US2831429A

US2831429A - Shaped charge for perforating oil well casing

Info

Publication number: US2831429A
Application number: US488939A
Authority: US
Inventors: Allan B Moore
Original assignee: Moore Tool Co Inc
Current assignee: Moore Tool Co Inc
Priority date: 1955-02-17
Filing date: 1955-02-17
Publication date: 1958-04-22
Anticipated expiration: 1975-04-22

Description

April 22, 1958 'A. B. MOORE 2, 3

SHAPED CHARGE FOR PERFORATING OIL WELL CASING .Filed Feb. 17, 1955, 2 Sheets-Sheet 1 F/G. l v 17 A/Zm fifloare v INVENTOR.

I ATTORNEY April 22, 1958 A. a. MOORE 2,831,429

SHAPED CHARGE FOR PERFORATING OIL WELL CASING Filed Feb. 17.1955 2 Sheets-Sheet 2 FIG. 6

FIG. 9 2

INVENTOR.

. 7:::: BY (L; z 2.

'SHAPED CHARGE. FOR'PERFORATING YOIL WELL CASING nited States Patent Allen. B. Moore, Arlington,fTex;, assignor in; Moore Tool Co .,sllnc.,-Arlington, Tex.,-a corporation of Texas Application February "17, 1955, Serial No. 488,939

. 5. Claims. ;(Cl. .l.02-+20) mon to such formations, which present impediments to t the freeflow oftoil into the borehole andlthus interferes with the :maximum production of .the well.

. .Another object. of the. invention islthat or providing a method and apparatus. forperforating. or,.dissecting...oil well casing, both vertically andlhorizonfally, .so as tolpro- ,vide elongated openings therein atudifferent elevations. to encourage the flow of w'ellifluids thereinto,.tandvin.such instances as where certain portions .ofa wellcasing may be. liberated from, its subterranean anchorage as. when such casing is to be salvaged fromnon-productive wells, anclthe like, and which is .incapable ofb'eingi withdrawn until detached from any type ofss'ubterranean.securement, suchas cementing, andthe like. 7 t

, It is an object of the inventiontoprovide apparatus by which an explosive can-be; employed baseduponlthe so called Munroe Principle by which.elongatedflslitseor openings canbe defined in oil Well casing by inciting explosive materials formed in so..called fshaped: charges having definite ,conformations capable of directing: the force of the charges in controlled patterns, both vertically and horizontally, to produce rectangular openings .ofpredetermined length longitudinally of the casing and a spaced cincumferentiallythereof rather than circular perforations which are obviouslytless .efiectivethanslotted openingstof relatively great length.

A still further object of the inventionis that of providinglcharges shaped, in their containers, to insure a combination of both horizontal and vertical inclinations sofas to produce-intersecting cuts sonlruptures which will form windows or elongated g openi ngs,.or ,by which, when it"is'desired to sever a casing at a definite levelin the bore-hole for salvage as when the casing has been securely anchored by some process of cementing, or thelike. Yet another object ofthe.inventionrresidesiin .the tprovision of a method and apparatus for. usesin relatively .hard formations for fracturing the .sameina horizontal 'radial patternvto form, fluid passages 1 and. defineach-annels by which :mineral :fluids .can.enterrthe;taccessiblesarea for 7 recovery through the. bore-hole.

. .wBroadly, the invention: contemplatesrthe provisioniof a method for perforatingorsevering 'Oi1 gWel1';CaSlng,lI1 the -borehole,=;and fracturing ,or-separating: hard subterranean toil-bearing formations; and. apparatus 'for. performing vthe method, which. utilizesushaped directional charges of an texplosiverby which-accurate cuts'canwbe accomplished in bothzzhorizontal' and .vertical planes at dillerent elevations along a borehole.

:While: the *aforegoing objectszrare; paramount 1 other; and IJESSBI: objects :will becomezmanifest .as the description proweeeds etakenwinw connectiom ,with tthe appended.- drawings wherein:

' 2 F igure 1 is a fragmentary illustration ofone form of apparatus .showing a: multiple arrangement of liners, shown in partial section, ina refractorycontainer. Figure 2 is a plan view of. one ofthe liners forproviding a radial arrangement of vertical cuts.

Figure 3 is a plan view of .the circular horizontahliner for horizontal cuts. p u Eigure 4 schematically illustratesthe action oftthe vertical explosion on the casing, showing themdirectionnof .the shock waves to form vertical cuts. 3 t

:Figure 5.;is another schematic-illustration showing: the horizontal. movement of the shock waves and; showing the vertical radii of. the vertical. .jetsin dotted. lineszas projected'through the casing.

.':Figure 6 .illustratesa portion of a.unit formedxofl-a plurality-of vertical and horizontal liners'ina refractory container installed in a well casing, and indicating, by

.dottedlines, the horizontal .and vertical "action of the jets.

