U.S. patent application number 12/544318 was filed with the patent office on 2011-02-24 for remote actuated downhole pressure barrier and method for use of same.
This patent application is currently assigned to HALLIBURTON ENERGY SERVICES, INC.. Invention is credited to Robert L. Thurman, Jimmie R. Williamson, JR..
Application Number | 20110042099 12/544318 |
Document ID | / |
Family ID | 42782219 |
Filed Date | 2011-02-24 |
United States Patent
Application |
20110042099 |
Kind Code |
A1 |
Williamson, JR.; Jimmie R. ;
et al. |
February 24, 2011 |
Remote Actuated Downhole Pressure Barrier and Method for Use of
Same
Abstract
A downhole pressure barrier (100) operatively positionable in a
subterranean well. The downhole pressure barrier (100) includes a
housing (102) having a flow passage (122) formed therethrough. A
plug member (124) that is positioned within the flow passage (122)
selectively prevents flow through the flow passage (122) and allows
flow through the flow passage (122) responsive to contact with an
activating agent. At least one retainer assembly (130) supports the
plug member (124) within the housing (102). The retainer assembly
(130) selectively prevents communication between the activating
agent and the plug member (124). An activating assembly including a
combustible agent (164) that is positioned between the retainer
assembly (130) and the plug member (124) is operable to create a
communication path through the retainer assembly (130) upon
combustion of the combustible agent (164) to allow communication
between the activating agent and the plug member (124).
Inventors: |
Williamson, JR.; Jimmie R.;
(Carrollton, TX) ; Thurman; Robert L.; (Frisco,
TX) |
Correspondence
Address: |
LAWRENCE R. YOUST;Lawrence Youst PLLC
2900 McKinnon, Suite 2208
DALLAS
TX
75201
US
|
Assignee: |
HALLIBURTON ENERGY SERVICES,
INC.
Carrollton
TX
|
Family ID: |
42782219 |
Appl. No.: |
12/544318 |
Filed: |
August 20, 2009 |
Current U.S.
Class: |
166/373 ;
166/192 |
Current CPC
Class: |
E21B 29/02 20130101 |
Class at
Publication: |
166/373 ;
166/192 |
International
Class: |
E21B 34/06 20060101
E21B034/06; E21B 33/12 20060101 E21B033/12 |
Claims
1. A downhole pressure barrier operatively positionable in a
subterranean well, the downhole pressure barrier comprising: a
housing having a flow passage formed therethrough; a plug member
positioned within the flow passage that selectively prevents flow
through the flow passage and allows flow through the flow passage
responsive to contact with an activating agent; at least one
retainer assembly supporting the plug member within the housing,
the retainer assembly selectively preventing communication between
the activating agent and the plug member; and an activating
assembly including a combustible agent positioned between at least
a portion of the retainer assembly and the plug member, the
activating assembly operable to create a communication path through
the retainer assembly upon combustion of the combustible agent to
allow communication between the activating agent and the plug
member.
2. The downhole pressure barrier as recited in claim wherein the
plug member further comprises a mixture of sand and salt.
3. The downhole pressure barrier as recited in claim 1 wherein the
activating agent further comprises at least one of a wellbore fluid
and water.
4. The downhole pressure barrier as recited in claim 1 further
comprising at least one seal element positioned between the
retainer assembly and the housing.
5. The downhole pressure barrier as recited in claim 1 wherein the
retainer assembly includes a discoidal portion that has a spaced
apart relationship with the plug member.
6. The downhole pressure barrier as recited in claim 5 wherein the
combustible agent is positioned in the space between the plug
member and the discoidal portion of the retainer assembly.
7. The downhole pressure barrier as recited in claim 6 further
comprising a separator member positioned between the combustible
agent and the plug member.
8. The downhole pressure barrier as recited in claim 7 wherein the
discoidal portion of the retainer assembly and the separator member
are metallic.
9. The downhole pressure barrier as recited in claim 1 wherein the
combustible agent further comprises a mixture of a metal powder and
a metal oxide.
10. The downhole pressure barrier as recited in claim 1 wherein the
activating assembly further comprises an ignition agent operably
positioned proximate the combustible agent and an electronic
package operable to receive a wireless signal and send a signal to
the ignition agent.
11. The downhole pressure barrier as recited in claim 1 wherein the
housing further comprises a fluid chamber operable to contain the
activating agent.
12. A downhole pressure barrier operatively positionable in a
subterranean well, the downhole pressure barrier comprising: a
housing having a flow passage formed therethrough; a plug member
positioned within the flow passage that selectively prevents and
allows flow through the flow passage; at least one retainer
assembly supporting the plug member within the housing; and an
activating assembly including a combustible agent that is
integrally formed in the plug member, the activating assembly
operable to create a communication path through the retainer
assembly upon combustion of the combustible agent.
13. The downhole pressure barrier as recited in claim 12 wherein
the plug member further comprises a mixture of sand and salt.
14. The downhole pressure barrier as recited in claim 12 wherein
the plug member further comprises a polymer matrix.
15. The downhole pressure barrier as recited in claim 12 wherein
the plug member consists essentially of the combustible agent.
