US2530707A - Perforating gun assembly - Google Patents

Description

Nov. 2l, 1950 R. A. LlLLlcH PERFORMING GUN ASSEMBLY Filed May 5l, 1946 I N VEN TOR.

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Patented Nov. 21, 1950 UNITED STATES PATENT OFFICE PERFORATING GUN .AS SEMBLY.'

Ralph A. Lillich, Houston, Tex.

Application May 31, 1946, Serial No. 673,538`

3. Claims.

' This;nventionfrelates;to afnewzand useful improvement in a gun assembly foryuse on perforating guns and the like.

In perforating pipe inl oil orwater well drilling,

a` perforating gun containing explosive chargesv andprojectiles to be discharged through the pipe to -be perforated, islowered into the well. The

charges are red by an electrical impulse and are controlled through an instrument", lowered into the well with the gun; When,1in the well, a iluid is encountered of alight. character having little,

if any, viscosity, and-.as is `-often thecase, under. high pressure, such fluid often*4 seeps through the connectionsV of the. various-parts. of the gun assembly, causing .a shcrtingzinrthe electrical` connections and va consequent-:failuretof the ex-` plosives to discharge., necessitating/a removal of4 the gunv assembly from therwell and afnewat-A tempt to perform thex-perforating-operation. It4

is anv object of. this:invention-:tozprovide= a--novel gun assembly so constructed fasrtofpositivelyprea vent seepage of'ifluid into thefgun'and to assure dryfwires` at all' times;

A union of the character described inmy applicationV for patent on'v Union, Serial Number 673,537 flied Vof even-date'herewith', is employed.

in this invention.

operations.

The above and other objectsfwill be apparentm fromA the .following descriptionand illustrated in" the accompanying drawings,` wherein:

Figure` 1v is ay vertical. elevational in view cross section, and

Figure2 is a continuance of :Figure-1 .-inzvertical elevation, partly-in cross section.'

Referring-now more particularlyto the drawings, the numerall indicates. asection of pipehaving the -male threads-Ito,bereceived bythev female threads of the conventional tubing (not shown) used in forming the-.operating string of pipef-inwell operations. An insulated electrical conductor, or cable, 3;.havinga -press seal 4, passing,v through.the-boreof-said-string of pipe is maintained insaid section Iy bymeansof the plug tif-which has one-end-flared and carries thevouta side threads to-:befreceived-.by the. -inside `threads 640isection. I; The section-:I has.-the'-circumfer entially reduced. portion 'I which tapers inwardlyA` and which has the outside threaded portion .-xv Adjacent the point of reduced circumference there is an annular groove 9 in which an O-ringj- I!! of rubber, or-similarresilient packing material,

is seated. The O-ring is circular in cross section and is of Va slightly greater cross sectional diameter than'the depth of the groove 9. The section Il has the outwardly taperedfemale threads I2 at one end thereof which terminate in the smooth Wall I3 adapted to abut against and slightly compress .the O-ring Itwhen the two sections 2V and,` Il are moved into joined relation. The section@ II has the outwardly tapered female threads` I4 at the opposite end thereof terminating in the` circumferentially enlargedjwall I5; A pipe sec-v tion forming a union member I5 having the ina- Wardly tapered outside threads II is received by.: said-.threads Illof the section II. A plug I'I `of.'- Bakelite or similar. non-conducting material.; bears outsidethreads to befreceived by the insidethreadedcharnb-er I8 in said union member I6): said plug havingan axial bore throughwhich the-.f electrical impulse conductor I9-- extends. When.; the assembly has been thus far assembled, thei unit is tested and. if; found to be satisfactorily.V assembled, the union member I6 is welded to the f section II as yshown` by the numeral 20.

The unionmember i6" is flared at one end-:1 formingl the'annular extension 2l. A coupling.y member Z2' being` inwardly ared at one end-4 forming the inner annular extension 23 is mount.- ed on said union member i6, the shoulder formed` bythe extension 23 abutting against the shoulder formed by the extension 2l. The opposing endY of` said coupling 22 is internally threaded, preferably with acme threads. The end face-df the-- flared-end of said union member. IG-has an` an-l nular groove 24 having tapering side walls in; which an O-ring 25 of rubber or similar resilientpacking material is mounted, said O-ring being.; circular in cross section and of greater cross sec-4 tionaldiameter than the depth of the groove 2A.- The quick-change unit section 26 has the reduced portion?! atv one end thereof, said portion. 2lbearing the outside threads, preferably acme threads, 28 to be received by the internally threaded portion of the coupling 22. A plug 29, of Bakelite or similar ncnconducting material, is seated in the chamber 3Q at one end of saldi section 2?, said plug having an axial-bore into; which one end-ofthe-conductor I9 extends. Whenthe section. 26-is1screyved into the coupling meme@ ber 22, coupling member 22 is turned, tightening the connection, bringing the end faces of the sections of pipe snugly together and the end face of the section Z6 abuts against the O-ring 25, slightly compressing the same.

An axial bore 3l extends through said section 25 and an electrical impulse conductor 32 extends through said bore 3l and contacts the conductor I9, the connection being made within the bore of the plug 25. A chamber- 33 at the opposing end of the section 26 is internally threaded to receive the plug formed of Bakelite or similar nonconducting material, 34, said plug having an axial bore through which the conductor 32 extends. rIhe section 26 has one end circumferentially reduced and inwardly tapered, a portion of said tapered area bearing the outside threads 35. Adjacent the point of reduced circumference said tapered area has the annular groove 35 in which is seated an O-ring 3l of rubber or similar resilient packing material, said O-ring bein-g circular in cross section and being of greater cross sectional dimension than the depth of the groove.

