US2212044A

US2212044A - Method and apparatus for perforating well casings

Info

Publication number: US2212044A
Application number: US286194A
Authority: US
Inventors: Ralph M Ridley
Original assignee: HOWARD W STEPP
Current assignee: HOWARD W STEPP
Priority date: 1939-07-24
Filing date: 1939-07-24
Publication date: 1940-08-20
Anticipated expiration: 1957-08-20

Description

Aug, 2@ 94@ R; M. RIDLEY 2,212,044

METHOD AND APPARATUS FR PERFORATING WELL CASINGS /OfL7 Filed July 24, 1959 Hiya/g77 @A www Patented ug. 20, 1940 UNITED sTATEs METHOD AND APPARATUS FOR PERFORAT- ING WELL CASIN GS Ralph M. Ridley, Whittier, Calif., assigner of dne- A`third to Howard W.` Stepp and one-third to Tillman JiileS, both 0f Whittier, Calif.

Application July 24, 1939, Serial No. 286,194

18 claims.

This invention relates to Well tools and well production methods, and relates more particularly to a tool and method for perforating Well casing. A general object of this invention is to provide a practical, eifective, gun perforator and novel projectiles for the same, and a rapid, efficient method for perforating well casing.

It is often necessary to perforate a well casing at a productive zone of the well following the setting and cementing of the casing. Tools have been developed that re projectiles through the Wall of a set casing to perforate the same. These so-called gun perforators are successful and effective but their use is restricted to wells that are more or less free of sand. The projectiles red by the gun perforators make large holes or perforations in the casing and where the oil or other produced uid carries alarge amount of sand, excessive quantities of sand are admitted by the large perforations and the well soon becomes sanded up.

l Another object of this invention is to provide a gun perforator that is useful and effective in the perforation of casing installed in Wells where the produced iiuid is accompanied by large percentages of sand and other solid matter.

Another object of this invention is to provide a gun perforator that vforms or provides perforations in the casing that are reduced or limited in fluid capacity to restrict the entrance of sand and other solid matter into the casing.

Another object of this invention is to provide a gun perforator lthat automatically beans, lines, or bushes the perfoations'in the casing to reduce their size andfiuid capacity, and to assure uniformity in the capacity and shape of the several perforations.

Another object of this invention is to provide a gun perforator of. the character mentioned that inserts the beans or bushings in the perforations in such a manner that they are securely and dependably xed in the perforations to form re- .ducers and wear resistant linings for the perforations.

Another object of this invention is to provide a gun perforator that may handle and install perforation beans or bushings of hard material that are very resistant to wear to prevent or reduce theenlargement of the iiuid admitting openings by the abrasive action of the solid matter in the produced uid.

Another object of this invention is to provide a novel projectile for casing perforators that embodies a trailing part that lodges in the perforation when the projectile pierces the well casing,

and that forms a' reducer, bean or bushing in the perforation.

Another object of this invention is to provide a projectile of the character mentioned in which flciently high to assure the full piercing of the casing by the projectile. Y

Another object of this invention is to provide 10 a cartridge for a gun perforator that embodies the projectile, the above-mentioned perforation bushing, the charge container and the squib associated as a single iiuid-tight unit that is easily handled and quickly loaded'in the gun unit of 15 the perforator.

A further object of the invention is to provide a method for perforating well casing in which the casing is perforated after being set in the well and the resultant perforations are provided with liningsor bushings for reducing the fluid capacity.

The various objects and features of my inventionwill be fully understood froml the following detailed description of. typical preferred forms 26 and applications of the apparatus and manner of carrying out the I method ofmy invention, throughout which description reference is made to the accompanying drawing, in which:

Fig. 1 is a side elevation of a gun perforator $0 embodying the present invention. Fig. 2 is an enlarged, vertical, detailed, sectional view of the perforator illustrating one of the gun units and tion. Fig. 5 is a view similar to Fig. 4 illustrating still another type of projectile. Fig. 5a is a trans- 40 verse, sectional view taken on line tia-5a of. Fig.

5. 'Fig. 6 is an end View of one of the trailers or bushings after it has left the gun unit, and Fig. 7

is a fragmentary, longitudinal, sectional View of a Well casing, illustrating a lining or bushing set 45 in a perforation in the casing.

'Ihe perforator of the present invention illustrated in Figs. 1, Zand 3 may be said to comprise, generally, a body Ill, a plurality of gun units Il carried by the body Ill, and improved 50 cartridges I2 for, the gun units.

