Patent Application
20220325586
Not applicable.
Like all steps in the process of establishing a productive hydrocarbon-producing wellbore, perforating the wellbore takes time and is performed using a substantial team and therefore, perforating efficiently and quickly is a pressing concern for the well operator. One aspect for time and cost savings is to space out the perforations where one perforating gun or just a few perforating guns are fired at a single position in the wellbore and then the tool string is then moved up the wellbore slightly to a second location for another one or several perforating guns are fired. This process of “shoot-and-move” and “shoot-and-move again” may be repeated a substantial number of times before the tool string is fully shot and then withdrawn for fracking the new perforations. One point that may be understood regarding the shoot-and-move process is that the “un-shot” perforating guns must be built to withstand the explosive force, shock, and pressure pulses resulting from the firing of explosive charges of the perforating guns positioned downhole from the un-shot perforating guns. Considering that the downhole environment of the wellbore is full of liquid, and liquids are particularly good at propagating pressure blasts, robustness is a critical design consideration for perforating guns. Typically, the inside of a given perforating gun is configured to remain dry to avoid damaging the explosive charges, provide an interior void space versus being filled with an incompressible liquid, and to avoid potentially damaging electrical components positioned within the perforating gun. A long known weak link for perforating guns is the means for electrically connecting the perforating guns together or to other tools in the tool string. This connection needs to reliably convey electrical signals and power through the connection, and withstand the explosion of an adjacent gun.
Conventionally, double-ended tandem subs have been employed for a number of years with screw threads at each end to connect adjacent perforating guns of the tool string. These tandem subs are substantially sized steel components that are typically quite heavy and robust with a small throughbore extending from end to end for the electric signal to pass between the pair of perforating guns. Typically, a pressure bulkhead or, more commonly, a pair of pressure bulkheads enclose a wire or pin and seals to the end or inside of the throughbore of the tandem sub. A small diameter pressure bulkhead is typically preferred in that a small cross-sectional area reduces the effective magnitude of a pulse or blast.
During operations for completing a hydrocarbon-producing wellbore, it is conventional practice to perforate or puncture a casing or liner string situated in the wellbore using explosive shaped charges housed within perforating guns. The perforations in the casing or liner string provide paths for formation fluids (e.g., hydrocarbons) to flow from a subterranean hydrocarbon-bearing zone into the wellbore from where the formation fluids may be conducted to the surface. It is generally desired that these paths are enlarged and extended by hydraulic fracturing or fracking after the perforation step to make each perforation more hydrocarbon productive.
Better and more reliable systems for electrically connecting and for mechanically protecting perforating guns are desired for the hydrocarbon production industry.
An embodiment of a system for connecting a perforating gun to at least one other component in a perforating tool string comprises a perforating gun that includes a gun housing and a charge carrier received within the gun housing wherein the charge carrier includes a first electrical connector for conducting at least one of electrical signals and electrical power, a tool connected end-to-end with the perforating gun where the tool includes an outer sleeve and a second electrical connector within the outer sleeve for conducting at least one of electrical signals and electrical power, a solid signal puck arranged with the perforating gun and the tool where the puck forms a pressure resistant barrier between the gun and the tool and wherein the solid signal puck includes a first endface oriented generally transverse to a longitudinal axis of the gun housing, a second endface longitudinally opposite the first endface and an outer periphery between the endfaces, and wherein the largest outer diameter of the outer periphery is at least 40% of the length between the first endface and the second endface of the puck, and wherein the solid signal puck is in direct physical contact with both the first electrical connector and with the second electrical connector for conducting at least one of electrical signals and electrical power between the first electrical connector and the second electrical connector. In some embodiments, the tool that is connected end to end with the perforating gun is a second perforating gun. In some embodiments, the perforating guns each include a separate interior void space within the gun housings, and the solid signal puck not only forms a pressure resistant barrier for the perforating guns, but also seals fluids from entering either of the interior void spaces at the end to end connection. In certain embodiments, the perforating gun includes an interior void space within the gun housing, and the solid signal puck not only forms a pressure resistant barrier for the perforating gun, but also seals fluids from entering the interior void space of the gun housing. In certain embodiments, an electrically conductive signal pathway is formed between the first endface and the second endface of the solid signal puck, wherein the signal pathway is electrically insulated from the gun housing. In certain embodiments, the solid signal puck further includes an electrically insulating surface on the outer periphery. In some embodiments, the solid signal puck is at least one of frictionally, slidably and threadably received in at least one of the gun housing and the outer sleeve. In some embodiments, the system further comprises a coupler that connects end to end to both the gun housing and the outer sleeve in a manner that secures the perforating gun to the tool. In certain embodiments, the coupler is positioned to coextend with at least a portion of each of the gun housing and the outer sleeve. In certain embodiments, at least a portion of the coupler is positioned external to the gun housing and also external to the outer sleeve and at least a portion of the solid signal puck is within a portion of the gun housing and also within a portion of the outer sleeve. In some embodiments, the solid signal puck and coupler are spaced apart and not in direct physical