WO2019083870A1

WO2019083870A1 - Systems and methods for perforating tubular strings

Info

Publication number: WO2019083870A1
Application number: PCT/US2018/056835
Authority: WO
Inventors: David Ayre
Original assignee: Bp Corporation North America Inc.
Priority date: 2017-10-23
Filing date: 2018-10-22
Publication date: 2019-05-02

Abstract

A method for perforating a tubular string (30) disposed in a wellbore (20) includes transmitting a first firing signal from a control system disposed at the surface of the wellbore along an electrical cable (42) extending to a first addressable detonator assembly (160) of a first perforating tool (100A). In addition, the method includes firing a first shaped charge (150) disposed in a first thermally insulating container (142) of the first perforating tool (100A) in response to the first addressable detonator assembly (160) receiving the first firing signal. The first addressable detonator assembly (160) is ballistically coupled to the first shaped charge (150). Further, the method includes firing a second shaped charge (150) disposed in a second thermally insulating container (142) of a second perforating tool using a second addressable detonator assembly (160) disposed with respect to the second thermally insulating container that is ballistically coupled to the second shaped charge (150).

Description

SYSTEMS AND METHODS FOR PERFORATING TUBULAR STRINGS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 62/575,959 filed October 23, 2017 and entitled "Systems and Methods for Perforating Tubular Strings," which is hereby incorporated herein by reference in its entirety for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.

BACKGROUND

[0003] In some applications, during completion operations for a wellbore extending through an earthen formation, a tubular casing string may be deployed in the wellbore. Additionally, cement may be pumped into the annulus formed between the inner surface of the wellbore and the casing string to restrict fluid communication between at least a portion of the wellbore and the formation. In some applications, following the installation of the casing string, the casing string may be perforated with a perforating tool or gun at one or more production zones of the formation to provide paths for formation fluids (e.g., hydrocarbons) to flow from the production zones into the wellbore. To ensure that each production zone is isolated within the wellbore, plugs, packers, and/or other sealing devices are installed within the wellbore between each production zone prior to perforation activities. In order to save time as well as reduce the overall costs of completion activities, it is often desirable to simultaneously lower both a setting tool and at least one perforating tool along the same tool string within the wellbore in order to set the sealing device as well as perforate the wellbore in a single trip downhole.

SUMMARY

[0004] An embodiment of a casing perforating system for use in a wellbore comprises a first perforating tool comprising a first thermally insulating container, a first addressable detonator assembly disposed with respect to the first thermally insulating container, and a first shaped charge disposed in the first thermally insulating container, the first shaped charge ballistically coupled to the first addressable detonator assembly and the first addressable detonator assembly configured to fire the first shaped charge in response to receiving a first firing signal, a second perforating tool disposed with respect to the first perforating tool and comprising a second thermally insulating container, a second addressable detonator assembly disposed in the second thermally insulating container, and a second shaped charge disposed in the second thermally insulating container, the second shaped charge ballistically coupled to the second addressable detonator assembly and the second addressable detonator assembly configured to fire the second shaped charge in response to receiving a second firing signal, an electrical cable in signal communication between the first perforating tool and the second perforating tool, a first electrical connector disposed in the first thermally insulating container, the first electrical connector providing an electrical connection between the electrical cable and the first addressable detonator assembly, and a second electrical connector disposed in the second thermally insulating container, the second electrical connector providing an electrical connection between the electrical cable and the second addressable detonator assembly. In some embodiments, wherein the first thermally insulating container comprises a cylindrical outer housing, a charge tube disposed in the outer housing, the first shaped charge disposed in the charge tube, and an annular thermally insulating layer disposed radially between the outer housing and the charge tube, the thermally insulating layer configured to thermally insulate the first shaped charge from the environment surrounding the first perforating tool. In some embodiments, the first thermally insulating container comprises a vacuum flask and the thermally insulating layer comprises a vacuum chamber. In certain embodiments, the thermally insulating layer is filled with a thermally insulating material having an R-value (thermal conductivity with units of K.m²/W) between R-5 and R-50. In certain embodiments, the thermally insulating layer is configured to prevent a temperature in a central passage of the charge tube from reaching a temperature in excess of 360 °F when the first thermally insulating container is exposed to a temperature in the wellbore of 400 °F for a period of five hours. In some embodiments, the first and second shaped charges each comprise at least one of the organic compounds of RDX (royal demolition explosive, cyclotrimethylenetrinitramine) and HMX (high melting explosive, cyclotetramethylene-tetranitramine). In other embodiments, one or more other high explosive materials or combinations of high explosive materials may be used. In some embodiments, the perforating system further comprises a control system disposed at a surface of the wellbore, the control system configured to transmit the first firing signal to the first addressable detonator assembly. In certain embodiments, the first firing signal comprises at least one of an electrical signal, an optical signal, an acoustic signal, and a pressure signal. In certain embodiments, the control system is configured to transmit the first firing signal to the second detonator assembly, the second detonator assembly is configured to transmit the first firing signal to the first addressable detonator assembly without firing the second shaped charge in response to receiving the first firing signal, and wherein the control system is configured to transmit a second firing signal to the second addressable detonator assembly, and wherein the second detonator assembly is configured to fire the second shaped charge in response to receiving the second firing signal. In some embodiments, the first addressable detonator assembly comprises a processor configured to execute a firing instruction stored on a memory of the first addressable detonator assembly, and wherein the first addressable detonator assembly is configured to fire the first shaped charge in response to executing the firing instruction, and the first addressable detonator assembly is configured to transmit the firing instruction to the second addressable detonator assembly and the second addressable detonator assembly is configured to fire the second shaped charge in response to receiving the firing instruction. In some embodiments, the second perforating tool comprises a pressure sensor disposed in the second thermally insulating container and in signal communication with the second addressable detonator assembly, and wherein the second addressable detonator assembly is configured to fire the second shaped charge in response to receiving a pressure signal from the pressure sensor indicative of the firing of the first shaped charge.