The body l0 forms the carrier for the gun units Il and the other parts of the tool and is adapted to be run into and out of the well. In practice the body l0 may be an elongate member 55 of generally cylindrical shape provided with a suitably rounded lower end. A rope socket I3 is provided on the upper end of. the body for securing the tool to a line L for running the tool into and out of the well. One or more openings or sockets I4 are provided in the body I0 to receive the gun units II. In the case illustrated there is a plurality of longitudinally and circumferentially spaced sockets I4. The sockets I4 may be arranged in longitudinal rows with the sockets of the adjacent rows in vertically offset relation. The sockets I4 are cylindrical bores open at the exterior of the body I0 and fully closed at their inner ends. Longitudinal external grooves I5 are provided in the body I0 to be adjacent the mouths of, the sockets I4. Transverse notches I6 may connect the grooves I5 with the mouths of the sockets I4. The grooves I5 extend upwardly to the rope socket I3.

The gun units II are arranged in the sockets I4 to receive the cartridges I2. The gun units II are preferably alike and each includes a body or block I1 and a barrel I8. The blocks I'I are cylindrical elements proportioned to flt the sockets I4. Pins or wedges I9 are passed through transverse openings 20 in the body I0 and cooperate with notches 2I in the blocks I1 to removably secure the blocks in the sockets. Central longitudinal openings 22 enter the blocks I'I from forward ends of the blocks. The inner portions of the openings 22 are reduced in diameter to form chambers 23 and to provide forwardly facing annular shoulders 24. The chambers 23 are fully closed at their inner ends.

The barrels I8 are tubular parts removably secured in the openings 22 of the blocks I1. tIn the preferred construction the barrels I8 are threaded in the outer portions vof the openings 22. The barrels I8 and the walls of the openings 22 have coarse, heavy threads. The walls of the openings 22 and the inner portions of the barrels I8 are preferably unthreaded or plain. The outer portions of the barrels I8 are polygonal for engagement by wrenches and the outer ends of the blocks I'I are recessed to render the polygonal parts of the barrels accessible. The barrels I8 are provided with central longitudinal bores 25. The bores 25 are cylindrical except at their inner end portions where they are tapered or flaring. In accordance with the invention the bores 25 are rifled, being provided with longitudinal grooves 2B. The grooves 26 are circumferentially spaced and are of like size and shape. The grooves 26 may either be straight or spiralled. In the form of the invention described the grooves 26 are pitched or spiralled. The grooves 26 extend inwardly from the mouths of the bores 25 to the tapered inner parts of the bores where they die out. l

A cartridge I2 is loaded in each gun unit I I and each cartridge includes a projectile 28, a perforation lining member or bushing 29 on the projectile 28, and a container 30 holding a charge 3|. for firing the projectile. The projectiles 28 are arranged in the bores 25 and are designed to pierce or perforate the well casing. Fig. 'I of the drawing illustrates av portion of well casing C' having a perforation P formed by a projectile 28. The projectiles 28 are lgenerally cylindrical elements `proportioned to bear on or fit the lands 32 of the bores 25, which lands occur between the grooves 26. The forward ends of the projectiles 28 are pointed or otherwise shaped to pierce the casing C. The rear ends of the projectiles 28 are flat and provided with rearwardly -formity to the rifled bores 25.

projecting stems 33 of reduced diameter. In the form of the invention being described, central longitudinal openings 34 extend through the projectiles 28. The openings 34 extend from the forward ends of the projectiles to the rear endsof the stems 33. The projectiles 28 may be formed of any selected material, for example, they may be constructed of hardened steel.

The perforation lining members or bushings 29 are important features of the invention. The bushings 29 are carried by the projectiles 28 and are designed to lodge in the perforations P formed in the casing C by the'projectlles. The lining members or bushings 29 are ring-like or spool-like elements arranged on the stems 33 of the projectiles 28. The bushings 29 are secured to the projectiles 28 in such a manner that they are fired together with the projectiles and become detached from the projectiles as the projectiles pass through the casing C. In practice the bushings 29 may be press-tted on the stems 33 in such a manner that they travel with the projectiles until they enter the perforations P. The perforation lining members or bushings 29 are adapted to fit the tapered inner portions of the bores 25, being provided with tapered peripheries.