16. The downhole pressure barrier as recited in claim 12 wherein
the combustible agent further comprises a mixture of a metal powder
and a metal oxide.
17. The downhole pressure barrier as recited in claim 12 wherein
the activating assembly further comprises an ignition agent
operably positioned proximate the combustible agent and an
electronic package operable to receive a wireless signal from a
surface source and send a signal to the ignition agent.
18. The downhole pressure barrier as recited in claim 12 wherein
the housing further comprises a fluid chamber operable to contain
an activating agent.
19. A method for remotely actuating a downhole pressure barrier
positioned in a subterranean well, the method comprising: receiving
a wireless signal at a receiver positioned within the downhole
pressure barrier; generating an activation signal responsive to the
received wireless signal; activating an ignition agent responsive
to the activation signal; igniting a combustible agent with the
ignition agent; creating a communication path between an activating
agent and a plug member of the downhole pressure barrier responsive
to the combustion; and contacting the plug member with the
activating agent to disperse the plug member, thereby opening a
communication path through the downhole pressure barrier.
20. The method as recited in claim 19 wherein receiving a wireless
signal at a receiver positioned within the downhole pressure
barrier further comprises sensing a series of pressure fluctuations
via the receiver.
21. The method as recited in claim 19 wherein activating an
ignition agent responsive to the activation signal further
comprises activating a magnesium fuse.
22. The method as recited in claim 19 wherein igniting a
combustible agent with the ignition agent further comprises
igniting a mixture of a metal powder and a metal oxide.
23. The method as recited in claim 19 wherein contacting the plug
member with the activating agent to disperse the plug member
further comprises contacting the plug member with at least one of a
wellbore fluid and water.
24. The method as recited in claim 19 wherein contacting the plug
member with the activating agent to disperse the plug member
further comprises contacting a mixture of sand and salt with the
activating agent.
25. The method as recited in claim 19 further comprising containing
the activating fluid in a fluid chamber of the downhole pressure
barrier.
Description
FIELD OF THE INVENTION
[0001] This invention relates, in general, to equipment utilized in
conjunction with operations performed in subterranean wells and, in
particular, to remote actuated downhole pressure barriers for use
in subterranean wells and methods for use of same.
BACKGROUND OF THE INVENTION
[0002] Without limiting the scope of the present invention, its
background is described with reference to using dissolvable members
in plugging devices, as an example.
[0003] It is well known in the completion and production arts to
install and retrieve plugs in subterranean wells via intervention
into the wells. For example, when it is desired to plug a well, a
plugging device may be latched in an internal profile of a tubular
string using a conveyance such as a slickline, a wireline, a coiled
tubing or the like. When it is later desired to produce or
otherwise access the well, the plugging device may be retrieved
using the appropriate conveyance.
[0004] It has been found, however, that in some well
configurations, such as certain deviated or horizontal wells, the
use of such conveyances may not be desirable or feasible for
installation or retrieval of a plugging device. In such well
configurations, the plugging device may be installed at the desired
location within the tubular string at the surface then conveyed
into the well as part of the tubular string in which it is
installed. Once installed, such plugging devices have been remotely
actuated using a variety of techniques such as dissolving all or
part of the plugging device using a chemical solution, ultraviolet
light, a nuclear source or an explosive. For example, certain
plugging devices have utilized a dispersible plug member that is
dissolvable or otherwise dispersible by contact with fluid,
including chemical solutions or water. In such cases, the member
may be initially isolated from contact with the fluid and then,
when it is desired to permit flow through the plugging device, the
fluid is placed in communication with the member, thereby
dispersing the member. In one commonly used plugging device, the
dispersible plug member has been constructed using a mixture of
compacted salt and sand. These and other types of plugging devices
have used activation mechanisms including timer-controlled
mechanical, hydraulic and electrical devices as well as wireless
communication systems.
[0005] It has been found, however, that conventional dispersible
plug members are not suitable for service over an extended time
period and thus cannot operate as pressure barriers. Accordingly, a
need has arisen for a plugging device that is suitable installation
and deployment in a tubular string. A need has also arisen for such
a plugging device that is operable to be remotely actuated.
Further, a need has arisen for such a plugging device that has an
extended service life and may therefore operate as a pressure
barrier.
SUMMARY OF THE INVENTION
[0006] The present invention disclosed herein is directed to remote
actuated downhole pressure barriers for use in subterranean wells
and methods for use of same. The downhole pressure barrier of the
present invention is suitable for installation and deployment in a
tubular string and is operable to be remotely actuated. In
addition, the downhole pressure barrier of the present invention
has an extended service life.
[0007] In one aspect, the present invention is directed to a
downhole pressure barrier that is operatively positionable in a
subterranean well. The downhole pressure barrier includes a housing
having a flow passage formed therethrough and a plug member
positioned within the flow passage that selectively prevents flow
through the flow passage and allows flow through the flow passage
responsive to contact with an activating agent. At least one
retainer assembly supports the plug member within the housing. The
retainer assembly selectively prevents communication between the
activating agent and the plug member. An activating assembly
includes a combustible agent that is positioned between at least a
portion of retainer assembly and the plug member. The activating
assembly is operable to create a communication path through the
retainer assembly upon combustion of the combustible agent to allow
communication between the activating agent and the plug member.