contact with one another. In some embodiments, the tool string includes an electric circuit with a positive side of the circuit and a ground side. In certain embodiments, the coupler is part of the ground side of the electrical circuit and the solid signal puck is part of the positive side of the electrical circuit. In certain embodiments, a portion of the coupler is positioned internal to the gun housing and another portion of the coupler is positioned internal to the outer sleeve. In some embodiments, the coupler includes a throughbore and the solid signal puck is positioned within the throughbore and is sealed to the coupler, and wherein the coupler is sealed to the gun housing. In some embodiments, at least one of the endfaces of the solid signal puck is generally planar. In certain embodiments, the solid signal puck is devoid of any throughhole between the first endface and the second endface. In certain embodiments, at least one of the endfaces of the solid signal puck includes a recess for engaging one of the electrical connectors. In some embodiments, at least one of the endfaces of the solid signal puck includes a projection extending away from a center of the solid signal puck for engaging with at least one of the electrical connectors. In some embodiments, the largest outer diameter of the outer periphery is at least 50% of the length between the first endface and the second endface of the solid signal puck. In certain embodiments, the largest outer diameter of the outer periphery is at least 75% of the length between the first endface and the second endface of the solid signal puck. In certain embodiments, the largest outer diameter of the outer periphery is at least 100% of the length between the first endface and the second endface of the solid signal puck. In some embodiments, the largest outer diameter of the outer periphery of the solid signal puck is at least ¾ inch in diameter. In some embodiments, the largest outer diameter of the outer periphery of the solid signal puck is at least ¾ inch in diameter and also at least 75% of the length between the first end face and the second end face of the solid signal puck.
An embodiment of a system for connecting a perforating gun to at least one other component in a perforating tool string comprises a perforating gun that includes a gun housing having an inner surface defining a central passage of the gun housing, and a charge carrier received within the central passage of the gun housing wherein the charge carrier includes a first electrical connector for conducting at least one of electrical signals and electrical power, a tool connected end-to-end with the perforating gun where the tool includes an outer sleeve and a second electrical connector received in the outer sleeve for conducting at least one of electrical signals and electrical power, a solid signal puck positioned within the gun housing where the solid signal puck forms a pressure resistant barrier between the gun and the tool and wherein the solid signal puck includes an outer surface in sealing engagement with the inner surface of the gun housing, and wherein the solid signal puck is electrically connected to both the first electrical connector and the second electrical connector for conducting at least one of electrical signals and electrical power between the first electrical connector and the second electrical connector. In some embodiments, the tool connected end to end with the perforating gun is a second perforating gun. In some embodiments, the perforating guns each include a separate interior void space within the gun housings, and the solid signal puck not only forms a pressure resistant barrier for the perforating guns, but also seals fluids from entering either of the interior void spaces at the end to end connection. In certain embodiments, the solid signal puck includes a first endface oriented generally transverse to a longitudinal axis of the gun housing and a second endface longitudinally opposite the first endface and an electrically conductive signal pathway is formed between the first endface and the second endface of the solid signal puck, wherein the signal pathway is electrically insulated from the gun housing. In certain embodiments, the solid signal puck includes an electrically insulating outer surface. In some embodiments, the solid signal puck is at least one of frictionally, slidably and threadably received in the gun housing. In some embodiments, the solid signal puck includes a first endface oriented generally transverse to a longitudinal axis of the gun housing and a second endface longitudinally opposite the first endface wherein at least one of the endfaces of the solid signal puck is generally planar. In certain embodiments, the solid signal puck includes a first endface oriented generally transverse to a longitudinal axis of the gun housing and a second endface longitudinally opposite the first endface wherein the solid signal puck is devoid of any throughhole between the first endface and the second endface. In certain embodiments, the solid signal puck includes a first endface oriented generally transverse to a longitudinal axis of the gun housing and a second endface longitudinally opposite the first endface and the outer surface between the end faces wherein the largest outer diameter of the outer surface of the solid signal puck is at least 40% of the length between the first endface and the second endface. In some embodiments, the solid signal puck includes a first endface oriented generally transverse to a longitudinal axis of the gun housing and a second endface longitudinally opposite the first endface wherein at least one of the endfaces of the solid signal puck includes a recess for engaging with one of the electrical connectors. In some embodiments, the solid signal puck includes a first endface oriented generally transverse to a longitudinal axis of the gun housing and a second endface longitudinally opposite the first endface wherein at least one of the endfaces of the solid signal puck includes a projection for engaging with at least one of the electrical connectors. In some embodiments, the outer surface of the solid signal puck has a largest outer diameter that is at least one inch in diameter. In certain embodiments, the solid signal puck includes a first end face oriented generally transverse to a longitudinal axis of the gun housing and a second end face longitudinally opposite the first end face and an outer periphery between the end faces, and further wherein the largest outer diameter of the outer surface of the solid signal puck is at least one inch in diameter and is also at least 75% of the length between the first end face and the second end face of the solid signal puck.