[0005] An embodiment of a method for perforating a tubular string disposed in a wellbore comprises transmitting a first firing signal from a control system disposed at the surface of the wellbore along an electrical cable extending to a first addressable detonator assembly of a first perforating tool, firing a first shaped charge disposed in a first thermally insulating container of the first perforating tool in response to the first addressable detonator assembly receiving the first firing signal, the first addressable detonator assembly being ballistically coupled to the first shaped charge, and firing a second shaped charge disposed in a second thermally insulating container of a second perforating tool using a second addressable detonator assembly disposed with respect to the second thermally insulating container that is ballistically coupled to the second shaped charge. In some embodiments, the method further comprises transmitting the first firing signal from the first addressable detonator assembly along an electrical cable extending between the first and second perforating tools to the second addressable detonator assembly. In some embodiments, the method further comprises transmitting a second firing signal from the control system to the second addressable detonator assembly, wherein the second firing signal is transmitted within less than a millisecond of transmitting the first firing signal; and firing the second shaped charge in response to the second addressable detonator assembly receiving the second firing signal. In some embodiments, the first perforating tool occupies the same position within the wellbore during the firing of both the first shaped charge and the second shaped charge. In certain embodiments, the method further comprises receiving the first shaped charge in a charge tube, disposing the charge tube in an outer housing of the first thermally insulating container, and forming a vacuum in an annular insulating layer formed between the charge tube and the outer housing. In some embodiments, the method further comprises receiving the first shaped charge in a charge tube, disposing the charge tube in an outer housing of the first thermally insulating container, and disposing a thermally insulating material in an annular thermally insulating layer formed between the charge tube and the outer housing, the thermally insulating material having an R-value between R-5 and R-50. In some embodiments, the method further comprises receiving the first shaped charge in a charge tube, disposing the charge tube in an outer housing of the first thermally insulating container, and disposing a thermally insulating material in an annular thermally insulating layer formed between the charge tube and the outer housing, the thermally insulating layer configured to prevent a temperature in a central passage of the charge tube from reaching a temperature in excess of 360 °F when the first thermally insulating container is exposed to a temperature in the wellbore of 400 °F for a period of five hours.

[0006] Embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical characteristics of the disclosed embodiments in order that the detailed description that follows may be better understood. The various characteristics and features described above, as well as others, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the disclosed embodiments. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the principles disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a detailed description of various exemplary embodiments, reference will now be made to the accompanying drawings in which:

[0008] Figure 1 is a schematic view of an embodiment of a perforating system for completing a well in accordance with the principles disclosed herein;

[0009] Figure 2 is a schematic, side cross-sectional view of an embodiment of a perforating tool of the perforating system of Figure 1 in accordance with the principles disclosed herein;

[0010] Figure 3 is a schematic, side cross-sectional view of another embodiment of a perforating tool of the perforating system of Figure 1 in accordance with the principles disclosed herein;

[0011] Figure 4 is a schematic, side cross-sectional view of another embodiment of a perforating tool of the perforating system of Figure 1 in accordance with the principles disclosed herein;

[0012] Figure 5 is a chart depicting thermal exposure curves for exemplary explosive materials in accordance with the principles disclosed herein;

[0013] Figures 6 and 7 are schematic views of the perforating system of Figure 1 during completion operations in accordance with the principles disclosed herein;

[0014] Figure 8 is a schematic view of another embodiment of a perforating system for completing a well in accordance with the principles disclosed herein;

[0015] Figure 9 is a schematic, side cross-sectional view of an embodiment of a perforating tool of the perforating system of Figure 8 in accordance with the principles disclosed herein;

[0016] Figure 10 is a schematic view of another embodiment of a perforating system for completing a well in accordance with the principles disclosed herein; [0017] Figure 1 1 is a schematic, side cross-sectional view of an embodiment of a perforating tool of the perforating system of Figure 10 in accordance with the principles disclosed herein; and

[0018] Figures 12 and 13 are schematic views of the perforating system of Figure 10 during completion operations in accordance with the principles disclosed herein.

DETAILED DESCRIPTION

[0019] The following discussion is directed to various exemplary embodiments. However, one of ordinary skill in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.

[0020] Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.

[0021] In the following discussion and in the claims, the terms "including" and

"comprising" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to... ." Also, the term "couple" or "couples" is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection of the two devices, or through an indirect connection that is established via other devices, components, nodes, and connections. In addition, as used herein, the terms "axial" and "axially" generally mean along or parallel to a particular axis (e.g., central axis of a body or a port), while the terms "radial" and "radially" generally mean perpendicular to a particular axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. Any reference to up or down in the description and the claims is made for purposes of clarity, with "up", "upper", "upwardly", "uphole", or "upstream" meaning toward the surface of the borehole and with "down", "lower", "downwardly", "downhole", or "downstream" meaning toward the terminal end of the borehole, regardless of the borehole orientation. As used herein, the terms "approximately," "about," "substantially," and the like mean within 10% (i.e., plus or minus 10%) of the recited value. Thus, for example, a recited angle of "about 80 degrees" refers to an angle ranging from 72 degrees to 88 degrees.

[0022] Referring now to Figure 1 , an embodiment of a completion or perforating system 10 for completing a well or wellbore 20 that extends from a surface 2 into an earthen formation 4 along a longitudinal axis 15 is shown. Formation 4 includes a first or lower production zone 6, and a second or upper production zone 8 disposed nearer to the surface 2 than lower production zone 6. In this embodiment, completion system 10 generally includes a surface system 12, a wellbore 20, a tubular or casing string ("casing") 30 extending within wellbore 20, and a tool string 40 suspended within casing 30. In general, surface system 12 may comprise any suitable surface equipment for drilling, completing, and/or operating wellbore 20 and may include, in some embodiments, derricks, structures, pumps, electrical/mechanical well control components, etc. In this embodiment, surface system 12 conveys tool string 40 through a central bore or passage 32 of casing 30 and includes a surface control system 14 for communicating signals and/or data between surface system 12 and various components of tool string 40.

[0023] Wellbore 20 of completion system 10 is defined by a generally cylindrical inner surface or sidewall 22. An annulus 24 is formed between the sidewall 22 of wellbore 20 and a cylindrical outer surface of casing 30. In this embodiment, cement is pumped into annulus 24 during the installation of casing 30 to seal or restrict fluid communication between wellbore 20 and the surrounding formation 4. As will be described further herein, with wellbore 20 isolated from formation 4 by casing 30 and cement positioned in annulus 24, tool string 40 may be used to perforate casing 30, and thereby establish fluid communication between passage 32 of casing 30 and predetermined zones of formation 4, such as production zones 4 and 6, to allow for the recovery of hydrocarbons from formation 4. In some embodiments, additional components may be installed in wellbore 20 (e.g., production tubing, packers, etc.) following the perforation of casing 30 by tool string 40 to complete wellbore 20 for hydrocarbon production. Additionally, although wellbore 20 is shown as a vertical wellbore in this embodiment, in other embodiments, wellbore 20 may comprise a deviated wellbore. [0024] In this embodiment, tool string 40 generally includes a wireline cable 42 extending from surface system 12, a first or lower perforating tool 100A disposed at a lower end of tool string 40, a second or upper perforating tool 100B suspended from wireline 42, and a signal pathway or cable 50 extending between tools 100A,