[0008] In one embodiment, the plug member may be a mixture of sand
and salt. In another embodiment, the activating agent may be at
least one of a wellbore fluid and water. In this embodiment, the
housing may include a fluid chamber operable to contain the
activating agent. In a further embodiment, the combustible agent
may be a mixture of a metal powder and a metal oxide.
[0009] In one embodiment, a seal element is positioned between the
retainer assembly and the housing to prevent fluid flow
therebetween. In another embodiment, the retainer assembly may
include a discoidal portion that has a spaced apart relationship
with the plug member. In this embodiment, the combustible agent may
be positioned in the space between the plug member and the
discoidal portion of the retainer assembly. Also in this
embodiment, a separator member may be positioned between the
combustible agent and the plug member. The discoidal portion of the
retainer assembly and the separator member may be metallic. In a
further embodiment, the activating assembly may include an ignition
agent operably positioned proximate the combustible agent used to
ignite the combustible agent. In addition, the activating assembly
may include an electronic package operable to receive a wireless
signal and to send a signal to the ignition agent.
[0010] In another aspect, the present invention is directed to a
downhole pressure barrier that is operatively positionable in a
subterranean well. The downhole pressure barrier includes a housing
having a flow passage formed therethrough. A plug member, formed
from a mixture of sand and salt, is positioned within the flow
passage to selectively prevent flow through the flow passage and
allow flow through the flow passage responsive to contact with an
activating agent. At least one retainer assembly supports the plug
member within the housing. The retainer assembly selectively
prevents communication between the activating agent and the plug
member. An activating assembly includes a combustible agent that is
integrally formed in the plug member. The activating assembly is
operable to create a communication path through the retainer
assembly upon combustion of the combustible agent to allow
communication between the activating agent and the plug member.
[0011] In a further aspect, the present invention is directed to a
downhole pressure barrier that is operatively positionable in a
subterranean well. The downhole pressure barrier includes a housing
having a flow passage formed therethrough. A plug member, formed
from a thermosetting polymer, is positioned within the flow passage
to selectively prevent and allow flow through the flow passage. At
least one retainer assembly supports the plug member within the
housing. An activating assembly includes a combustible agent that
is integrally formed in the plug member. The activating assembly is
operable to create a communication path through the downhole
pressure barrier upon combustion of the combustible agent.
[0012] In a further aspect, the present invention is directed to a
method for remotely actuating a downhole pressure barrier
positioned in a subterranean well. The method includes receiving a
wireless signal at a receiver positioned within the downhole
pressure barrier, generating a activation signal responsive to the
received wireless signal, activating an ignition agent responsive
to the activation signal, igniting a combustible agent with the
ignition agent, creating a communication path between an activating
agent and a plug member of the downhole pressure barrier responsive
to the combustion and contacting the plug member with the
activating agent to disperse the plug member, thereby opening a
communication path through the downhole pressure barrier.
[0013] The method may also include one or more of sensing a series
of pressure fluctuations via the receiver, activating a magnesium
fuse, igniting a mixture of a metal powder and a metal oxide,
contacting the plug member with at least one of a wellbore fluid
and water, contacting a mixture of sand and salt with the
activating agent and containing the activating fluid in a fluid
chamber of the downhole pressure barrier.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a more complete understanding of the features and
advantages of the present invention, reference is now made to the
detailed description of the invention along with the accompanying
figures in which corresponding numerals in the different figures
refer to corresponding parts and in which:
[0015] FIG. 1 is a schematic illustration of an offshore oil and
gas platform operating a remote actuated downhole pressure barrier
according to an embodiment of the present invention;
[0016] FIGS. 2A-2B are cross sectional views of consecutive axial
sections of a remote actuated downhole pressure barrier according
to an embodiment of the present invention;
[0017] FIGS. 3A-3B are cross sectional views of consecutive axial
sections of a remote actuated downhole pressure barrier according
to an embodiment of the present invention;
[0018] FIGS. 4A-4B are cross sectional views of consecutive axial
sections of a remote actuated downhole pressure barrier according
to an embodiment of the present invention;
[0019] FIGS. 5A-5B are cross sectional views of consecutive axial
sections of a remote actuated downhole pressure barrier according
to an embodiment of the present invention; and
[0020] FIGS. 6A-6B are cross sectional views of consecutive axial
sections of a remote actuated downhole pressure barrier according
to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] While the making and using of various embodiments of the
present invention are discussed in detail below, it should be
appreciated that the present invention provides many applicable
inventive concepts, which can be embodied in a wide variety of
specific contexts. The specific embodiments discussed herein are
merely illustrative of specific ways to make and use the invention,
and do not delimit the scope of the invention.
[0022] Referring initially to FIG. 1, a remote actuated downhole
pressure barrier being operated from an offshore oil and gas
platform is schematically illustrated and generally designated 10.
