US2679899A - Mechanism for perforating well casings - Google Patents

Description

| c. osBoRN 2,679,899

MECHANISM FOR PERFORATING WELL CASINGS 2 Sheets-Sheet l June l, 1954 Filed Dec. 5l, 1949 June 1, 1954 l.. c. SBORN 2,679,899

MECHANISM FOR PERFORATING WELL CASINGS Filed Dec. 5l, 1949 2 Sheets-Sheet 2 F/GS //Vl/E/\/7`OR LANDON C. OSBO/QN ATT RNEVS Patented June 1, 1954 UNITED STATES PATENT OFFICE rMECHANISM FOR PEREORATING WELL CASINGS Landon .-C. OsbormBakerseld, Calif., assignerl to YLane-Wells Company, Los' Angeles, Calif., `a

corporation-of Delaware Application yDecember 31, 1949, serial-No. 136,205

(iClaims. l

vThis invention relates to improvements in mechanism for perforating well .casings and, While not restricted thereto, said mechanism is especially adapted for perforatingrthe casingsof oil `Wells.

The oil-bearing formations that are drained by wells frequently are soft, unconsolidated sands. Under these conditions a well must be lined or cased with -steel -pipe vin order to maintain the well hole open. Sometimes vthe oil vpipe casing is run into the Well without per-forations and is perforatedafter the casingis mounted in place within the well hole. Suchcasing isalso commonly used to keep water from entering the Well from Water-bearing strata either above or below those containing-oil. The annular space between the casing vand the strata formations usually is-lled with cement. Sometimes, an oil stratum is cemented off in back of a string of-casing pipes-or a number of strings of -casing may be cemented together inside of one another. Later, if it is .desired to open the well to such oil stratum, perforations are-made through thevcasingor casings and the cement.

In modern Well drilling, it hasbecome a common practice to accomplish such aforementioned perforating Aby shooting small, yhard projectiles of various shapes and sizes against the inner .surface'of such casings vso as tolpenetrate thev same and any cementrwhich may be in back of the casing, as Well as the stratum in back .-offthe cement. The projectiles aredrivenby vanexplosive charge from a gun. Such operation is 'known as lgun perforating and is accomplished :by means l-of a gun made, forexamplaof aiheavyfoylindricalbar of steel of a size that can readilybe introduced into the interior of the casingVsupportedby a cable from the upper end of the Wellor casing.

The cable usually includes insulatedelectrical conductors by means of which the shotsor cartridges are selectively-fired as desired. The gun is provided with a plurality of chambers or barrels which arerspaced longitudinally of thegun relative to each other, the axes Vvof the barrels being disposed transversely to the axes ofthe gun. Said chambers or barrels carrythe-explosive material and bullets or projectiles whichmay be hereinafter referred to as cartridges. rSaid chambers or barrels are fitted into Arecesses .provided in the cylindrical bar of the gun by-screw threads or otherwise.

A means is usually employed softhat-onlyone electrical conductor inthe cable is required-for the selective dischargeof individual-shots erprojectiles from the `gun perforator. One way which 'this may be accomplished is by having progressively greater resistances in series with theV live wire used for detonating and having Yall of :these circuits in Yparallel with the 'insulating Wire in the cable -and the cable itself. At the surface adjacent `the upper end of the well, a circuit runs from -the cable through a source of current, an ammeter, a variable resistance, and then to the insulated line in the-cable. Other suitable arrangements may be used.

11n order `to reach oil-bearing sands-with+pro jectiles `red from the barrels -of said gun, said projectiles sometimes mu'stpenet'rate through several strings of steel l'casing Vas stated above, disposed one Voutside of the other, in -addition to cement between -the casing-s and a yconsiderable additional-thickness-of cement betvveenthe outermost casing Yand the formation of oil-bearing sands. In addition to the necessityof having Ythe projectile-pass through these considerable thicknesses of steel and-cement,- it is l desirable -toi have the projectile penetrate as far as possibleinto the oil-bearing formation itself. A number of factors, and particularly the diametery of the bore -h'oleof-fthe well, place a-practical limit upon the amount of explosive charge that may be used and therefore the amount `of vpenetration.that maybe attempted with presently used perforators.