In the form of the invention being described the bushings 29 are made of a formable or malleable material such as brass, copper, bronze, or alloys of such materials so that the force developed `by the charges 3| shapes them into con- This provides the bushings 29 with pluralities of circumferentially spaced lugs 35. Fig. 6 of the drawing illustrates a bushing 29 after it has left a barrel bore 25. It is to be understood that the perforation lining members or bushings 29 are initially formed without the lugs 35 and that the high pressure developed by the charges 3I drives the bushings 29 through the rifled bores 25 so that the bores act as dies. The rifles or grooves 26 of the bores 25 receive the metal of the bushings 29 as the bushings are forced out through the bores and serve to shape the spaced lugs 35. The explosive pressure behind the bushings 29 has no tendency to detach the bushings from the stems 33 and the bushings leave the bores25 with the projectiles. The projectiles 28 of course form perforations P whose diameter is substantially equal to the diameter of the projectiles, and when the members or bushings 29, carried by the projectiles, encounter the perforations P their lugs 35 bind or stick in the perforations. The lugs 35 may be flattened down through their contact with the walls of the perforations P or may remain as ears or projections on the bushl ings.

'I'he wedging or lodging of the lugs 35 in the perforations P stops the bushings so that the bushings become detached from they projectiles and remain in the perforations P while the projectiles continue outwardly to perforate the surrounding cement where the same is present. 'I'hus the bushings 29 remain in the perforations P asreducers, beans, or linings. In this connection it is to 'be noted that the size of the openings 36 in the bushings 29 depends upon the diameter of the projectile stems 33 and that the stems 33 may be formed to provide fluid admitting openings 36 in the casing C of any selected diameter. The openings 36 are, of course, considerably smaller than the perforations P and the bushings 29 serve to prevent or limit the entrance of gravel, sand particles, etc. into the well. y

The containers 30 occupy the chambers 23 and are connected with the bushings 29 and the projectiles 28. The containers 30 are tubular cylindrical elements closed at their rear ends by plugs 3'I. 'Ihe plugs 31 are inserted following the loading of the powder charges 3I.- outwardly projecting annular anges 38 are provided on the forward ends of the containers 30 and are adapted to bear against the shoulders 24. A carrier plate or element 39 is arranged across'the mouth or outer end ofv each container 30. The elements 39 are secured and sealed to the anges 38 by welding, brazing, sweating, or the like. The elements 39 are perforate or annular having central openings 49 in alignment with the projectile openings 34. 'Ihe elements 39 serve to connect the projectile assemblies .with the containers 30. The rear ends of the bushings 29 are secured to the elements 39 by sweating, or the like. The forward faces of the elements 39 are engaged by the rear ends of the barrels I8 and when the barrels are threaded in and tightened `down the elements 39 and the flanges 38 are clamped between the barrels I8 and the shoulders 24. This provides effective fluid-tight and pressure-tight seals at the forwards ends of the charge containers 3|. It will be observed that the cartridges I2 are complete assemblies that may be easily and quickly loaded in the gun units II.

The means for firing or igniting the powder charges 3| include igniters or squibs 4| in the containers 30. Wires 42 are connected with the squibs 4| and pass outwardly through the

openings

40 and 34 to the mouths of the bores 25. Seals 43 are provided in the outer portions of the openings-34 to seal about the wires 42 and prevent the leakage of fluid through the openings. The wires 42 are trained through notches 44 in the outer parts of the barrels I8 and through the notches I6. The wires 42 continue upwardly through the grooves I5 to suitable means for controlling the ignition of the squibs 4|. 'Ihe present invention is not primarily concerned with the means or method of controlling the ignition of the squibs 4| As indicated in Fig. 1 of the drawing, the ignition wires 42 may enter the rope socket I3 and may connect with a controlling device or distributor 45 governed by a'control wire 46 associated with the line L.

