US2358951A - Perforator gun - Google Patents

Description

Patentecl Sept. 26 1944 I toLan e-Wells Company, Los eles, Calm, a

corporation of Delaware Application April 30, 1940, Serial No. 3325M 4 Claims. (Cl.,89-1) My invention relates to gun perforator cartridges, that is, to cartridges designed to be used in gun perforators which are lowered within well casing for the purpose of opening the casing to the surrounding formation. Among the objects of my invention are:

First, to provide a gun perforator cartridge which increases the effective length of the gun perforator barrel with which the cartridge is associated;

Second, to provide a gun perforator cartridge which is particularly designed for use in connection with a gun perforator of the type shown in the Johnston Patent No. 2,048,451 issued July 21, 1936, or the Lane Patent No. 2,062,974 issued December 1, 1936, or the 'Iurechek Patent No. 2,092,294 issued September 7, 1937;

Third, to provide a gun perforator cartridge which increases the penetration of the gun perforator in which it is used; and

Fourth, to provide a cartridge of this kind which lends itself to the provision of adequate bulletdeiaying means whereby the desired propelling pressure may be built up in the powder chamber before the bullet is released.

With the above and other objects in view, as may appear hereinafter, reference is directed to the accompanying drawing, in which:

Figure 1 is a fragmentary sectional view through a gun unit of a. gun perforator, showing my special cartridge positioned therein and partially in section;

Figure 2 is an elevational view of the bullet used in my cartridge;

Figure 3 is a sectional view through the bullet retainer;

Figure 4 is a partial elevational, partial sectional view of a modified form of bullet and retainer;

Figure 5 is a similar view showing the appearance of the bullet after it has been fired from the cartridge;

Figure 6 is a sectional view similar to Figure 4, showing a further modified form of bullet and retainer; and

Figure 7 is a View similar to Figure 5, showing the bullet as it appears immediately after discharge of the cartridge.

The gun perforator for which my cartridge is especially adapted comprises a gun body i having is coaxial with the cartridge chamber and .of somewhat smaller diameter, The inner end of .the cartridge chamber 2 may be provided with a suitable contact plug 5. I

My cartridge comprises a cylindrical shell ll formed of fiber or analogous insulating material. The inner end is closed. by an insulation disc 12 which carries a contact l2a adapted to engage the plug 5. The other or forward end of the shell I i is covered by a retainer ring I3. The outer periphery of the ring it is provided with a rearwardly directed skirt it which fits over the end of the shell ll. The ring has a, central bore to accommodate a bullet i5 and is provided around the bore with a rearwardly directed rim or sleeve it which extends into the shell Bi and forms, in effect, a continuation of the gun barrel 3. The ring rests against the inner end of the a socket formed therein, at the inner end of which is provided a cartridge chamber 2. Outwardly from the cartridge chamber the socket is enlarged and internally threaded to receive a gun barrel 3 having a gun bore a therethrough which gun barrel and the skirt it serves to limit the pressure area against the gun barrel to the diameter of the retainer ring, as more fully setforth in the aforementioned Patent No. 2,092,294.

The bullet i5 is provided at its rear end with a shear disc ll which may be welded thereto and which is of larger diameter so that its margin rests upon the inner end of the rim it. A fuse wire it is connected by one end to the shear disc i7 and by its other end to the contact Ma.

The cartridge is filled with an explosive powder it and the cartridge is preferably assembled by placing the bullet and retainer ring on the shell M, then filling the shell with powder and placing the retainer ring it thereover. In this manner the powder may be packed in tightly so that the desired powder pressures may be generated. The cartridge is loaded as a unit in the gun so that all loading of the powder directly into the gun, or other handling of the powder itself, in conjunction with loading the gun is eliminated.

With the shear disc il provided, as shown in Figures 1, 2 and 3, a fire delay or expansion delay is obtained which is comparable to that obtained in the gun perforator of the type disclosed in the above entitled patents. By reason of the rearward extension or rim it. the effective length of the barrel a is increased. This is high- 1y important for, assuming a bullet of given mass. the penetration increases materially with increased length of barrel. Increase in the mass of the bullet also increases penetration, thus the increased efiective barrel length may be utilized by increasing the length of the bullet it so that its mass is greater without shortening the length of the bullet. It will be noted that the walls of the extension or rim is are made relatively heavy and are tapered. However, they do not have to withstand the internal stresses of the barrel 4 for the reason that the powder charge is packed around the outside of the extension. Before the disc i1 ruptures, the bullet supports the extension and after the disc gives way th pressures are equalized;

If it is desired to increase the delayed fire effect so as to impart higher acceleration to the bullet, this may be done by the arrangement shown in Figures 4 and 5. The retainer here shown is the same as that illustrated in Figures 1 and 3, with the addition that internal threads II are provided in the bore of the retainer, which threads cooperate with threads 22 provided on the bullet it. These threads are preferably square and relatively shallow so that the effective diameter of the bullet is decreased a minimum amount. Upon generating a predetermined pressure within the cartridge the threads shear as shown best in Figure 5 and form, in effect, piston rings 23 around the thread 22 of the bullet.

. which tend to prevent gas leakage around the bullet.

A still further modification is illustrated in Figures 8 and '7. In this construction the bullet Si is formed of tungsten carbide and the retainer '(similar in form to that previously described) is molded or cast upon the bullet itself, or it may be drop-forged or otherwise pressed in place, inasmuch as the tungsten carbide is capable of withstanding the necessary heat. Within the extremities of the retainer the tungsten carbide particles of. the bullet do not extend. to the full bullet's diameter so that. the tungsten carbide bullet" itself is not placed in shear, but only the metal comprising the retainer. Thuaafter the bullet is sheared from its retainer a comparatively soft shell 32 is formed around the rear end of the bullet and tends to form a gas seal.

Inasmuch as tungsten carbide has almost twice the density of a Steel bullet, it can be seen that the increased mass will materially increase the penetrating power of the bullet. Thus, with the construction shown in Figures 6 and 'I there is gained not only th increased'barrel length, but also the fire-delay effect may be materially increased and, in addition, the mass of the bullet a,ssa,os1

for a given size may be materially increased. so

.This is not to mention the further advantage gained, namely, the tight packing of the explosive charge in the powder chamber made possible by the unitary construction of the gun cartridge as a whole.

Various changes and alternate arrangements may be made within the scope of the appended claims, in which it is my intention to claim all novelty inherent in the invention as broadly as the prior art permits.

I claim:

l. The combination with a gun perforator having a gun unit in which is provided a gun barrel having a bore therethrough and an explosive chamber at the inner end of the gun barrel of a cartridge comprising: a shell adapted to contain an explosive and fit said chamber; an axially directed barrel extension fitting an end of said shell and abutting said' gun barrel bore to form an extension thereof; an integral skirted flange radiating from said barrel extension and overlapping the periphery of said shell to localize the pressure generated therein; and a bullet within said barrel extension and projecting partially into said gun barrel bore.

2. A combination, as set forth inclaim 1, wherein means are provided between said bullet and said barrel extension to restrain said bullet until the pressure within said shell exceeds a predetermined value.

3. A combination, as set forth in claim 1, wherein the bullet is integral with said barrel extension and forms therewith a cleavage face which is substantially coaxial with said gun barrel, adapted to give way when the pressure within said cartridge exceeds a predetermined value.

4. A combination, as set forth in claim 1, wherein a screw-threaded connection is provided between the bullet and barrel extension, said connection being designed to give way when the pressure within said cartridge exceeds a predetermined value.

' GEORGE F. TURECHEK.

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