An embodiment of a perforating gun for use in a perforating tool string for perforating a casing string in a wellbore comprises a generally tubular gun housing having opposite open ends and an outer wall extending between the open ends, a charge carrier received within the tubular gun housing wherein the charge carrier includes a pair of electrical connectors with one positioned at each open end of the tubular gun housing for conducting at least one of electrical signals and electrical power, a solid signal puck arranged to close and seal a first of the open ends of the tubular gun housing thereby closing an interior void space within the tubular gun housing with the charge carrier positioned therein, a closure arranged to close and seal a second of the open ends of the tubular gun housing thereby closing the other end of the interior void space within the tubular gun housing at a first end of the generally tubular gun housing, wherein the solid signal puck forms a pressure resistant barrier protecting the interior void space at the second end of the tubular gun housing, and wherein the solid signal puck is electrically connected with one of the electrical connectors of the charge carrier for conducting at least one of electrical signals and electrical power with the one electrical connector and also electrically insulated from the tubular gun housing. In some embodiments, the solid signal puck includes an outer periphery in sealing engagement with an inner surface of the tubular gun housing. In some embodiments, the solid signal puck is devoid of any throughhole. In certain embodiments, the solid signal puck includes a first endface oriented generally transverse to a longitudinal axis of the tubular gun housing and a second endface longitudinally opposite the first endface and an outer periphery wherein a largest outer diameter of the outer periphery is at least 40% of the length between the first endface and the second endface of the solid signal puck. In certain embodiments, the largest outer diameter is at least ¾ inch in diameter. In some embodiments, the largest outer diameter is at least 75% of the length between the first end face and the second end face of the solid signal puck. In some embodiments, the solid signal puck includes a first endface oriented generally transverse to a longitudinal axis of the tubular gun housing and a second endface longitudinally opposite the first endface wherein at least one of the endfaces of the solid signal puck includes a recess for engaging with the respective electrical connector. In certain embodiments, the solid signal puck includes a first endface oriented generally transverse to a longitudinal axis of the tubular gun housing and a second endface longitudinally opposite the first endface wherein at least one of the endfaces of the solid signal pucks includes a projection for engaging with the respective electrical connector. In certain embodiments, the closure comprises a second solid signal puck arranged to close and seal a second of the second of the open ends of the tubular gun housing and forming a pressure resistant barrier protecting the interior void space at the second end of the generally tubular gun housing. In some embodiments, the closure includes an assembly comprising a generally tubular body with an open bore and a second solid signal puck is sealed within the bore of the tubular body. In some embodiments, the closure comprises a second generally tubular gun housing that is inserted into the second end of the first mentioned tubular gun housing and wherein the second end of the first mentioned tubular gun housing is closed and sealed by O ring seals engaged with an inside of the second end of the first mentioned tubular gun housing, and further wherein a second solid signal puck is positioned inside the second tubular gun housing and sealed to a bore of the second tubular gun housing, and further wherein the second solid signal puck is arranged to be in direct physical contact with the other of the electrical connectors of the charge carrier inside the first mentioned tubular gun housing.
