as) United States
`a2) Patent Application Publication 10) Pub. No.: US 2008/0149338 Al
` Goodmanetal. (43) Pub. Date: Jun. 26, 2008
`
`
`
`US 20080149338A1
`
`(54) PROCESS FOR ASSEMBLING A LOADING
`TUBE
`Inventors:
`
`(75)
`
`Kenneth Goodman,Sugar Land,
`TX (US); Michael Bertoja,
`Pearland, TX (US); Luis Ochoa,
`Sugar Land, TX (US)
`
`Cc
`di
`Address:
`SCHLUMBERGERRESERVOIR COMPLE-
`TIONS
`14910 AIRLINE ROAD
`ROSHARON,TX 77583
`
`(73) Assignee:
`
`SCHLUMBERGER
`TECHNOLOGY
`CORPORATION,Sugar Land, TX
`(US)
`
`(21) Appl. No.:
`
`11/614,193
`
`(22)
`
`Filed:
`
`Dec. 21, 2006
`
`Publication Classification
`
`(51)
`
`Int. Cl.
`(2006.01)
`E21B 29/02
`(52) US. Ch oe 166/299; 89/1.151; 89/1.15
`
`(57)
`ABSTRACT
`A process is disclosed for assembling a loading tube for a
`perforating gun for use in a perforating system. At a first
`location, e.g., a shop, which is not the location at which
`perforating operations will be conducted, the loading tube is
`completely assembled. The completely assembled loading
`tubing is then transported to a second location where perfo-
`rating operations are to be conducted. In one embodiment, an
`RF-safe initiator, wiring, a detonating cord and a plurality of
`shaped charges are installed into the loading tubeata first
`location. The RF-safe initiators may comprise an exploding
`foil initiator or an exploding bridge wire. A process for
`assembling a loading tubefor a single-shot perforating gun is
`also disclosed.
`
`f °°
`
`
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 001
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 001
`
`

`

`Patent Application Publication
`
`Jun. 26,2008 Sheet 1 of 5
`
`US 2008/0149338 Al
`
`co
`—
`
`FIG.1
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 002
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 002
`
`

`

`Patent Application Publication
`
`Jun. 26,2008 Sheet 2 of 5
`
`FIG.2
`
`US 2008/0149338 Al
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 003
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 003
`
`

`

`&Sls
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 004
`
`

`

`Patent Application Publication
`
`Jun. 26,2008 Sheet 4 of 5
`
`US 2008/0149338 Al
`
`FIG.4
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 005
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 005
`
`

`

`US 2008/0149338 Al
`
`GOld
`
`Publication
`
`
`
`Patent Application
`
`osJ
`
`Jun. 26, 2008 Sheet 5 of 5
`
`
`
`
` TLASSLSSLserer
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 006
`
`
`
`
`
`

