Oil and gas well completion processes include perforating a hydrocarbon formation to liberate the oil and gas within reservoirs therein. Hydrocarbon formations may include, for example, subterranean oil and gas shale formations, sandstone formations, and/or carbonate formations. Perforating guns perform the perforating operations. The perforating guns carry explosive charges, i.e., “shaped charges”, into a wellbore that has been drilled into the hydrocarbon formation. The shaped charges detonate and an explosive jet formed by each shaped charge may perforate one or more of a structure surrounding the shaped charge or perforating gun within the wellbore, a layer of cement surrounding the wellbore, and the hydrocarbon formation. For example, the wellbore may include cemented-in casing pipes and other tubulars (collectively, “wellbore casing”) that isolate an environment within the wellbore from the hydrocarbon formation prior to perforating. For brevity within this disclosure, the term “wellbore” refers to the drilled wellbore and any wellbore casing therein, except where otherwise specified.
The shape and configuration of the shaped charge and resulting explosive jet may vary depending on operational requirements. For example, abandonment procedures for decommissioned wells include permanently sealing the wellbore using cement. Unwanted vertical channels or voids may exist in a previously cemented wellbore annulus between the wellbore casing and the hydrocarbon formation may produce migration pathways for fluids or gas to contaminate surrounding areas. A “cement squeeze” operation uses perforating guns to perforate through the wellbore casing, but not necessarily into the hydrocarbon formation, to access the wellbore annulus via perforations through which cement is squeezed, under pressure, into the wellbore annulus. A goal for cement squeeze operations is for perforations to provide 360-degree access from within the wellbore casing to the wellbore annulus, to increase the coverage of cement in the annulus. Accordingly, a conventional perforating gun for a cement squeeze operation may include a helical arrangement of overlapping “slotted” shaped charges (
The wellbore casing may also be a conduit for a wellbore fluid that is pumped into the wellbore casing to “pump down” perforating guns and reduce the time required for the perforating guns to reach their positions. The shaped charges must be sealed and protected against the wellbore fluids and hydraulic pressures within the wellbore. For example, in a typical “gun carrier”-type perforating gun, the shaped charges are retained and oriented in a charge carrier, such as a metal tube, housed with other perforating gun components within a sealed interior chamber of, e.g., a cylindrical gun housing such as a metal tube. Components within the sealed interior chamber need not be individually protected, but the shaped charge explosive jets must penetrate the gun housing in addition to, e.g., the wellbore casing. Alternatively, a typical “exposed” perforating gun includes shaped charges retained and oriented in a charge carrier that is exposed to the wellbore environment. The shaped charges must be individually protected against the wellbore environment, but the explosive jets need not first penetrate a gun housing, nor is the extra material, weight, machining, or cost a gun housing required. The shaped charges are typically protected by, among other things, sealing the interior of the shaped charges, including the explosive components, with a charge lid that covers and seal an open end of the shaped charge. The charge lid protects the components during normal use, but the sealed interior may present safety risks if, for example, the sealed charge is exposed to fire and the heat therefrom causes a buildup of gas pressure from the explosive within.
For at least the above reasons, a need exists for an encapsulated shaped charge that provides both a strong seal for the charge and safety.
In an aspect, the disclosure relates to an encapsulated shaped charge. The encapsulated shaped charge may include a charge case and a charge lid. The charge case may hold an explosive and a liner. The charge lid may cover an open end of the charge case. The encapsulated shaped charge may further include an external clip assembly connected to each of the charge case and the charge lid.
In an aspect, the disclosure relates to an exposed perforating gun system. The exposed perforating gun system may include a charge carrier retaining a plurality of encapsulated shaped charges. Each shaped charge may include a charge case holding an explosive and a liner, a charge lid covering an open end of the charge case, and an external clip assembly. The external clip assembly may be connected to each of the charge case and the charge lid.
In an aspect, the disclosure relates to a method for reducing a buildup of gas pressure in an encapsulated shaped charge exposed to fire. The method may include enclosing an explosive within a charge case by, e.g., positioning a charge lid on an open end of the charge case within which the explosive is contained. The method may further include releasably connecting the charge lid to the charge case. Releasably connecting the charge lid to the charge case may include positioning a retainer ring on the charge lid and connecting a first end of a clip to the retainer ring and a second end of the clip to a bottom surface of the charge case. The retainer ring may be configured to melt or burn in response to exposure to fire. The method may further include releasing the clip from encapsulated shaped charge, in response to the retainer ring melting or burning in response to exposure to fire.
A more particular description will be rendered by reference to exemplary embodiments that are illustrated in the accompanying figures. Understanding that these drawings depict exemplary embodiments and do not limit the scope of this disclosure, the exemplary embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
Various features, aspects, and advantages of the exemplary embodiments will become more apparent from the following detailed description, along with the accompanying drawings in which like numerals represent like components throughout the figures and detailed description. The various described features are not necessarily drawn to scale in the drawings but are drawn to aid in understanding the features of the exemplary embodiments.