A semi-submersible platform 12 is centered over an offshore oil and
gas formation 14 located below sea floor 16. A subsea conduit 18
extends from deck 20 of platform 12 to wellhead installation 22
including subsea blow-out preventers 24. Platform 12 has a hoisting
apparatus 26 and a derrick 28 for raising and lowering pipe strings
such as work string 30.
[0023] A wellbore 32 extends through the various earth strata
including formation 14. A casing 34 is cemented within wellbore 32
by cement 36. The portion of wellbore 32 extending through
horizontal portion 38 includes a plurality of perforations 40 that
allow fluid communication between formation 14 and wellbore 32.
Work string 30 includes various tools such as a plurality of sand
control screens 42, a remote actuated downhole pressure barrier 44
and a packer 46. In operation, remote actuated downhole pressure
barrier 44 provides a pressure barrier that allows the operator to
set production and isolation packers as well as pressure test the
production tubing.
[0024] In the illustrated embodiment, even though remote actuated
downhole pressure barrier 44 has been disposed in a horizontal
portion of wellbore 32, it should be understood by those skilled in
the art that the remote actuated downhole pressure barriers of the
present invention are equally well-suited for use in other well
configurations including, but not limited to, inclined wells, wells
with restrictions, non-deviated wells, multilateral wells and the
like. As such, use of directional terms such as "above", "below",
"upper", "lower" and the like are used for convenience in referring
to the illustrations. In addition, even though an offshore
operation has been depicted in FIG. 1, the remote actuated downhole
pressure barriers of the present invention are equally well-suited
for use in onshore operations.
[0025] Referring now to FIGS. 2A-2B, therein is representatively
illustrated a remote actuated downhole pressure barrier that is
generally designated 100. Barrier 100 includes a generally tubular
housing assembly 102. Housing assembly 102 that includes a top sub
104 that is securably and sealingly connected to a middle sub 106
by a plurality of set screws 108 and seal 110. At its lower end,
middle sub 106 is securably and sealingly connected to a bottom sub
112 at threaded connection 114 and by seal 116. Disposed within
middle sub 106 is an inner mandrel 118. Seals 120, 121 provide a
sealing relationship between middle sub 106 and inner mandrel 118.
Housing assembly 102 has a flow passage 122 formed axially
therethrough. Even though housing assembly 102 is shown as being
made up of several interconnected portions 104, 106, 112, 118, it
is to be understood that greater or fewer numbers of housing
portions may be utilized in the housing assembly 102 and the
portions may be otherwise configured and otherwise attached to each
other without departing from the principles of the present
invention.
[0026] Fluid flow through passage 122 is initially blocked by a
dispersible plug member 124. Plug member 124 includes a dispersible
portion 126 which is initially compacted within a plug sleeve 128.
Plug member 124 is supported within housing assembly 102 by a pair
of oppositely disposed retainer assemblies 130, 132. Retainer
assembly 130 is sealingly coupled to inner mandrel 118 by a seal
134. Retainer assembly 132 is sealingly coupled to bottom sub 112
by a seal 136. Retainer assemblies 130, 132 are axially positioned
between lower shoulder 138 of inner mandrel 118 and upper shoulder
140 of bottom sub 112. Retainer assemblies 130, 132 respectively
include discoidal portions 142, 144 that are generally impervious
and serve to isolate dispersible portion 126 from contact with any
fluid in flow passage 122. Retainer assemblies 130, 132 including
discoidal portions 142, 144 are preferable formed from a metal such
as a stainless steel including, but not limited to, a 625 stainless
steel.
[0027] In the illustrated embodiment, dispersible portion 126 is a
compacted salt and sand composition which has sufficient
compressive strength to resist fluid pressure in flow passage 122.
When an activating agent such a wellbore fluid, water or other
fluid, is permitted to contact dispersible portion 126, however,
the salt constituent will dissolve. This dissolving of the salt
constituent significantly reduces the compressive strength of
dispersible portion 126, so that it is no longer able to resist
fluid pressure in flow passage 122.
[0028] Plug member 124 may be dispersed by dissolving dispersible
portion 126 or a constituent part thereof using wellbore fluid in
flow passage 122. In certain implementations, however, a wellbore
fluid capable of dispersing plug member 124 may not available, for
example, if the fluid in flow passage 122 is salt-saturated, oil-
based or otherwise incapable of dissolving a constituent part of
dispersible portion 126. In the illustrated embodiment, barrier 100
includes a fluid chamber 146 disposed within inner mandrel 118 and
an upper portion of middle sub 106 and is protected from
contamination with other fluids and debris in the well during
conveyance by a debris barrier 148. Debris barrier 148 extends
laterally across flow passage 122, thus isolating the fluid in
fluid chamber 146 from contact with any other fluid or debris in
flow passage 122 above debris barrier 148. As such, the fluid in
fluid chamber 146 is available for interaction with dispersible
portion 126 when desired.
[0029] As representatively illustrated, debris barrier 148 includes
a body portion 150 extending across flow passage 122 and a somewhat
enlarged annular-shaped peripheral portion 152 sealingly received
between top sub 104 and middle sub 106 of housing assembly 102.