`

`US 2008/0149338 Al
`
`Jun. 26, 2008
`
`PROCESS FOR ASSEMBLING A LOADING
`TUBE
`
`BACKGROUND OF THE INVENTION
`
`assembled and pre-armed perforating gun string. The pre-
`assembled and pre-armed perforating gun string is trans-
`ported to the second location for deployment downhole.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`1. Field of the Invention
`[0001]
`[0002] The present invention generally relates to perforat-
`In the accompanying drawings:
`[0008]
`ing apparatus, and, moreparticularly, to a loading tube for use
`
`[0009] FIG. 1isapictorial diagram in partial cross-section
`in a perforating system.
`of a loading tube in accordancewith the present invention.
`[0003]
`2. Description of the Prior Art
`[0010]
`FIG. 2 is a pictorial diagram in partial cross-section
`[0004]
`For purposes of enhancing production from a sub-
`of a perforating gun in which a loading tube in accordance
`terranean formation, a perforating gun typically is lowered
`with the present inventionis installed.
`down into a wellbore that extends through the formation. A
`[0011]
`FIG. 3 isa pictorial diagram in partial cross-section
`perforating gun may, for example, comprise a plurality of
`ofa perforating string composedofperforating gun apparatus
`radially-oriented shaped charges which are detonated to form
`in accordance with the present invention.
`perforations in the formation proximate the wellbore. The
`[0012] FIG. 4isapictorial diagram in partial cross-section
`
`shaped charges may, for example, be placed at points along a
`ofa single shot perforating gun in accordance with thepresent
`helical spiral that extends around a longitudinal axis of the
`invention.
`perforating gun.
`[0005] Current gun systems use separate components for
`the pressure bulkhead, detonator, charge holder, detonation
`cord and wiring to the guns below. When a gun isbuilt, all the
`pieces are assembled together except
`the detonator and
`shipped to the location where the perforating operation is to
`be conducted. At that location, the gun is opened and the
`detonatoris installed. The detonator may, for example, be an
`RF-safe detonator provided by the assignee of the present
`application, and this detonator may include an addressable
`switch, a fireset and an initiator. Accordingly, the installation
`of the detonator assembly at the site where perforating is to
`take place involves the connection of a numberof wires in a
`very small space.
`
`FIG. 5isa pictorial diagram in partial cross-section
`[0013]
`of a perforating string composedofa plurality of single shot
`perforating gunsasillustrated in FIG.4.
`
`DESCRIPTION OF THE SPECIFIC
`EMBODIMENTS
`
`It will be appreciated that the present invention may
`[0014]
`take many forms and embodiments. In the following descrip-
`tion, some embodiments of the invention are described and
`numerousdetails are set forth to provide an understanding of
`the present invention. Those skilled in theart will appreciate,
`however, that the present invention may be practiced without
`those details and that numerousvariations and modifications
`
`SUMMARYOF THE INVENTION
`
`from the described embodiments maybe possible. The fol-
`lowing description is thus intended to illustrate and not to
`limit the present invention.
`In accordance with the present invention, a process
`[0006]
`[0015]
`In the specification and appended claims: the terms
`is provided for assembling a loading tube for a perforating
`“connect”, “connection”, “connected”, “in connection with’,
`gun for use in a perforating system. A process in accordance
`and “connecting” are used to mean “in direct connection
`with the present invention comprises installing an RF-safe
`with” or “in connection with via another element”; and the
`initiator and wiring into the loading tubeatafirst location
`term “set” is used to mean “one element” or “more than one
`whichis notthe site at which the perforating operation will be
`conducted. In some embodiments, the RF-safe initiator com-
`element”. As used herein,
`the terms “up” and “down”,
`“upper”
`and “lower”,
`“upwardly”
`and downwardly”,
`prises an electronics board including an addressable switch, a
`“upstream” and “downstream”; “above” and “below”; and
`fireset, and either an exploding foil initiator or an exploding
`otherlike terms indicating relative positions above or below a
`bridge wire. A process in accordance with the present inven-
`given point or element are used in this description to more
`tion also comprisesthestep ofinstalling a detonating cord and
`clearly described some embodiments of the invention. How-
`shaped charges into the loading tubeatsaid first location.If
`ever, when applied to equipment and methodsfor use in wells
`needed, a pressure bulkhead is connected to one end of the
`that are deviated or horizontal, such terms mayreferto a left
`loading tube suchthat one or more loading tubes—including
`to right, right to left, or other relationship as appropriate.
`the pressure bulkheads—naybe insertedinto carriers to form
`a perforating string. Once that assembly is complete, a pro-
`[0016]
`In general, the present invention regards improved
`cess in accordance with the present invention comprises
`perforating gun apparatuses and processes of manufacture
`transporting the perforating string to a second location which
`and use for RF-safe gun systems. As used herein, the term
`is the site where perforating operations are to be conducted.
`“RF-safe” means that the initiator of the gun system is
`[0007]
`In accordance with the present invention, a perfo-
`designed to be substantially immuneto typicallevels of elec-
`rating apparatus is provided which comprises a loading tube
`trostatic discharge, RF radiation, and/or accidental or unin-
`with connectorsatits respective ends anda plurality ofrecep-
`tended applications of power. Moreover, various embodi-
`tacles for receiving shaped charges, a detonating cord, wiring
`ments of the perforating gun apparatus and processes of
`and an RF-safe initiator. An RF-safe initiator, wiring, shaped
`manufacture and use are described with respect to selective
`charges and a detonating cord are installed in the loading tube
`fire (e.g., wherein the RF-safe initiator includes an address-
`at a first location which is not the site where perforating
`able switch). It is intended, however, that other embodiments
`operations are to be conducted. If needed, for example in
`of the present invention include improved perforating gun
`selective-fire gun systems, a pressure bulkhead is connected
`apparatuses and processes of manufacture and use for non-
`to one endofthe loading tube for connection with other such
`selective fire gun systems(e.g., wherein the RF-safe initiator
`loading tubes andinsertion into a gun carrier to form a pre-
`does not include an addressable switch).
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 007
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 007
`
`