A more complete understanding of the present invention may be obtained from the following detailed description with reference to the attached drawing figures as summarized below, in which:
The following discussion is directed to various exemplary embodiments of the present disclosure. However, one skilled 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. 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.
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, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central 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. Further, the term “fluid,” as used herein, is intended to encompass both fluids and gasses.
Referring now to
Focusing now on the system that enables recovery of hydrocarbons from the well, in this exemplary embodiment, wellsite 10 includes a surface assembly 11 at the surface or ground level 5 with a tool string 20 attached to the end of a wireline cable 22. The wireline cable is a very long, high strength, armored cable with an included capability for communicating with and powering the down hole tools in the tool string 20. Surface assembly 11 may comprise any suitable surface equipment for drilling, completing, and conducting other downhole work in the wellbore 4 and may include derricks, structures, work trucks such as a coiled tubing truck but most commonly includes a wireline truck along with surface equipment such as valves, pumps, gauges and other electrical/mechanical well control components.
Tool strings such as the tool string 20 shown in
In this exemplary embodiment, the tool string 20, as is common, has a central or longitudinal axis 25 and includes a number of separate tools including, for example, a cable head 24 at the top which connects to the wireline 22, a casing collar locator 26 that generally indicates the depth of the tool string 20 in the wellbore 4, a direct connect sub 28, and a series of perforating guns of which two perforating guns 100A and 100B are shown that carry and orient the shaped charges. The direct connect sub 28 may include a safety switch that provides a second electrical barrier between the surface assembly 11 and switches in each perforating gun 100A and 100B. This further prevents arming of the explosives until the operators at the surface are ready to perforate the casing 12. In some embodiments, a safety switch may be included in a separate safety sub (not shown). At the bottom of the tool string 20 is a frac plug 60 which is used to create sealed partitions in the wellbore 4 so that the hydraulic fracturing may be focused on a limited number of perforations or channels at one time and thereby be more effective in enlarging many of the channels. The frac plug 60 includes various support tools including a setting tool 50, and a plug shoot firing head 40 which communicates with the surface and triggers the setting tool 50 to set the plug 60 in the wellbore 4 when signaled by the operators at the surface. It should be understood that the tool string 20 is a representative example where most tool strings typically include more than two perforating guns. It may be understood that the cable head 24, casing collar locator 26, direct connect sub 28, perforating guns 100A, 100B, frac plug 60, and other equipment of tool string 20 may also be referred to herein as tools (e.g., tools 24, 26, 28, 100A, and 100B) of tool string 20. Tool string 20 may of course comprise additional tools in other embodiments. For example, in some embodiments, tool string 20 may include additional tools such as a fish neck, weight bars, and release tools, etc.
The focus of the present disclosure relates to systems for connecting perforating guns and/or other tools in a tool string together. For example, systems for connecting the uphole perforating gun 100A to the downhole perforating gun 100B are described herein. The system generally includes a closure or solid signal puck 200 for electrically connecting the uphole perforating gun 100A with the downhole perforating gun 100B or other tools of tool string 20 where the first discussed embodiment is shown in
Focusing on
The gun housings 102 of the perforating guns 100A and 100B are shown not only connected end-to-end in
In this exemplary embodiment, the charge carrier 120 of each of the perforating gun 100A and 100B generally includes a charge tube 122 with a first or uphole electrical connector 130 and a second or downhole electrical connector 140. It should be understood that the term “electrical connector” used herein is broadly construed as including a variety of types of connectors used to form an electrical connection including, for example, pins, wires, recesses, cup-shaped indentions and even off-center connectors such as a radial ring or brush connector, etc. The electrical connectors 130 and 140 connect to a signal puck 200 as will be described and explained below. The uphole electrical connector 130 is coupled to a first or uphole end of charge tube 120 while the downhole electrical connector is coupled to a second or downhole end of the charge tube 120 opposite the uphole end of charge tube 120. In this exemplary embodiment, charge carrier 120 includes a plurality of explosive shaped charges 124 received in the charge tube 122 thereof. While this described exemplary embodiment has the charge carrier 120 include explosive charges 124, in other embodiments, the charge carrier 120 may include other types of energetic mechanisms for forming perforations in a casing or liner string such as directed electric pulses, lasers or other means for puncturing the casing 12. Each explosive charge 124 is oriented generally radially outward towards the gun housing 102 but may also be oriented upwardly in the horizontal run, downwardly, or to the side. Moreover, adjacent charges may be arranged to have phased orientations relative to one another being 180 degrees different, 120 degrees different, 90 degrees different and any other phase differences as may be desired. The charge tube 122 is configured to couple with and house each explosive charge 124 and, when signaled from the surface, detonate the explosive charges 124 to perforate the gun housing 102 and casing 12.