It is an objectof the present inventionzto provide means which areattachable to one end-lof ya multi-barrelled perforating gun and lowered therewith `into awell casing, .said means including vpositioning or support mechanism which Ais operable rmlyto engage the inner surface of the Well casing at a predetermined position therein, :and gun shifting means .operable following the initial'firing of a cartridge. from one or more of thebarrels Vofsaid gun successively to position other barrels and cartridges vopposite the penetration made 'by the initially red projectile, whereby additional projectiles may successively be red into and through said-initial penetration to effect extended penetration. of the Well casing or-casings, any cementassociated therewith and the `stratum :in'backY of .said cement.

.It is anotherpbjectof the invention to provide gun positioning and shifting :meanswith actuatingand controlmeans which may be operatedffrom `the surface at the iupper endof 'the Wellcasingand, ywhen so operated, eifectthesuccessive positionings-of additional cartridges oppositelan initially ymade penetration or penetrations, iwhereby -said additional cartridges `may `be successively iiredtherethrough vvso as:;to make repeated attack at the same location in a well casing and thereby effect a satisfactory penetration into the stratum behind said casing.

A still further object of the invention is to so construct said gun positioning and shifting mechanism that it is simple in construction and operation, rugged and durable, adapted to the limited spaces within Well casings, and may readily be disengaged from an oil well casing to permit movement of the positioning and shifting mechanism relative to said casing such as when it is desired to withdraw the same from the casing.

Details of these objects and of the invention, as well as other objects thereof, are set forth in the following specificationV and illustrated in the accompanying drawings forming a part thereof.

In the drawings,

Figure 1 is a fragmentary sectional view of part of a well hole lined with casing and cement andY illustrating within said casing a multibarrelled perforating gun connected to gun positioning and shifting mechanism embodying the principles of the present invention.

Y Fig. Y2 is a longitudinal sectional view of the gun shifting mechanism secured to part of the upper portion of the gun positioning means of the invention and illustrated on a larger scale than in Fig. l.

Fig. 3 is a longitudinal sectional view of the lower portion of the gun positioning means emllcaodying the present invention, said figure, when considered in conjunction with and below Fig. 2, comprising a sectional view of the entire assembled gun shifting and positioning means of the invention. In Fig. 3, the lower end of the positioning means is shown secured to a fragmentary portion of a well casing.

Fig. 4 is a sectional view taken on the line l-i of Fig. 3 and shown on a larger scale than in the latter figure.

Fig '5 is a sectional view taken on the line 5-5 of Fig. 3.

Fig. 6 is a vertical sectional View taken on line 6 6 of Fig. 3. Fig. 7 is a vertical sectional view of the lower portion -of the positioning means of the inven tion illustrated in the lower portion of Fig. 3 but showing the gripping members of the holding means in retracted position.

Referring to the drawings, a longitudinal sectional view of part of an oil well casing I is illustrated in Fig. l, the same being disposed within a bore hole I2 formed in a section of stratum I which will be presumed to be oil bearing. The exemplary casing I0 is secured within the bore hole i2 by cement I6 which iills the space between the walls of the bore hole IZ and the exterior surface of the casing Il). The

` cement is primarily for purposes of securing the casing Iii fixed within the bore hole i2. This illustration is merely exemplary of one type of well arrangement in which the present invention may be utilized. It is to be understood, as stated above, that it is not uncommon in oil well bore holes to have two or more strings of casings disposed within each other, the casings, of course, being of different sizes so that the `smaller strings of casing may extend through those of larger size. Under such circumstances, it is customary practice to seal and hold the thus nested strings of casing in operative relationship by disposing cement between the pipes or tubes comprising the Y nested casings. It is contemplated that the pres- 4 ent invention be used with all such various arrangements which are customarily found in wells and especially oil wells. Y

