Integrated wireless perforating round with composite insert

Abstract

An integrated wireless perforating round includes a projectile, a sabot within which the projectile is positioned, an external electrical contact in electrical communication with the sabot, an insert defining a propellant chamber in which the sabot is received, an ignitor in electrical communication with the sabot and disposed in the propellant chamber, an electrically conductive case within which the composite insert is disposed, and a normally open (NO) electrical connection configured for selective electrical communication with the ignitor, and the NO electrical connection is in electrical communication with the case.

Description

TECHNOLOGICAL FIELD OF THE DISCLOSURE

[0001] One or more example embodiments disclosed herein are directed to projectiles and associated components such as may be employed in downhole perforation operations. More specifically, example embodiments comprise a projectile comprising a kinetic energy perforating round, and methods for using the same.BACKGROUND

[0002] Perforating is a process used to create holes in a well casing disposed in a wellbore, and may be performed as part of a hydraulic fracturing process. Typically, the holes, or perforations, are created using a perforation gun that fires a projectile of some kind. While conventional projectiles are effective in creating perforations, the size, quality, and shape, of the perforations are inconsistent and can vary widely from one perforation to another, even when the same type of projectile is used to create the various perforations. Such variations can cause problems, such as by inhibiting the free flow of hydrocarbons into a well bore. As another example, some processes, such as hydraulic fracturing, or frac'ing, may require the use of symmetric and uniform holes for optimal performance. However, conventional projectiles often create holes that are asymmetric. Further, the ignition systems for conventional projectiles typically employ wires that are often delicate and subject to damage when employed in the extreme conditions found in downhole environments.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The appended drawings contain figures of various example embodiments to further illustrate and clarify the above and other aspects of example embodiments. It will be appreciated that these drawings depict only example embodiments and are not intended to limit the scope of this disclosure or of any claims. Example embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings.

[0004] FIG. 1 is a side view of an integrated wireless perforating round (IWPR), according to one embodiment.

[0005] FIG. 2 is a line drawing version of the IWPR of FIG. 1.

[0006] FIG. 3 is a section view of an example IWPR, according to one embodiment.

[0007] FIG. 4 is a line drawing version of the IWPR of FIG. 2.

[0008] FIG. 5 is a partial section view of an upper portion of an IWPR, according to one embodiment.

[0009] FIG. 6 is a detail view of a case for an IWPR, according to one embodiment.ASPECTS OF SOME EXAMPLE EMBODIMENTS

[0010] One or more example embodiments disclosed herein are directed to projectiles and associated components such as may be employed in downhole perforation operations, one example of which is a hydraulic fracturing, or frac'ing, operation. More specifically, some example embodiments comprise a projectile in the form of an integrated wireless perforating round (IWPR), and a method for using the same.

[0011] In one embodiment, an integrated wireless perforating round comprises a projectile positioned within a sabot that may include a spacer to adjust the vertical position of the projectile relative to the interior of the sabot. A conductive element may be attached to the insert and configured and arranged to ground the sabot to a barrel of a perf gun when the integrated wireless perforating round is positioned in the barrel. An ignitor, comprising a PCB (printed circuit board) that may be grounded to the sabot, may be positioned in an opening at the bottom of the sabot. The sabot, carrying the projectile and the ignitor, may be partly received within a propellant chamber defined by a composite, non-electrically conductive insert. The insert, in turn, is received within a case that is electrically isolated from the ignitor. Except for an exposed contact portion, the exterior of the case may be electrically insulated. The case may comprise any electrically conductive material including, but not limited to, anodized aluminum.

[0012] According to one embodiment, an ignition circuit of the integrated wireless perforating round comprises various elements, including a contact portion of the case, and a pogo pin or other spring-loaded electrical connector mechanism, carried in the insert and contacting the case. The pogo pin is arranged for contact with the ignitor so that upon application of a voltage to the contact portion of the housing, electrical current is conducted by the housing to the pogo pin, which is in a normally open (NO) state with respect to the ignitor, causing the pogo pin to move into contact with, and conduct electrical current to, the ignitor, which then ignites a propellant that is in the propellant chamber. The ignited propellant generates pressurized gas that propels the projectile and sabot out of the barrel of a perf gun, or other carrier, and into / through a target, such as a well casing, cement, and geological formation, for example.