As is generally conventional in perforating system, an overall tool string electric circuit is formed which extends from the surface assembly 11 through the wireline cable 22 and on to and through each of the perforating guns and most other tools in the tool string 20. In particular, the wireline cable 22 includes at least one positive and one negative wire where signals and power are directed down a positive wire to be returned back through a negative wire thereby forming a completed circuit. In this explanation, the negative wire may also be described as a ground wire and the positive wire may be described as a signal or power wire.
As is also generally conventional, each of the perforating guns and most other tools in the tool string include their own electrically conductive pathways for the positive side and negative side of the electric circuit essentially forming a number of parallel circuits within the overall tool string electric circuit through the various guns and tools. The general design paradigm for the tools and guns is to use the housing or periphery as part of the ground side of the circuit and a more internal pathway, that is electrically insulated from the ground side, for the positive side of the circuit. In the present disclosure, the positive side of the electric circuit within each gun is not shown per se, but extends between each of the electrical connectors 130 and 140 while the gun housing is part of the ground side of the electric circuit and is accessed by the charge carrier 120 via ground contacts 128.
In this first exemplary embodiment, each of the electrical connectors 130 and 140 are formed as an electrical contact pin extending from the ends of the charge carrier 120. However, it should be understood that the configuration of electrical connectors 130 and 140 may vary in other embodiments as described above. Electrical connectors may also be longitudinally translatable relative to charge carrier 120 in some embodiments such as having a spring-loaded arrangement to adjust or accommodate jolts while being run downhole, or when the frac plug 60 is set, or when the perforating guns 100A and 100B are fired, or simply to accommodate thermal expansion or contraction or other imperfections between the charge carrier 120 and the pucks 200 at either end of the gun housing 102.
Each perforating gun preferably uses the signals and power coming in to the perforating gun at the uphole electrical connector 130 in its operation by forming a completed circuit path to the gun housing 120 but, in parallel, must also pass the signals and power on to the next perforating gun or tool in the tool string via the downhole electrical connector 140. The completed circuit path for each gun includes a switch such as an addressable switch that interprets signals received from the surface 5 to selectively enable power to pass to a detonation system circuit within the perforating gun to initiate detonation of the explosive charges 124. It should be understood that both the signals and the electric power are preferably supplied through one common circuit but separate circuits may be an option for a tool string with signals conducted separately from the electric power. Preferably in operation, signals that are unique and distinctive for each operable tool in the tool string are sent to all of the tools via the parallel circuits but where only one addressable switch reacts to its authentic signal. For the perforating guns, the switch therein responds to its authentic signal by enabling electric power to pass from the uphole electrical connector 130 to the detonator circuit. Power going into the detonator circuit initiates a detonation process where the detonator converts electric power to an explosive or ballistic energy. The detonator is physically arranged with det cord to quickly pass the explosive or ballistic energy released by the detonator to the det cord to undertake its own explosive or ballistic energy release. The det cord is itself arranged and positioned to extend to all of the shaped charges 124 in the perforating gun such that when the det cord release explosive or ballistic energy to the shaped charges 124, those shaped charges 124 undertake their own release of explosive or ballistic energy. This quickly progressing process results in the firing of the perforating gun. It should be understood that the foregoing description is only exemplary and the explosive charges of perforating guns and may be triggered via other mechanisms.
Referring still to
Typically, the process of getting the tool string to the bottom of the wellbore can include significant shock loads and vibrations. The setting of the plug can involve particularly violent jarring forces. Finally, as each gun is fired (often independent of the firing of other guns) there are further pressure pulses and jarring of the tool string. Through all of these circumstances, the guns need to be protected to preserve their reliability for eventual firing. In addition to providing a pressure barrier, the solid signal puck 200 itself preferably seals the open ends 103 and 105 of the gun housing 102 to close and define the interior void space therein.
