Patent Grant
11781845
In general, the disclosure describes an apparatus and method for the safe transport of shaped charges. The method and apparatus of the present disclosure may enable shaped charges with high explosive load to be transported via commercial air transportation.
When a hydrocarbon well is drilled, a casing may be placed in the well to line and seal the wellbore. Cement is then pumped down the well under pressure and forced up the outside of the casing until the well column is also sealed. This casing process ensures that the well is isolated, and prevents uncontrolled migration of subsurface fluids between different well zones, and provides a conduit for installing production tubing in the well. However, to connect the inside of the casing and wellbore with the inside of the formation to allow for hydrocarbon flow from the formation to the inside of the casing, holes are formed throughout the casing and into the wellbore. This practice is commonly referred to as perforating of the casing and formation. Open-hole wells are also possible, i.e., where a casing is not used and jetting, fracturing or perforation is directly applied to the formation.
During the perforating process, a gun-assembled body containing a plurality of shaped charges is lowered into the wellbore and positioned opposite the subsurface formation to be perforated. Initiation signals are then passed from a surface location through a wireline or tubing holding the shaped charges to one or more blasting caps located in the gun body, thereby causing detonation of the blasting caps. The exploding blasting caps in turn transfer a detonating wave to a detonator cord which further causes the shaped charges to detonate. The detonated shaped charges form an energetic stream of high-pressure gases and high velocity particles, which perforates the well casing and the adjacent formation to form perforation tunnels. The hydrocarbons and/or other fluids trapped in the formation flow into the tunnels, into the casing through the orifices cut in the casing, and up the casing to the surface for recovery.
For purposes of transporting shaped charges to the location of the well to be perforated, shaped charges are provided an explosive shipping classification. For instance, the United Nations provides hazard classification codes that dictate the available modes of transportation. Currently heavy loaded shaped charges are given a hazard classification of 1.1D, which is given to primary explosive devices that may only be transported by land and sea. The inability to transport shaped charges through the air increases both the cost and the time needed to transport the shaped charges to the well-site.
What is needed is an improved, method and apparatus for the safe transport of shaped charges with a hazard classification that enables air transport.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. However, many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limited the scope of the claimed subject matter.
Embodiments described herein provide a shaped charge comprising a case; an energetic material disposed in the case; a metallic liner with a first surface disposed in contact with the energetic material and a second surface that is opposite from the first surface, and that defines a cavity; and an attenuator disposed in the cavity.
Another embodiment provides a packaging system for shaped charges, comprising two partition portions defining a plurality of receptacles for shaped charges, the two partition portions separated by one or more containment plates; and a plurality of attenuators for disposing an attenuator in the cavity of each shaped charge.
Another embodiment provides a method of transporting shaped charges, comprising placing an attenuator comprising one or more bodies having a hardness of at least about C60 within the cavity of each shaped charge; and placing the shaped charge in a package having shock absorbing members.
Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It is emphasized that, in accordance with standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or reduced for clarity of discussion. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein, and:
In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments are possible. This description is not to be taken in a limiting sense, but rather made merely for the purpose of describing general principles of the implementations. The scope of the described implementations should be ascertained with reference to the issued claims.
As used herein, the terms “connect”, “connection”, “connected”, “in connection with”, and “connecting” are used to mean “in direct connection with” or “in connection with via one or more elements”; and the term “set” is used to mean “one element” or “more than one element”. Further, the terms “couple”, “coupling”, “coupled”, “coupled together”, and “coupled with” are used to mean “directly coupled together” or “coupled together via one or more elements”. As used herein, the terms “up” and “down”; “upper” and “lower”; “top” and “bottom”; and other like terms indicating relative positions to a given point or element are utilized to more clearly describe some elements. As used herein, the terms “coils”, “pipes”, and “tubes” are used individually or in combination to mean the internal fluid carrying elements of a fired heater.
The present disclosure generally relates to an apparatus and method for the safe transport of shaped charges. More specifically, the present disclosure provides a method and apparatus that enables shaped charges to be given a hazard classification of 1.4D for charges having up to 75 grams of explosive. With this 1.4D classification, even heavy charges (up to 75 grams of explosive) may be transported by commercial air transportation, thus reducing the time and cost associated with transporting the shaped charges by land and sea.