[0013] As will be apparent from this disclosure, example embodiments may be advantageous in various respects. For example, an embodiment may comprise an ignition circuit that does not employ any wires, which can be fragile and prone to damage, or destruction, from rough handling such as can occur in surface and downhole operations and environments. An embodiment may be self-contained such that all components of an ignition circuit for a projectile are integrated within a single assembly, which includes the projectile, that can be loaded into a perf gun, or other carrier. An embodiment may comprise an internal ignition circuit that is protected from damage resulting from operations, and / or from conditions in a downhole environment. An embodiment may implement an increase in reliability of an ignition circuit, relative to approaches that employ wires within, and / or outside of, a projectile assembly. An embodiment may eliminate the need to attach wires to an IWPR. Various other advantages of one or more embodiments will be apparent from this disclosure.

[0014] It should be noted that nothing herein should be construed as constituting an essential or indispensable element of any embodiment. Rather, and as the person of ordinary skill in the art will readily appreciate, various aspects of the disclosed embodiments may be combined in a variety of ways so as to define yet further embodiments. Such further embodiments are considered as being within the scope of this disclosure. As well, none of the embodiments embraced within the scope of this disclosure should be construed as resolving, or being limited to the resolution of, any particular problem(s). Nor should such embodiments be construed to implement, or be limited to implementation of, any particular effect(s).DETAILED DESCRIPTION OF SOME EXAMPLE EMBODIMENTS

[0015] As noted above, one or more example embodiments comprise an integrated wireless penetrating round (IWPR) that may be fired from a perforation gun. An example IWPR may be able to penetrate a variety of structures and materials including, but not limited to, a steel well casing, concrete, and a geological formation. In one example application, an embodiment of a IWPR may penetrate all of the foregoing structures after being fired from a perforation gun. In an embodiment, a perforation gun may carry, and fire, multiple IWPRs. In an embodiment, an IWPR may comprise a consumable item that can only be fired once.A. Discussion

[0016] With attention now to the examples of FIGS. 1, 2, 3, 4 and 5, details are provided concerning aspects of some example IWPRs, referenced in the Figures at 100, according to an embodiment. The embodiments disclosed in the Figures are presented by way of example and are not intended to limit the scope of this disclosure, or of any claims, in any way.A.1 Aspects of an Example Embodiment of an IWPR

[0017] In an embodiment, the IWPR 100 comprises a projectile 102 that may be made of tungsten, tool steel, depleted uranium (which may primarily comprise U-238), or any other suitably heavy and dense material(s). As shown in FIG. 3, a terminal portion 102a of the projectile 102 may comprise a tangent ogive geometry, although no particular geometry is necessarily required. As shown, the projectile 102 may may truncated, or flattened, at the tip. Parameters such as the length and diameter of the projectile 102 may be selected as needed based on a particular application.

[0018] The projectile 102, which may be cast, forged, or machined, for example, may define an internal chamber 102b for receiving propellant gas generated by ignition of a propellant. In an embodiment, the chamber 102b may be partly, or completely, filled with one or more propellants, which would be in addition to the propellant(s) disposed in a propellant chamber 110a (discussed below). In an embodiment, this additional propellent may ignite while the projectile 102 is perforating a target material such as a metal casing, cement, and / or, a rock formation. This secondary ignition of propellant in the propellant chamber 110a may extend the time of the total ignition process of all the propellent of the IWPR 100 while the projectile is in the rock formation. In an embodiment, this ignition may result in the production of relatively more gas inside the tunnel that is created as the projectile passes through the target material. This additional gas may cause the tunnel to break down.

[0019] The projectile 102 may be received within a sabot 104 that may be press-fit, or otherwise attached, about the projectile 102. In an embodiment, the sabot 104 remains with the projectile 102 after the projectile 102 has been fired. The sabot 104, which may or may not be reusable in some embodiments, may comprise an electrically conductive material, such as a metal, examples of which include aluminum, titanium, copper, and brass. The sabot 104 may define an opening 104a at the bottom which may admit propellant gases into contact with the projectile 102 so that pressure from the propellant gases can be exerted directly on the projectile 102.

[0020] Part or all of the projectile 102 and / or sabot 104 may be coated with various types of coatings. Examples include low friction coatings comprising PTFE (polytetrafluoroethylene) or nanostructured coatings, abrasion resistant coatings such as tungsten carbide or ceramic, heat resistant coatings such as ceramics, and anti-corrosion coatings such as zinc.

[0021] One or more spacers 106, or other components, may be provided within the sabot 104 to adjust the vertical position of the projectile 102 relative to the sabot 104 and / or other components of the IWPR 100. The spacers 106, which may be made of metal such as steel, may comprise a washer geometry, for example, with holes 106a that are axially aligned with the opening 104a in the sabot 104. The holes 106a enable propellant gases to come into contact with, and exert pressure on, the projectile 102.

