US2307360A

US2307360A - Well perforating gun

Info

Publication number: US2307360A
Application number: US369147A
Authority: US
Inventors: Arthur J Collins
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-12-09
Filing date: 1940-12-09
Publication date: 1943-01-05
Anticipated expiration: 1960-01-05

Description

Jan. 5, 1943. A. J. COLLINS 2,307,360

WELL PERFORATING GUN 1 Filed Dec. 9, 1940 2 Sheets-Sheet 1 &

3R k Rim 3 ammo/whom g- Auzhw JCd/ms Jam. 5, 194.3. A. J. COLLINS WELL PERFORATING GUN Filed Dec. 9, 1940 2 Sheets-Sheet 2 a vwq/rvbo'v lento Jan.

ascvsco were rirnr'onad arm Arthur .lT. Collins, Borpus sti, Tex.

Application December 9, 19%, Serial No. 369,147

it tllaims. (Cl. ltd-0.5)

invention relates to new and useful improvements in methods of and means for firing well perforating guns.

There are several types or perforating guns which are now commonly used, and are referred to as electrical guns and mechanical guns. In the held today an electrical gun is the most commonly used, and a user of an electrical gun has a certain degree of control over the firing of the gun which is not true of the present type of mechancal gun. However, an electrical gun has numerous disadvantages. I'he electrical circuit of the gun may develop a short, thereby causing the gun to fire accidentally, or it may he fired accidentally by static electricity set up in the gun while it is being run into the well casing. These disadvantages make an electrical gun dangerous to run.

It is pointed out that a mechanical gun has numerous disadvantages also, such as the operator not having the degree of control over the firing mechanism that he has in an electrical gun. A mechanical gun is usually fired by dropping a go-devil through the rg tubing or along a wire line so as to fall upon a trigger or the like and cause said trigger to fire the gun. The dropping of a go-devil oftentimes has its disadvantages as said go-devil may hang up within the casing, thereby not permitting it to fall so as to trip said trigger; and also the mud within the tubing retards the downward travel of the godevil. it has often been experienced that when the gun did not fire, it was brought to the surface, the go-devil becoming dislodged fell and fired the gun.

its can he seen, both an electrical and a mechanical gun may the accidentally due to the laclr of control over the hiring mechanism; and, therefore, it is one object of this invention to provide an improved method oi firing a gun whereby the gun is under the positive control oi the operator at all times and can not he accidentally fired.

an important object or the invention is to provide an improved method, of the character described, wherein agun equipped with mechanical firing means is lowered into the well and the firmeans is subjected to a pressure fluid by holding it under restraint and the firing mens is then released from the surface of the well whereby the pressure fluid operates the firing means.

A further object of the invention is to provide an improved method of actuating the firing elements of a perforating gun entirely by fluid pressure.

Another object of the invention is to provide an improved method of firing a perforating gun either by fluid pressure in the well bore or by an auxiliary pressure fluid introduced into the here of the gun.

A still further object of the invention is to provide an improved method of firing a gun wherein the efficiency of the gun is not affected by the depth of the well, but, to the contrary, the efficiency of the gun is increased due to the fluid pressure within the well.

Another object of the invention is to provide an improved gun of the type described, wherein the explosive charge is mechanicall detonated by means normally held in restraint and adapted to be impelled by a pressure fluid when released.

Still another object or" the invention is to provide a gun of the type set forth. wherein the mechanical detonating means, which is under nuid pressure, is released from the surface, thus providing definite control thereof.

A further object of the invention is to provide an improved method wherein the firin charge is mechanically detonated, and the mechanical means is actuated by a pressure fluid.

A construction designed to carry out the invention will be hereinafter described, together.

with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and wherein:

Figure 1 is a view, partly in elevation and partly in section, of a gun constructed in accordance with the invention and adapted to carry out the method, and

Figure 2 is a view, similar to Figure 1, show ing the gun after it has been fired,

Figure 3 is a horizontal cross-sectional view taken on the line 3-3! of Figure 1,

Figure 4 is a horizontal cross sectional View taken on the line t-t of Figure 1,

Figure 5 is a horizontal cross-sectional view taken on the line 5-5 of Figure 1,

Figure 6 is a horizontal cross-sectional view; taken on the line 6-6 of Figure 1, and v Figure 7 'is an enlarged vertical view; partly in. section and partly in elevation, showing the;

detonating and percussion caps.