`

`US 2008/0149338 Al
`
`Jun. 26, 2008
`
`[0017] A perforating gun comprising a loading tube in
`accordancewith the present invention has certain advantages
`overthe priorart. First, a perforating gun comprising a load-
`ing tube accordingto the present invention can be pre-armed
`at a first location such as a shop and then maybe shippedto the
`field. Prior to the present invention, armingofthe perforating
`gun occurredin thefield at the well site, because non-secure
`detonation devices could mistakenly be connected and to
`avoid explosive regulatory concerns. With the present inven-
`tion such mistakes are avoided. Second,it is more efficient to
`pre-arm the perforating gun in a shop location, as opposed to
`arming at the location where perforating is to be conducted
`and where rig time and operating timeis costly.
`[0018]
`In general, the assembly ofthe loading tube ata first
`location comprisesinstalling shaped charges and a detonation
`cord into the loading tube. An RF-safe initiator is also
`installedinto the loading tube, along with wiring. An embodi-
`ment of the RF-safe initiator comprises an electronics board
`including an addressable switch, fireset and either an explod-
`ing foil initiator or an exploding bridge wire. An addressable
`switch comprises a circuit facilitating selection (e.g., from a
`surface location)of a particular perforating gun in a string of
`perforating guns. The loading tube maythen beinstalled in a
`carrier of a perforating string and shippedto a field location
`for deployment downhole. The carrier may be a tubular hous-
`ing within which the loading tube is installed. In other
`embodiments, the electronics board comprises an integrated
`RF-safe initiator without an addressable switch.
`
`[0019] With reference to FIG. 1, there is illustrated an
`embodiment of a loading tube 10 in accordance with the
`present invention. Loading tube 10 may, for example, be
`fabricated by a molding process and comprises a receptacle
`18 for receiving an initiator, receptacles 13 for receiving
`shaped charges, anda receptacle 14 for receiving a detonating
`cord. Loading tube 10 also comprises connectors 11 and 12 at
`its respective ends and a receptacle 17 for receiving wiring.
`[0020]
`Ata first location (e.g., a shop or manufacturing or
`assemblyfacility) that is not the well site, detonating cord 24
`and shaped charges 23 maybeinstalled in the loading tube 10,
`as illustrated in FIG. 2. RF-safe initiator 15 is also installed in
`
`a receptacle in loading tube 10. In some embodiments, the
`RF-safe initiator 15 comprises an electronics board, an
`addressable switch and either an explodingfoil initiator or an
`exploding bridge wire. In other embodiments, the RF-safe
`initiator 15 comprises an electronics board and either an
`exploding foil initiator or an exploding bridge wire without an
`addressable switch. A booster 29 is connected between RF-
`initiator 15 and the detonating cord 24. Wiring 27is disposed
`in receptacle 17 (FIG.1) and provides a connection between
`connectors 11 and 12 and to RF-safeinitiator 15.
`
`[0021] Withreferenceto FIGS. 2 and 3, a pressure bulkhead
`16 is connected to one end ofloading tube 10, and the pressure
`bulkhead 16 engages connector 12. The pressure bulkhead 16
`between perforating guns in the string provides a path for
`electrical continuity between the earth’s surface and the guns
`in the string and isolates each loading tube assembly from
`fluids (e.g., wellbore fluids) transported by adjacent loading
`tube assemblies.
`
`[0022] Withreference now to FIG.3, a perforating string 30
`in accordance with some embodiments of the present inven-
`tion is provided by installing a plurality of loading tubes 10
`and pressure bulkheads 16 into carrier 31. Each perforating
