US2202887A - Well casing perforator - Google Patents

Description

June 4, 1940. M. F. ALol WELL CASING PERFORATOR Filed June 26, 1939 Patented June 4, 1940 UNITE STATES 13 Claims.

My invention relates to a Well casing perforator of the gun type and has for its principal object, the provision of a relatively simple and practical casing perforating device including a body that is adapted to be lowered into well casing to the desired depth and, said body carrying a plurality of projectiles and an explosive charge which when ignited by an electric spark res said projectiles outwardly through the wall of the casing, thereby perforating the same and, said projectile carrying body carrying means for producing the electric spark required to re the explosive charge, thus eliminating al1 electrical connections between the gun-like member that is lowered into the casing and the ground surface at the top of the Well hole.

A further object of my invention is, to provide simple and convenient means, preferably a weight that is permitted to slide by gravity downward on the cable that is utilized for lowering the perforator into the casing and which weight is effective in imparting motion to the electric spark producing means carried within the perforator so as to effect the firing of the explosive charge.

A further object of my invention is, to provide simple and eflicient means for rendering the explosive charge firing means ineffective so as to prevent accidental or premature ring of the charge while the perforator is being assembled and made` ready to be lowered into the casing.

With the foregoing and other objects in view, my invention consists in certain novel features of construction and arrangement of parts that will be hereinafter more fully described and claimed and illustrated -in the accompanying drawing in which:

Fig. l is a vertical section taken through the center of a casing perforator constructed in accordance with my invention.

Fig. 2 is an elevational view of the upper end portionof the perforator and looking in the direction indicated by the arrow 2 in Fig. 1.

Fig. 3 is a plan view of the perforator.

Fig. 4 is a vertical section taken through the center of the Weight that is utilized for electing operation of the electric spark producing means.

Fig. 5 is a horizontal section taken on the line 5-5 of Fig. 4.

Fig. 6 is an enlarged horizontal section taken on the line 6-6 of Fig. 1.

Fig. 7 is an enlarged vertical section taken on the line 1-1 of Fig. 3.

Fig. 8 is an enlarged vertical section of the lower end portion of the perforating device.

Referring by numerals to the accompanying drawing which illustrates a preferred embodiment of my invention, IIl designates a body, preferably cylindrical in form and composed of metal and which may be of any desired and convenient length. 'Ihe diameter of this body is such that it will readily pass downward through oil well casing of standard sizes.

Formed in the upper portion of body I is a chamber II and, leading from the lower end of said chamber to the lower end of body II) is an axial bore I2.

A head I3 is removably seated, preferably by being screw seated in the upper portion of chamber I I, and removably seated in the center of this head is a socket I4 to which is suitably connected, the lower end of a cable I that is utilized in lowering the perforator into the casing.

Arranged to slide freely through a vertically disposed bore I6 that is formed through head I3 to the side of socket I4, is a plunger I'l, the upper end of which is enlarged to form a head I8 through the central portion of which is formed an aperture I9. An expansive spring 20 surrounds the upper portion of plunger I1 and bears against the lower end of the head I8 and against a shoulder 2I that is formed in the upper portion of the bore I6, thus normally maintaining the plunger in elevated position. i

Plunger I'I passes through a fluid pressure tight gland or stufng-box 22 that is arranged in the lower portion of head I3 and, that portion of the plunger that projects below said gland is provided with rack teeth 23. These teeth engage the teeth of a pinion 24, which latter is xed on the armature shaft of a conventional magneto 25.

While plunger I1 is in its normal position or at the upper end of its limit of movement, the teeth of pinion 24 engage the lowermost teeth of rack 23. An opening formed in the wall of body IU surrounding chamber I I directly opposite the central portion of the magneto and which opening is closed by a readily removable plug 26, gives access to the magneto for the purpose of inspection, adjustment, repairs, etc.

Removably positioned in the aperture I9 in head I8 is a' pin or key 2'I that serves to secure the plunger in its elevated position and prevent the same from being accidentally moved downward to operate the magneto while the perforator is being charged and made ready for use and before it is inserted in the upper end of the well casing.

