US2686472A - Torpedo shell for shooting wells - Google Patents

Description

7, 1 4 H. B. BURNS 2,686,472

TORPEDO SHELL FOR SHOOTING WELLS Filed Dec. so, 1948 2 Sheets-Sheet 1 1 2| 33 as as B 27 I I a E III Y Z 20 z X Y Z 33 a 20V I a s 8 36 38 v i Y 35 A I 15 s 20 a Y v, 20

I X 4 5 X X 5 20k 5 5 F! e 5. ZO-x h C- 26X 7 I F I 5- 4 INVENTOR. 71,; F 1 Howard 5. Burns.

A TTORNE Y.

A 17, 1954 H. B. BURNS 2,686,472

TORPEDO SHELL FOR SHOOTING WELLS 2 Sheets-Sheet 2 Filed Dec. 30, 1948 II. I...

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Howard 5. Burns ATTORNEY.

Patented Aug. 17 1954 UNITED STATES OFFICE TORPEDO SHELL FOR SHOOTING WELLS Howard B. Burns, Wichita, Kans.

Application December 30, 1948, Serial No. 68,259

2 Claims.

My invention relates to an improvement in torpedo shells for shooting wells, and refers more particularly to the type employed in shooting oil wells.

Due to the design of my improved torpedo shell the torpedo possesses some very unique and desirable characteristics, for example, the torpedo is adaptable for use at any selected point or points along the depth of the well without the sealing off of the well adjacent or below the point where the well is to be shot.

A further characteristic of the torpedo is that, due to the structure of the torpedo shell, a jelly form of explosive, preferably solidified nitroglycerin, may be used, and that is a much safer form of explosive to handle than the liquid form, yet the explosive is just as powerful and effective in its work.

Another feature of the shell is that the shell is made in two halves that may be opened and closed to form the complete shell and provide an easy way of loading the shell with the explosive.

A further feature of the shell is that provision is made therein such that as the shell halves are placed together after being loaded with the explosive there is no danger of the halves rubbing together or mashing in the joints between the halves that might ignite or cause the explosive to explode.

Another characteristic of the shell is that due to the design of the shell the distribution direction of the force of the explosion may be predetermined and directed.

A still further characteristic of a torpedo in which my improved shell is employed will perforate the metal casing in the Well at the points of thrust of the explosion and also break up the rock, sand or other formations around the well casing at the points of the explosion whereby runways or feeder channels are created in the formation outside the well casing for considerable distances and the well will therefore yield a much greater flow of oil than can be procured with the other methods or type of torpedoes.

A still further advantage of my improved torpedo shell is that while it can be made of sheet metal it can also be made very easily of cast or pressed plastic material, therefore the shell can be made at a very low cost and can be made speedily and accurately in large quantities. These and other characteristics and objects of the invention will be more fully explained as this description progresses.

Now referring to the accompanying drawings in which similar numerals of reference designate 2 the same parts throughout the several figures of the drawings:

Fig. 1 is a side View of the torpedo shell.

Fig. 2 is an enlarged top plan view of the torpedo shell shown in Fig. 1.

Fig. 3 is an enlarged detail cross sectional View of the torpedo shell, the View being as seen from the line IIIIII in Fig. 1 and looking in the direction of the arrows.

Fig. 4 is an enlarged detail perspective view of a portion of the torpedo shell illustrating several features that will later be described in detail.

Fig. 5 is a view showing the torpedo shell in an open position and ready to be filled with the explosive material.

Fig. 6 is an enlarged detail corner view of a portion of the torpedo shell and illustrating still further features that will later be described in detail.

Fig. 7 is a detail perspective view of one of the edges of one of the torpedo shell halves and illustrating a padding that may be employed as a safety measure in the proces of placing and fastening the two halves together after the two halves have been filled with the explosive material.

Fig. 8 is a detail perspective view of a portion of the edges of the two shell halves in their closed position.

Fig. 9 is a detail perspective view of a modified design of a joint that may be employed between the two halves of the torpedo shell.

Fig. 10 is an enlarged longitudinal sectional view through the fastening means for holding the two halves of the torpedo shell in their closed position.

Fig. 11 is an enlarged detail perspective view of the fastening end of one of the fastening members for holding the two halves of the torpedo shell in closed position.

Fig. 12 is a view of the lower and upper ends of two torpedo shells hooked together as they would be where several torpedoes are employed at once in shooting a well.

Fig. 13 is an enlarged detail of the hook portion of the couplin device employed in attaching the torpedoes, one to another.

Fig. 14 is an inside view of the lower end of a torpedo shell in an open position and ready to be filled with the explosive material, and illustrating the hook coupling elements in their open position.