Such sealing engagement of debris barrier 148 acts to completely
isolate the fluid in fluid chamber 146 from other fluids in the
well. Debris barrier 148 may be formed from an elastomeric
material, however, in certain implementations, debris barrier 148
may alternatively be made of a nonelastomeric material. An
elastomeric material is preferred, however, since applications of
fluid pressure are made to flow passage 122 to initiate activation
of plug member 124 as described below.
[0030] In the illustrated embodiment, barrier 100 includes an
activating assembly that is operable to create a communication path
through retainer assembly 130 to allow communication between the
fluid in fluid chamber 146 and dispersible portion 126. The
activating assembly includes an electronic package and a combustion
assembly. The electronic package includes a pressure sensor 154, a
logic module 156, batteries 158 and various signal and current
conductors (not pictured). The combustion assembly includes
ignition agents 160, 162 and combustible agents 164, 166. As
illustrated, separator members 168, 170 are positioned respectively
between combustible agents 164, 166 and dispersible portion 126.
Separator members 168, 170 are preferable formed from a metal such
as a stainless steel including, but not limited to, a 625 stainless
steel. An optional heat shielding sleeve 172 is positioned between
plug member 124 and middle sub 106. Heat shielding sleeve 172 is
preferably formed from a ceramic materials or other material
capable of shielding middle sub 106 from the heat and temperature
generated in the combustion reaction discussed below.
[0031] Pressure sensor 154 is operable to receive and interpret
pressure signals sent from the surface. For example, by applying a
predetermined number and sequence of fluid pressure fluctuations to
flow passage 122 via the tubular string at the surface, pressure
sensor 154 receives the signal via the fluid in fluid chamber 146.
The pressure signals are transferred to the fluid in fluid chamber
146 from the fluid in the tubular string through debris barrier
148. When pressure sensor 154 receives the proper pressure
signature, pressure sensor 154 sends a signal to logic module 156
to begin the activation process. Even though the signal for
initiating the activation of plug member 124 has been described as
a pressure signal received by a pressure sensor, those skilled in
the art will understand the other types of signals both wireless
and wired could alternatively be used including, but not limited
to, acoustic signals, electromagnetic signals, hydraulic signals,
electrical signals, optical signals and the like, such signals
being received and interpreted by the corresponding type of
receiver.
[0032] Logic module 156 receives the activation signal from
pressure sensor 154 and causes a current to be sent to ignition
agents 160, 162. Logic module 156 may include various controllers,
processors, memory components, operating systems, instructions,
communication protocols and the like. As should be understood by
those skilled in the art, any of the functions described with
reference to logic module 156 herein can be implemented using
software, firmware, hardware, including fixed logic circuitry or a
combination of these implementations. As such, the term logic
module as used herein generally represents software, hardware or a
combination of software and hardware. For example, in the case of a
software implementation, the term logic module represents program
code and/or declarative content, e.g., markup language content that
performs specified tasks when executed on a processing device or
devices such as one or more processors or CPUs. The program code
can be stored in one or more computer readable memory devices. More
generally, the functionality of the illustrated logic module may be
implemented as distinct units in separate physical grouping or can
correspond to a conceptual allocation of different tasks performed
by a single software program and/or hardware unit.
[0033] Batteries 158 are used to power the electronic devices
within barrier 100 such as pressure sensor 154 and logic module
156. In addition, batteries 158 are used to provide suitable
current to initiate the combustion of combustible elements 164,
166. Batteries 158 may be of any suitable type such as alkaline
batteries that provide sufficient power and current and are capable
of withstanding the temperature in the well environment.
[0034] In the illustrated embodiment, ignition agents 160, 162 are
metal burning fuses such as magnesium fuses which are activated by
the electrical current supplied from batteries 158 in response to
the activation signal. Metal fuses are preferred as metals burn
without releasing cooling gases and can burn at extremely high
temperatures. Magnesium fuses are most preferred as due to the
reactive nature of magnesium and temperature at which magnesium
burn which is sufficiently high to ignite combustible agents 164,
166. Alternatively, a nichrome wire such as a NiCr60 wire, may be
used to directly ignite combustible agents 164, 166. As another
alternative, a nichrome wire may be used in an ignition train to
ignite a metal burning fuse which in turn ignites one of the
combustible agents 164, 166. In this case, both the nichrome wire
and the metal burning fuse may be considered to be one of the
ignition agents 160, 162.
[0035] Combustible agents 164, 166 are preferable formed from a
composition of a metal powder and a metal oxide that produces an
exothermic chemical reaction at high temperature such as a thermite
reaction. The metal powder used in the composition may include
aluminum, magnesium, calcium, titanium, zinc, silicon, boron and
the like. The metal oxide used in the composition may include boron
(III) oxide, silicon (IV) oxide, chromium (III) oxide, manganese
(IV) oxide, iron (III) oxide, iron (II, III) oxide, copper (II)
oxide, lead (II, III, IV) oxide and the like. For example, a
composition of aluminum and iron (III) oxide may be used which has
a reaction according to the following equation:
Fe.sub.2O.sub.3+2Al->2Fe+Al.sub.2O.sub.3+Heat
[0036] Use of combustible agents 164, 166 that produce a thermite
reaction is advantageous in the present invention as the reactants
are stable at wellbore temperatures but produce an extremely
intense exothermic reaction following ignition. The combination of
the high temperature and the heat generated by the reaction are
sufficient to melt both the metallic separator members 168, 170 and
discoidal portions 142, 144 of retainer assemblies 130, 132. In the
illustrated embodiment, this process creates a communication path
through retainer assembly 130 to allow communication between the
fluid in fluid chamber 146 and dispersible portion 126. The fluid
in fluid chamber 146 dissolves the salt in dispersible portion 126
such that the remaining sand component of dispersible portion 126
lacks sufficient compressive strength to plug flow passage 122.
