U.S. patent application number 11/369501 was filed with the patent office on 2007-09-13 for downhole trigger device.
Invention is credited to Steve Rosenblatt, Yang Xu.
Application Number | 20070209802 11/369501 |
Document ID | / |
Family ID | 38158087 |
Filed Date | 2007-09-13 |
United States Patent
Application |
20070209802 |
Kind Code |
A1 |
Xu; Yang ; et al. |
September 13, 2007 |
Downhole trigger device
Abstract
A trigger device keeps a downhole tool from setting until it is
properly positioned. Regardless of the type of tool or the type of
associated trigger, the retainer of the present invention is
combusted. The material is preferably one that combusts readily
such as a material used in fuses for explosives. The battery
requirements are to simply create the brief spark that starts the
combustion, making the battery size significantly smaller than what
would be needed to power a heater to melt materials that were used
in the past.
Inventors: |
Xu; Yang; (Houston, TX)
; Rosenblatt; Steve; (Houston, TX) |
Correspondence
Address: |
DUANE MORRIS LLP
3200 SOUTHWEST FREEWAY
SUITE 3150
HOUSTON
TX
77027
US
|
Family ID: |
38158087 |
Appl. No.: |
11/369501 |
Filed: |
March 7, 2006 |
Current U.S.
Class: |
166/373 ;
166/66.7 |
Current CPC
Class: |
E21B 23/04 20130101 |
Class at
Publication: |
166/373 ;
166/066.7 |
International
Class: |
E21B 34/06 20060101
E21B034/06 |
Claims
1. A trigger device for a downhole tool for selectively actuating
the tool, comprising: a body; an actuating member mounted to said
body whose movement sets the tool; a restraining member to
selectively directly or indirectly restrain movement of said
actuating member with respect to said body, said restraining member
when subjected to an initial energy input initiates a process
within said restraining member that continues without further
energy input to the point of allowing said actuating member to
move.
2. The device of claim 1, wherein: said process releases heat.
3. The device of claim 1, wherein: said process comprises a
chemical reaction.
4. The device of claim 1, wherein: the response of the restraining
member to energy input is pyrotechnic.
5. The device of claim 1, wherein: said restraining member
comprises an explosive material.
6. The device of claim 1, wherein: said energy input comprises a
spark.
7. The device of claim 6, wherein: said spark is supplied by a
battery supported by said housing.
8. The device of claim 6, wherein: said spark is generated
mechanically.
9. The device of claim 1, wherein: said actuating member comprises
a piston that is subjected to an initial force.
10. The device of claim 9, wherein: said restraining member
comprises a wire that initially retains said piston.
11. The device of claim 10, wherein: said wire passes through said
piston.
12. The device of claim 1, wherein: said restraining member
comprises a wire fuse.
13. A method of selectively actuating a downhole tool, comprising:
retaining directly or indirectly a triggering member with a
restraining member; applying energy to the restraining member to
initiate a response in said restraining member; removing said
applied energy while said response continues; and defeating said
restraining member to let the triggering member move.
14. The method of claim 13, comprising: releasing heat from said
response.
15. The method of claim 13, comprising: creating a chemical
reaction as said response.
16. The method of claim 13, comprising: using a wire fuse for said
restraining member.
17. The method of claim 13, comprising: making said response a
pyrotechnic one.
18. The method of claim 14, comprising: obtaining said response
without the presence of oxygen.
19. The method of claim 13, comprising: creating a spark for said
applying energy.
20. The method of claim 19, comprising: using a piston as said
triggering member; using a wire to retain said piston; passing said
wire around or through said piston; and allowing said response to
break said wire.
21. The device of claim 1, wherein: said restraining member opens a
port as a result of being subjected to said energy input.
22. The device of claim 21, wherein: said actuating member
comprises a piston flanked by chambers; said restraining material
is disposed initially in a port in one of said chambers such that
application of said energy input opens said port to create a net
force on said piston to set the tool.
