US3259064A - Shaped charge devices - Google Patents

Description

July 5, 1966 N. G. OWENS 3,259,064

SHAPED CHARGE DEVI CES Filed July 8, 1964 /Vevr/ 6. OWflJ INVENTOR.

)5 BY If/WM United States Patent 3,259,064 SHAPED CHARGE DEVICES Nevyl Gregory Owens, Houston, Tex., assignor to Schlurnberger Weil Surveying Corporation, Houston, Tex., a corporation of Texas Filed July 8, 1964, Ser. No. 381,117 2 Claims. (Cl. 10224) This invention relates to shaped explosive charges for use in perforating a well; and, more particularly, to apparatus and methods for securing shaped explosive charges within a case or container.

Where explosive shaped charges for perforating a well are to be mounted on expendable carriers, the shaped charges must be encapsulated and fluidly sealed within a frangible case to protect the explosive from fluids within the well bore. It is recognized by those skilled in the art that when the charges are detonated, these cases must be substantially broken up so as to leave only small particles in the well bore. Accordingly, it has become customary to fabricate cases for shaped charges from such highly disintegrable materials as aluminum and glass. These cases are typically formed in two parts, a charge container and a cover, which are adapted to be joined and sealed along their abutting surfaces to form a completely sealed case. A transverse recess along the outer surface of the rearward end of the container portion of the case is suitably arranged for receiving and securing a strip of detonating cord, such as Primacord.

It will be appreciated, of course, that to ensure reliable operation of the shaped charge device, the booster explosive at the base of the encapsulated charge must be maintained within detonating proximity of the detonating cord outside of the case. Thus, it is important that the shaped charge and its booster be suitably secured within the case to be certain that they can not shift from a predetermined position. Accordingly, it has been customary, heretofore, to form an internal shoulder in the cover which is suitably arranged and adapted to engage the forward peripheral edge of the shaped charge and maintain the base of the charge near the rear wall of the case within detonating proximity of the detonating cord. Because of normal dimensional variations usually found in pre-formed shaped charge pellets as well as in massproduced glass cases, it is sometimes necessary to select and match a given explosive pellet to particular case portions or else custom-fit each shaped pellet into a particular case.

Accordingly, it is an object of the present invention to provide new and improved means for fluidly sealing and securing shaped charges within a charge case.

This and other objects of the present invention are accomplished by inserting a shaped charge into the container portion of a two-part case; coating an abutting surface of the cover and container as well as an adjacent interior surface of the cover with a hardenable adhesive sealing material; and bringing the case portions together to extrude a portion of the adhesive material around the forward edge of the shaped charge so that, when hardened, the adhesive provides a forward support of the charge.

The novel features of this invention are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation together with further objects and advantages thereof, may best be understood by way of illustration and example of a typical embodiment when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an elevational view, with a portion thereof being in cross-section, illustrating a typical method for assembling a shaped charge device in accordance with the principles of the present invention; and

FIGURE 2 is a view in longitudinal cross-section show- "ice ing a representative shaped charge device as arranged and assembled in accordance with the principles of the present invention.

Turning now to the drawings, a shaped charge device 10 is comprised of a two-part case 11 having a dished cover portion 12 and a generally cylindrical, hollowed container portion 13 for receiving a typical cyclindrically shaped explosive charge 14. As is customary, the shaped charge 14 has a pre-formed pellet 15 of a suitable highexplosive material, such as RDX, having an axially aligned, frusto-conical cavity diverging outwardly toward its forward end. A hollowed, complementarily shaped liner 16 of a suitable metal is disposed in the frusto conical cavity with the base of the liner terminating at the forward peripheral edge 17 of the shaped charge 14. A suitable booster charge 18 is disposed in a recess formed in the rear wall 19 of the container portion 13.

The mating abutting surfaces 20, 21, respectively, of the cover and container portions 12, 13, are suitably prepared to ensure that a fluid-tight seal will be made whenever these portions are sealingly joined. On the exterior of the rear wall 19 of the container portion 13, two spaced-apart, axially projecting lugs 22 form a transverse groove 23 suitably sized and adapted to sungly receive and retain a suitable detonating cord (not shown) such as, for example, Primacord. In addition, spacedapart, lateral projections 24 are centrally located on opposite sides of the container portion 13 to form opposed peripheral grooves 25 suitably sized and adapted for mounting of the assembled shaped charge device 10 to an expendable-type carrier (not shown).