In. the drawings, the numeral? designates a sectional gun. The gun has a head A at its.- upper end which forms its upper section, and-a firing portion B at its lower end which iormsits lower section. The head A includes a tubular sleeve H at its upper end, and the sleeve is provided with a bore l2 extending therethrough. The lower end of the bore I2 is counterbored to form a shoulder 13. Below the shoulder l3, the bore is enlarged to provide a lower shoulder l4, and the enlarged portion below the shoulder I4 is internally screw-threaded. The exterior of the sleeve H is provided with a plurality of inwardly-extending vertical recesses l5 adapted to receive dogs I6. The dogs are forced outwardly beyond the surface of the sleeve by an upright flat spring I! disposed within the recesses. A collar I8 lie around the lower end of the recesses I5 and is embedded within the sleeve H. A similar collar l8 lies around the upper end of said recesses and is also embedded within the sleeve. The ends of the dogs underlie the collars, thereby the collars retain the dogs and the springs 11 are urging the dogs outwardly at all times.

A sleeve I9 is provided with an upstanding screw-threaded pin on its upper end which is screwed into the enlarged portion of the sleeve I I so as to abut the shoulder I l. The sleeve I9 is provided with a bore 2| which is enlarged and tapered outwardly at its upper end to form a bowl 22 and a shoulder 23 at the lower end of said bowl. Below the shoulder 23, the bore is further enlarged to form a shoulder 24. A ring 25 abuts the lower end of the sleeve l9, and has an annular upstanding neck 26 provided on its periphery. A plurality of balls 21 lie between the upstanding neck and the inner periphery of the sleeve I!) so as to rotatably lock the neck and sleeve together. It is pointed out that the balls 'are inserted through an opening 21' in the sleeve IS in the usual manner. The ring 25 carries a plurality of depending rods 28 which are securely fastened to the ring 25. It is pointed out that the ring 25 and the upstanding neck 26 are free to rotate in relation to the sleeve Hi. The lower ends of the rods 28 are each cut on its inner side so as to form a wedge 30.

A mandrel 3 I extends through the head A and has its upper end connected to the tubing, or other suitable means, upon which the device is run into the well. The lower end of the mandrel is provided with internal screw threads 32 to which is connected a choke 33. The mandrel is also provided with external screw threads 34. A

portion 35 of the outer surface of the mandrel 3| is provided with screw threads which are of sawtooth or ratchet cross-section. Surrounding the mandrel 3|, and engaging within the bowl 22 of the sleeve [9, is a split nut 36 which has its outer surface tapered correspondingly to the bowl 22, i

and its inner surface screw-threaded to mate with the screw threads 35 of the mandrel 3|.

In order to hold the nut aganist rotation, a key 31, embedded in the bowl, engages in the split or gap of said nut. Thus the construction of the teeth of the mandrel and the bowl are so as to permit the mandrel to be moved upwardly through said nut. The nut is elevated in the bowl sufllciently to permit the nut to expand, thereby allowing the threads to pass each other. When the nut is moved upwardly into the enlarged portion of the bowl 22, it will be free and may spread so that the threads will not be in constant engagement and will not act to screw said mandrel downwardly; but, as the threads engage, the nut will spread and snap over the threads of the.

mandrel. However,.when the nut is down within the lower portion of the bowl 22, the threads will act so as to screw the mandrel downwardly when the mandrel is rotated. This is clearly brought out in my co-pending application, Serial No. 318,050, filed February 9, 1940.

A sleeve 36, having a bore 39, is attached to the lower end of the mandrel 3| by means of the screw threads 34 which mate with the screw threads of the bore 39 within the sleeve 38. The bore 36 is decreased in size so as to form an orifice 40. Below the orifice 40, the bore is again enlarged greater than that portion above the orifice, so as to form an annular shoulder 4|. The sleeve 39 is provided with a plurality of downwardly-directed openings 42 through which the rods 26 may pass (Figure 1). At a point below the shoulder 4|, there is provided an inwardlydirected annular flange 43. The lower portion of the flange 43 forms a shoulder 45, and the sleeve below the shoulder is internally screw-threaded at 46.

A cylinder block 41 is connected to the sleeve 36 by means of the screw threads 46. The block is provided with an axial bore 48 extending therethrough. The upper end of said block is countersunk to form an annular recess 49 surrounding the bore 48. It is pointed out that the recess does not come in contact wtih the shoulder of the flange 43. Disposed between the shoulder and the recess is an annular ring 5|] which is securely held in place by the shoulder 45 and the bottom of the recess 49. A plurality of arms 5| are pivotally connected to the ring 50, and are provided with a roller 52 at their upper ends. An inwardly-directed lug 53, carrying a roller 53', is provided on each of said arms below the roller 52 and above the ring 50. .It is pointed out that the arms are always in alinement with the rods 28 and the openings 42.