An instrument chamber 38 carrying the firing instrument 39 is internally threaded at one end to receive the threads 35 of the section 25, said internally threaded portion terminating in the outwardly tapered smooth Wall 40, said wall being adapted to abut against the O-ring 3l and slightly compress the same when the chamber 39 is moved into joined relation with the section 25.

The conductor 32 contacts the instrument 3S (not shown in detail) and conveys the electrical impulse thereto.

The chamber 38 has the internal outwardly tapered threads 4! terminating in the outwardly tapering smooth wall y42. A gun connecting union 43 has the circumferentially reduced inwardly tapered portion 44 which has the groove 45 in which an 0ring 45, of the same construction as above described for the O-ring 37, is seated. When the union 43 is screwed into the threads 4I of the section 38 the wall 42 will abut against said O-ring 46 and slightly compress the vvz same. The bore of the union 43 has the internal threads 41 to receive the outside threads of the conductor plug 48. The conductor 49 passes through the axial bore 50 of the plug 48 and is in contact at one end with the instrument 39 and at the other end with the conductor 5|, mounted in the plug 52. The union 43 has the internal threads 53 which taper outwardly and terminate at the outwardly tapered wall 54. rhe gun 55 is circumferentially reduced at one end and said reduced portion has the groove 56 in which the O-ring 5l, of the same construction as above described for the O-ring 3l, is mounted and said reduced portion has the outside threads 58 to be received by the threads 53 of the union 43, the wall 54 of the union 43 abutting and slightly compressing said O-ring 5'! when the threaded portion of the gun 55 is screwed tightly into the threads 53 of the said union 43. The plug 52 is formed of Bakelite, or similar nonconducting material, and has the external annular flange 59 midway of the two ends thereof. The bore Gil of the gun 55 has the circumferentially enlarged chamber 6l forming a shoulder on which is seated an O-ring 62 of the construction described above for the O-ring 31, the flange 59 of the plug 52 abutting against said O-ring 62 and slightly compressing the same when the union and gun are screwed tightly together. Conducting studs 63 convey the electrical impulses to the Wires 64 -through the wire plug 65. The Wires 54 are in contact with the explosives (not shown) which discharge the projectiles (not shown) through the projectile openings 6B, in the conventional manner.

When it is desired to change the gun and instrument, such as after a perforation is made and another perforation is desired, the coupling member 22 may be quickly and easily separated from the section 2S and a new section, instrument and gun substituted.

When fluid of a light nature, such as water, under high pressure, is encountered, if the pressure is great enough to force the iiuid through the various connections of the assembly, it will exert a force against the O-rings and will cause the material of the O-rings to flow and spread, positively blocking the fluid from entering the gun assembly. rlhe plug 52, carrying the electrical impulse conducting studs 63 being particularly vulnerable to snorting by contact with Water, or the like, is doubly protected from within or without the instrument by the construction shown in Figure 2, employing the O-ring 62 in a novel manner.

The embodiment of the invention herein shown and described is to be regarded as illustrative only, and it is to be understood that the invention is susceptible to Variation, modication and change within the scope cf the appended claims.

What I claim is:

1. In a perforating gun assembly, a series of connecting sections, a projectile discharging unit on one end of said assembly, said projectile discharging unit having an axial bore therein, said bore being circumferentially enlarged at one end forming a ledge, an O-ring of resilient packing material seated on said ledge, a plug carrying a plurality of electrical impulse conducting means mounted in said bore, an annular iange on said plug, said flange adapted to contact and slightly compress said O-ring when the gun is in assembled relation.

2. In a perforating gun assembly having a series of interconnected main subsections, one end of said subsections being reduced fo-rming a shoulder, and tapering inwardly, external threads on said tapered portion, an annular groove between said threads and said shoulder, the opposing end of the connecting subsection having inwardly tapered interna-l walls having threads to mesh with the threads 0f the connecting subsection and having smooth surfaces on the outer ends of said inner walls, a resilient O-ring mounted in the said annular groove of slightly greater cross-sectional circumference than the circumference 0f the groove and adapted to be slightly compressed by the smooth surface of the inner wall of the connecting subsection when said subsections are moved into connecting relation.

3. In a perforating gun assembly, a series of connecting sections, a projectile discharging unit on one end of said assembly, said projectile discharging unit having an axial bore therein, said borerbeing circumferentially enlarged at one end forming a ledge, an O-ring of resilient packing material seated on said ledge, a plug carrying a plurality 0f electrical impulse conducting means mounted in said bore, an annular flange on said plug, said flange adapted to contact and slightly compress said O-ring when the gun is in assembled relation, the outer wall of said end of said projectile discharging unit being inwardly reduced forming a shoulder, said inwardly reducedend being tapered inwardly and having external threads thereon, anfannular groove between said shoulder andu threads, a resilient O-ring'being of slightly greater cross sectional groove, a connecting subsection of said assembly having internal threads v,adapted to mesh with the external threads ``,oi said projectile discharging unit and having ajfsmooth internal face adapted to abut against ndslightly compress said O-ring when the subsections are in connected position.

RALPH A. LILLICH.

'radial Vdimension than the radial depth of the 5 REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,062,974 Lane Dec. l, 1936 2,202,887 Aloi June 4, 1940 2,264,450 Mounce Dec. 2, 1941 2,381,081 Schlumberger Aug. 7, 1945 2,388,938 Smylie Nov. 1'3, 1945

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