Turning now to the new and improved means for securing the shaped charge 14 within its case, the container-engaging surface 20 of the cover portion 12 and the adjacent interior surface portions of the cover are coated, as shown in FIG. 1, with a layer of an appropriate hardenable adhesive material 26, such as Epoxylite No. 810 manufactured by The Epoxylite Corporation of South El Monte, California. A sufiicient amount of the adhesive 26 is disposed around the interior surface of the cover portion 12 to ensure that a portion of the adhesive will be squeezed upwardly around the shaped charge 14 and project slightly over its forward peripheral edge 17 whenever the cover is moved in the direction of the arrows 27 toward the container portion 13. Similarly, a sufficient quantity of the adhesive 26 is spread around the mating surface 20 to totally cover the mating abutting surfaces 20 and 21, and leave a slight excess amount thereof to be extruded outwardly therearound and form a peripheral sealing bead 28 as shown in FIG. 2.

As the cover portion 12 is moved in the direction of the arrows 27 toward the container portion 13, a portion of the adhesive 26 is displaced upwardly over the forward edge 17 of the shaped charge 14 and forms an annular bead 29 (FIG. 2). Similarly, as the two case portions 12 and 13 are pressed together, another portion of the adhesive material 26 is extruded inwardly around the charge 14 to form an annular support 30 between the charge 14 and the container portion. The remainder of the adhesive 26 is squeezed outwardly between the surfaces 20, 21 and forms the peripheral sealing head 28 at the junction of the abutting surfaces.

Thus, upon hardening of the adhesive material 26, the two case portions 12 and 13 are sealingly secured together by the peripheral bead 28 and the adhesive between their mating surfaces 20, 21; the hardened head 29 provides a forward abutment which retains the shaped charge 14 longitudinally fixed Within the case 11; and the hardened annular support 30 holds the shaped charge in a laterally fixed position.

Accordingly, it will be appreciated that the present invention securely retains the shaped charge 14 in the case 11 without an integral shoulder being required in the cover portion 12 as well as eliminates the necessity of maintaining close dimensional tolerances in either portion of the case 11 or in the pre-formed shaped charge.

While a particular embodiment of the present invention has been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broadest aspects; and therefore, the aim of the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. A shaped charge device comprising: a frangible, multi-part, hollow charge case sized and adapted to receive an explosive charge, said case including a dished cover portion and a container portion having abutting marginal surfaces adapted to be joined and sealed together; shaped explosive charge means having a forward peripheral edge of selected diameter received in said case; and firming adhesive means for sealingly joining said case portions and having a portion abuting and securing said charge means against forward longitudinal movement relative to said case and being the sole forward support for the charge means within the case, the case having an internal diameter larger than the selected diameter forwardly of said forward peripheral edge of the charge means.

2. A shaped charge device comprising: a frangible,

multi-part, hollow charge case sized and adapted to receive an explosive charge, said case including a dished cover portion and a container portion having abutting marginal surfaces adapted to be joined and sealed together; shaped explosive charge means having a forward peripheral edge of selected diameter received in said case; and a firming adhesive material having a first portion operatively disposed between said abutting surfaces for joining and fluidly sealing said case and a second portion extending into said case and including a hardened bead of adhesive material surrounding and operatively engaged with said forward peripheral edge forming a forward abutment for securing said charge means against forward longitudinal movement relative to said case and being the sole forward support for the charge means Within the case, the case having an internal diameter larger than the selected diameter forwardly of said forward peripheral edge of the charge means.

References Cited by the Examiner UNITED STATES PATENTS 2,629,325 2/1953 Sweetman l0220 BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Examiner.

V. R. PENDEGRASS, Assistant Examiner.

Claims (1)

1. A SHAPED CHARGE DEVICE COMPRISING: A FRANGIBLE, MULTI-PART, HOLLOW CHARGE CASE SIZED AND ADAPTED TO RECEIVE AND EXPLOSIVE CHARGE, SAID CASE INCLUDING A DISHED COVER PORTION AND A CONTAINER PORTION HAVING ABUTTING MARGINAL SURFACES ADAPTED TO BE JOINED AND SEALED TOGETHER; SHAPED EXPLOSIVE CHARGE MEANS HAVING A FORWARD PERIPHERAL EDGE OF SELECTED DIAMETER RECEIVED IN SAID CASE; AND FIRMING ADHESIVE MEANS FOR SEALINGLY JOINING SAID CASE PORTIONS AND HAVING A PORTION ABUTTING AND SECURING SAID CHARGE MEANS AGAINST FORWARD LONGITUDINAL MOVEMENT RELATIVE TO SAID CASE AND BEING THE SOLE FORWARD SUPPORT FOR THE CHARGE MEANS WITHIN THE CASE, THE CASE HAVING AN

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