As has also been stated above, Voil-bearing strata of sands, shale, and the like, are sometimes drilled or bored through and sealed off by means of cement surrounding the oil well casing, as well as the casing per se which is imperforate. Subsequently, should it be desired to tap any of the said sealed-off strata in back of the well casing Vand cement, the present invention is utilized for purposes of perforating the casing or casings and cement which surround the casings so as to effect communication between such stratum and the interior of the innermost string of casing. Further, the present invention in used to vperforate oil well casing or casings and cement surrounding the same which occurs at the lowermost levels of an oil Well so as to render the normally imperforate section of casing in said lowermost levels capable of permitting the flow of oil into the casing by perforating the casing or casings and surrounding cement in addition to permitting the flow of oil up through the open lower end of the casing or through any filtering or straining device which is usually mounted in the lower end of said casing in an oil well.

The present invention comprises means for initially positioning and subsequently shifting a multi-barrelled casing perforating gun I8 relative to the casing I0. Guns of this nature usually comprise a heavy cylindrical bar of steel of a size which can readily be introduced into the casing I9, the gun being supported within the casing by having attached to the upper end of the gun a cable 2U by means of which the gun IB is lowered from the upper end of the well into the casing I0. Such cable usually is a composite type and includes, in addition to the steel tension portion, insulated electrical conductors by means of which the explosives in the barrel or chamber units 22 in the gun casing are fired. The barrel or chamber units 22 may be secured to the gun casing I8 by threading said units laterally into suitable apertures provided in the casing I8. The units normally contain an axial barrel opening for supporting and directing a projectile, and a communicating cavity in the rear of the barrel which contains an explosive charge. The exemplary illustration of the gun I8 shown herein shows a longitudinal row of barrel units 22 spaced apart even distances, twelve of such units being illustrated herein with the barrels of the units extending laterally to the axis of the guns I8.

Well casings which are most frequently perforated are of the order of six or seven inches in diameter, for example. Successful perfora tion of such casings requires a relatively large charge of explosive material in order successfully to propel a projectile from a barrel unit with suflicient force to penetrate the well casing and, preferably, the cement lining I6 surrounding the casing and part of the stratum behind the cement. Various sizes and shapes of projectiles may be used, depending upon the thickness and kinds and combinations of casings and cement to be penetrated. The amount of explosive charge may be varied by using barrel units having suitable capacitiesfor the charge, as well as barrel diameters suitable to accommodate the shape and size of the projectile. Relatively small sized cartridges generally are ineffective and only high powered, relatively large explosive charges are satisfactory to eiect penetration with `projectiles of substantial size. In viewfof the limited size within which the gunmay be disposed withinan -oil well and also, in view of the fact that the projectiles and charges must be held within barrel units mounted within the gun casing, conventional specially designed units are used, the same not comprising part of the present invention and, therefore, further description thereof not being believed to be necessary.

In accordance with the present invention, a gun positioning means 274 is used in association with a multi-barrelled perforating gun I8 and one or more gun shifting units 26 are connected to and between the positioning means 2i and the perforating gun i8. When the gun, shifting units, and positioning means are assembled in a string arrangement as illustrated in Fig. 1, there is alsofprefera-bly provided, adjacent the opposite ends of said assembly, centering means ZB-which may comprise for example, a plurality of semi-elliptical leaf springs 29 of which the intermediate portions engage the interior surface of the ycasing ii! so as to maintainthe axis of the assembled string of elements substantially in coincidence with the axis of the casing l. The'springs 28 may be supported at their ends by 4any suitable anchoring mechanism by which the springs may be attached'to the ends of the assembled string of mechanisms.