In this first particular exemplary embodiment, the solid signal puck 200 generally includes a first or uphole endface 202, a second or downhole endface 204 at the opposite end or longitudinally opposite the uphole endface 202, and an outer periphery 206 extending between endfaces 202 and 204. Notably, the solid signal puck 200 is devoid of any throughhole in any orientation and particularly from the uphole endface 202 through to the downhole endface 204. Additionally, in this first exemplary embodiment, each endface 202 and 204 is shown to be generally planar. It should be understood that the end configuration of the endfaces 202 and 204 may have a different and more complicated shape including convex and concave portions with ring like ridges or grooves as needed or desired. Ultimately, a shorter length of solid signal puck 200 between the endfaces is generally preferred in that a shorter puck makes for shorter tools that thereby permits more tools in a tool string. More tools in every tool string generally translates to less runs and therefore less time creating perforations and thereby less total cost for a producing hydrocarbon well.
In this first exemplary embodiment, the end portions of the solid signal puck 200 includes outside threads 208 along the outer periphery 206 where each end is received and connected to the ends of the respective gun housings 102. The solid signal puck 200 further includes O-rings 212 for sealing against the inside surface of the gun housings 102 closing the respective ends of the tubular gun housings 102. As seen in
At least a portion of each endface 202 and 204 solid signal puck 200 is electrically conductive while the outer periphery 206 of solid signal puck 200 is electrically insulated so that the positive and ground circuits are electrically separated. In this exemplary embodiment, the endfaces 202 and 204 of solid signal puck 200 includes a recess or cup-shaped portion 210 for engaging each of the electrical connectors 130 and 140, as shown. For example, the recess 210 on the uphole endface 202 engages or receives the pin shaped electrical connector 140 of the downhole electrical connector 140 of the uphole perforating gun 100A. Similarly, the recess 210 of downhole endface 204 engages or receives the pin shaped uphole electrical connector 130 of the downhole perforating gun 100B. In this manner, an electrical signal pathway (identified by double-end arrow 205 in
The outer periphery 206 of the puck along the outer surface thereof is electrically insulated from the gun housing 102 of both perforating guns 100A and 100B. In some embodiments, the electrically insulation may be a coating, an overmolded material (plastics, elastomers, and/or non-conductive metallic materials), a chemically or electrically modified surface, an anodized material, or an additive manufactured material. In some embodiments, the outer periphery 206 of solid signal puck 200 is defined by an electrically insulating material. In other embodiments, the outer periphery 206 of solid signal puck 200 may be electrically conductive while at least a portion of an inner surface of gun housing 102 is electrically insulating. For example, in some embodiments, an electrically insulative coating may be applied to the interior of gun housings 102 of both perforating guns 100A and 100B and the puck may or may not include an electrically insulative coating.
One particular aspect of the solid signal puck 200 is the size and shape thereof and particularly the large diameter. It is mechanically advantageous to design pressure bearing surface with a small cross-section to reduce the effective magnitude of a pulse or blast. In contrast, the solid signal puck 200 is preferably large to fill the open end of the tubular gun housing 102. To handle the anticipated forces, the solid signal puck 200 is made of strong material (preferably steel) with sufficient thickness or length between the endfaces to bear the load. This leads to a solid signal puck to have a relatively large diameter to length ratio where the first embodiment is the smallest diameter to length ratio of all the disclosed embodiments. In this first embodiment, the diameter is approximately 40% of the length exclusive of any appendages that may be added to the end faces of the puck 200. It is noted that the pucks are not generally smooth periphery designs as they may have shoulders for bracing against other structures and grooves for holding O-rings and even threads as shown at 208. So, it is seen that the outer periphery 206 of solid signal puck 200 will have a maximum or largest diameter while solid signal puck 200 has a largest or maximum length 228 extending between endfaces 202 and 204. In this first exemplary embodiment, the largest diameter of solid signal puck 200 is at least 40% of the largest length 228 of solid signal puck 200. However, in other embodiments, the largest diameter 226 of solid signal puck 200 may be greater than 40% of the largest length 228. For example, in other embodiments, the largest diameter may be greater than 50% of the largest length 228 or 75% of the length, 100% of the length and even greater ratios up to, for example, 125% of the maximum length 228 between the endfaces 202 and 204. In the embodiments, the solid signal puck has a largest diameter of at least ¾ of an inch and may be formed in various diameters including 1.5 inches, 2 inches, 2.5 inches and even 3 inches or larger in diameter.