Accordingly, the sand disintegrates leaving an open bore within
plug sleeve 128.
[0037] Referring next to FIGS. 3A-3B, therein is representatively
illustrated a remote actuated downhole pressure barrier that is
generally designated 200. Barrier 200 includes a generally tubular
housing assembly 202 that includes a top sub 204 that is securably
and sealingly connected to a middle sub 206 by a plurality of set
screws 208 and seal 210. At its lower end, middle sub 206 is
securably and sealingly connected to a bottom sub 212 at threaded
connection 214 and by seal 216. Disposed within middle sub 206 is
an inner mandrel 218. Seals 220, 221 provide a sealing relationship
between middle sub 206 and inner mandrel 218. Housing assembly 202
has a flow passage 222 formed axially therethrough.
[0038] Fluid flow through passage 222 is initially blocked by a
dispersible plug member 224. Plug member 224 includes a dispersible
portion 226 which is initially compacted within a plug sleeve 228.
Plug member 224 is supported within housing assembly 202 by a pair
of oppositely disposed retainer assemblies 230, 232. Retainer
assembly 230 is sealingly coupled to inner mandrel 218 by a seal
234. Retainer assembly 232 is sealingly coupled to bottom sub 212
by a seal 236. Retainer assemblies 230, 232 are axially positioned
between lower shoulder 238 of inner mandrel 218 and upper shoulder
240 of bottom sub 212. Retainer assemblies 230, 232 respectively
include discoidal portions 242, 244 that are generally impervious
and serve to isolate dispersible portion 226 from contact with any
fluid in flow passage 222.
[0039] In the illustrated embodiment, dispersible portion 226 is
preferably a compacted salt and sand composition, as described
above. Barrier 200 includes a fluid chamber 246 disposed within
inner mandrel 218 and an upper portion of middle sub 206 and is
protected from contamination with other fluids and debris by a
debris barrier 248. Debris barrier 248 includes a body portion 250
extending across flow passage 222 and a somewhat enlarged
annular-shaped peripheral portion 252 sealingly received between
top sub 204 and middle sub 206 of housing assembly 202.
[0040] In the illustrated embodiment, barrier 200 includes an
activating assembly that is operable to create a communication
path, through retainer assembly 230 to allow communication between
the fluid in fluid chamber 246 and dispersible portion 226. The
activating assembly includes an electronic package and a combustion
assembly. The electronic package includes a pressure sensor 254, a
logic module 256, batteries 258 and various signal and current
conductors (not pictured). The combustion assembly includes
ignition agents 260, 262 and combustible agents 264, 266. In the
illustrated embodiment, combustible agents 264, 266 are integrally
disposed within dispersible portion 226 such that the greatest
concentration of the combustible agents 264, 266 is located in the
two ends of dispersible portion 226 proximate discoidal portions
242, 244 of retainer assemblies 230, 232. Ignition agents 260, 262
are preferably metal fuses, as described above. Combustible agents
264, 266 are preferably formed from a composition of a metal powder
and a metal oxide, as described above. An optional heat shielding
sleeve 272 is positioned between plug member 224 and middle sub
206.
[0041] In operation, pressure sensor 254 receives and interprets
pressure signals sent from the surface. When pressure sensor 254
receives the proper pressure signature, pressure sensor 254 sends a
signal to logic module 256 to begin the activation process. Logic
module 256 then causes a current to be sent to ignition agents 260,
262 from batteries 258. The current is used to ignite ignition
agents 260, 262 which in turn ignite combustible agents 264, 266.
The combination of the high temperature and the heat generated by
the reaction of combustible agents 264, 266 are sufficient to melt
discoidal portions 242, 244 of retainer assemblies 230, 232, which
creates a communication path through retainer assembly 230 to allow
communication between the fluid in fluid chamber 246 and
dispersible portion 226. The fluid in fluid chamber 246 dissolves
the salt in dispersible portion 226 such that the remaining sand
component of dispersible portion 226 lacks sufficient compressive
strength to plug flow passage 222. Accordingly, the sand
disintegrates leaving an open bore within plug sleeve 228.
[0042] Referring next to FIGS. 4A-4B, therein is representatively
illustrated a remote actuated downhole pressure barrier that is
generally designated 300. Barrier 300 includes a generally tubular
housing assembly 302 that includes a top sub 304 that is securably
and sealingly connected to a middle sub 306 by a plurality of set
screws 308 and seal 310. At its lower end, middle sub 306 is
securably and sealingly connected to a bottom sub 312 at threaded
connection 314 and by seal 316. Disposed within middle sub 306 is
an inner mandrel 318. Seals 320, 321 provide a sealing relationship
between middle sub 306 and inner mandrel 318. Housing assembly 302
has a flow passage 322 formed axially therethrough.