Referring now particularly to Figs. 2 and 3, the gun positioning means 24 comprises a tubular body 30 which has a plurality of radially disposed openings or slots 32 formed in the lower portion thereof as shown in Fig. 3, the same slidably supporting'for lateral movement relative to the `body 30 a plurality of casing gripping members 3d shown in detail in Figs. 3 and 5. The outer ends of the gripping members 3d are provided with a row of hardened teeth 36 which engage 'and bite into the inner surface of the casing Ill when the gripping members 124i are moved radially outward from the slots 32 by means to be described.

In the present embodiment, only two diametrically opposed gripping members are illustrated, but it is to be understood that such number is not to be considered restrictive since other numbers of such uni-ts may readily be used. Said gripping members 3A are normally biased in- Ward to their retracted position, illustrated in Fig. '7, by any suitable means such as a pair of coil'springs 38 secured at their ends to opposite sides of the gripping members 34 by bolts or pins The lower end of the casing 3@ has a shouldered plug d2 which threads into said lower end of the casing until the shoulder preferably abuts the end thereof as shown in Fig. 3. A threaded extension lli of a smaller diameter than the plug is integral with the lower end thereof for purposes of permitting attachment thereto of the lower centering means 28. The upper end of the plug is provided with a central conical or wedge-shaped recess 46 for purposes to be described.

Telescopically mounted for slidable movement relative to the upper end of tubular body 3G is a cylindrical member 43 which is detachably connected to the lower end of a sleeve 5@ by means of threads as clearly shown in Fig. 2. The upper end of sleeve'5ll is threadedly connected to the lower end of a coupling 52, the upper end of which is threadedly connected to a tube 54 comprising part Vof one gun shifting unit 26. Slidably mounted within and projecting beyond the upper end of -tubei5'4 of thef-'gunshiting unit is an inner sleeve -5B, the-upperendof which is provided with threads 58 to'whichfthe lower end of the casing of gun I8 isithreadably secured. In the assembly shown in Fig. -1,1two gun shifting units 26 are shown, while in Fig. r2, only one such shifting unit isshown for purposesof simplification. Assuming that the assembled gun, shifting units and positioning means have been lowered into the well by cable-250 until uthe gun I8 is opposite the position in the well where perforation is desired, the support orpositioning means 2li is operated as follows:

An auxiliary gun 65 is positioned in thelo-wer end of sleeve 5G between the upper end `of cylindrical member Q8 and an annular shculderd-Z formed on the interior of sleeve 50. The auxiliary gun 6!) may simply be acylindricallblock having a breech chamber and barrel Eliin which is positioned a projectile '65 and a charge 68 `of explosive material. An electr-ically controlled detonating member 'i0 is threaded into the upper end of barrel openingvli anda fir-ing cable 'I2'is connected to detonating member l-saidl-oable extending upward to the support cable -f2lll-and the cable l2 may comprise part of the-assembly of wires and other strands comprising cableZD as described above. Thus, the upper end of-the firing cable will be disposed atvthe upper end of the Well so that the Acontrol for the operationof detonating member lil may be performed byan attendant at the surface. The cylindrical member 13B is provided in one wall `with a longitudinal hole 'it axially aligned with the barrel-6d of the auxiliary gun 6D.

An actuating member l@ is disposed in the. lower portion of thertubular -body 39 for movement axially thereof as can be seen from Fig. v3. The lower end of the actuating mem-ber lois formed to comprise a wedge 78, the sides of which are engageable with surfaces Se onthe inner ends of gripping members 344, said surfaces being complementary to the inclined sides-of wedge 78. Threaded into the upper end of vactuating member lS is an enlarged headi which is, initially positioned with the actuating member 16 in the dotted line position of the head illustrated in Fig. 3. Said initial position of the lower end of actuating member 'E6 and wedge i8 is as illustrated in Fig. '1.