As described above, the length of the solid signal puck 200 is preferably kept short while still within design limits for anticipated maximum pressure pulse and strength of the materials of the puck 200 and other connecting structure. In other words, by minimizing a length of solid signal puck 200, the effective lengths of the perforating guns may enable one or more guns to be installed in a tool string 20 getting more effectiveness from each trip of a tool string 20 into the wellbore 4.
Referring now to
The gun housing 251 of each perforating gun 250A and 250B includes an open first or uphole end 252, an open second or downhole end 254 longitudinally opposite uphole end 252, a central bore or passage forming an interior void space 107 within which charge carrier 120 is received. In this second arrangement the gun housings 251 are connected end-to-end in a pin-by-box arrangement where each gun housing 251 includes an internal uphole connector 262 and an external downhole connector 264 where the ends of the gun housings 251 overlap when connected. In this exemplary embodiment, uphole connector 262 comprises a threaded “pin” connector while the downhole connector 264 comprises a threaded box connector. In this configuration, the box connector 264 of downhole perforating gun 250B directly connects to the pin connector 262 of the uphole perforating gun 250A. In this manner, solid signal puck 280 is in the end-to-end connection but does not secure the gun housings 251 to one another. The solid signal puck is more accurately trapped or “sandwiched” between the two charge carriers 120.
In this second exemplary embodiment, the solid signal puck 280 generally includes a first or uphole endface 282, a longitudinally opposite second or downhole endface 284, and an outer periphery 286 extending between the endfaces 282 and 284. While this exemplary embodiment is described with an uphole and downhole orientation, it is reasonable to expect that the orientation could be reversed and still work well in operation. It is emphasized that the solid signal puck 280 is devoid of any throughhole between the endfaces such that the solid signal puck 280 itself defines the electrical signal pathway (identified by double arrow 285 in
The outer periphery 286 of solid signal puck 280 has a maximum or largest diameter 290 while solid signal puck 280 has a largest or maximum length 292 extending between endfaces 282 and 284. In this exemplary embodiment, the largest diameter 290 of solid signal puck 280 is at least 100% of the largest length 292 of solid signal puck 280. Indeed, in this exemplary embodiment, the largest diameter 290 of solid signal puck 280 is larger than the length 282 thereof.
Similar to the first exemplary embodiment, solid signal puck 280 includes two pairs of annular seal assemblies 294 which are positioned on the outer periphery 286 thereof where one set of O-rings seal on the inside of one gun housing 251 at the larger diameter and a second set of O-rings sealed on the inside of the other gun housing 251 along the smaller diameter outer periphery of the solid signal puck 280. In other embodiments, the configuration of the seal assemblies 294 may vary. And it is noted that while the ends of the gun housings overlap, the connection is still described as end-to-end where the gun housings 251 follow the tool string axis 25 in
Turning now to a third exemplary embodiment shown in
The gun housing 301 of each perforating gun 300A and 300B includes an open first or uphole end 302, an open second or downhole end 304 longitudinally opposite uphole end 302, a central bore or passage defining an interior void space 107 where charge carrier 120 is positioned. Gun housings 301 are connected end-to-end in a box-by-pin arrangement where each gun housing 301 includes a threaded internal or “box” connector 312 at the uphole end and a threaded external or “pin” downhole connector 314 at the downhole end. In this configuration, the pin connector 314 of uphole perforating gun 300A directly connects to the box connector 312 of the downhole perforating gun 300B in an overlapping arrangement with solid signal puck 320 between the charge carriers 120 again in a trapped or “sandwiched” arrangement.
In this exemplary embodiment, solid signal puck 320 generally includes a first or uphole endface 322, a longitudinally opposite second or downhole endface 324, and an outer periphery 326 extending between the endfaces 322 and 324. While this exemplary embodiment is described with an uphole and downhole orientation, it is reasonable to expect that the orientation could be reversed and still work well in operation. For emphasis, the solid signal puck 320 is devoid of any throughhole in any orientation and particularly extending between endfaces but instead defines an electrical signal pathway (identified by double arrow 325 in
This third embodiment shown in
Turning now to the fourth embodiment shown in
As with other embodiment, each perforating gun housing 351 includes a charge carrier 370 and sealed via an annular seal assembly 364 comprised of a pair of O-rings positioned on an outer periphery of the gun housing 351 while the annular seal assembly 388 seals the puck 380 to the inside of the inserted end of the gun housing 351. The solid signal puck 380 like the other embodiments provides an electrical connection between guns and also provides bi-directional pressure isolation for adjacent guns from all pressure pulses and other potentially comprising events downhole.