A piston or hammer 54 has a tight sliding fit within the axial bore 48 of the block 41, and is provided near its upper end with a plurality of recesses 55 so that when the hammer is in the position shown in Figure 1, the rollers 53 may enter said recesses and hold the hammer in said position, due to the fact that the rods 28 are urging the arms 50 inwardly. Below the recesses 55, the hammer is provided with a plurality of packing rings 56, so that fluid from the bore 39 may not flow downwardly past the hammer. The sleeve 33, above the orifice 40, is provided with a plurality of. openings 51 which establish communication between the bore 39 and the exterior of the sleeve 38. The lower end of the block 41 is reduced to form a. shoulder 58, and the portion below the shoulder is externally screw-threaded. Attached to the lower end of the block 41 is a sub 59. The sub has its upper end countersunk I and internally screw-threaded so as to mate with the lower end of the block 41, and the central portion of the countersunk portion of the sub 59 is further countersunk so as to form a recess 60. Depending downwardly from the recess 60 is a plurality of longitudinal openings 6 I, and lying in between the lower ends of the openings BI is a guide member 62.

A piston 63 is slidable within the countersunk circumference reduced to form a. shoulder t1, and

1 is provided with an enlarged recess 68 on its bottom. Slidable within the recess 68 is an initial firing means 69 which contains a pair of cartridges 'lll that are in axial alinement with the openings 6|. A gun barrel H is attached to the lower end of the sub 59. As will be seen in the drawings, the upper end of the barrel is provided with a countersunk portion-12, and is internally screw-threaded so as to confine the initial firing charge within the recess 66. The barrel is preferably cylindrical in shape, and is provided with a plurality of elongate transverse recesses or firing chambers 13 extending inwardly toward the center of said barrel. It is pointed out that the chambers are preferably cylindrical in crosssection, and constitute a plurality of firing chamhere so that cartridges or explosive charges may be inserted therein. An axial channel it extends throughout the barrel ll, and is so disposed as to underlie the cartridges it. The lower end of the barrel is reduced and internally screwthreaded so as to receive a collar l which is at tached thereto. A sleeve it surrounds the gun barrel H, and is suitably paclred ofi so as to prevent moisture from entering said barrel. The lower end of the collar i5 is reduced and receives a, retaining collar ll. The collar ll abuts the lower end of the sleeve iii and acts to retain the same on said barrel.

In the operation of the gun herein described, the gun is lowered into the well by means of a tubing, or other suitable means, which is connected to the upper end of the mandrel it. When the point at which it is desired to perforate has been reached, the tubing is rotated. In the usual case the well has a certain amount of fluid within the casing ill, but the amount of fluid is not sufficient to flow to the top of the well. In some instances, it may be desired to shoot a well which i9 is flowing for various reasons; however, when the stratum or point has been reached at which the casing id is desired to be perforated, as above stated, the pipe is rotated which will rotate the mandrel ill. The dogs it, being in engagement with the casing '58, will not allow the head A to rotate. However, the portion B of the gun will rotate due to the fact that the lower end of the mandrel iii is connected therewith.

The rods 29, being within the openings M, will rotate with the portion B, and the ring 25 and the upstanding neck it will also rotate with the portion B. As the mandrel ii is rotated, the head A will not be rotated but will remain stationary. The mandrel will be fed through the nut it due to the fact that the pipe is lowered as it is rotated, thereby lowering the portion B away from the portion A and withdrawing the rods it out of the openings 32 until said rods have reached the position shown in Figure 2. At this time the arms bl are free to pivot outwardly, thereby releasing the hammer 5d. The hammer has a tight sliding fit within the bore it of the block ti and therefore will not readily fall. Pressure exerted by the fluid within the casing is free to enter through the ports ii and act upon the top of the hammer it, thereby causing the hammer to move downwardly and strike the piston tit, which will also be carried downwardly. The pins M will strike the cartridges it, thereby exploding the same, and the flame of the explosion will be conducted down through the channel it to the cartridges within the chamber it. The firing may be accomplished by pins or a tire train as is disclosed in my"copendlng applicaspring I56 is of suflicient strength to hold the hammer upwardly, together with the piston 63, so that the cartridges 10 may not be discharged until pressure is applied to the top of the hammer. Thus, as will be seen, this gun depends upon pressure acting upon the' top of the hammer 54 to fire the same.