23. The device of claim 22, wherein: said port, when opened admits
hydrostatic well pressure to one of said chambers.
24. The device of claim 22, wherein: said body further comprises a
pressurized chamber, said port, when opened allows pressure from
said pressurized chamber to reach said piston via one of said
chambers to set the tool.
25. The device of claim 24, wherein: the other of said chambers is
exposed to well hydrostatic pressure.
26. The device of claim 2, wherein: said restraining member
comprises a final element that is in contact with the actuating
member and said heat compromises said final element to allow the
actuating member to move.
27. The device of claim 26, wherein: said final element comprises a
cord connected to the actuating member that fails from said
heat.
28. The device of claim 10, wherein: said wire holds a plurality of
sleeve segments together until said initial energy input starts a
process that undermines said wire.
29. The device of claim 10, wherein: said wire holds a split ring
together around said piston until said initial energy input starts
a process that undermines said wire.
Description
FIELD OF THE INVENTION
[0001] The field of this invention is trigger devices that are
actuated downhole to operate a tool and more particularly triggers
that are held immobilized until properly positioned and then
released preferably with a spark, however initiated.
BACKGROUND OF THE INVENTION
[0002] Space is always a concern in downhole tool design. Some
tools need to be retained in an unset position until properly
placed in the well. It is only when they are properly located that
it is desired to set the tool. Such tools in the past have had
trigger mechanisms that are retained in an immovable position for
run in until proper placement of the associated downhole tool is
achieved. One technique for holding things immobile until the tool
is properly placed has involved disabling the trigger with a
mechanical device that is held against movement by a Kevlar.RTM.
high strength fiber and an associated electrically powered heat
source generally powered by stored batteries in the downhole tool.
The generation of sufficient heat burns the fibers and releases the
trigger so that the tool can set. Such a system is described in
U.S. Pat. No. 5,558,153. The problem is that to generate enough
heat downhole to burn the fibers and not damage adjacent components
proves to be challenging for several reasons. One issue is the
physical size of the battery pack to get a heater hot enough for
long enough to compromise the fibers. Another issue is the very
high temperatures needed to undermine the fibers and the effect on
the overall design of the tool from having to keep heat sensitive
components away from the heated area.
[0003] Another design featured a battery operated heater coil in a
downhole tool to release the trigger by applying heat and melting a
plug to start the setting sequence. This design is reflected in
U.S. Pat. No. 6,382,234. Here again the same problems described
above are encountered. The battery size to have the required
electrical capacity to create enough heat to melt the fusible plug
presents a very real space concern in a downhole tool where space
for a large power supply is at a premium. The cost and the
reliability of a large battery pack is an issue. On many occasions,
safety is another issue since some batteries need special shipping
and handling requirements.
[0004] Other alternatives still involved the large battery pack to
accomplish a release of the trigger. For example, U.S. Pat. No.
5,558,153 also suggests using solder wire that melts at relatively
low temperatures to be the trigger material or using the stored
power in the battery to advance a knife to physically cut the fiber
as opposed to undermining it with a battery operated heat
source.
[0005] The present invention seeks to address the issues described
above with the prior designs. One way it approached the problem is
to choose a material that will readily go away by being
combustible. The power then required to release the trigger is
greatly reduced since it takes significantly less energy to create
a spark that will create a burning of the trigger retainer to
result in a release of the tool. What is proposed in one embodiment
is the use of fuse material that is designed to be readily ignited.
While no explosives need be set off, the fuse material that serves
to hold the trigger against the setting of the tool simply readily
ignites with a brief spark and burns to the point where it releases
its hold on the setting mechanism and the tool simply sets. In
another embodiment the wire burns and removes a barrier to flow
that in turn set the tool. These and other advantages of the
present invention will become more apparent to those skilled in the
art from a review of the preferred embodiment that is described
below along with the associated drawings while recognizing that the
claims further below indicate the scope of the invention.