[0043] Fluid flow through passage 322 is initially blocked by a
plug member 324. Plug member 324 includes a removable portion 326
which is initially compacted within a plug sleeve 328. Plug member
324 is supported within housing assembly 302 by a pair of
oppositely disposed retainer assemblies 330, 332. Retainer assembly
330 is sealingly coupled to inner mandrel 318 by a seal 334.
Retainer assembly 332 is sealingly coupled to bottom sub 312 by a
seal 336. Retainer assemblies 330, 332 are axially positioned
between lower shoulder 338 of inner mandrel 318 and upper shoulder
340 of bottom sub 312. Retainer assemblies 330, 332 respectively
include discoidal portions 342, 344 that are generally impervious
and serve to isolate removable portion 326 from contact with any
fluid in flow passage 322.
[0044] In the illustrated embodiment, removable portion 326 may be
a compacted salt and sand composition, as described above, that is
generally uniformly mixed with a combustible agent 364. In this
embodiment, barrier 300 includes a fluid chamber 346 disposed
within inner mandrel 318 and an upper portion of middle sub 306 and
is protected from contamination with other fluids and debris by a
debris barrier 348. Debris barrier 348 includes a body portion 350
extending across flow passage 322 and a somewhat enlarged
annular-shaped peripheral portion 352 sealingly received between
top sub 304 and middle sub 306 of housing assembly 302.
Alternatively, removable portion 326 may be substantially
completely formed from a compaction of the combustible agent 364.
In this embodiment, fluid chamber 346 and debris barrier 348 are
optional.
[0045] In the illustrated embodiment, barrier 300 includes an
activating assembly that is operable to create a communication path
through retainer assembly 330 to allow communication between the
fluid in fluid chamber 346 and removable portion 326. The
activating assembly includes an electronic package and a combustion
assembly. The electronic package includes a pressure sensor 354, a
logic module 356, batteries 358 and various signal and current
conductors (not pictured). The combustion assembly includes a
plurality of ignition agents, only two of which, ignition agents
360, 362 are shown and combustible agent 364. The ignition agents
are preferably metal fuses, as described above. Combustible agent
364 is preferably formed from a composition of a metal powder and a
metal oxide, as described above. An optional heat shielding sleeve
372 is positioned between plug member 324 and middle sub 306.
[0046] In operation, pressure sensor 354 receives and interprets
pressure signals sent from the surface. When pressure sensor 354
receives the proper pressure signature, pressure sensor 354 sends a
signal to logic module 356 to begin the activation process. Logic
module 356 then causes a current to be sent to the ignition agents
from batteries 358. The current is used to ignite the ignition
agents, which in turn ignites combustible agent 364. The
combination of the high temperature and the heat generated by the
reaction of combustible agent 364 is sufficient to melt discoidal
portions 342, 344 of retainer assemblies 330, 332. In those
embodiments including fluid chamber 346 and wherein removable
portion 326 includes a salt constituent, a communication path is
created through retainer assembly 330 to allow communication
between the fluid in fluid chamber 346 and removable portion 326.
The fluid in fluid chamber 346 dissolves the salt in removable
portion 326 such that the remaining sand component of removable
portion 326 lacks sufficient compressive strength to plug flow
passage 322. Accordingly, the sand disintegrates leaving an open
bore within plug sleeve 328. In those embodiments wherein removable
portion 326 is substantially completely formed from a compaction of
the combustible agent 364, combustion of combustible agent 364 not
only melts the discoidal portions 342, 344 of retainer assemblies
330, 332 but also creates the open bore within plug sleeve 328.
[0047] Referring next to FIGS. 5A-5B, therein is representatively
illustrated a remote actuated downhole pressure barrier that is
generally designated 400. Barrier 400 includes a generally tubular
housing assembly 402 that includes a top sub 404 that is securably
and sealingly connected to a middle sub 406 by a plurality of set
screws 408 and seal 410. At its lower end, middle sub 406 is
securably and sealingly connected to a bottom sub 412 at threaded
connection 414 and by seal 416. Disposed within middle sub 406 is
an inner mandrel 418. Seals 420, 421 provide a sealing relationship
between middle sub 406 and inner mandrel 418. Housing assembly 402
has a flow passage 422 formed axially therethrough.
[0048] Fluid flow through passage 422 is initially blocked by a
plug member 424. Plug member 424 includes a removable portion 426
which is initially positioned within a plug sleeve 428. Plug member
424 is supported within housing assembly 402 by a pair of
oppositely disposed retainer assemblies 430, 432. Retainer assembly
430 is sealingly coupled to inner mandrel 418 by a seal 434.
Retainer assembly 432 is sealingly coupled to bottom sub 412 by a
seal 436. Retainer assemblies 430, 432 are axially positioned
between lower shoulder 438 of inner mandrel 418 and upper shoulder
440 of bottom sub 412. Retainer assemblies 430, 432 respectively
include discoidal portions 442, 444 that are generally impervious
and serve to isolate removable portion 426 from contact with any
fluid in flow passage 422. In the illustrated embodiment, removable
portion 426 is preferably a polymer material such as a
thermosetting polymer including, but not limited to, an epoxy.