[0022] It is noted that any, or all, of the holes 106a, opening 104a, and chamber 102b, may be configured to provide one or more desired effects with respect to the action of the propellant gases on the projectile 102. Thus, for example, the diameter of the holes 106a and opening 104a may be selected so as to enable implementation of such effects, as the selected diameter sizes, and spacer 106 thicknesses / materials, for example, can affect performance parameters such as pressure and flow rate of the propellant gases.

[0023] A conductor 108, which may take the form of an annular strip or ring in an embodiment, may be provided that contacts the sabot 104 and serves to ground the sabot 104 to a barrel of a perf gun or other device when the IWPR 100 is situated in a barrel of one of these carriers. The conductor 108 may comprise any electrical conductor, including metals such as copper, gold, or aluminum, for example, and may have an annular configuration that extends around the top edge of the sabot 104.

[0024] With continued reference to the Figures, the IWPR 100 may comprise an insert 110 that comprises a composite material, including electrically non-conductive materials such as a ceramic or a woven carbon composite for example, within which the sabot 104 is received. The insert 110 material may be electrically non-conductive. In an embodiment, the entire sabot 104 may be received within the insert 110, although in some cases, less than the entire sabot 104 may be positioned within the insert 110. The insert 110 and the sabot 104 may be glued together with a suitable adhesive, or otherwise attached to each other.

[0025] As shown, the insert 110 may define a propellant chamber 110a in which the sabot 104 is partly received. The propellant chamber 110a may hold one or more propellants which, when ignited, generate one or more propellant gases which become pressurized due to their confinement in the interior of the IWPR 100. As discussed in more detail below, in operation, pressurized propellant gases exert a force on the sabot 104 and projectile 102, propelling both into / through a target.

[0026] An ignitor 112, which may comprise an ignition circuit capable of generating a spark, and implemented on a PCB (printed circuit board), may be positioned at the bottom of the sabot 104. The ignitor 112 may comprise an electrical contact 112a arranged for physical contact with a pogo pin assembly 114. The pogo pin assembly 114 may be in a normally open (NO) state in which the pogo pin 114a does not contact the electrical contact 112a. In an embodiment, when a voltage is applied to the pogo pin assembly 114, the pogo pin 114a moves into contact with the electrical contact 112a, causing the ignitor 112 to generate a spark that ignites a propellant in the propellant chamber 110a.

[0027] With continued reference to the Figures, the IWPR 100 may comprise a case 116 in which the insert 110 is received. The case 116, which may have a relatively greater wall thickness at its bottom than at its sides, may comprise an electrically conductive material, such as aluminum for example, and may be electrically insulated over its exterior, except for a contact strip 116a which may remain uninsulated. As shown, the contact strip 116a, which may be annular to accommodate the orientation of the IWPR 100 in a gun barrel, may comprise an area of reduced diameter, or wall thickness, relative to a diameter or wall thickness of other parts of the case 116. As shown in the example of FIG. 6, the case 116 may comprise a contact 116b which may serve to conduct an electrical current from the case 116 to the pogo pin assembly 114. The insert 110 and the case 116 may be glued together with a suitable adhesive, or otherwise attached to each other.

[0028] In an embodiment, the contact strip 116a is configured and arranged to receive electrical current from a source that is exterior to the IWPR 100, such as by way of another pogo pin or other electrical contact. The current received at the contact strip 116a may be passed through the body of the case 116 and to the pogo pin assembly 114.A.2 Aspects of an Example Ignition Circuit

[0029] As discussed herein, various elements of an example IWPR are electrically conductive. These elements may collectively define, or constitute, an ignition circuit for an embodiment of an IWPR. In particular, such an ignition circuit may comprise elements including, but not limited to, the contact strip 116a, the case 116, the pogo pin assembly 114, the pogo pin 114a, and the ignitor 112. As a result of this configuration of an ignition circuit, an electrical current input provided by an external source to the contact strip 116a may pass through the case 116 to the pogo pin assembly 114, and then to the ignitor 112, causing the ignition of a propellant in the propellant chamber 110a. The ignition circuit may be grounded, for example, through a barrel of a perf gun or other charge carrier.