SUMMARY OF THE INVENTION
[0006] A trigger device keeps a downhole tool from setting until it
is properly positioned. Regardless of the type of tool or the type
of associated trigger, the retainer is combusted which results in
setting the tool. This can happen by freeing a piston to move, or
allowing flow through a port or by other mechanisms. The material
is preferably one that combusts readily such as a material used in
fuses for explosives. The battery requirements are to simply create
the brief spark that starts the combustion, making the battery size
significantly smaller than what would be needed to power a heater
to melt materials that were used in the past.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows one type of trigger using opposed sleeves held
together by wire;
[0008] FIG. 2 is the rotated view of FIG. 1 showing the wire;
[0009] FIG. 3 is an alternative embodiment of a trigger that uses a
piston retained by a wire going through it;
[0010] FIG. 4 shows an alternative embodiment to hold a piston with
the wire until the tool is ready to be actuated when the wire is
compromised and the piston moves;
[0011] FIG. 5 shows another embodiment where an opening in a plug
is created that sets the tool with the flow through the opening
where the opening is created by compromising the wire.
[0012] FIG. 6 is another embodiment showing a piston held by a
shearing member with chambers on opposed sides so that when the
material in the opening is compromised well hydrostatic reaches one
side of the piston to break the shear device and move the piston
against the opposite chamber to set the tool.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] Referring to FIGS. 1 and 2, one type of retainer for a
trigger mechanism or device for a downhole tool is illustrated. It
shows a piston 10 that has some applied force 12 acting on it that
would otherwise make it move but for a restraint. In this case the
restraint is a pair of sleeves 14 and 16 that are longitudinally
split and held together by a spring or split ring 18, for example.
What completes the assembly to keep the piston 10 immovable despite
the applied force 12 is a wire 20 shown in FIG. 2. In this
application, the term "wire" refers to the shape as being elongate
without limitation to composition or cross-sectional shape or area
and without limitation to any specific function such as conducting
power. The force 12 can come from a variety of sources such as
hydrostatic pressure, various springs or other energy storage
devices or equivalents. In general, movement of the piston 10 sets
an associated tool that is not shown. While a piston is shown, any
type of trigger for the downhole tool is envisioned regardless of
shape or the nature of its movement or whether the movement
directly or indirectly sets the underlying tool. The design of
FIGS. 1 and 2 contemplates variations such as retaining the piston
10 with a c-ring whose open end is held fast against the piston 10
to keep it from moving by the wire 20. When the wire or ignitable
material 20 is compromised the c-ring is pushed apart by the force
12 and the piston 10 advances to set the tool.
[0014] The wire 20 is such that initial energy input to it,
preferably in the form of a brief spark that can be actuated
electrically, mechanically or by other equivalent methods, sets in
motion an event that continues without need for further energy
input. Because of this feature, the battery or other energy source
22 and the ultimate recipient of the energy or power that creates a
spark 24 collectively can be significantly smaller than prior
designs that required continuous power input to disable the wire
20. Mechanical spark devices that employ relative movement to
create a spark can also be used as well as other devices that will
transmit the initial burst of energy necessary to disable the wire
20. For example the wire 20 can be made from PYRO FUZE.RTM. which
consists of two metallic elements in intimate contact with each
other. When these two elements are brought to the initiating
temperature, they alloy rapidly resulting in instant deflagration
without support of oxygen. Initiation is by heat and heat alone.
All that is required is the exposure of the composite to the proper
minimum temperature. The trigger reaction will reach temperatures
in excess of the boiling point of the constituents. Once started,
the reaction will not stop until alloying is completed or the
unalloyed composite is subjected to some form of massive cooling
that overwhelms the composite so that it cannot reach minimum
operating temperature. The reaction end products consist normally
of tiny discreet particles of the alloy of the participating
materials. The present PYROFUZE composition was chosen for a number
of desirable characteristics; it is a composite of alloys of
Palladium and Aluminum. It is available in the following physical
forms: Wire; and, Ribbon rolled from wire.