Formed through that portion of the perforator body I0 through which the bore I2 passes are radially disposed apertures 2B, preferably disposed in spaced and staggered relation and which serve prising a thin walled casing 32 containing a` charge 33 of explosive substance, such as gun powder. Embedded in the explosive charge 33 isa plate 34 of insulating material, carrying .a pair of spaced spark terminals 35. The upper one of these terminals is connected by a conductor 36 to a contact 31 that is seated in the top of casing 32 and, when the casing is properly positioned in bore i2 this contact 31 directly engages a contact 38. Y

This contact 38 is carried by the lower end Vof a pin or rod 39 formed of metal: and serving as a conductor for electric current and, which passes through that portion of the body i0 between the upper end of bore I2 and the lower 'portion of chamber II. This conductor 39 is suitably insulated from the metal in body I0, preferably by a sleeve 40 of insulating material.

One side of the magneto is grounded on the body I0 while the other side is connected by a conductor 4i to the upper end of conductor 39.

The lower end of the cartridge receiving bore or chamber 23 is closed by a screw plug 42, there being a packing ring or gasket 43 arranged between the upper portion of said plug and the body i0 around the lower end of bore I2 and, arranged for sliding movement in the upper portion of this plug is an axially arranged pin 44 prbvided on its upper end with a head 45. An expansive coil spring 46 is arranged between the head e5 of contact pin 44 and a shoulder 41 that is formed in the upper portion of plug 42 around the aperture that receives said contact pin.

Seated in the lower end of the cartridge that is positioned in bore I2 is a contact pin '48 provided on its lower end with a head 49 and, which latter engages the head 45 of the spring-held contact pin 44.

Connecting contact pin 48 with the lower one of the spark terminals 35 is a conductor 50.

The means utilized for forcing plunger I1 downward to operate the magneto is illustrated in Fig. 4 and 5 and comprises a two-part weight 5I substantially cylindrical in form and, the two parts of which are hingdly connected to each other, preferably by a vertically disposed hinge pin 52. The two parts of the weight are normally held in closed position by means of a hook 53 that is hinged to one of the parts of the weight and which engages in a recess 54 in the other part (seeA Fig. 5). Formed in the lower portion of this weight is a chamber 55 open at its lower end and which is of such size as to receive the socket I4 and, formed through the upper portion of said weight is an axial opening 56 that receives the cable I5 that carries the perforator.

To load the perforator, key 21 is inserted through opening I9 in head I8 so as to prevent the plunger from being moved downward to operate the magneto and the projectiles 29 are now inserted in their chambers 28, after which the disc-like closures 3l are pressed into the recesses 32. thereby closing the projectile containing chambers.

The explosive cartridge vis now inserted in bore I2 and plug 42 is screw seated in the lower end of body III and, when so seated the spring-held contact 45 engages contact 49 on the lower end oi' the cartridge and the latter is maintained in the bore I2 with contact pin 31 in engagement with contact 38.

Just before the perforator is lowered into the casing, the key 21 is removed from head Il, thus leaving plunger I1 tree to move downward as a.

result of the engagement of the weight 5I with said head at the termination of its travel down the cable I5.

The perforator is now lowered into the well casing by proper manipulation of cable I5 and, when said perforator has reached the depth at which the casing is to be perforated, the two-part weight 5I is opened and afterbeing applied to A the cable the parts of the weight are closed and held in such position by the engagement of t free end of hook 53 in recess '54.

The weight is now released and by gravity it will slide down the cable from which the perforator is suspended and, when the weight reaches 4the upper end oi' the perforator it will strike the top of head I8, thereby moving the same and plunger I1 downward and, the engagement of the rack 23 with pinion 24 will actuate the armature of the magneto so as to produce an electric spark between the terminals 35. As thel spark is produced between the sparking terminals, the explosive charge of the cartridge will be iired and the resulting force will drive the projectiles 29 outwardly from their chambers through the adjacent wall of the casing so as to perforate the same, thereby accomplishing thev desired results.

After the casing operation as just described has been accomplished, the perforator is withdrawn from the well by means of cable I5 and said perforator may be re=used after the chambers 25 have-been relled with projectiles and a cartridge inserted in bore or chamber I2.