Currently, the packaging of high explosive load shaped charges results in a hazard classification of 1.1D, which restricts transport to land and sea. An example of current packaging is shown in
In embodiments of the present disclosure, when the shaped charge 100 is detonated by an external ballistic transfer, the explosive 114 inside the charge 100 creates a shockwave that propagates and makes the shaped charge liner 112 collapse, forming a jet. The jet of the shaped charge 100 attempts to form but when it strikes the hardened steel ball 122 it is not capable of forming a jet that penetrates the adjacent object. Moreover, the jet interrupter 120 is located inside the shaped charge cavity 115. During discharge, the jet tends to form near the central conical axis of the cavity 115. The hardened steel ball 122 is positioned to occupy much of the central axial area of the cavity 115, which restricts formation of the jet and mitigates projection of energy by the shaped charge 100. The concrete 124 can be shaped to fill the inside of the shaped charge 100, and to position the steel ball 122 centrally within the cavity 115 to perform the function of interrupting formation of the jet. Due to the wide range of sizes of shaped charges 100, concrete 124 works to accommodate a wide variety of shapes while holding the hardened steel ball 122 in the center of the axis of the liner 112.
In addition to the effectiveness of minimizing damage to the surroundings, embodiments of the present disclosure are cost effective. The cost of the hardened steel balls 122 and concrete 124 is relatively low compared to other more elaborated or customized types of packaging. Additionally, due to the 1.4D classification, it is not needed to charter private airplanes to deliver the shaped charges 100 in a timely manner since the new packaging is suitable for air cargo transportation which is provided by commercial carriers.
Referring to
As has been described above, embodiments of the present disclosure provide an innovative way of packaging shaped charges 100. The attenuators described herein negate the function of the shaped charge 100 which is to project kinetic energy to penetrate an object. In addition to the attenuator, the packaging 200 is provided with thick chipboard pads 214 that help in reducing the hazard classification of shaped charges 100 for transportation purposes.
As has been discussed, the attenuators and the packaging 200 of the present disclosure enable a 1.4D shipping classification for high explosive load shaped charges 100. To acquire the 1.4D classification, guidelines have been established for test methods relating to explosives. The United Nations Section 16 Series 6 (Recommendations on the Transport of Dangerous Goods, Fifth Rev. Ed., UN 2009, pp. 143 ff) contains the guidelines for such tests. These guidelines provide the following criteria: (a) no crater at the test site, (b) no damage to the witness plate, (c) no mass detonation, and (d) whether a blast can be measured.
A stack test of the present disclosure was performed with two boxes of charges and a witness plate in the bottom of the stack. Upon discharge of a charge in the stack, it was observed that there was no damage to the witness plate. Such result meets two points of the criteria to acquire the 1.4D classification. There was no crater at the test site and no damage to the witness plate. Additionally, since only the charge that was intentionally detonated went off and none of the rest, this is considered as no mass detonation. Moreover, all the charges remained within the confining material (sandbags) that were surrounding the two boxes of charges. This means that the blast distance is very small, and it is within the 1.4D criteria. The section 16 series 6 (a) (b) & (c) tests were conducted on shaped charges with 75 grams of explosives content.
An attenuator 620 is located in the cavity 614 to attenuate the energy of the energetic gases and particles of the shaped charge 600, reducing the discharge energy of the gases and particles. In some cases, the attenuator 620 disrupts formation of the jet, functioning essentially as a jet interrupter. In other cases, the attenuator 620 merely reduces potency, focus, velocity, or temperature of the gases and particles. To attenuate the energetic gases and particles, the attenuator 620 occupies at least about 50% of the volume of the cavity 614 providing a hard, dense material at the location where a jet of energetic gases and particles would form in the cavity 614 or generally blocking expulsion of energetic materials from the shaped charge. The hard, dense material alters the trajectory of the energetic gases and particles, reducing focus, potency, velocity, and/or temperature of the energetic gases and particles.
