with the piston opposite the existing hole to be sealed,
the
abutment 10 arranged circumferentially opposite the hydraulically activated
punch is positioned so that it abuts the casing. Subsequently, the
hydraulically
activated punch is moved radially from the retracted position to the projected
position so that the plug is placed in the hole and the hole is sealed. The
installation of the plug may require that a further radial force is applied to
the
plug, e.g. to plastically deform part of the plug. To apply a further radial
force to
the plug, the hydraulically activated punch may be moved to a fully projected
position, thereby deforming the plug.
After having installed the plug in the existing hole 2c constituting the inlet
to the
defect annular barrier, the defect annular barrier is sealed off. Hereby the
well
may once again be pressurised to inflate the remaining annular barriers as the
injected fluid does not escape through the defect annular barrier.
In another embodiment, the punching tool may comprise multiple punching units,
wherein one or more punching units comprises a hydraulically activated punch
adapted to provide a hole in the casing and one or more other punching units
comprises a hydraulic activated punch adapted to install a plug. The punching
tool may thus install a plug in an existing hole to seal off that hole as
described
above and provide a new hole adjacent to the hole sealed off. Alternatively,
the
punching tool may provide a new hole, enlarge an existing hole or trim a
fracture
in order to allow installation of a plug to seal off the existing hole or
fracture.
By fluid or well fluid is meant any kind of fluid that may be present in oil
or gas
wells downhole, such as natural gas, oil, oil mud, crude oil, water, etc. By
gas is
meant any kind of gas composition present in a well, completion, or open hole,
and by oil is meant any kind of oil composition, such as crude oil, an oil-
containing fluid, etc. Gas, oil, and water fluids may thus all comprise other
elements or substances than gas, oil, and/or water, respectively.
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By a casing is meant any kind of pipe, tubing, tubular, liner, string etc.
used
downhole in relation to oil or natural gas production.
In the event that the tools are not submergible all the way into the casing, a
downhole tractor can be used to push the tools all the way into position in
the
well. A downhole tractor is any kind of driving tool capable of pushing or
pulling
tools in a well downhole, such as a Well Tractor .
Although the invention has been described in the above in connection with
preferred embodiments of the invention, it will be evident for a person
skilled in
the art that several modifications are conceivable without departing from the
invention as defined by the following claims.