-' Figure 7. is a vertical sectional view of one of the vertical liners. Figure -8'.is aplan view of one of the end plates forthe vertical liners showing :its angular faces conforming to said vertical liners, and

. Figure .9 is a side elevational view-ofpne of the-,end

plates, as illustrated inF igure 8. i r ..It. isdesirable to penetrate the fluid-laden formations as :far as possiblerin all directions from theboreehqle, where theporosity of--suchareas are-heavily congested, and blast reservoirs and channels thereinfor'theaccumulation of oilwhich will subsequently'find its Way-into the bore. 'It is also' desirable to controlvthe shots. so that varying conditions ofthe several strata in a ,given well PIESGIllZgthQ' minimum of interference. inrdrillinglroperations-after the charges have been detonatedlimthesborehole. v a '1- Accordingly, the apparatus primarily comprises; amnitarystructuretof a' plurality of individualzliner's lfl' wliich are connected in axial alignment by a shaft-:or:rod.L-11 concentrically thereof, as illustrated in Figures 1t-,and"6, and separatedby

spacer plates

12 or 13 which;have conforming .concavities therein, as 'shown'in Figuresifi, Brand 9. "I'he'spacerplates 12 or 13 arearranged at .each' end ofthe liners 10 and these are spaced by rings orhorizontal liners 14, a locking plate 15being applied to each lend of the assembly and secured by a nut 16-threaded upon-the rod 11,.in the manner shownin Figures 1 and 6.

Aseries of the unitary structures just describedcanlbe associated by threading the upper'threaded end 1'7 of.. the

rods 11 into the internally threaded sockets 18 onthe lower ends"thereof.

spaced apart. Each arrangement of-individu'alunits; as shown in Figures l-or 6, are-preferably encasedwithin a refractory tube 19, such as a glass material-havingsuitable tensility, and each section of the tube 19 can bejoi-ned "by a light-metal sleeve (not shown)=Whichcan-functio1r as a coupler. lhetasseniblies :can be extended tozanyrde- .sired and practicable length.

5, Each of the vertical containers or liners 10*aresubst-antia lly cylindrical but also spheroidalyin general form,;having. their outer diameters extended,intermediatetheirzopen ends curving inwardly toward the ends which are open,

It is"therefore pos'sible to locate several units in a=well casing at dififerent levels, it desirable, and

jet into a relatively narrow course, in the manner shown in Figure 4, so thata vertical out can be accomplished by the explosive 23 contained in the containers or liners 10.

Between each'of the containers or liners isarranged either of the spacer plates '12 or 13 which comprises a 6 and 7, to present a bulbous circular plate, shown in detail in Figures 8 and 9, formed preferably of zinc'por similar materials, due 'tolthedesirabi1ity of the dissolution or fragmentation of such mate rials to present a minimum of hazardin fouling the well with hard materials having some capability of deterring the'drill bit if further drilling become necessary, The

spacer plates '12 and 13 have a conformation of V-shaped angularly inclined recesses or concavities 25 conforming to the complementary features and 21-of the liners 10 to present the structure shown in Figures 1 and 6'when these members are assembled. plates 12 are illustrated as having regular surfaces 12.

- Thes'pacer plates 13, shown in Figure 6, are formed with circular recesses 26 on their planesurfaces which are defined by circular shoulders 27 into'which the parallel circular flanges 28 of the rings 14 are seated, as apparent in Figure 6. In the structure shown in Figure'l the rings 14 are seated against the surfaces of the plates 12 which, as in the modified structure shown in Figure 6, closes each side of the rings 14 to provide a circular chamber for an explosive material 23. Y 4

It is a phenomenon peculiar to the Munroe Principle that explosive charges shaped in theangular manner of those described and illustrated herein react to resistances presented bysurfaces arranged at right angles to each other, or where right'angular lines from their opposing surfaces can intersect, as illustrated in Figures 4 and 5. Thus the rings 14 have V-shaped perimeters between-the flanges 28 thereof which will cause a convergence of the jetto effect a horizontal cut 29 in the well casing 30, indicated by'the dotted lines in Figure 5,1acting in coordination with the vertical V -shaped recesses or concavities 20 formed about the liners 10 which etfectthe vertical or longitudinal cuts 31 also indicated by dotted linesin Figures 4- and 5.

In Figure l'the spacer The shapes of the charges of explosives 23, present rings 14 will be directed in a horizontal plane, the sur- I faces 32 causing the jet to converge into a relatively thin line, asindicated by the arrows in Figure 5, to effect a horizontal cut.

1 Referring to Figures 4 and 5 which illustrate the action of the explosive 23, it will become apparent that there is a controlled focussing of the jet force both vertically and horizontally so that a predetermined cut can be accomplished on each plane. This action is illustrated by the arrows and by dotted lines in these views. the solid V-shaped lines indicate a convergence of the jet action to effect the vertical cuts while Figure 5 shows the convergence of thejet from the ring 14 in dotted lines,

the horizontal cuts being indicated by the arrows, and the radial action of the liner jets being shown in dotted lines which intersect the horizontal cuts effected by the rings In Figure 4 1 4 14. This action is also indicated by dotted lines, with pointers, in Figure 6.