In the operation of the perforator described above, and in carrying out the method of thev invention, the gun units are loaded with the cartridges I2 and the body IIJ carrying the units Il is lowered into the well on the line L. When the perforator is in the portion of the casing to be perforated the device or distributor 45 is operated to ignite the squibs 4|. ferred to ignite the squibs 4I in succession so that the projectiles 28 are successively fired. When apowder charge 3| is fired by its squib 4I the charge builds up a high pressure. The element 39 resists the immediate discharge of this pressure and the tapered bushing 29 fitting the tapered part of the bore 25 oers substantial resistance tothe pressure. When a very high pressure has built up, the element 39 fails and the pressure acting on the bushing 29 shapes the bushing to the riiied bore 25 and drives the bushing and its projectile 28 from the barrel I8. The heat generated by the powder charge 3| may assist in they forming ofthe bushing 29. The bushing 29 forced through the ried-bore 25 has spaced peripheral lugs 35 when it leaves the bore It is usually pre-y 25. The projectile 28 pierces the casing C yto provide a perforation? and the bushing 29 travel- 'ing with the projectile encounters or enters the perforation. The lugs 35 on the bushing lodge in the perforation P and this stops the bushing. The lugs 35 are very tightly driven into the perforation P and the bushing 29 is securely fixed in the perforation. The bushing 29 thus remains as a permanent reducing element or screen element 'of the casing C. 'I'he opening 36 of the bushing 29 may be of a predetermined or selected diameter trated somewhat modifled forms of gun units II and cartridges I 2.

The construction shown in Fig. 4 of the drawing includes a barrel |88 having a ried bore 25a whose inner portion' may be ared or tapered in the same manner as the bore 25. The projectile 28a employed in the bore 25a may be the same as the projectile 28 and ts the bore. A perforation lining or bushing 29a is arranged on the stem 33a of the projectile 28a. The bushing 29a is press-fitted on the stem 33a or is otherwise detachably connected with the projectile 28a. The bushing 29 is formed of steel, or the like, so that an electrolytic action will not be set up between the bushing and the steel casing when the bushing is lodged in the perforation. The body of the 'bushing 29 is of substantially the same diameter as the bore 28a to pass through the bore and lugs 50 are provided on the periphery of the bushing.A The lugs 50 are arranged and proportioned to pass through the grooves 26 of the rified bores 25a and are intended to catch or lodge ln the perfora- .21

4with the projectile. The lugs 50 pass out through the grooves 26a. 'As the projectile 28 passes through the wall of the casing C the lugs 50 strike the wall of the perforation formed by the projectile and thusvstopl the bushing 29H. The bushing 29a vis thus detached from the projectile 28a and the projectile continues outwardly. The

` Figs. 5 and 5a has a plain unried bore 25b.re ceiving 'a projectile 28h. 'llhe vprojectile 28b has a suitably pointed forward end and its inner end has a reduced' stem 33h. In this form of the invention spacedl longitudinal grooves 60 are pro-v vided in the projectile 28h. The grooves 60 are continuous and extend from the inner end of the projectile 28b to the pointed forward end where they die out. When the projectile 28D is fired to pierce the casing, the grooves 60 form. or leave lugs on the wall of the perforation. A perforation liner or bushing 29b is detachably arranged on the stem 33a to line the perforation formed by the projectile 28. The bushing 29b is plain or ungrooved and suitably fits the bore 25h. When the projectile 28b is fired the bushing 29b travels with the -projectile and| lodges in the perforation formed in the casing by the projectile. The bushing 29b encounters the lugs formed on the y wall of the perforation by the grooves 60 and is stopped -by the lugs, while the projectile continues on through the casing, cement and earth forma.- tion. The lugs on the wall of the perforation stop and hold the bushing so that the bushing is retained in the perforation to act as a reducer or liner vfor the perforation. Instead of forming grooves in the projectile as shown in Figs. 5 and 5a the projectile may .be made slightly smaller in diameter than the bore .25W and the bushing 29b so that the bushing will lodge in the perforation formed in the casing by the smaller projectile.

lHaving described only typical preferred forms of apparatus and of the manner of carrying out the method of my invention', I .do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art or fall Within the scope of the following claims:

Having described my invention, I claim:

1. A well tool for .perforating well casing comprising a body, a gun unit carried by the body, a projectile in the gun unit, a charge for firing the projectile, and a perforate trailer associated with the projectile to be fired therewith and formed to lodge in the perforation formed in the casing by the projectile.-

2. A well tool for perfor-ating Well casing comprising a body, a gun unit carried by the body, a projectile in @e gun unit, a charge for firing the projectile, and a tubular bushing ybehind the projectile adapted to be red with the projectile to lodge in the opening formed in the casing by the projectile.

3. A well tool for perforatlng Well casing comprising a body, a gun unit carried by the body, a projectile in the gun unit, a charge for firing the projectile so that the projectile forms a perforation in the casing, and a bushing for the perforation carried :by the projectile to line the perforation.

4. A well tool for perforating well casing comprising a body, a gun unit carried by the body, a projectile in the gun unit, a charge for firing the projectile, a stem on the rear end of the projectile, and a tubular member detachably carried on the stem and designed to remain in the perforation as a liner therefor as the projectile pierces the 'casing wall.