Fig. 15 is a corner view of the lower end of the torpedo and showing the shell in its closed position and also showing the hook coupling elements in their closed position.

Fig. 16 is a sectional view through a portion of the earth and showing a well and well casing therein, and illustrating how the torpedo is used and what it does in shooting a well.

In the drawings the torpedo shell i shown as having two V-shaped trough like halves A and B. Each side of each half A and B is provided with a series of inwardly directed cup shaped formations 20. The cups 2!) on the adjacent sides of each half A and B are positioned alternately so that the cups are spaced equally up and down each side and the cups 2% on opposite sides of the shell, when the two halves A and B are placed together, oppose each other at points intermediate the cups 2!! on the other opposite sides of the halves A and B. This arrangement places a row of cups 2!) in all four sides of the torpedo shell as will be readily understood.

If the torpedo shell is made of sheet metal, the cups 25 can be die pressed from the sheet and the sheet bent to form the V-shaped half A or B of the shell; or, if the shell is made of plastic material, the entire half A or B can easily be pressed or cast as a single unitary piece.

The upper and lower ends of each half A and B are drawn inwardly and longitudinally to form a half of a four sided pyramid shape 2i and 22 at the base and merging into a half of a substantially conical formation at the outer ends thereof.

One of the upper end halves 2| is provided with a tubular element 23 that is rigidly attached, or even integrally formed on the apex portion of the half end formation 2! and is longitudinally positioned on the center longitudinal axis of the torpedo shell when the two shell halves A and B are placed together to form the assembled torpedo shell. The tube 23 is for receiving and holding a detonator or other devices, a time clock controlled detonation cap striker or the like, not shown, for igniting the explosive material contained in the shell AB at a predeterminedtime or whenever desired.

The upper end of one of the shell halves A or B is provided with a bail 2 3, the ends of the legs of which are rigidly attached to opposite end edges of the same shell half A or B as clearly shown in Figures 2 and 5. If the shell is made of sheet metal, the base of the pyramid portion may be provided with holes immediately adjacent the opposite edges of the half A or B and the ends of the bail legs passed through the holes to rest against the inner surface of the edges of the shell and then be welded thereto to provide a rigid mounting or attachment of the bail to the shell half A or B as the case may be. If the shell is made of plastic material the bail 24 may be cast in place in the body of the material of which the shell half is made.

At the bottom of the shell, each shell half is provided with a hook element 25 and 25a which separate one from the other when the shell halves A and B are in an open position as shown in Fig. 14:, and when the shell halves A and B are are in their closed position the hook elements 25 and 25a are positioned, one against the other with the hooks directed in opposite directions as shown in Figures 13 and 15. Each leg of the hook elements 25 and 25a is provided with a slide element 26 and 25s that is adapted to slide up and down on its respective leg 25 and 25a. and receive and hold its companion hook end so that the two hooks 25 and 25a are solidly bound and held together as shown in Fig. 13.

If several torpedoes are suspended, one from the other by the hooks of one torpedo being hooked under the bail 24 of the succeeding torpedo, the hooks 25-2511 of the last torpedo may be dispensed with and a short length of tube 26:1: that may be made in two halves C and D as shown in Fig. 5 may be rigidly attached to or made as a part of the conical end of the lower portion of the shell AB. The tube 280: will act as a support or stop for the torpedo if the torpedo be lowered to the bottom of the well; or if desired additional lengths of tubing, not shown, may be attached to the tube 265:: to stop the torpedo at a higher point from the bottom of the well.

The edges .of the halves A and B are beveled as at X and then turned inwardly to form parallel lips Y, one or both of which, if desired, if the shell is made of metal, is covered with a strip of soft material such as cloth, tape, felt, rubber or the like, Z, or to avoid sufiicient pressure between the halves A and B that might cause the explosive to be prematurely ignited in the process of assembling the two halves A and B together as will later be described.

In Fig. 9 is shown a modified form of the edge joinder of the halves A and B. In this modification, one edge is formed into the shape of a channel E that may be lined with a soft ma terial F such as used to face the flanges Y in Figures 7 and 8, and the bevel lip X of the other shell half is receivable in the channel E.