The headings used herein are for organizational purposes only and are not meant to limit the scope of the disclosure or the claims. To facilitate understanding, reference numerals have been used, where possible, to designate like elements common to the figures.
Reference will now be made in detail to various exemplary embodiments. Each of the exemplary embodiments is illustrative, provided by way of explanation, and not limiting. The exemplary embodiments do not constitute a definition of all possible embodiments. It is understood that reference to a particular “exemplary embodiment” of, e.g., a structure, assembly, component, configuration, method, etc. includes exemplary embodiments of, e.g., the associated features, subcomponents, method steps, etc. forming a part of the “exemplary embodiment”.
For purposes of this disclosure, the phrases “devices,” “systems,” and “methods” may be used either individually or in any combination referring without limitation to disclosed components, grouping, arrangements, steps, functions, or processes.
With reference to
A charge lid 120 covers and seals an open end 117 opposite the base wall 110c of the charge case 110 (thereby making the shaped charge “encapsulated”). The charge lid 120 seals the encapsulated shaped charge 100 with, for example, an o-ring 150 (
The exemplary embodiment shown in
With additional reference to
The clip 140 may be formed from a resilient material including a metal, plastic, or stiff elastomer, and dimensioned such that a resilient force of the clip 140 pulls the hook end 145 and the wave-shaped end 143 towards each other, after the clip 140 has been positioned on the encapsulated shaped charge 100. In an aspect, and with particular reference to
The retainer ring 130 may be made of, for example and without limitation, plastic or other resilient material consistent with this disclosure. In the exemplary embodiments as shown in
If the encapsulated shaped charge 100 experiences, e.g., high temperatures, the retainer ring 130 is configured to melt or burn and thereby release each clip 140 that is supported on the retainer ring 130. Thus, the clips 140 will disengage from the encapsulated shaped charge 100, and the charge lid 120 will no longer be held to the charge case 110. Gas pressure within the charge case 110 may then vent through a separation between the charge lid 120 and the charge case 110, and the venting may prevent a potentially damaging buildup of pressure within the charge case 110.
With reference now to
With particular reference to
With reference back to
In an aspect, the disclosure relates to a method for reducing a buildup of gas pressure in an encapsulated shaped charge exposed to fire. With reference to the exemplary embodiments of an encapsulated shaped charge 100, 800 as discussed throughout this disclosure, the method may include providing the encapsulated shaped charge 100, 800 with a charge case 110 holding an explosive 111 and a liner 112, a charge lid 120 covering an open end 117 of the charge case 110, and a fastening assembly 160 connected to each of the charge case 110 and the charge lid 120. The fastening assembly 160 may include a retainer ring 130 and an external clip assembly 140. The retainer ring 130 and/or the external clip assembly 140 may be configured to melt or burn and thereby release the external clip assembly 140, when the encapsulated shaped charge 100, 800 is exposed to fire.
More specifically, an exemplary embodiment of a method for reducing a buildup of gas pressure in an encapsulated shaped charge 100, 800 exposed to fire includes enclosing an explosive 111 within a charge case 110 and positioning a charge lid 120 on an open end 117 of the charge case 110 within which the explosive 111 is contained. The method may further include releasably connecting the charge lid 120 to the charge case 110. For example, releasably connecting the charge lid 120 to the charge case 110 may include positioning a retainer ring 130 on the charge lid 120, connecting a first end (e.g., hook end 145) of the external clip assembly 140 to the retainer ring 130, and connecting a second end (e.g. wave-shaped end 143) of the external clip assembly 140 to a bottom 113 or a bottom surface 115 of the charge case 110. In an aspect, the retainer ring 130 is configured to melt or burn in response to exposure to fire. The method may further include releasing the external clip assembly 140 from the charge lid 120 and/or encapsulated shaped charge 100, 800, in response to the retainer ring 130 melting or burning. In response to the external clip assembly 140 being released from the charge lid 120 and/or encapsulated shaped charge 100, 800, the charge lid 120 is separable from the charge case 110 at least sufficiently to release gas pressure that has built up within the charge case 110.
In an aspect of the exemplary method, the external clip assembly 140 may extend from the bottom 113 or the bottom surface 115 of the charge case 110 to the retainer ring 130 positioned on the charge lid 120. The external clip assembly 140 may be formed from a resilient material.
With reference now to
For example, the exemplary embodiments shown in
In a further aspect and as illustrated in
In a further aspect, the inner skirt 121 includes a gap 330 on short sides 123 of the inner skirt 121 corresponding to the side walls 110b of the charge case 110. The gap 330 may allow gasses to escape from within the charge case 110 in the event of a fire exposure. The gap 330 is formed, e.g., as a void between a first skirt portion 121a and a second skirt portion 121b.