`gun 10 in FIG.3 is formed in accordance with the preceding
`description. Equipment at the earth’s surface (not shown)
`
`selects a loading tube for detonation by addressing the
`addressable switch in a loading tube and by providing signals
`to activate the tireset in the selected loading tube. This results
`in the initiation of the exploding foil initiator or exploding
`bridge wire in the RF-safe initiator 15 and the detonation of
`the shaped chargesin the selected loading tube. The number
`of loading tubes 10 in the perforating string 30 will be deter-
`minedbythe particular application.
`[0023] After assembly, the perforating string 30 may then
`be transported from the first location to a second location
`whichis the site where perforating operations are to be con-
`ducted.
`
`[0024] With reference nowto FIG.4,there is illustrated an
`embodimentof a single-shot perforating gun 40 in accor-
`dance with the present invention. Perforating gun 40 com-
`prises loading tube 41 which is formed with a receptacle to
`receive shaped charge 42, a receptacle to receive wiring 46,
`and a receptacle to RF-safe initiator 45. At a first location,
`shaped charge 42 is installed in loading tube 41. RF-safe
`initiator is also installed in the loading tube atthefirst loca-
`tion, and RF-safe initiator 45 may comprise an explodingfoil
`initiator which is designated 47 in FIG. 4. Alternatively,
`device 47 may comprise an exploding bridge wire or other
`RF-safe initiator. Wiring 46 interconnects the connectors 43
`and 44 at the respective ends of loading tube 41 andis also
`operatively connected to RF-safe initiator 45 to provide a
`communication link between equipmentat the earth’s surface
`and RF-safe initiator 45.
`
`[0025] After the RF-safe initiator 45, wiring 46 and shaped
`charge 42 are installed at a first location, the loading tube 41
`may be inserted into a gun carrier and transported from that
`first location to a second location where perforating is to be
`performed.In this single-shot embodiment,the exploding foil
`initiator or exploding bridge wire 47 in the RF-safe initiator
`45 is operatively connected to the primer end of shaped
`charge 42.
`[0026] With reference to FIG. 5, a perforating string 50 is
`illustrated which comprises a plurality of perforating guns
`51-54 as described with respect to FIG. 4. A pressure bulk-
`head 49is disposed between adjoining gunsin the perforating
`string 50 for the same purposes or pressure bulkhead 16 in
`FIGS. 1-3.
`
`[0027] Embodiments ofthe perforating gun of the present
`invention—as described above—include apparatuses, pro-
`cesses, and methods wherein a perforating gun is assembled
`at a first location that is not the site of perforating operations.
`The“first location” can actually comprise one location thatis
`not the actual perforating site (1.e., at the well), or alterna-
`tively a combination of locations each of which are not the
`actual perforating site. For example, the initiator may be
`manufactured andinstalled into the loading tube at a shop in
`China, and then the loading tube maybetransported to a shop
`in the United States where the detonating cord and shaped
`charges are installed and the loading tube is inserted into a
`carrier to forma perforating gun. One or moreofthe guns may
`be connected together to form a pre-assembled and pre-armed
`perforating gun string. Finally, the perforating gun string may
`be transported to the well site for deployment and detonation
`downhole.
`
`1.A process for assembling a loading tubefora perforating
`gun for use in a perforating system, said loading tube having
`first and second ends with a connector at each end compris-
`ing:
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 008
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 008
`
`