100B. The length of cable 50 is configured to allow lower perforating tool 100A to be positioned adjacent lower production zone 6 and upper perforating tool 100B to be positioned adjacent upper production zone 8 while tool string 40 is held stationary in wellbore 20. In some applications, each perforating tool of the completion system may be limited to a maximum axial length (e.g., approximately 14 feet, etc.) to allow the perforating tools to be run into the wellbore using a wireline system. Thus, in this embodiment, instead of using a single, continuous perforating tool extending through both production zones 6, 8, multiple perforating tools 100A, 100B, separated by cable 50, are used. In this embodiment, wireline 42 and cable 50 comprise electrical cables or conductors for passing electrical signals; however, in other embodiments, wireline 42 and cable 50 may comprise fiber optic cables for transmitting optical signals. In some embodiments, perforating tools 100A, 100B may be coupled together via a mechanical connector, such a tubular member. In certain embodiments, one or more pressure barriers may be formed between the tubular member and perforating tools 100A, 100B to protect components of perforating tools

100A, 100B. In still other embodiments, tool string 40 may include varying numbers of perforating tools (e.g., perforating tools 100A and/or 100B), including only a single perforating tool. In some embodiments, tool string 40 may include additional components not shown in Figure 1 , such as a cable head, setting tools, packers, plugs, casing-collar locators (CCLs), etc. Further, although in this embodiment perforating tools 100 and 100B are conveyed via wireline 42 through wellbore 20, in other embodiments, perforating tools 100 and/or 100B may be pumped down, or conveyed using tubing (e.g., drillpipe, coiled tubing, etc.), slickline, tractors, etc.

[0025] Perforating tools 100A, 100B are each configured to puncture or perforate casing 30 to provide fluid communication between passage 32 of casing 30 and formation 4. In this embodiment, lower perforating tool 100A may perforate, via one or more shaped explosive charges, the section of casing 30 disposed adjacent lower production zone 6 of formation 4 while upper perforating tool 100B may simultaneously or near-simultaneously perforate, via one or more shaped explosive charges, the section of casing 30 disposed adjacent to upper production zone 8 without needing to transport or adjust the positions of perforating tools 100A, 100B within wellbore 20 following the actuation of lower perforating tool 100A. In other words, fluid communication may be established between passage 32 of casing 30 and both production zones 6 and 8 simultaneously or near-simultaneously while the position of perforating tools 100A, 100B are held stationary within wellbore 20. Additionally, as will be described further herein, perforating tools 100A, 100B comprise thermally insulating containers 100A, 100B, configured to thermally insulate one or more components carried therein from the surrounding environment.

[0026] Referring to Figure 2, upper perforating tool 100B is shown. In this embodiment, upper perforating tool 100B has a central or longitudinal axis 125 and generally includes a cylindrical outer housing 122 and a carrier or charge tube 140 disposed within housing 122. Charge tube 140 includes an addressable detonator assembly 160 that is ballistically coupled to a plurality of axially and circumferentially spaced shaped charges 150. In general, detonators and detonator assemblies are devices designed and configured to initiate an explosive charge. Housing 122 has a first or upper end 122A, a second or lower end 122B, a cylindrical outer surface 124 extending axially between ends 122A, 122B, and a central chamber or passage 126 defined by a cylindrical inner surface 128. In this embodiment, the outer surface 124 of housing 122 includes a plurality of axially and circumferentially spaced circular indentations or scallops 130. When charge tube 140 is received in housing 122, scallops 130 axially and circumferentially align with shaped charges 150 of charge tube 140. In this arrangement, when shaped charges 150 are fired or ignited, each shaped charge 150 is configured to emit a jet of fluidized material directed towards a corresponding scallop 130 of housing 122. The jets released by shaped charges 150 break or "punch" through scallops 130 and perforate casing 30. Scallops 130 are configured to reduce or inhibit the formation of burrs on the outer surface 124 of housing 122 following the firing of shaped charges 150, allowing upper perforating tool 100B to be more conveniently transported through wellbore 20 after the firing of shaped charges 150. Although in this embodiment housing 122 includes scallops 130, in other embodiments, housing 122 of upper perforating tool 100B may not include scallops 130.

[0027] Chamber 126 of the housing 122 of upper perforating tool 100B is sealed from the surrounding environment (e.g., passage 32 of casing 30). In this embodiment, chamber 126 is sealed from the surrounding environment such that chamber 126 can be maintained at a negative pressure differential relative to pressure in the surrounding environment (e.g. , the environment in casing 30 outside of housing 122). Additionally, in this embodiment, housing 122 includes a first or upper electrical connector 132A at upper end 122A and a second or lower electrical connector 132B at lower end 122B. Upper electrical connector 132A connects wireline 42 to a first or upper electrical cable 134A extending from upper electrical connector 132A to addressable detonator assembly 160, while lower electrical connector 132B connects cable 50 with a second or lower electrical cable or conductor 134B extending between detonator assembly 160 and lower electrical connector 132B. Although in this embodiment connectors 132A, 132B comprise electrical connectors, in other embodiments, connectors 132A, 132B may comprise fiber optic connectors for communicating optical signals therebetween.

[0028] Charge tube 140 is coaxially disposed in chamber 126 of housing 122 and has a first or upper end 140A, a second or lower end 140B, a generally cylindrical outer surface 142 extending axially between ends 140A, 140B, and a central chamber or passage 146. In this embodiment, outer surface 142 of charge tube 140 includes radially outwards extending flanges 144A, 144B, located at upper end 140A and lower end 140B, respectively. Flanges 144A, 144B of charge tube 140 engage or are disposed directly axially adjacent the inner surface 128 of the chamber 126 of housing 122. In some embodiments, the outer surface 142 defining flanges 144A, 144B may comprise a thermally insulating material to reduce or inhibit heat transfer between housing 122 and flanges 144A, 144B of charge tube 140. Flanges 144A, 144B centralize charge tube 140 within chamber 126 of housing 100B, forming an annulus 127 between the inner surface 128 of chamber 126 and the portion of outer surface 142 of charge tube 140 extending between flanges 144A, 144B. Shaped charges 150 are located in the portion of outer surface 142 extending between flanges 144A, 144B, and thus, are surrounded by annulus 127. Annulus 127 comprises an annular thermally insulating layer 127 configured to reduce or inhibit heat transfer between shaped charges 150 and the environment surrounding upper perforating tool 100B (e.g., passage 32 of casing 30).