At intervals along the rods 11 are formed circumferential grooves 33 in which are arranged booster charges 34, and these are placed intermediate the opposing sides or ends of the charges of the explosives 23 within the liners 10 and the rings 14, as illustrated in Figure 1, which co-act with the primer cord or fuse 35 arranged through a concentric bore 36 longitudinally of the rods 11. The angular concavities of the

plates

12 or 13, which conform to those of the liners 10, .serve the function of directing the jet downwardly and upwardly to intersect the radial jets of the vertical concavities 20 of the liners 10 to complete the vertical cuts in the casing 30, and insure an intersection of the jet waves with the horizontal action of the rings 14.

An important feature of the form of apparatus shown in Figure 6 is the recessed faces of the spacer plates 13 of this structure with the identical face of the locking plates 15. As previously stated, the plates 13 have anannular recesses 26 formed in their surfaces opposing the angular recesses or concavities 25 thereon, thus providing a seat for the lips or flanges 28 of the rings 14 which confine these members until the jet is formed. Concentric with the annular recess 26 in each of the members 13 is a circular recess 37 ,to accommodate additional explosive 23 on each side of the rings 14, as apparent in Figure 6. The'spacer plates 13 and the locking plates 15 thus provide a casing for the explosive 23 and confines the shock waves to afford greater effectiveness.

The shape of the liners 10, as illustrated in Figure 2, for example, will insure radiation of the shock waves or jet in all directions horizontally, and by reason of the convex formof the members, radiation will occur vertioally also to intersect the horizontally directed shock waves of the horizontal liner ring 14, as demonstrated in Figures 4 and 5. It is not intended to limit the liners 10, however, to any particular form as to the shape of the indentations or concavities 20, orthe number of these conformations, but it is of importance to shape these so as to accomplish the radiation desired; The overall shape of the units, when the liners 10 and the spacer plates 13 are combined, will effect the desired radial pattern in a manner to form both horizontal and vertical cuts in the casing 30, or formation, without interference between the planes of force.

Manifestly, the structure herein shown and described is capable of certain changes and modifications from time to time, by persons skilled in the art, without departing from the spirit and intent of the invention or the scope of the appended claims.

What is claimed is:

1. Apparatus for perforating well casing in a bore hole comprising a truncated substantially spheroidal container formed with open ends and having an explosive therein, a series of convolutions formed by the wall of the container defining longitudinal concavities, the concavities being arcuate in a plane parallel to the axis of the container, a closure for each end of the container comprising a spacer plate having angularly inclined concavities formed thereabout' complementing the longitudinal concavities of the container and defining a circumferential V-shaped juncture with the arcuate concavities, a ring container having a an anular recessed face arranged adjacent each of the 'closing each end of the container and formed wtih angular recesses complementing those of the-container and inclined at right angles inwardly with respect to the recesses of the container at each end thereof, an annular V-shaped casing arranged in a horizontal plane adjacent each of the spacer plates, an explosive material in the container and the V-shaped casing, means for rigidlyassociating a plurality of the containers and the spacer plates in an operative unit, and a refractory casing for the unit.

3. In apparatus for perforating oil well casing by performing horizontal and vertical cuts therein by an explosive, a truncated substantially spheroidal container having a convoluted wall forming arcuate recesses therein axially of the container,spacer plates having angular recesses therein corresopnding to the recesses in the container and closing the ends of the container, the recesses in the plates being disposed at right angles to the ends of the recesses in the container, defining a V-shaped concavity circumferentially of the ends of the container, an annular container, formed with inwardly directed V- shaped walls and having parallel flanges extended from the walls, arranged adjacent each of the spacer plates, an explosive in the spheroidal container and in each of the annular containers, means rigidly associating said members in axial alignment, and ,a cylindrical container for said associated members.

4. A device for cutting oil well casing by explosives comprising a liner having a truncated substantially spheroidal form, open at each end, the liner having a convoluated wall defining axially arranged recesses, an explosive in the liner, a spacer plate at each end of the liner closing the ends of the liner and having angularly disposed recesses comformable to those of the. liner and inclined inwardly to connect with the convolutions of the wall of 6 the spheroidal liner, an annular liner having an inwardly formed V-shaped face arranged adjacent each of the spacer plates opposite the substantially spheroidal liner, an explosive in the annular liner, means for associating a plurality of the substantially spheroidal liners, the spacer plates and the annular liners in a unitary assembly, and a refractory casing for the assembly.

5. A device for penetrating oil well casing and productive oil formations by explosives comprising a unitary structure consisting of a truncated spheroidal container having axially convoluted walls defining vertically arcuate spaced recesses and open at each end, spacer plates closing the ends and formed with axial recesses inclined inwardly to complement the recesses of the container, an annular casing having a V-shaped face presenting radially inwardly inclined surfaces about its circumference, an explosive in the container and the annular casing, means for associating the container, spacer plates'and annular casing in a unit, means for detonating the explosives, and a refractory casing for the assembly.

References Cited in the file of this patent UNITED STATES PATENTS Germany Dec. 21, 1953