The torpedo shell halves having been constructed as above described may now be hingedly fastened together by flexible textile or leather strap pieces 2?, 28 and 29, the ends of which are riveted as at 30 to provide a soft hinge connection for the two halves A and B which holds from little or no likelihood of igniting the explosive from pressure or rubbing as the two halves A or B are rocked together in the process of closing the shell after it has been loaded with explosive material as will later be described. In Fig. 4 the two shell halves are shown as being joined together with ordinary type hinges 3|. The flexible elements 21, 28 and 29 are seated in indentures as indicated at 32 so that the elements 2T, 28 and 29 do not project beyond the outer surface of the shell A-B. The object of this construction is that as the torpedo is lowered through the string of well casing there will be nothing projecting from the torpedo that can catch on the coupled ends of the well casing and obstruct the passage of the torpedo and possibly damage or prematurely explode the torpedo.

As shown in Fig. 4 and further illustrated in Figures 10 and 11, the two shell halves are provided with a closure fastening device which compresses a strip of textile, felt, rubber or similar material 33, one end of which is riveted as at 34 to one of the shell halves. The fastening member 33 is long enough to reach over the joint between the two shell halves A and B and lap over onto the other shell half, and the free end of the fastener 33 is provided with an opening 35 therein and a slit 36 that joins with the opening 35 and extends a short way toward the rivets 34. The other shell half is provided with a stud 31 that has a head 38 that is eccentrically positioned on the stud 3'! with the overhang of the head 38 being directed in a direction opposite to the pull of the fastener strap 33 when the strap is hooked over the stud 3? to hold the two halves A and B in their closed position. The fastener strap 33 and stud 31-38 are positioned in depressions 39 in the two shell halves A and B for the same yr in purpose as the hinge straps 21, 28 and 29 are seated in their depressions 32.

The torpedo may be prepared for use at the well where the torpedo is to be used by laying the shell on its side and then opening the torpedo as shown in Fig. 5 whereupon the explosive material, preferably solidified nitro-glyoerin in a jelly form, may be placed in the two halves by the use of preferably a wooden paddle. When the two halves A and B have been filled, the two halves A and B may be rocked, one over the other to a closed position, whereupon the latch straps 33 may be brought across the joint between the two halves A and B and the head 38 of the stud 31 forced into and through the eye 35-46, whereupon the slit 36 opening into the eye 35 will open or spread enough to admit the passage of the stud head 38 therethrough and the two halves are then looked in their closed position.

The torpedo having been thus loaded may be washed clean of any explosive material on the outside and the torpedo is then ready for use.

In drilling an oil well it sometimes happens that one or more strata of oil sand J and K may be drilled through in the hope or expectation of a better paying stratum might be found. As the well is drilled the steel casing 4i: is moved downwardly in the well following the drill bit to prevent the wall of the well from caving in, therefore the casing d6 will be passed through the strata of oil sand that has been drilled through. This sort of drilling casing of the well is and has been common practice, however when the well has been drilled as deep as it is considered worthwhile going, the problem then is to perforate or dispose of the casing 40, at, or up to the desired stratum from which it is desired to pump the oil.

In shooting the well, a torpedo is lowered to the top, or nearly to the top of the concrete at which point the torpedo is exploded by any of the conventional methods as will later be described.

The characteristics of the torpedos now in use is that the explosion of the torpedo exerts its force mainly outwardly as an equally distributed force of expansion which usually splits the casing 40, or breaks the casing 49 off in a ragged break or tear, either of which is likely to leave a large portion of the depth of the oil sand sealed off and thereby restrict the flow or/and production of oil from the well.

In using my improved torpedo shell, which has been loaded and perforated for use as above described, and if the thickness of the oil sand is of considerable thickness, several of my torpedos may be hooked together as previously described and as shown in Fig. 12, to build up a string of torpedos long enough to reach through the entire thickness of the oil sand from which the oil is to be pumped. Also if it is desired to pump the oil from a second or even a third stratum of oil sand, a string of one or more torpedos may be used as above described and the two or three strings of torpedos spaced apart by lengths of suitable cable attached to the top bail 2d of one string of torpedos and to the hooks 25-25a on the lower end of the lower torpedo of the next above string of torpedos as illustrated in Fig. 16, and so on, with a third set of torpedos if desired.

The torpedo, or strings of torpedos having been thus prepared are provided with some suitable means of igniting the explosive in the torpedo shells. A suitable and common means for doing this is a time clock operated detonation detonator, not shown, a portion of which is received in the upper tubular element 23. Another suitable means for igniting the explosive material in the torpedo shells, is to place an electric detonator, not shown, in the tubular element 23, the detonator being included in a suitable electric circuit that is manually controlled whereby the spark may be produced in the detonator at a selected time and the spark of the detonator will ignite the explosive in the shell.

The string or strings of torpedos having been prepared as the above described, one end of a suspension cable ti may be attached to the bail 24 of the uppermost torpedo and the entire string of sets of torpedos spaced apart therein may be lowered within the well casing 40 to such a position that the one or more sets or strings of torpedos are positioned within the thickness or depth of the stratum of oil sand that is to be shot or penetrated.