[0029] In this embodiment, a vacuum is formed in annulus 127 to reduce or eliminate conductive and convective heat transfer between housing 122 and shaped charges

150, and between housing 122 and chamber 146 of charge tube 140 to thermally insulate other components disposed in charge tube 140 (e.g., detonating cords 164, etc.). Thus, in this embodiment, upper perforating tool 100B (as well as lower perforating tool 100A) comprises a vacuum flask with annulus 127 comprising a vacuum chamber. In some embodiments, chamber 146 of charge tube 140 may be sealed from chamber 126 of housing 122 to isolate the vacuum in annulus 127; however, in other embodiments, chamber 146 may not be sealed from chamber 126. In still other embodiments, annulus 127 is filled with a thermally insulating material to reduce or inhibit heat transfer between housing 122 and shaped charges 150. In some embodiments, the thermally insulating material disposed in annulus 127 has a

ft " x°f x i

thermal resistance or R-value (- ) between R-5 and R-50; however, in other embodiments, the thermal resistance of the thermally insulating material disposed in annulus 127 may vary. In this embodiment, the upper end 140A of charge tube 140 is spaced from a first or upper end of the chamber 126, forming a first or upper cylindrical chamber 129A therebetween, and the lower end 140B of charge tube 140 is spaced from a second or lower end of the chamber 126, forming a second or lower cylindrical chamber 129B therebetween. In this embodiment, a vacuum is formed in both cylindrical chambers 129A, 129B to further inhibit heat transfer between housing 122 and charge tube 140; however, in other embodiments, chambers 129A, 129B may be disposed at the same pressure as the surrounding environment. In still other embodiments, chambers 129A, and 129B may be filled with a thermally insulating material to inhibit heat transfer between housing 122 and charge tube 140.

[0030] In this embodiment, addressable detonator assembly 160 is disposed in chamber 146 of charge tube 140 and is ballistically coupled to shaped charges 150 by detonating cords 164 extending therebetween. Although in this embodiment detonator assembly 160 is positioned proximal upper end 140A of charge tube 140 and distal lower end 140B, in other embodiments, detonator assembly 160 may be positioned proximal lower end 140B. Detonating cords 164 extend through the axial portion of charge tube 140 surrounded by annulus 127, and thus, cords 164 are also thermally insulated from the environment surrounding upper perforating tool 100B by annulus 127. In this embodiment, addressable detonator assembly 160 comprises an addressable detonator 160 including an integrated switch 162. Switch 162 allows addressable detonator assembly 160 to be addressed by a predetermined firing signal. In other words, in response to receiving a predetermined firing signal communicated from wireline 42 that is specifically addressed to upper perforating tool 100B, switch 162 of addressable detonator assembly 160 commands addressable detonator assembly 160 to ignite or fire detonating cord 164, thereby firing or igniting shaped charges 150. However, in response to receiving a firing signal that is not addressed to upper perforating tool 100B, switch 162 of addressable detonator assembly 160 will not command assembly 160 to fire detonating cord 164, and instead, will transmit the firing signal further downhole to lower perforating tool 100A via cables 134B and 50. In some embodiments, lower perforating tool 100A may be configured similarly to the upper perforating tool 100B shown in Figure 2. Thus, lower perforating tool 100A may include an outer housing 122, a charge tube 140 including a plurality of shaped charges 150, and an addressable detonator assembly 160. However, in some embodiments, lower perforating tool 100A may not include lower electrical cable 134B or lower electrical connector 132B.

[0031] Although in this embodiment addressable detonator assembly 160 comprises a detonator with an integrated addressable switch 162, in other embodiments, the addressable switch of the detonator assembly may not be integrated with the detonator. For example, referring briefly to Figure 3, an embodiment of a thermally insulating container or perforating tool 180 of tool string 40 is shown. In the embodiment of Figure 3, perforating tool 180 has a central or longitudinal axis 185 and includes housing 122 and charge tube 140. However, instead of including upper electrical cable 134A and addressable detonator assembly 160, perforating tool 180 includes upper electrical cable 182 and an addressable detonator assembly 184 that includes a detonator 186 and a separate addressable switch 188. In this embodiment, upper cable 182 is connected between upper electrical connector 132A and both detonator 186 and addressable switch 188. Similar to the functionality provided by the switch 162 of addressable detonator assembly 160 shown in Figure 2, addressable switch 188 of addressable detonator assembly 184 is configured to command detonator 186 to fire detonating cords 164 in response to receiving a firing signal addressed specifically to perforating tool 180, and to transmit further downhole via cables 134B and 50 firing signals not addressed to perforating tool 180 without commanding detonator 186 to fire detonating cords 164.

[0032] Although in the embodiment of Figure 2 addressable detonator assembly 160 is disposed within chamber 146 of charge tube 140, in other embodiments, detonator assembly 160 may be external of or disposed separately from charge tube 140. For example, referring briefly to Figure 4, an embodiment of a thermally insulating container or perforating tool 200 of tool string 40 is shown. In the embodiment of Figure 4, perforating tool 200 has a central or longitudinal axis 205 and includes housing 122 and a charge tube 140' similar to charge tube 140 but having a reduced axial length relative to housing 122, thereby providing an upper cylindrical chamber 129A' having an axial length that is greater than the upper cylindrical chamber 129A shown in Figure 2. In this embodiment, addressable detonator assembly 160 is disposed within upper cylindrical chamber 129A' of housing 122, directly adjacent upper end 140A of charge tube 140'. Although in this embodiment addressable detonator assembly 160 is not thermally shielded by annulus 127, detonator assembly 160 may be configured or hardened to withstand elevated temperatures and pressures experienced in passage 32 of casing 30. In still other embodiments, addressable detonator assembly 160 may not be disposed in chamber 126 of housing 122, and instead, may be disposed external of housing 122. For instance, addressable detonator assembly 160 may be disposed in a separate tool of tool string 40, including a tool coupled with housing 122.

In some embodiments, the addressable detonator assembly may include a plurality of detonators networked with a controller or switch. For instance, referring briefly to Figure 5, an embodiment of a thermally insulating container or perforating tool 220 of tool string 40 is shown. In the embodiment of Figure 5, perforating tool 220 has a central or longitudinal axis 225 and includes housing 122, charge tube 140, and an addressable detonator assembly 222 comprising addressable switch 188, a signal network 224, and a plurality of detonators 226 actuatable by addressable switch 188. In this embodiment, signal network 224 comprises a plurality of electrical conductors or cables for providing a hardwired electrical connection between addressable switch 188 and detonators 226; however, in other embodiments, signal network 224 may comprise a wireless network (e.g., a Bluetooth® wireless network, etc.) for providing wireless signal communication between addressable switch 188 and detonators 226. In this embodiment, each detonator 226 is directly coupled or attached to a corresponding shaped charge 150, eliminating the need for extending detonating cords 164 through chamber 146 of charge tube 140.

[0033] Referring now to Figures 1 , 2, and 6-8, the operation of completion system 10 will be described. In particular, Figure 1 illustrates completion system 10 following the transport of tool string 40 into the passage 32 of casing 30 but prior to the perforation of casing 30 by perforating tools 100A, 100B. In some embodiments, it may take several hours of transporting tool string 40 through casing 30 before lower perforating tool 100A is aligned with lower production zone 6 and upper perforating tool 100B is aligned with upper production zone 8. During this period of time, perforating tools 100A, 100B are exposed to elevated temperatures within passage 32 of casing 30 produced by elevated temperatures in formation 4.