5. A tool for perforating well casing comprising a body tovbe run into the casing, a gun unit carried by the body and including a ybarrel having a bore and grooves in the wall of the bore, a projectile to be red from the bore to form a perforation in the casing, means for firing the projectile, and a bushing for the perforation associated with the projectile to be ilred therewith and designed to have parts that pass through the grooves and lodge in the .perforation to stop the bushing in the perforation.

6. A tool for perforating `well casing comprising a body to be run into the casing, a gun unit carried by the .body and including a barrel having a .bore and grooves in the wall of the Ibore, the inner portion of the bore being enlarged, a projectile to be fired from the bore to form a perforation in the casing, a charge for ring the proj ectlle, and a formable member in the enlarged portion of the bore and associated with the projectile to be red therewith and to be formed through cooperation with the bore and grooves to have parts which retain it in the perforation.

7. A tool for perforating well casing comprising a body to be run into the casing, a gun unit carried by the body and including a barrel having a bore and a groove in the wall of the bore, the inner portion of the bore being flared, a projectile to be red from the bore, means for firing the projectile, and a tapered member in the flared portion of the bore associated with the projectile to be fired vtherewith and cooperating with the flared portion of the 'bore to resist the pressure developed by said means until the member is formed to pass through the bore and itsV groove and Ythus have a lug for retaining the member in the perforation.

* 8. A tool for perforating well casing comprising a body to be run into the casing, a gun unit carried by the body and including a barrel having a bore and a groove in the wall of the bore, the inner 4portion of the bore being enlarged, a projectile to be fired from the bore, means for firing the projectile, a member detachably connected with the projectile to be fired therewith, and a lug on the mem-ber adapted to pass through the groove and to cooperate with the perforation to retain the member in the perforation.

9. A tool for perforating well casing comprising a body to be run into the casing, a gun unit carried .by the body and including a barrel having a bore, 'the inner portion of the bore being enlarged, a projectile in the -bore having a longitudinal opening, a powder charge in the gun unit for firing the projectile, means for firing the charge including an ignition wire extending through the opening to the charge, and a liner for the perforation in the enlarged portion of the bore adapted to be fired with the projectile to lodge in the perforation.

l10. A well tool for .perforating well casing comprising a body, a. gun unit carried by the body, a projectile in the gun unit, a charge for ring the projectile, a reduced stem on the rear end of Athe projectile, the projectile having a longitudinal opening which extends through the stem, a bushing removably arranged on the stem to be fired with the projectile and adapted to lodge in the perforation formed -in the casing by the projectile, and means for ring the charge including an ignition wire extending through the opening.

11. A' tool for perforating well casing comprising a body to be run into the casing, a gun unit carried by the body and including a barrel having a bore, the inner portion of the bore being enlarged, and a cartridge in the gun unit including a projectile in the bore, a bushing member in the enlarged portion of the bore associated with the projectile to be fired therewith and designed to remain in the perforation in the casing, a carrier element connected to the member, and a charge container secured to and sealed with the carrier element.

12. In a casing perforator for perforating a Well casing in a weil, a projectile for piercing the casing, and a bushing detachably arranged on the projectile'I to lodge in the perforation in the casing.

13. In a perforator for perforating well casing, a projectile for piercing the casing, and a tubular bushing element detachably connected with the rear end of the projectile to lodge in the perforation in the casing,

14. In a casing perforator to be lowered into a 9,212,044 well casing, a projectile for piercing the casing,

and a tapered bushing member oi' formable material detachably associated with the projectile to lodge in the perforation in the casing.

15. In a. casing pei-forator for perforating a casing in a. well, a projectile for piercing the casing, and a bushing element detachably arranged on the projectile to lodge in the perforation in the casing. the said element having projecting lugs.

16. In a casing perforator for perforating a casing in a well. a projectile for piercing the casing. the 'projectile having a longitudinal groove,

and a bushing element detachably arranged on the projectile to lodge in the opening formed by the projectile.

17. The method of perforating a casing set in a well comprising nring a projectile through the wall ofthe casing to form s. perforation therein, and lodging a bushing in the perforation.

18. The niethod of perforatlng a casing set in a well comprising ilring a projectile through the wall of the .casing to form a perforation therein. and firing a perforate element to' lodge in the perforation to form a lining therefor.

RALPH M. RIDLEY.