The torpedos having been placed as above described may then be exploded, either by the time clock device or the electric device above mentioned.

It is characteristic of the explosive used to exert its force in the path or paths of least resistance, and advantage of this fact is taken in the design of my improved torpedo shells. The performance of the force of the explosion as it is eifected by my improved torpedo shell is, as has been many times demonstrated in experimental use, that when the explosion occurs the cup indentures 28 provide yieldable spaces to which the force of the explosion rushes and as the force increases it is projected outwardly from each of the cups 26 and will perforate or make a hole in the well casing 4i) opposite each cup 20, and due to the concentration of the force of the explosion the earth formation, that is the stratum of oil sand around the well casing d0, is also penetrated and broken up for considerable distances away from the casing 40, this provides numerous open and free runways in the oil sand and through the well casing 49 for the oil to drain into the well, therefore the well is developed to be a much larger producer than it would have been, had the well been shot with one of the common type torpedos now in use. The increased producing well is the thing sought and achieved by the use of my improved type of shell for torpedos for shooting wells.

While the torpedo shell as shown in the drawings and described in the foregoing specification is probably the preferred form of the torpedo shell, it is to be understood that such modifications of my invention may be employed as lie within the scope of the appended claims without departing from the spirit and intention of the invention.

Now having fully shown and described my invention, what I claim is:

1. In a torpedo shell of the kind described; said shell comprising the combination of a pair of elongated cross-sectional V-shaped halves that are hingedly attached on one side, one to the other, said halves being closable toward each other to form a rectangular tube, and resilient packing means between the two edges of the two halves for the purpose specified, each side wall of the rectangular tube having conical shaped indentures therein that open to the outside thereof, the indentures of one wall approaching the indentures of the opposite wall of the tube to within a short distance of each other and being in axial alignment with each other,

and means engaging :both halves of the tube for holding the tube in a closed position, said means for holding the tube halves in a closed. position being contained within a circle, circumscribing the cross section of the tube, and touching each of the four corners thereof, both ends of said tube having a tapering closure element therefor, the apex portion of one of said tapering closure elements having a holder for a detonation element therein and being open to the inside of the tube, and bail means having its ends attached, one to the edge of one of the sides of one of the tube halves and the other attached to the diagonally opposed edge of the other side of the tube half, for the support of the tube; the other end of said tube having a sloping wall closure therefor and the bottom apex end of the closure having means thereon for supporting the shell a predetermined spaced distance above the bottom of a well.

2. In a torpedo shell of the kind described; said shell comprising the combination of a pair of elongated cross-sectional V-shaped halves that are hingedly attached on one side, one to the other, said halves being closable toward each other to form a rectangular tube, and resilient packing means between the two edges of the two halves for the purpose specified, each side wall of the rectangular tube having conical shaped indentures therein that open to the outside thereof, the indentures of one wall approaching the indentures of the opposite wall of the tube to Within a short distance of each other and being in axial alignment with each other, and means engaging both halves of the tube for holding the tube in a closed position, said means for holding the tube halves in a closed position being contained within a circle circumscribing the cross section of the tube, and touching each of the four corners thereof, both ends of said tube having .a tapering closure element therefor, the apex portion of one of said tapering closure elements having a holder for a detonation element therein and being open to the inside of the tube, and bail means having its ends attached one to one corner of the tube, and the other to the diagonally opposed corner of the tube for the support of the tube; the other end of said tube having a sloping wall closure therefor; a pair of hook elements attached to the lower end of each tube half, the hooks thereof being directed in opposite directions when the two tube halves are in a closed position, and means for attaching each hook end to the shank of the other hook for the purpose specified, said hooks serving as a support for a second torpedo shell depending from the first torpedo shell, said second torpedo shell being substantially the same as the first defined torpedo shell and having means on the lower end thereof for supporting the torpedo shell in a predetermined spaced distance above the bottom of a Well.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 204,590 Mackh June 4, 1878 482,060 Lowe Sept. 6, 1892 1,367,938 Bettica Feb. 8, 1921 2,031,505 Rison Feb. 18, 1936 2,067,408 Morris Jan. 12, 1937 2,409,848 Greulich Oct. 22, 1946 2,494,256 Muskat Jan. 10, 1950 2,588,957 Brown Mar. 11, 1952 FOREIGN PATENTS Number Country Date 113,685 Australia Aug. 14, 1941 369,237 Italy Dec. 22, 1938 562,984 Great Britain July 25, 1944

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