[0034] The explosive materials comprising the shaped charges 150 and/or detonating cords 164 of perforating tools 100A, 100B may only be exposed to elevated temperatures for limited periods of time before they become damaged or their performance becomes unreliable. In other words, different explosive materials may have varying "time-temperature performance" curves or envelopes that define the maximum temperature over a given period of time the explosive material may be exposed to before the performance of the explosive material becomes compromised. A first time-temperature performance envelope 152A of a first explosive material and a second time-temperature performance envelope 154A of a second explosive material are shown in a chart 155 of Figure 6. In the embodiment of Figure 6, the first explosive material comprises RDX while the second explosive material comprises HMX; however, other explosive materials including, without limitation, 2,6- Bis(Picrylamino)-3,5-dinitropyridine (PYX, very high temperature explosive), and hexanitrostilbene (HNS, heat resistant high explosive) may also comprise time- temperature performance envelopes that define the maximum temperature over a given period of time the explosive material may be exposed to before the performance of the explosive material becomes compromised.

[0035] Explosive materials, including the first and second explosive materials indicated on chart 155, may be used in forming the shaped charges 150 and/or detonating cords 164 of upper perforating tool 100A and/or lower perforating tool 100B. As described above, perforating tools 100A, 100B, each comprise thermally insulating perforating tools 100A, 100B, configured to reduce or inhibit heat transfer between the shaped charges 150 and detonating cords 164 disposed within perforating tools 100A, 100B, and the surrounding environment (e.g. , passage 32 of casing 30). Given that perforating tools 100A, 100B, reduce the rate of heat transfer between their respective shaped charges 150 and the surrounding environment, perforating tools 100A, 100B, may artificially alter or shift the time-temperature performance envelope of the explosive materials comprising shaped charges 150. In other words, the thermal insulation provided by perforating tools 100A, 100B, allows the explosive materials comprising shaped charges 150 and/or detonating cords 164 to be used in higher temperature environments for greater periods of time than if shaped charges 150 and detonating cords 164 were not thermally insulated from the surrounding environment.

[0036] In this embodiment, chart 155 of Figure 6 illustrates a shifted time- temperature performance envelope 152B of the first explosive material and a shifted time-temperature performance envelope 154B of the second explosive material. Due to the thermal insulation provided by perforating tools 100A, 100B, shifted time- temperature performance envelopes 152B, 154B, each comprise a maximum temperature in excess of the maximum temperatures of time-temperature performance envelopes 152A, 154A, respectively. Additionally, given that perforating tools 100A, 100B, reduce but do not eliminate heat transfer between shaped charges 150 and the surrounding environment, shifted time-temperature performance envelopes 152B, 154B, approach time-temperature performance envelopes 152A, 154B, respectively, as exposure time increases.

[0037] For example, as indicated by time-temperature performance envelope 154A of this embodiment, without thermal insulation, the second explosive material may not be exposed to a temperature of approximately 360°F for a period of approximately five hours without compromising the performance of the second explosive material. However, as indicated by shifted time-temperature performance envelope 154B of this embodiment, with the thermal insulation provided by perforating tools 100A, 100B, perforating tools 100A, 100B, including shaped charges 150 and/or detonating cords 164 formed from the second explosive material, may not be disposed in a surrounding environment having a temperature of approximately 400°F for a period of approximately five hours without compromising the performance of shaped charges 150 and detonating cords 164. Thus, in this embodiment, the thermally insulating layer 127 of each perforating tool 100A, 100B, is configured to prevent a temperature in chamber 146 of charge tube 140 from reaching a temperature in excess of 360 °F when perforating tools 100A, 100B, are exposed to a temperature in passage 32 of casing 30 of 400 °F for a period of five hours. However, in other embodiments, the degree of thermal insulation provided by perforating tools 100A, 100B, and thus, the shape and/or position of shifted time- temperature performance envelopes 152B, 154B, may vary. [0038] The thermal insulation provided by perforating tools 100A, 100B, as indicated by shifted time-temperature performance envelopes 152B, 154B, allows the first and second explosive materials to be used in perforating applications that require exposure to elevated temperatures for extended periods of times, such as applications with relatively deep or extended wellbores. The thermal insulation provided by perforating tools 100A, 100B, may also allow for the use of explosive materials that have relatively better performance characteristics (e.g., greater degree of explosive force per amount of explosive material, etc.) but are more sensitive to elevated temperatures, such as RDX and HMX, for example, which are more sensitive to elevated temperatures than PYX and HNS, but may offer performance advantages over PYX and HNS when adequately insulated from elevated temperatures.

[0039] Once lower perforating tool 100A is aligned with lower production zone 6 of formation 4, and upper perforating tool 100B is aligned with upper production zone 8, a first firing signal 45 (indicated schematically by arrow 45 in Figure 1 ) addressed to the addressable detonator assembly 160 of lower perforating tool 100A is transmitted through wireline 42 from surface control system 14. In some embodiments, switch 162 of addressable detonator assembly 160 comprises a processor 162 configured to either transmit a firing instruction stored on a memory of the processor 162 or to execute the firing instruction to fire the shaped charges 150 of upper perforating tool 100B depending upon whether the firing signal is addressed to the upper perforating tool 100B.

[0040] In this embodiment, given that the first firing signal 45 is not addressed to the addressable detonator assembly 160 of upper perforating tool 100B, the detonator assembly 160 of upper perforating tool 100B transmits the first firing signal 45 to lower perforating tool 100A along cable 50 without firing its shaped charges 150. Additionally, given that the first firing signal 45 is addressed to the addressable detonator assembly 160 of lower perforating tool 100A, upon receiving the first firing signal 45, the detonator assembly 160 of lower perforating tool 100A fires its shaped charges 150 towards casing 30, thereby forming a plurality of first or lower perforations 34A (shown in Figure 7) in casing 30. Lower perforations 34A are positioned in casing 30 such that lower perforations 34A provide fluid communication between lower production zone 6 and the passage 32 of casing 30. [0041] Following the transmission of the first firing signal 45 through wireline 42, surface control system 14 transmits a second firing signal 47 (indicated schematically by arrow 47 in Figure 7) through wireline 42 that is addressed to the addressable detonator assembly 160 of upper perforating tool 100B. Given that the second firing signal 47 is addressed to the addressable detonator assembly 160 of upper perforating tool 100B, upon receiving the second firing signal 47 (following the transmission of the first firing signal 45 to cable 50 via the lower electrical cable 134B of upper perforating tool 100B), the detonator assembly 160 of upper perforating tool 100B fires its shaped charges 150 towards casing 30, thereby forming a plurality of second or upper perforations 34B (shown in Figure 8) in casing 30. Upper perforations 34B are positioned in casing 30 such that upper perforations 34B provide fluid communication between upper production zone 8 and the passage 32 of casing 30.