Referring to a fifth embodiment shown in
The solid signal puck 420 is within the end-to-end connection but does not carry any tensile or compressive load of the tool string but seals against the inside of the internal coupling. Like other exemplary embodiments, solid signal puck 420 generally includes a first or uphole endface 422, a longitudinally opposite second or downhole endface 424, and an outer periphery 426 extending between the endfaces 422 and 424. While this exemplary embodiment is described with an uphole and downhole orientation, it is reasonable to expect that the orientation could be reversed and still work well in operation. For emphasis, the solid signal puck 420 is devoid of any throughhole in any orientation and particularly between the endfaces 422 and 424. The solid signal puck 420 further defines an electrical signal pathway (identified by double arrow 425 in
Turning now the sixth described embodiment shown in
Solid signal puck 470 is not connected end-to-end with the gun housings 451 of perforating guns 450A and 450B and instead is received within the central passage 492 of external coupler 490 and sealed to the gun housings. The solid signal puck 470 generally includes a first or uphole endface 472, a longitudinally opposite second or downhole endface 474, and an outer periphery 476 extending between the endfaces 472 and 474. Solid signal puck 470 is devoid of any throughhole between uphole endface 472 and downhole endface 474. Solid signal puck 470 instead defines an electrical signal pathway (identified by double arrow 475 in
Solid signal puck 470 is trapped between the ends of gun housings 451 although the connection of the guns is characterized as an end-to-end connection. The solid signal puck 470 includes a pair of annular seal assemblies 480 which are positioned on the outer periphery 476 thereof In this exemplary embodiment, each seal assembly 480 comprises a pair of O-ring seals positioned on the outer periphery 476 of solid signal puck 470. However, in other embodiments, the configuration of seal assemblies 480 may vary. Seal assemblies 480 sealingly engage or contact the inner walls 460 of the gun housings 451 of perforating guns 450A, 450B, thereby sealing the connection formed between solid signal puck 470 and the perforating guns 450A and 450B.
Turning now to the seventh described embodiment in
Turning now to an eighth embodiment shown in
In this exemplary embodiment, solid signal puck 580 generally includes a first or uphole endface 582, a longitudinally opposite second or downhole endface 584, and an outer periphery 586 extending between endfaces 582, 584. While this exemplary embodiment is described with an uphole and downhole orientation, it is reasonable to expect that the orientation could be reversed and still work well in operation. For emphasis, the solid signal puck 580 is devoid of any throughhole between endfaces 582 and 584. Solid signal puck 580 defines an electrical signal pathway (identified by double arrow 585 in
In this exemplary embodiment, the endfaces 582 and 584 of solid signal puck 580 each include a projection 588 for engaging one of the receptacles 568 of electrical connectors 562 and 570. It may be understood that the term “projection” as used herein as construed broadly to cover projections which vary from the configuration of projection 588, including projections which are off-line. In this exemplary embodiment, the projection 588 of the downhole endface 584 is received within the receptacle 568 of the uphole electrical connector 562 to electrically connect the solid signal puck 580 with downhole perforating gun 550B. Similarly, the projection 588 of the uphole endface 582 is received within the receptacle 568 of the downhole electrical connector 570 to electrically connect the solid signal puck 580 with uphole perforating gun 550A. In this manner, projections 588 form male electrical contacts which are received in the female electrical contacts defined by electrical pin contacts 564 and 574 of electrical connectors 562 and 570, respectively. It should be noted that when considering the length of the solid signal pucks, the extent of the projections 588 should not be included in that consideration.
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.
The present application claims benefit of U.S. provisional patent application No. 63/172,042 filed Apr. 7, 2021, entitled “Reusable Tandem Sub for a Perforating Gun System,” U.S. provisional patent application No. 63/193,057 filed May 25, 2021, entitled “Reusable Tandem Sub for a Perforating Gun System,” and U.S. provisional patent application No. 63/219,541 filed Jul. 8, 2021, entitled “Reusable Tandem Sub for a Perforating Gun System,” which are incorporated herein by reference in their entirety for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 63172042 | Apr 2021 | US | |
| 63193057 | May 2021 | US | |
| 63219541 | Jul 2021 | US |