[0030] Thus, as explained in the example above, an embodiment may comprise a wireless ignition circuit that is devoid of any wires except as may be present on an ignitor PCB. Moreover, potentially vulnerable components of the ignition circuit, such as the pogo pin assembly 114 and ignitor circuit 112, are completely housed within the case 116 and, as such, are protected from damage that could result from handling and / or downhole conditions. Further, because the contact strip 116a is integral with the case 116, it is likewise resistant to damage from handling and environmental conditions.

[0031] In an embodiment, an assembly may comprise a IWPR, embodiments of which are discussed herein, and a perf gun. The IWPR 100 may be loaded into a barrel of the perf gun. The perf gun may be run downhole to one or more perf locations, and one or more instances of the IWPR fired to create one or more perforations in the desired locations.A.3 Operational Aspects of an Example IWPR Device

[0032] With continued reference to the examples of FIGS. 1 and 3, details are provided concerning some operational aspects of the example IWPR 100. These are provided by way of example and are not intended to limit the scope of this disclosure, or of any claims, in any way.

[0033] In general, an embodiment of an IWPR, such as the IWPR 100, may used as part of a perforating process to create a perforation in one or more target materials. It is noted that as used herein in the discussion of one or more embodiments, the term ‘perforating’ refers to the ability of an example IWPR 100 to create holes or openings in a target material, or materials, such as an opening through which fluids, gases, solids, and any combination of these, may flow. Similarly, a ‘perforation’ refers, in discussions concerning one or more embodiments, to a hole or opening created by a IWPR, regardless of the material(s) in which the hole or opening was created.

[0034] In operation, electrical current may be supplied to the IWPR 100 by way of an electrical contact, such as a perf gun, that is in electrical communication with the contact strip 116a. The applied electrical current flows to the pogo pin assembly 114 by way of the case 116, causing the pogo pin 114a to contact the contact 112a of the igniter 112. The current flowing to the igniter 112 causes the igniter 112 to generate of a spark which ignites the propellant in the propellant chamber 110a. The burning propellant may, in turn, cause ignition of the propellant(s) in the internal chamber 102b. The ignited propellant(s) generates propellant gases which may be directed to the interior of the projectile 102 by way of the openings 104a and 106a. The propellant gases may also exert a force on the exterior of the portion of the sabot 104 that is positioned within the propellant chamber 110a. The propellant gases then act on the projectile 102 and sabot 104, propelling the projectile 102 and sabot 104 into, and through, one or more target materials.B. Further Example Embodiments

[0035] Following are some further example embodiments. These are presented only by way of example and are not intended to limit the scope of this disclosure, or of the claims, in any way.

[0036] Embodiment 1. An apparatus, comprising: a projectile; a sabot within which the projectile is positioned; an external electrical contact in electrical communication with the sabot; an insert defining a propellant chamber in which the sabot is received; an ignitor in electrical communication with the sabot and disposed in the propellant chamber; an electrically conductive case within which the composite insert is disposed; and a normally open (NO) electrical connection configured for selective electrical communication with the ignitor, and the NO electrical connection is in electrical communication with the case.

[0037] Embodiment 2. The apparatus as recited in any preceding embodiment, wherein the insert comprises a non-electrically conductive composite material.

[0038] Embodiment 3. The apparatus as recited in any preceding embodiment, wherein an exterior of the electrically conductive case is electrically insulated except for an annular contact strip arranged for communication with an electrical power source when the apparatus is positioned in a barrel of a perf gun.

[0039] Embodiment 4. The apparatus as recited in any preceding embodiment, wherein one or more propellants are disposed in the propellant chamber.

[0040] Embodiment 5. The apparatus as recited in any preceding embodiment, wherein the NO electrical connection is responsive to an applied current so as to contact the ignitor and close a wireless ignition circuit of the apparatus.

[0041] Embodiment 6. The apparatus as recited in any preceding embodiment, wherein the external electrical contact comprises annular contact disposed about the projectile and arranged to contact a barrel of a perf gun when the apparatus is positioned in the barrel.

[0042] Embodiment 7. The apparatus as recited in any preceding embodiment, further comprising a spacer positioned below the projectile in the sabot.

[0043] Embodiment 8. The apparatus as recited in any preceding embodiment, wherein the electrically conductive case comprises aluminum.

[0044] Embodiment 9. The apparatus as recited in any preceding embodiment, wherein the electrically conductive case comprises anodized aluminum.

[0045] Embodiment 10. The apparatus as recited in any preceding embodiment, wherein the ignitor comprises a PCB.

[0046] Embodiment 11. The apparatus as recited in any preceding embodiment, wherein the ignitor is grounded to the sabot, and the sabot is grounded to the external electrical contact.