`

`US 2008/0149338 Al
`
`Jun. 26, 2008
`
`installing an RF-safe initiator into the loading tubeata first
`location which is not the site at which the perforating
`operation will be conducted;
`installing wiring into said loading tubeatsaidfirst location
`whichinterconnects said connectors and whichis opera-
`tively connected to the RF-safe initiator; and
`installing shaped charges and a detonating cord into the
`loading tube at said first location, the detonating cord
`being operatively connected to the primer ends of the
`shaped charges and to the RF-safe initiator.
`2. The process of claim 1, wherein the RF-safe initiator
`comprises an electronics board including an addressable
`switch, a fireset and an exploding foil initiator.
`3. The process of claim 1, wherein the RF-safe initiator
`comprises an electronics board including an addressable
`switch, a fireset and an exploding bridge wire.
`4. The process of claim 4, further comprising the steps of:
`connecting a pressure bulkhead on one endofthe loading tube
`at said first location;
`installing the loading tube and pressure bulkhead into a gun
`caterat said first location to form a perforating gun string; and
`transporting the perforating gun string to a second location
`where perforating operations will be conducted.
`5. A methodof assembling a perforating gun system, com-
`prising:
`(a) installing an RF-safe initiator and wiring into a loading
`tubeat a first location whichis notthesite of the perfo-
`rating operation;
`(b) installing shaped charges and a detonating cord into the
`loading tubesaid first location;
`(c) repeating steps (a) and (b) for as many loading tubes as
`are required in the system;
`(d) installing a pressure bulkhead on an end of each said
`loading tube;
`(e) inserting the loading tubesinto a carrier; and
`(f) transporting the carrier to a second location whichis the
`site where perforating operations will be conducted.
`6. The methodof claim 5, further comprising the steps of:
`(a) lowering the carrier into the wellbore; and
`(b) detonating the shaped charges.
`7. The method of claim 5, wherein the RF-safe initiator
`comprises an electronics board including an addressable
`switch, a fireset and an exploding bridge wire.
`8. The method of claim 5, wherein the RF-safe initiator
`comprises an electronics board including an addressable
`switch, a fireset and an exploding foil initiator.
`9. A process for assembling a loading tubefor a single-shot
`perforating gun for use in a perforating system, comprising:
`installing an RF-safe initiator into the loading tubeata first
`location which is not the site at which the perforating
`operation will be conducted; and
`installing a shaped chargeinto the loading tube atsaidfirst
`location the shaped charge wheninstalled, being opera-
`tively connected to the RF-safe initiator.
`10. The process of claim 9, wherein the RF-safe initiator
`comprises an electronics board including an addressable
`switch, a fireset and an exploding foil initiator.
`
`11. The process of claim 9, wherein the RF-safe initiator
`comprises an electronics board including an addressable
`switch, a fireset and an exploding bridge wire.
`12. The process of claim 9, wherein the primer end of the
`shaped charge is connected directly to the RF-safe initiator.
`13. Loading tube apparatus for use in a perforating gun,
`comprising:
`a loading tube comprising (1) first and second ends with
`connectorsat said ends and(i1) a plurality of receptacles
`for receiving shaped charges, a detonating cord, wiring
`and an RF-safe initiator;
`an RF-safe initiator installed in said loading tubeat a first
`location whichis notthe site at which perforating opera-
`tions are to be conducted; and
`wiring which is installed at said first location which is
`operatively connected betweenthe connectors and to the
`RF-safe initiator; and
`a detonating cord and shaped charges whichare installed
`into the loading tubeat a saidfirst location, the detonat-
`ing cord being operatively connected to the primer ends
`of the shaped charges and to the RF-safe initiator.
`14. The loading tube apparatus of claim 13, wherein the
`RF-safe initiator comprises an electronics board including an
`addressable switch, a fireset and an exploding foil initiator.
`15. The loading tube apparatus of claim 13, wherein the
`RF-safe initiator comprises an electronics board including an
`addressable switch, a fireset and an exploding bridge wire.
`16. The loading tube apparatus of claim 13, further com-
`prising a pressure bulkhead which is connected to one end of
`the loading tubeatsaid first location.
`17. (canceled)
`18. (canceled)
`19. (canceled)
`20. A perforating gun apparatus for deploymentat a well
`location, comprising:
`a tubular cater having a hollow interior bore;
`an integrated loading tubefor installation within the bore of
`the carrier, the loading tube comprising: (i) an RF-safe
`initiator receptacle,(11) a wiring receptacle,(iii) a shaped
`charge receptacle, and a (iv) detonating cord receptacle;
`an RF-safe initiator installed into the RF-safe initiator
`
`receptacle of the loading tube;
`wiring installed into the wiring receptacle ofthe loading tube,
`the wiring operatively connected to the RF-safe initiator;
`a shaped chargeinstalled into the shaped charge receptacle of
`the loafing tube; and
`a detonating cordinstalled into the detonating cord receptacle
`of the loading tube, the detonating cord operatively connect-
`ing the shaped charge to the RF-safe initiator,
`wherein the RF-safe initiator, wiring, shaped charge, and
`detonating cordare installed at a location other than the
`well location.
`21. The perforating gun apparatus of claim 20, wherein the
`RF-safe initiator comprises an electronics board including an
`addressable switch, a fireset and an exploding foil initiator.
`22. The perforating gun apparatus of claim 20, wherein the
`RF-safe initiator comprises an electronics board including an
`addressable switch, a fireset and an exploding bridge wire.
`uf
`uf
`uf
`uf
`uf
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 009
`
`Hunting Titan, Inc.
`Ex. 1018
`Pg. 009
`
`