In some instances, there is not enough fiuid within the casing 18 to apply sufilcient pressure to the top of the hammer. In this case, the ports 51 may be left out of the gun or suitably blocked by a sleeve (not shown), or in any other suitable manner. Fluid may then be pumped down through the tubing and through the mandrel 3| so that it will act upon the top of the hammer 5t. Thus the gun cannot be accidently fired due to the fact that pressure is required to fire the gun and the atmospheric pressure under which the gun is assembled is not sufiicient to fire said gun.

It is further pointed out that as the gun is lowered farther into the well, there will be more fluid above the hammer M. In this manner there will be a hydrostatic pressure built up above the hammer and, in the instance where pressure is introduced into the tubing, there will be built up a hydrostatic pressure within the tubing. In many instances, where there is not a sufiicient amount of fluid within the casing 18 to fire the gun, auxiliary fluid may be introduced into the casing so as to build up a hydrostatic head to fire the gun. This particular method of firing a gun by pressure can be applied to various guns and is not limited to the structure herein disclosed; however, the structure illustrated may be used to perform the method of this invention and eliminates disadvantages of guns now in common use.

Various changes, alterations and modifications may be made in the size, shape and arrangement of the herein described elements, within the scope of the appended claims.

What I claim and desire to secure by Letters Patent is:

1. A well bore perforating apparatus composed of a gun having a cartridge carrying member, spring tensioned means in the member to fire the cartridge, a hammer slidably within the member, means to latch the hammer at points spaced from the firing means, means for unlatching the hammer, and means for supplying fluid pressure to the member to act upon. the hammer thereby tocause same to actuate the firing means.

2. A well bore perforating apparatus in accordance with claim 1, wherein the spring means is of a strength to resist operation of the firing means upon the hammer moving into engagement therewith when not under the influence of the fluid pressure.

3. A well bore perforating apparatus including an upper member receivable in the casing, means carried by the member and engageable with the casing to hold the member against rotation, a lower member, a rotatable mandrel extending through the upper member and into the lower member, means which upon rotation of the man drel efiects sliding movement of the lower member away from the upper member and while the latter remains stationary, cartridge firing means in the lower member, a slidable hammer in the lower member for actuating the firing means, means for releasably holding the hammer inoperative, means having connection with the upper member for releasing the means which holds the hammer inoperative, and means for conveying fluid pressure into the lower member to act upon the hammer thereby to move same to cartridge firing position.

4. A well bore perforating apparatus in accordance with claim 3, wherein the means to releasably hold the hammer inoperative consists of pivoted latches and wherein the means to release the hammer holding means consists of rods having connection with the upper member to partake of the sliding movement thereof and slidably connected to the lower member, to move the latches to unlatched position thereby to release' the hammer.

5. A well bore perforating apparatus composed of a gun having a cartridge carrying member, a second member, a rotatable mandrel connecting the members, a hammer for firing the charge carried by one of the members, means to latch the hammer spaced from the firing means, means carried by the other member for efiecting release of the latching means, means operable by the mandrel to move the members toward each other upon rotation of the mandrel, and means to actuate the hammer to fire the charge upon release of the latching means from the hammer.

6. A well bore perforating apparatus in accordance with claim 5, wherein the means to release the latching means is slidably mounted in the other member.

'7. A perforating gun firing apparatus includmg, a suspending mandrel, a non-rotatable memasoaaeo means carried by the rotatable member for holding the means inoperative, and means for releasing the latch means actuated by the rotation of the mandrel and the rotatable member.

8. A perforating gun firing apparatus set forth in claim 7 wherein the rotatable member is provided with inlets for the well fluid, and means for conducting the admitted well fluid to the firing means.

9. In a well gun firing device, the combination of a gun barrel, 9. support having means for connecting with said gun barrel and provided with a chamber, a firing hammer disposed and slidable within said chamber above the gun barrel, latch means carried by the support for holding the hammer in its inoperative position, rotatable means for unlocking said hammer, and fluid means for applying fluid pressure so as to actuate said hammer.

10. The method of firing a well bore perforating gun having an explosive responsive media for perforating the well bore and also having firing means to fire the explosive by impact, whichresides in disposing the media substantially transversely of the longitudinal axis of the gun, holding the firing means at a point spaced above the media under restraint by engagement therewith to resist actuation thereof, lowering the gun into the well bore to be perforated, re-

her carried by said mandrel, a rotatable member carried by said mandrel, fluid actuated firing means carried by the rotatable member, latch leasing the firing means to free the same from restraint when the point of firing in the well bore is reached, and constantly subjecting the firing means to fluid pressure throughout the period of restraint to impact the same against the explosive by movement of said firing means axially of said gun so as to fire the explosive and thereby discharge the media to perforate said well bore.

ARTHUR J. COLLINS.