[0047] Embodiment 12. The apparatus as recited in claim 1, wherein the projectile defines an internal chamber that carries a propellant.

[0048] Embodiment 13. A system, comprising: a perforation gun; and the apparatus of any of embodiments 1-12, and the apparatus is configured to reside in a chamber of the perforation gun and, when positioned in the chamber, the apparatus is aligned with a barrel of the perforation gun.

[0049] Embodiment 14. A method for using the apparatus of any of embodiments 1-12.

[0050] Embodiment 15. A method for using the system of embodiment 14.

[0051] Embodiment 16. A method performed in connection with an integrated wireless perforating round (IWPR), comprising: using a flow of electrical current to trigger a wireless ignition system of the IWPR; with an ignitor of the wireless ignition system, igniting a propellant; and using gases generated by the propellant to propel a projectile of the IWPR into a target material.

[0052] Embodiment 17. The method as recited in embodiment 16, wherein the igniting, and propelling of the projectile, are performed in a downhole environment.

[0053] Embodiment 18. The method as recited in any of embodiments 16-17, wherein the electrical current is provided to the wireless ignition system by way of a barrel of a perf gun.

[0054] Embodiment 19. The method as recited in any of embodiments 16-18, wherein the target material comprises one or more of metal casing, cement, and a geological formation.

[0055] Embodiment 20. The method as recited in any of embodiments 16-19, wherein the method is performed as part of a hydraulic fracturing operation.

[0056] Embodiment 21. The method as recited in any of embodiments 16-20, wherein igniting the propellant comprises igniting a propellant in a propellant chamber of the IWPR, and igniting a propellant in an interior chamber defined within the projectile.

[0057] The described embodiments are to be considered in all respects only as illustrative and not restrictive. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. An apparatus, comprising:a projectile;a sabot within which the projectile is positioned;an external electrical contact in electrical communication with the sabot;an insert defining a propellant chamber in which the sabot is received;an ignitor in electrical communication with the sabot and disposed in the propellant chamber;an electrically conductive case within which the composite insert is disposed; anda normally open (NO) electrical connection configured for selective electrical communication with the ignitor, and the NO electrical connection is in electrical communication with the case.

2. The apparatus as recited in claim 1, wherein the insert comprises a non-electrically conductive composite material.

3. The apparatus as recited in claim 1, wherein an exterior of the case is electrically insulated except for an annular contact strip arranged for communication with an electrical power source when the apparatus is positioned in a barrel of a perf gun.

4. The apparatus as recited in claim 1, wherein one or more propellants are disposed in the propellant chamber.

5. The apparatus as recited in claim 1, wherein the NO electrical connection is responsive to an applied current so as to contact the ignitor and close a wireless ignition circuit of the apparatus.

6. The apparatus as recited in claim 1, wherein the external electrical contact comprises an annular contact disposed about the projectile and arranged to contact a barrel of a perf gun when the apparatus is positioned in the barrel.

7. The apparatus as recited in claim 1, further comprising a spacer positioned below the projectile in the sabot.

8. The apparatus as recited in claim 1, wherein the electrically conductive case comprises aluminum.

9. The apparatus as recited in claim 1, wherein the case comprises anodized aluminum.

10. The apparatus as recited in claim 1, wherein the ignitor comprises a PCB (printed circuit board).

11. The apparatus as recited in claim 1, wherein the ignitor is grounded to the sabot, and the sabot is grounded to the external electrical contact.

12. The apparatus as recited in claim 1, wherein the projectile defines an internal chamber that carries a propellant.

13. A system, comprising:a perf gun; andthe apparatus as recited in claim 1.

14. A method performed in connection with an integrated wireless perforating round (IWPR), comprising:using a flow of electrical current to trigger a wireless ignition system of the IWPR;with an ignitor of the wireless ignition system, igniting a propellant; andusing gases generated by the ignited propellant to propel a projectile of the IWPR into a target material.

15. The method as recited in claim 14, wherein the igniting, and the propelling of the projectile, are performed in a downhole environment.

16. The method as recited in claim 14, wherein the electrical current is provided to the wireless ignition system by way of a barrel of a perf gun.

17. The method as recited in claim 14, wherein the target material comprises one or more of metal casing, cement, and a geological formation.

18. The method as recited in claim 14, wherein the method is performed as part of a hydraulic fracturing operation.

19. The method as recited in claim 14, wherein igniting the propellant comprises igniting a propellant in a propellant chamber of the IWPR, and igniting a propellant in an interior chamber defined within the projectile.

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