The attenuator 620 typically has a hardness measurable on the Rockwell C scale. Materials having Rockwell hardness of at least about C60 work well, but materials of lower Rockwell C hardness can also be used, either for the full attenuator or a component thereof such as a ball captured within the attenuator. Materials that can be used include zirconia (˜55), hardened steel (˜C60), alumina (˜C77), tungsten carbide (˜C75), silicon nitride (˜C70), gold (˜C10), platinum (˜C40), and tungsten metal (˜C30). Rockwell C hardness can be tested using ASTM methods E18 and E110. ISO 6508 is another standard method for Rockwell hardness testing. For lower hardness materials, higher density can also be helpful in the attenuator 620. Density provides inertia to prevent or minimize propulsion of the attenuator 620 by the energetic gases and particles.
The attenuator 620 may be a homogeneous body or a heterogeneous body having two or more members. In one case, the attenuator 620 is a cement body with a hardened steel ball embedded therein. In another case, the attenuator is a hard, dense, homogeneous material such as steel powder dispersed in cement or dense polymer. The dense polymer can be a shock resistant polymer such as Kevlar, polypropylene, polyethylene, or hard rubber. The attenuator 620 is typically molded, for example by placing a hard, dense body such as a hardened steel ball into a mold and molding a material capable of containing the hard, dense body, such as the cement or polymers described above, around the hardened steel ball. For a homogeneous attenuator, a hardening material, such as steel powder, can be dispersed within a solidifiable medium such as a cement precursor or polymerization precursor. The mixture thus formed is applied to a mold and solidified, or partially solidified. The resulting body is removed from the mold and, if necessary, allowed to completely solidify.
The attenuator 620 of
The second member 642 typically has a higher density and hardness than the first member 640. In this case, the second member 642 has a cylindrical profile, with an upper surface 644 that forms part of the upper surface 626 of the attenuator and a lower surface 646 that forms part of a lower surface 648 of the attenuator 636. Here, the upper surface 644 of the second member 642 is substantially coplanar with an upper surface 645 of the first member 640, and the lower surface 646 of the second member 642 is substantially coplanar with a lower surface 647 of the first member 640. Thus, in this case, and in other cases of heterogeneous attenuators with first and second members, the second member 642 may be visible within the first member 640 or may protrude from the first member 640. The first member 640 is typically made of a hard or tough material, such as cement or polymer, that holds the second member 642 in place. The second member 642 is typically made of hard, dense material, as described above, to provide a dampening effect on energetic gases and particles generated by activation of the shaped charge 634.
The plastic cage 660, in this case, has three prongs 666 that protrude from the containment plate 654 at locations along a circular perimeter at 120° angular displacements. In this cross-sectional view, the prong 666 in the foreground is removed. Following the shape of the shaped charge 650, the prongs extend toward each other and away from the containment plate 654 so that the prongs 666 can protrude deeply into the cavity 614 of the shaped charge 650. Each prong 666 ends with a restraint 668, which is an arc of a circle. The restraints 668 of the three prongs 666 abut together to form a ring. The prongs 666 and restraints 668 form a cage with a conical structure, following the general shape of the cavity 614. The attenuator 656, in this case, has a frustoconical shape that generally follows the shape of the cage 660 and the cavity 614.
The attenuator 656 is inserted into the cage 660. The plastic prongs 666 are formed to be flexible enough to separate the restraints 668 and insert the attenuator 656 into the cage. Once the attenuator 656 is inserted, the prongs 666 are released to return to their rest position, with restraints 668 abutting, or nearly so. The prongs 666 and restraints 668 hold the attenuator 656 in position, and when the containment plate 654 is positioned on the wide end 618 of the shaped charge 650, the attenuator 656 is positioned in the cavity 614.
In some cases, the containment plate 654, with plastic cage 660, can be molded as a single, integrally formed piece of plastic. A plurality of plastic cages 660 can be formed protruding from the containment plate 654 to accommodate a plurality of attenuators 658, one for each plastic cage 660. The entire containment plate 654, with plastic cages 660 and attenuators 658 deployed in the plastic cages 660, can be positioned with respect to a plurality of shaped charges 650 to provide attenuators 658 in the cavities 614 of all the shaped charges 650.