[0049] Barrier 400 includes an activating assembly that is operable
to create a communication path through passage 422. The activating
assembly includes an electronic package and a combustion assembly.
The electronic package includes a pressure sensor 454, a logic
module 456, batteries 458 and various signal and current conductors
(not pictured). The combustion assembly includes a plurality of
ignition agents, only two of which, ignition agents 460, 462 are
shown and combustible agent 464. In the illustrated embodiment,
combustible agent 464 is integrally disposed within removable
portion 426 in a substantially even distribution throughout
removable portion 426. The ignition agents are preferably metal
fuses, as described above. Combustible agent 464 is preferably
formed from a composition of a metal powder and a metal oxide, as
described above. An optional heat shielding sleeve 472 is
positioned between plug member 424 and middle sub 406.
[0050] In operation, pressure sensor 454 receives and interprets
pressure signals sent from the surface. When pressure sensor 454
receives the proper pressure signature, pressure sensor 454 sends a
signal to logic module 456 to begin the activation process. Logic
module 456 then causes a current to be sent to the ignition agents
from batteries 458. The current is used to ignite the ignition
agents, which in turn ignites combustible agent 464. The
combination of the high temperature and the heat generated by the
reaction of combustible agent 464 is sufficient to melt discoidal
portions 442, 444 of retainer assemblies 430, 432 as well as the
matrix material of removable portion 426 leaving an open bore
within plug sleeve 428.
[0051] Referring next to FIGS. 6A-6B, therein is representatively
illustrated a remote actuated downhole pressure barrier that is
generally designated 500. Barrier 500 includes a generally tubular
housing assembly 502 that includes a top sub 504 that is securably
and sealingly connected to a middle sub 506 by a plurality of set
screws 508 and seal 510. At its lower end, middle sub 506 is
securably and sealingly connected to a bottom sub 512 at threaded
connection 514 and by seal 516. Disposed within middle sub 506 is
an inner mandrel 518. Seals 520, 521 provide a sealing relationship
between middle sub 506 and inner mandrel 518. Housing assembly 502
has a flow passage 522 formed axially therethrough.
[0052] Fluid flow through passage 522 is initially blocked by a
plug member 524. Plug member 524 includes a removable portion 526
which is initially positioned within a plug sleeve 528. Plug member
524 is supported within housing assembly 502 by a pair of
oppositely disposed retainer assemblies 530, 532. Retainer assembly
530 is sealingly coupled to inner mandrel 518 by a seal 534.
Retainer assembly 532 is sealingly coupled to bottom sub 512 by a
seal 536. Retainer assemblies 530, 532 are axially positioned
between lower shoulder 538 of inner mandrel 518 and upper shoulder
540 of bottom sub 512. Retainer assemblies 530, 532 respectively
include discoidal portions 542, 544 that are generally impervious
and serve to isolate removable portion 526 from contact with any
fluid in flow passage 522. In the illustrated embodiment, removable
portion 526 is preferably a polymer material such as a
thermosetting polymer including, but not limited to, an epoxy.
[0053] Barrier 500 includes an activating assembly that is operable
to create a communication path through passage 522. The activating
assembly includes an electronic package and a combustion assembly.
The electronic package includes a pressure sensor 554, a logic
module 556, batteries 558 and various signal and current conductors
(not pictured). As illustrated, portions of the electronic package
are positioned within removable portion 526. In other
implementations, all of the components of the electronic package
could be positioned within removable portion 526. The combustion
assembly includes a plurality of ignition agents, only two of
which, ignition agents 560, 562 are shown and combustible agent
564. In the illustrated embodiment, combustible agent 564 is
integrally disposed within removable portion 526 in a substantially
even distribution throughout removable portion 526. The ignition
agents are preferably metal fuses, as described above. Combustible
agent 564 is preferably formed from a composition of a metal powder
and a metal oxide, as described above. An optional heat shielding
sleeve 572 is positioned between plug member 524 and middle sub
506.
[0054] In operation, pressure sensor 554 receives and interprets
pressure signals sent from the surface. When pressure sensor 554
receives the proper pressure signature, pressure sensor 554 sends a
signal to logic module 556 to begin the activation process. Logic
module 556 then causes a current to be sent to the ignition agents
from batteries 558. The current is used to ignite the ignition
agents, which in turn ignites combustible agent 564. The
combination of the high temperature and the heat generated by the
reaction of combustible agent 564 is sufficient to melt discoidal
portions 542, 544 of retainer assemblies 530, 532 as well as the
matrix material of removable portion 526 leaving an open bore
within plug sleeve 528.
[0055] While this invention has been described with reference to
illustrative embodiments, this description is not intended to be
construed in a limiting sense. Various modifications and
combinations of the illustrative embodiments as well as other
embodiments of the invention will be apparent to persons skilled in
the art upon reference to the description. It is, therefore,
intended that the appended claims encompass any such modifications
or embodiments.
* * * * *