In an aspect of the exemplary embodiments, the external clip assembly including one or both of the opposing clips 140 is bendable and resiliently connects to each of the charge case 110 and the charge lid 120. The one or both of the opposing clips 140 may be formed from a bendable steel or metal. The configuration and features of the external clip assembly, i.e., a bendable, resiliently connectable clip that extends vertically from the charge case 110 to the charge lid 120 on an outside of the encapsulated shaped charge 110, may avoid the need to crimp a charge lid to a charge case to form an encapsulated shaped charge. Accordingly, the exemplary configuration may avoid the need to crimp a charge lid to a charge case, which may avoid potential safety and operational issues created by, e.g., accidental deformation of seal surfaces.
Further, removing the need to crimp the charge lid to the charge case may provide an easier manufacturing method with cost savings and greater efficiency. For example, when crimping is used, non-axisymmetrically shaped encapsulated charges may require custom planning for individual designs.
In addition, the outside position of the external clip assembly allows the retainer ring
130 to be similarly positioned on the outside of the encapsulated shaped charge 100, thereby exposing the retainer ring 130 directly to flame/heat that may trigger melting or burning of the retainer ring 130. This may provide greater safety over, e.g., encapsulated shaped charges in which a melt ring is positioned within the metal of a charge lid or charge case, and therefore requires additional time to melt as the metal heats up.
In an aspect of the exemplary embodiments and as illustrated in
In an aspect of the exemplary embodiments, the retainer ring 130 is made from a polyamide, for example PA6.
Embodiments described herein relate generally to devices, systems, and methods for an encapsulated shaped charge for an exposed perforating gun system, and associated systems and methods. For purposes of this disclosure, the phrases “devices,” “systems,” and “methods” may be used either individually or in any combination referring without limitation to disclosed components, grouping, arrangements, steps, functions, or processes.
This disclosure, in various embodiments, configurations and aspects, includes components, methods, processes, systems, and/or apparatuses as depicted and described herein, including various embodiments, sub-combinations, and subsets thereof. This disclosure contemplates, in various embodiments, configurations and aspects, the actual or optional use or inclusion of, e.g., components or processes as may be well-known or understood in the art and consistent with this disclosure though not depicted and/or described herein.
The phrases “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.
In this specification and the claims that follow, reference will be made to a number of terms that have the following meanings. The terms “a” (or “an”) and “the” refer to one or more of that entity, thereby including plural referents unless the context clearly dictates otherwise. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. Furthermore, references to “one embodiment”, “some embodiments”, “an embodiment” and the like are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as “about” is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Terms such as “first,” “second,” “upper,” “lower” etc. are used to identify one element from another, and unless otherwise specified are not meant to refer to a particular order or number of elements.
As used herein, the terms “may” and “may be” indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and/or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of “may” and “may be” indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while taking into account that in some circumstances the modified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances an event or capacity can be expected, while in other circumstances the event or capacity cannot occur-this distinction is captured by the terms “may” and “may be.”
As used in the claims, the word “comprises” and its grammatical variants logically also subtend and include phrases of varying and differing extent such as for example, but not limited thereto, “consisting essentially of” and “consisting of.” Where necessary, ranges have been supplied, and those ranges are inclusive of all sub-ranges therebetween. It is to be expected that the appended claims should cover variations in the ranges except where this disclosure makes clear the use of a particular range in certain embodiments.
The terms “determine”, “calculate” and “compute,” and variations thereof, as used herein, are used interchangeably and include any type of methodology, process, mathematical operation or technique.
This disclosure is presented for purposes of illustration and description. This disclosure is not limited to the form or forms disclosed herein. In the Detailed Description of this disclosure, for example, various features of some exemplary embodiments are grouped together to representatively describe those and other contemplated embodiments, configurations, and aspects, to the extent that including in this disclosure a description of every potential embodiment, variant, and combination of features is not feasible. Thus, the features of the disclosed embodiments, configurations, and aspects may be combined in alternate embodiments, configurations, and aspects not expressly discussed above. For example, the features recited in the following claims lie in less than all features of a single disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this disclosure.
Advances in science and technology may provide variations that are not necessarily express in the terminology of this disclosure although the claims would not necessarily exclude these variations.
This application is a 371 of International Application No. PCT/EP2021/063717, filed May 21, 2021, which claims the benefit of priority to U.S. Provisional Application No. 63/171,432, filed Apr. 6, 2021, and U.S. Provisional Application No. 63/128,401, filed Dec. 21, 2020. The entire contents of each application is hereby incorporated by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/063717 | 5/21/2021 | WO |
Number | Date | Country | |
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63171432 | Apr 2021 | US | |
63128401 | Dec 2020 | US |