A particularly advantageous feature of my ime proved perforator is the mounting of a magneto or other spark producing means within or directly upon the perforator, for by such provision the requirement for spark producing means including electrical conductors extending from the top of the well hole downwardly therethrough to the perforator and which distance may be several thousand feet, is entirely eliminated.

Thus it will be seen that I have provided a casing perforator that is relatively simple in construction, inexpensive of manufacture and very eective in performing the functions for which it is intended.

It will be understood that minor changes in the size, form and construction of the various parts of my improved well casing perforator, may be made and substituted for those herein shown and described, without departing from the spirit of my invention, the scope of which is set forth in the appended claims.

I claim as my invention:

1. A casing perforator comprising a body provided with a chamber for the reception of an explosive charge, there being chambers formed in the body for directing the force of the exploded charge laterally against the well casing in which the perforator is positioned, projectiles located in said last mentioned chambers and magnets aclll tuated means located wholly within said body and operable from the exterior thereof for producing an electric spark within the explosive charge.

2. In a casing perforator the combination with a body, of a cable connected to said body for lowering the same into well casing, an explosive charge contained within said body, there being chambers formed in the body for directing the force of the exploded charge laterally toward the well casing, projectiles located in said chambers, magneto actuated means carried by the body for producing an electric spark in the explosive charge and means adapted to slide down the cable to said body for actuating the spark producing means.

3. A casing perforator as set forth in claim 1, with means for rendering the spark producing means inoperative while the body is being loaded for use and before it is lowered into the well casing.

4. In a casing perforator, a body adapted to be lowered into well casing, an explosive charge contained within said body, there being chambers contained in said body for directing the explosive force of said charge laterally toward the surrounding well casing and means including a magneto carried by said body for producing an electric spark in said explosive charge.

5. In a well casing perforator the combination with a body, of a cable connected to said body for lowering the same into well casing said body containing an explosive charge, there being chambers formed in said body for directing the force of the exploded charge toward the well casing surrounding said body, projectiles in said chambers, means including a magneto carried by said body for producing an electric spark in said explosive charge and a member adapted to travel downward on the cable that carries said body for actuating said magneto.

6. A well casing perforator as set forth in claim and with means for rendering the spark producing means inoperative while the body is being made ready for use and before being lowered into the casing.

7. In a well casing perforator, a body, an explosive charge contained within said body, there being chambers formed in said body for directing the explosive force of said charge outwardly toward the well casing in which the body is suspended, projectiles located in said chambers, a pair of spaced ignition points located in said explosive charge and means carried by the body for generating an electric current and causing the same to pass through said ignition points and the spark gap between the same.

8. A casing perforator as set forth in claim 7, with a cable connected to said body for lowering the same into well casing and means adapted to travel downwardly upon said cable for actuating said sparkv producing means.

9. In a well casing perforator, a body, an explosive charge contained Within said body, there being chambers formed in said body for directing the explosive force of said charge outwardly to- Ward the well casing in which the body is suspended, projectiles located in said chambers, a pair of spaced ignition points located in said ex plosive charge and means including a magneto carried by the body for generating an electric current and causing the same to pass through said ignition points and the spark gap between the same.

10. A well casing perforator as set forth in claim 9, with a cable connected to said body for lowering the same into well casing and means adapted to travel downwardly upon said cable and to actuate the magneto of said spark producing means.

11. In a well casing perforator, a gun body including a plurality of gun units arranged to discharge laterally from said body, said gun units including an explosive charge receiving chamber and a plurality of projectile receiving chambers that communicate with the explosive charge receiving chamber, an electric circuit including a pair of spaced spark terminals located within the charge occupying said explosive charge receiving chamber and magneto means carried by said gun body for energizing said circuit and producing an electric spark between said spaced spark terminais.

12. A well casing perforator as set forth in claim 1,1 and with means for actuating said magneto means from the exterior of said perforator.

13. In a well casing perforator, a body provided with a chamber for the reception of an explosive charge, said body being provided with a plurality of projectile receiving chambers that communicate with the explosive charge chamber and magneto means carried by said body for producing an electric spark within the charge located within said explosive charge receiving chamber.

MILLIO F. ALOI.

Images