[0015] The PYROFUZE.RTM. reaction is not of an explosive or
pyrotechnic nature. The only energy released is thermal
(approximate minimum reaction temperature 2800.degree.
C./5000.degree. F., 325 calories per gram, 2890 calories per cubic
centimeter). The minimum initiation temperature is 650.degree.
C./1200.degree. F.
[0016] Wire: TABLE-US-00001 Outer Jacket Inner Core Chemical
composition: Balance Palladium #5056 Aluminum 5% Ruthenium
Resistivity: 62 ohms per cmf
[0017] Other materials are contemplated that also have explosive
materials incorporated into the wire or result in a pyrotechnic
response with the distinguishing characteristic being that the
initial energy input that leads to the weakening of the wire 20
that ultimately lets the tool set continues after it is started
without continuous energy input of the prior designs. Regardless of
composition of the wire or the mechanism of the response to the
energy input the defining difference is that the process continues
without further energy input. Accordingly, fuses that are used to
set explosives could function as wire 20.
[0018] FIG. 3 shows another way to run a wire 20 through a piston
10 to hold it against a force 12. Here the wire 20 passes through
the piston 10 while being held near opposite ends by anchors 26 and
28.
[0019] FIG. 4 illustrates a piston 40 held in a body 42 by use of
the restraining material 44 and optionally further retained by an
adhesive such as epoxy 46. When the material 44 is ignited it burns
to undermine itself and the surrounding adhesive 46. At that point
the tool (not shown) can be set from movement of the piston 40 or
alternatively from fluid flow around it where the material 44 and
adhesive 46 used to be. This can occur with or without piston
movement.
[0020] FIG. 5 does not use any piston. Instead a body 48 has an
aperture 50 that is initially plugged by the ignitable material 52
optionally secured in a sealing manned with an adhesive 54. Upon
ignition of material 52 such as from a spark, however generated,
the assembly that blocks the aperture 50, and in so doing restrains
an actuating member from operating, no longer resists differential
pressure and flow through aperture 50 results in actuating the
member that sets the tool.
[0021] FIG. 6 illustrates a piston 60 held by a shear device 62.
Piston 60 separates atmospheric or low pressure chamber 64 from
chamber 66. Chamber 66 is also initially at atmospheric or low
pressure that is well below the surrounding hydrostatic pressure at
the anticipated depth for setting the tool. Plug 68 is in place in
port 70 of chamber 66 to restrain the piston 60 stationary with the
aid of shear device 62 which is optional if piston 60 is in
pressure balance from chambers 64 and 66. Plug 68 is made from a
material that will be compromised with a brief spark and will
continue to be compromised without additional energy input. This
opens port 70 and puts a sufficient differential pressure on the
piston 60 to break the shear device 62 and set the tool, not shown.
In this example, well hydrostatic is used to move the piston after
the spark.
[0022] In a different alternative a pressurized chamber can be
isolated from one side of the piston by a plug as illustrated in
FIG. 5. When that plug disappears the pressurized chamber, that is
higher than hydrostatic is allowed to cat on one side of the piston
when the opposite side of that piston is exposed to well
hydrostatic. As a result the piston moves and the tool sets.
[0023] In yet other embodiments the heat given off from the spark
igniting the material that continues to combust can also be
harnessed to trigger the tool to set. In such embodiments the heat
given off can cut a cord or compromise the actual retaining device
to allow the tool to set.
[0024] While the retaining member has been illustrated in the
preferred embodiment to be a wire, other shapes are contemplated as
it is the mechanism of what happens after initial energy input that
sets the present invention apart and a variety of shapes for the
retaining member are contemplated to be within the scope of the
invention apart from a wire shape.
[0025] While the preferred embodiment has been set forth above,
those skilled in art will appreciate that the scope of the
invention is significantly broader and as outlined in the claims
which appear below.
* * * * *