[0042] In the embodiment of Figures 1 , 2, and 6-8, surface control system 14 transmits the second firing signal 47 immediately following the transmission of the first firing signal 45. In some embodiments, the second firing signal 47 is transmitted within less than a millisecond of transmitting the first firing signal 45, although the time period between the transmission of the first and second firing signals 47 may vary. Based on the delay between the transmission between the first firing signal 45 and second firing signal 47, surface control system 14 may determine when each of perforating tools 100A, 100B, have fired using acoustic and/or pressure sensors.

The immediate transmission of the second firing signal 47 following the transmission of the first firing signal 45 results in the upper perforating tool 100B firing its shaped charges 150 simultaneously or near-simultaneously with lower perforating tool 100A firing its shaped charges 150. The simultaneous or near-simultaneous firing of perforating tools 100A, 100B allows for the underbalanced perforating of casing 30 at both production zones 6, 8, without needing to relocate or transport tool string 40 through casing 30. More specifically, prior to the firing of perforating tools 100A,

100B, pressure in passage 32 of casing 30 is less than pressure in production zones

6, 8, such that fluid trapped in production zones 6, 8, will naturally flow into passage

32 when fluid communication is provided therebetween. Thus, the portion of passage 32 disposed adjacent lower production zone 6 is underbalanced relative to lower production zone 6 when lower perforating tool 100A is fired. The underbalanced perforating performed by lower perforating tool 100A inhibits or prevents particulate damage to lower perforations 34A (which could otherwise potentially inhibit fluid flow through lower perforations 34A) as fluid disposed in passage 32 is not driven into lower perforations 34A due to an overbalance between passage 32 and lower production zone 6 prior to the firing of lower perforating tool 100A. Additionally, the vacuum formed in annulus 127 of lower perforating tool 100A assists with the creation of an underbalance in passage 32 of casing 30, as the vacuum formed therein may trap debris or particulates released during the firing of lower perforating tool 100A and thereby preventing the released debris from damaging lower perforations 34A.

[0043] The firing of lower perforating tool 100A produces a pressure or shock wave that travels through passage 32 of casing 30. However, given that upper perforating tool 100B is fired simultaneously or near-simultaneously with lower perforating tool 100A, upper perforating tool 100B is fired before the pressure wave released from lower perforating tool 100A is permitted to reach upper perforating tool 100B. Given that upper perforating tool 100B is fired before the pressure wave reaches gun 100B, upper perforating tool 100B also performs underbalanced perforating of upper production zone 8, thereby inhibiting or preventing particulate damage to upper perforations 34B, where particulate damage to upper perforations 34B could otherwise potentially inhibit fluid flow through upper perforations 34B. Thus, completion system 10 allows for the underbalanced perforating of casing 30 at multiple production zones 6, 8, of formation 4 without needing to transport tool string 40 through casing 30 between the formation of lower perforations 34A and upper perforations 34B.

[0044] Similarly, in applications that include one or more extended production zones that extend a greater distance than the maximum permitted axial length of each perforating tool 100A, 100B (e.g., limitations resulting from the use of wireline deployment, etc.), completion system 10 allows for the underbalanced perforating of the extended production zone without needing to rerun or reposition perforating tools

100A, 100B within casing 30. For example, in such an application, lower perforating tool 100A may be positioned towards a lower end of the extended production zone while upper perforating tool 100B may be positioned towards an upper end of the extended production zone, thereby providing for the underbalanced perforation of almost the entire length (the portion of the production zone disposed adjacent cable

50 not being perforated) of the extended production zone. [0045] Referring now to Figure 9, another embodiment of a completion or perforating system 250 for completing wellbore 20 is shown. Completion system 250 includes features in common with completion system 10 of Figures 1 -8, and shared features are labeled similarly. In the embodiment shown Figure 9, completion system 250 generally includes a surface system 252 having a surface control system 254, a tubular or casing string ("casing") 260 having a central bore or passage 262, and a tool string 270 extending within casing 260. Casing 260 is similar to casing 30 of completion system 10, but unlike casing 30, includes one or more signal repeaters 264 positioned along its axial length. In this embodiment, signal repeaters 264 comprise acoustic repeaters 264 configured to repeat or boost acoustic signals transmitted through casing 260 from surface control system 254, where surface control system 254 comprises an acoustic signal generator. In embodiments where perforating tools 100A, 280 are tubing or pipe conveyed, repeaters 264 may be located in the tubing or pipe from which perforating tools 100A, 280 are suspended rather than casing 260.

[0046] In this embodiment, tool string 270 includes a slickline 272 extending from surface system 252, cable 50, lower perforating tool 100A, and a second or upper perforating tool 280 suspended from slickline 272. Unlike wireline 42 of completion system 10, slickline 272 does not include any signal conductors and is used merely to transport and position perforating tools 100A, 280, in wellbore 20. Referring to

Figure 10, an embodiment of a thermally insulating container or upper perforating tool 280 of tool string 270 is shown. Upper perforating tool 280 includes features in common with perforating tools 100B and 200 of Figures 2 and 4, respectively, and shared features are labeled similarly. Particularly, upper perforating tool 280 has a central or longitudinal axis 285 and generally includes a cylindrical outer housing

282, charge tube 140', and addressable detonator assembly 160.

[0047] Housing 282 of upper perforating tool 280 has a first or upper end 282A, a second or lower end 282B, a cylindrical outer surface 284 extending axially between ends 282A, 282B, and a central chamber or passage 286 defined by a cylindrical inner surface 288. In the embodiment of Figure 10, housing 282 includes an acoustic sensor 290 disposed in outer surface 284. A first or upper electrical cable

292 extends between acoustic sensor 290 and addressable detonator assembly 160.

Acoustic sensor 290 is configured to receive acoustic signals transmitted through casing 260 from surface control system 254, and convert the received acoustic signals into electrical signals that may be transmitted to addressable detonator assembly 160 via upper electrical cable 292. Depending on whether the acoustic signal received by acoustic sensor 290 is addressed to upper perforating tool 280, addressable detonator assembly 160 may fire detonating cords 164 in response to receiving a signal from the acoustic sensor corresponding to the acoustic signal, or it may transmit the signal to lower perforating tool 100A via cables 50 and 134B.