The packaging system 700 has a bottom tray 702 with a plurality of depressions 704 in an ordered array. Here, there are three bottom trays 702, but any number can be used. The depressions 704 receive the narrow end of shaped charges to be packaged into the packaging system 700. The bottom tray 702 may be plastic, chipboard, fiberboard, or other suitable material. The bottom tray 702 is typically placed into the bottom of a shipping container 703, such as a box, prior to deploying shaped charges into the bottom tray 702.
Once every desired depression 704 is provided with a shaped charge, narrow end down to allow the shaped charge to stand momentarily unsupported in the depression 704, an attenuator frame 706 is placed over the bottom tray 702. The attenuator frame 706 includes two partition portions 708 (shown further in
A cage 714 is deployed in each receptacle 712 to hold an attenuator 716, which in this case is a simple hard, dense, spherical object, such as a hardened steel ball large enough to be captured within the cage 714. As in
Before the attenuator frame 706 is fitted to the bottom tray 702, attenuators 716 are loaded the receptacles 712 of one partition portion 708 of the attenuator frame 706, and cages 714 are installed to hold the attenuators 716. When the attenuator frame 706 is then fitted to the bottom tray 702, the loaded attenuators 716 are deployed in the cavities of each shaped charge 750 placed on the bottom tray 702, while the shaped charges therein are securely held in place by the depressions 704. The partitions 710 and the cages 714, with installed attenuators 716 help to contain and mitigate energy release in the event the shaped charge 750 discharges.
After placement of the attenuator frame 706 onto the bottom tray 702, attenuators are then loaded into the receptacles 712 on the top side of the attenuator frame 706, cages 714 are installed, and shaped charges 750 are placed, wide end down, into the cubicles 712 on the top side of the attenuator frame 706. As shown in
As noted above, the attenuator frame 706 can be molded as a single piece of plastic, which can be fiber reinforced for extra strength (any of the parts described herein as being optionally made of plastic can be fiber reinforced). If undamaged during shipment, the molded plastic attenuator frame 706 and cages 714 can be reused. Alternately, the parts of the attenuator frame 706 can be implemented as separate pieces. For example, the partition portions 708 can be separate pieces made of any suitable material, such as plastic, cardboard, wood, or the like. The containment plate 709 can also be a separate piece, made of similar materials. It should be noted that the partitions 710 described in connection with
At 804, the shaped charge is positioned in a transportation array with the wide ends of the shaped charges facing each other in the transportation array. The attenuator is also positioned in the transportation array. Here, “transportation array” refers to a configuration or arrangement for transportation. The attenuator may be positioned in the cavity of the shaped charge before or after placing the shaped charge in the transportation array. For example, in the embodiment of
At 806, the shaped charges are disposed into receptacles defined by a containment structure. The containment structure may include a partition tray, but in any case, each receptacle holds one shaped charge such that propagation of any energy release from activation of one shaped charge is further resisted by the containment structure. As noted above, the attenuator may be installed prior to disposing the shaped charges in the receptacles, or the attenuator may be pre-positioned in the receptacle before disposing the shaped charge into the receptacle, for example by using a restraint to position the attenuator in the cavity of the shaped charge when the shaped charge is disposed in the receptacle. Alternately, the attenuator can be attached to a wall of the receptacle, such as a containment plate, to project into the cavity of the shaped charge.
In general, operations 802, 804, and 806 can be performed in any order in different embodiments. For example, in the embodiment of
At 808, one or more outer containment plates can be used to cover the receptacles of the containment structure. The containment plates can be any shock absorbent material to further contain and resist propagation of energy release from activation of a shaped charge.
While the foregoing is directed to embodiments, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. The scope of the invention should be determined only by the language of the claims that follow. The term “comprising” within the claims is intended to mean “including at least” such that the recited listing of elements in a claim are an open group. The terms “a,” “an” and other singular terms are intended to include the plural forms thereof unless specifically excluded. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words “means for” together with an associated function.
This application claims benefit of U.S. Provisional Patent Application Ser. No. 62/743,631 filed Oct. 10, 2018, which is incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2019/055601 | 10/10/2019 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2020/142128 | 7/9/2020 | WO | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20210356241 A1 | Nov 2021 | US |
| Number | Date | Country | |
|---|---|---|---|
| 62743631 | Oct 2018 | US |