[0048] Particularly, surface control system 254 of completion system 250 is configured to transmit a plurality of acoustic firing signals through casing 260 that may be sensed by acoustic sensor 290 of upper perforating tool 280. Thus, surface control system 254 may transmit an acoustic first firing signal through casing 260 addressed to lower perforating tool 100A. The acoustic first firing signal is received by acoustic sensor 290 and translated into an electrical first firing signal, which is then transmitted to lower perforating tool 100A to thereby fire lower perforating tool

100A and perforate casing 260 at lower production zone 6. After a predetermined period of time or delay period following the transmission of the acoustic first firing signal from surface control system 254, system 254 may transmit an acoustic second firing signal through casing 260 addressed to upper perforating tool 280, which is received by acoustic sensor 290 to thereby fire upper perforating tool 280 and perforate casing 260 at upper production zone 8. Thus, completion system 250 may be used in applications where it is advantageous to transmit acoustic signals via casing 260 and repeaters 264 to the perforating tools of the tool string disposed therein rather than electric or optical signals transmitted via wireline.

[0049] In some embodiments, surface control system 254 may be configured to generate both acoustic signals transmittable through casing 260 and a pressure signal comprising one or more pressure pulses transmittable through the fluid disposed in the passage 262 of casing 260. In certain embodiments, tool string 270 may include a plurality of perforating tools 280 and casing 260 may include additional acoustic repeaters 264 located between the plurality of perforating tools

280, thereby permitting multiple firing signals addressed to different perforating tools

280 of tool string 270 to be communicated from surface control system 254 via acoustic repeaters 264 of casing 260. In such an embodiment, the plurality of perforating tools 280 of tool string 270 may be fired in any desired order.

[0050] Referring to Figure 1 1 , another embodiment of a completion or perforating system 300 for completing wellbore 20 is shown. Completion system 300 includes features in common with completion system 250 of Figure 9, and shared features are labeled similarly. In the embodiment shown in Figure 1 1 , completion system 300 generally includes surface system 252, casing 260, and a tool string 320 extending through passage 262 of casing 260.

[0051] In this embodiment, tool string 320 includes first or upper slickline 272 extending from surface system 252, a first or lower perforating tool 340A, and a second or upper perforating tool 340B suspended from upper slickline 272, and a mechanical connector or tubular member 330 extending between perforating tools 340A, 340B. Referring to Figure 12, an embodiment of lower perforating tool 340A of tool string 320 is shown. As with the other perforating tools described herein (e.g., perforating tools 100A, 100B, 280, etc.), perforating tools 340A, 340B, each comprise thermally insulating containers 340A, 340B, configured to thermally insulate components disposed therein from the surrounding environment (e.g., passage 262 of casing 260). Lower perforating tool 340A includes features in common with perforating tool 280 of Figure 10, and shared features are labeled similarly. Particularly, lower perforating tool 340A has a central or longitudinal axis 345 and generally includes a cylindrical outer housing 342, charge tube 140', and addressable detonator assembly 160.

[0052] Housing 342 of lower perforating tool 340A has a first or upper end 342A, a second or lower end 342B, a cylindrical outer surface 344 extending between ends 342A, 342B, and a central chamber or passage 346 defined by a cylindrical inner surface 348. The upper end 342A of housing 342 couples (e.g., via a threadable connection) with a lower end 330B of tubular member 330, where tubular member 330 includes a central bore or passage 332 extending between lower end 330B and an upper end 330A (shown in Figure 13). In this embodiment, the addressable detonator assembly 160 is coupled to a pressure sensor or receptor 350 that is configured to transmit a signal to detonator assembly 160 upon sensing the firing of upper perforating tool 340B, thereby firing the shaped charges 150 of lower perforating tool 340A.

[0053] Referring to Figure 13, an embodiment of upper perforating tool 340B of tool string 320 is shown. Upper perforating tool 340B includes a housing 342' similar to housing 342 of lower perforating tool 340A but including an additional scallop 347 formed in the lower end 342B of housing 342'. The lower end 342B of housing 342' of upper perforating tool 340B is coupled (e.g., threadably coupled) to the upper end 330A of tubular member 330. In the embodiment of Figure 13, upper perforating tool 340B includes a sensor 352 disposed in outer surface 344 of housing 342'. Upper electrical cable 292 extends between sensor 352 and addressable detonator assembly 160. In this embodiment, sensor 352 is configured to receive acoustic signals transmitted through casing 260 and/or pressure signals transmitted through fluid disposed in passage 262262 of casing 260260 from surface control system 254254, and convert the received acoustic or pressure signals into electrical signals that may be transmitted to addressable detonator assembly 160 via upper electrical cable 292. Thus, sensor 352 of upper perforating tool 340B comprises both an acoustic sensor and a pressure sensor. Additionally, in this embodiment, upper perforating tool 340B includes a trigger or "peanut" shaped charge 354 coupled to charge tube 140' at lower end 140B, where trigger charge 354 is oriented in the direction of scallop 347. Trigger charger 354 is ballistically coupled with addressable detonator assembly 160 via detonating cord 164. 254

[0054] Referring to Figures 1 1 -15, the operation of completion system 300 will be described. In particular, Figure 10 illustrates completion system 300 following the transport of tool string 320 into the passage 262 of casing 300 but prior to the perforation of casing 260 by perforating tools 340A, 340B. In the embodiment of

Figures 1 1 -15, once lower perforating tool 340A is aligned with lower production zone 6 of formation 4, and upper perforating tool 340B is aligned with upper production zone 8, an acoustic first firing signal (indicated by arrows 313 in Figure

1 1 ) addressed to the addressable detonator assembly 160 of upper perforating tool

340B is transmitted through casing 260 from surface control system 254. Sensor

352 of upper perforating tool 340B receives the acoustic first firing signal 313, and transmits an electrical first firing signal to the addressable detonator assembly 160 of upper perforating tool 340B, thereby firing upper perforating tool 340B to form a plurality of upper perforations 314B in casing 30 at upper production zone 8 of formation 4. In other embodiments, surface control system 254 may transmit a pressure first firing signal to upper perforating tool 340B through the fluid disposed in passage 262 of casing 260 to thereby fire upper perforating tool 340B.

[0055] The firing of upper perforating tool 340B includes the firing of trigger charge

354, which pierces the lower end 342B of housing 342', thereby transmitting a pressure pulse or Shockwave through passage 332 of tubular member 330 that eventually pierces the upper end 342A of the housing 342 of lower perforating tool 340A. Receptor 352 of lower perforating tool 340A receives the pressure wave generated by the firing of upper perforating tool 340B, and transmits an electric signal to the addressable detonator assembly 160 of lower perforating tool 340A indicative of the pressure wave generated by the firing of upper perforating tool 340B. In this embodiment, switch 162 of the addressable detonator assembly 150 of lower perforating tool 340A is configured to interpret the signal indicative of the pressure wave as being addressed to lower perforating tool 340A, and thus, commands detonator assembly 160 to fire detonating cords 164, which thereby forms a plurality of upper perforations 314A in casing 30 at lower production zone 6 of formation 4. In this embodiment, perforating tools 340A, 340B, of tool string 320 may be fired "top to bottom" in wellbore 20. Additionally, completion system 300 is configured to fire multiple perforating tools 340A, 340B, without needing to transmit electrical signals to either of perforating tools 340A, 340B.

[0056] While preferred embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1 ), (2), (3) before steps in a method claim are not intended to and do not specify a particular order to the steps, but rather are used to simplify subsequent reference to such steps.

Claims

CLAIMS What is claimed is:

1 . A casing perforating system for use in a wellbore, comprising:

a first perforating tool comprising a first thermally insulating container, a first addressable detonator assembly disposed with respect to the first thermally insulating container, and a first shaped charge disposed in the first thermally insulating container, the first shaped charge ballistically coupled to the first addressable detonator assembly and the first addressable detonator assembly configured to fire the first shaped charge in response to receiving a first firing signal;

a second perforating tool disposed with respect to the first perforating tool and comprising a second thermally insulating container, a second addressable detonator assembly disposed in the second thermally insulating container, and a second shaped charge disposed in the second thermally insulating container, the second shaped charge ballistically coupled to the second addressable detonator assembly and the second addressable detonator assembly configured to fire the second shaped charge in response to receiving a second firing signal;

an electrical cable in signal communication between the first perforating tool and the second perforating tool;

a first electrical connector disposed in the first thermally insulating container, the first electrical connector providing an electrical connection between the electrical cable and the first addressable detonator assembly; and

a second electrical connector disposed in the second thermally insulating container, the second electrical connector providing an electrical connection between the electrical cable and the second addressable detonator assembly.

2. The perforating system of claim 1 , wherein the first thermally insulating container comprises:

a cylindrical outer housing;

a charge tube disposed in the outer housing, the first shaped charge disposed in the charge tube; and

an annular thermally insulating layer disposed radially between the outer housing and the charge tube, the thermally insulating layer configured to thermally insulate the first shaped charge from the environment surrounding the first perforating tool.

3. The perforating system of claim 2, wherein the first thermally insulating container comprises a vacuum flask and the thermally insulating layer comprises a vacuum chamber.

4. The perforating system of claim 2, wherein the thermally insulating layer is filled with a thermally insulating material having an R-value between about R-5 and about R-50.

5. The perforating system of claim 2, wherein the thermally insulating layer is configured to prevent a temperature in a central passage of the charge tube from reaching a temperature in excess of about 360 °F when the first thermally insulating container is exposed to a temperature in the wellbore of about 400 °F for a period of about five hours.

6. The perforating system of any one of claims 1 to 5, wherein the first and second shaped charges each comprise at least one of the organic compounds of RDX and HMX.

7. The perforating system of any one of the preceding claims, further comprising a control system disposed at a surface of the wellbore, the control system configured to transmit the first firing signal to the first addressable detonator assembly.

8. The perforating system of any one of the preceding claims, wherein the first firing signal comprises at least one of an electrical signal, an optical signal, an acoustic signal, and a pressure signal.

9. The perforating system of claim 7 or claim 8 when dependent on claim 7, wherein:

the control system is configured to transmit the first firing signal to the second detonator assembly; the second detonator assembly is configured to transmit the first firing signal to the first addressable detonator assembly without firing the second shaped charge in response to receiving the first firing signal; and

wherein the control system is configured to transmit a second firing signal to the second addressable detonator assembly, and wherein the second detonator assembly is configured to fire the second shaped charge in response to receiving the second firing signal.

10. The perforating system of any one of claims 1 to 7, wherein:

the first addressable detonator assembly comprises a processor configured to execute a firing instruction stored on a memory of the first addressable detonator assembly, and wherein the first addressable detonator assembly is configured to fire the first shaped charge in response to executing the firing instruction; and

the first addressable detonator assembly is configured to transmit the firing instruction to the second addressable detonator assembly and the second addressable detonator assembly is configured to fire the second shaped charge in response to receiving the firing instruction.

1 1 . The perforating system of any one of claims 1 to 7, wherein the second perforating tool comprises a pressure sensor disposed in the second thermally insulating container and in signal communication with the second addressable detonator assembly, and wherein the second addressable detonator assembly is configured to fire the second shaped charge in response to receiving a pressure signal from the pressure sensor indicative of the firing of the first shaped charge.

12. A method for perforating a tubular string disposed in a wellbore, comprising: transmitting a first firing signal from a control system disposed at the surface of the wellbore along an electrical cable extending to a first addressable detonator assembly of a first perforating tool;

firing a first shaped charge disposed in a first thermally insulating container of the first perforating tool in response to the first addressable detonator assembly receiving the first firing signal, the first addressable detonator assembly being ballistically coupled to the first shaped charge; and firing a second shaped charge disposed in a second thermally insulating container of a second perforating tool using a second addressable detonator assembly disposed with respect to the second thermally insulating container that is ballistically coupled to the second shaped charge.

13. The method of claim 12, further comprising transmitting the first firing signal from the first addressable detonator assembly along an electrical cable extending between the first and second perforating tools to the second addressable detonator assembly.

14. The method of claim 13, further comprising:

transmitting a second firing signal from the control system to the second addressable detonator assembly, wherein the second firing signal is transmitted within less than a millisecond of transmitting the first firing signal; and

firing the second shaped charge in response to the second addressable detonator assembly receiving the second firing signal.

15. The method of any one of claims 12 to 14, wherein the first perforating tool occupies the same position within the wellbore during the firing of both the first shaped charge and the second shaped charge.

16. The method of any one of claims 12 to 15, further comprising:

receiving the first shaped charge in a charge tube;

disposing the charge tube in an outer housing of the first thermally insulating container; and

forming a vacuum in an annular insulating layer formed between the charge tube and the outer housing.

17. The method of any one of claims 12 to 15, further comprising:

receiving the first shaped charge in a charge tube;

disposing the charge tube in an outer housing of the first thermally insulating container; and disposing a thermally insulating material in an annular thermally insulating layer formed between the charge tube and the outer housing, the thermally insulating material having an R-value between about R-5 and about R-50.

18. The method of any one of claims 12 to 15, further comprising:

receiving the first shaped charge in a charge tube;

disposing a thermally insulating material in an annular thermally insulating layer formed between the charge tube and the outer housing, the thermally insulating layer configured to prevent a temperature in a central passage of the charge tube from reaching a temperature in excess of about 360 °F when the first thermally insulating container is exposed to a temperature in the wellbore of about 400 °F for a period of up to about five hours.