Latching means comprising a split clamp cooperates with the head t2 to maintain the same in the elevated dotted line position thereof il-lus-, trated in Fig. 3 while the assembled mechanism shown in Fig. l is being lowered into oper-ating position within the casing iii. Details of the clamping ring 84 are best shown in Fig. 4. The tubular body 3S is provided in opposite walls with a relatively small opening 8S and, in the lopposite wall, a larger, segmentally shapedslot or opening 88 is provided. The clamping ring 84 comprises a pair of respectively articulate inein-v bers 9i) which are semi-circular and the ends thereof extend radially in opposite directicnsas clearly shown in Fig. fl. One end 92 of each member 96 is bent intermediate the ends thereof 'toi provide angularly related portions. When lthe two members Se are in position to clamp the head 82 of the actuating member as illustrated in Fig.` 4, two of the angularly related portions of the ends 92 are in abutting position and will be held there by the ends 92 engaging the end walls of opening 86 'as shown in Fig. 4. The opposite ends 94 of each of the members 90 have juxtapositioned concavties 96 cooperating to form-a bearing-like opening which receivesrtheeshaft 98- of a trigger-like locking member |00. When the members 90 are positioned to clamp the head 82, the ends 94 of the members abut.

The locking member is vertically movable relative to the opening formed by the concavities 90 and the lower end of the shaft 98 is slidably supported with some friction within a suitable bearing member |02 secured to the tubular body 30 as clearly shown in Fig. 3 and Fig. 6. Extending outward from the shaft 98 intermediate the ends thereof is a pair of L-shaped locking arms |04 which have legs extending upward to engage said opposite ends 94 of articulate clamping members 90 so as to hold them in juxtaposition as shown in Figs. 4 and 6 when the locking member is disposed in its uppermost position shown in Fig. 6. The upper end of the locking member |00 is provided with a central conical cavity |06 in vertical alignment with the axis of hole 14.

When the assembly of mechanisms illustrated in Fig. 1 has been lowered into the casing l0 to the position wherein perforation of the casing is to take place, the lowering movement of the cable is stopped. Suitable control mechanism at the surface is actuated by an attendant to detonate the charge 68 within auxiliary gun 60, whereupon the projectile 66 is fired downward through hole 14 and into engagement with cavity |06. The impact of the projectile with locking member |00 drives it downward and disengages locking arms |04 from said opposite ends 94 of the split clamp members 90. From Figs. 3 and 6 especially, it will be seen that the head 02 terminates at its upper end in an enlargement, the lower annular edge 95 of which is tapered inward and downward. The engaging curved edges of clamping members 90 are complementary to surface 95 on head 82. Thus, when locking member |00 is disengaged from said ends 94 of the clamp members 90, the weight of the head S2 and the mechanism depending therefrom, as well as another force to be described, immediately moves the surface 95 of head 82 against the complementary surfaces of clamp members 90 with a camming action and spreads the ends 94 of the clamp members apart as shown in dotted lines in Fig. 4.

The ends 94 of the clamp members will be limited in their outward movement by engaging the end walls of slot 88 in body 30. In order that the inner surfaces of clamp members 90 will permit passage therebetween of head 82 and especially the enlargement at the upper end thereof within the confined space afforded by the interior of tubular body 30, each clamp member 90 is articulated, each comprising a pair of curvedY sections pivotally connected by a hinge 91 as shown in Fig. 4. The hinges are so constructed that they have inner shoulders 99, which preferably abut when in clamped position as shown in full lines in Fig. 4. However, the hinges also have outer shoulders |01 which are spaced when the curved sections of members 90 are in clamped position as shown in full lines in Fig. Ll, so as to permit further outward movement of sections |03 of the members 90 after the hinges Sl engage the inner surface of tubular body 30. Thus, it will be seen that sections |03 can be moved entirely out of obstructing positions relative to head 82, asis clearly illustrated in dotted lines in Fig. 4. When the clamp members 90 are moved to the released, dotted line position shown in Fig. 4, the other two angularly related portions of ends 92 of said members will be in abutting relation asshown in dotted lines in Fig. 4. and 94 of the articulated clamping members 90 will always be disposed within slots 86 and 88, whereby they maintain the members against movement longitudinally of body 30.

Actuating member 13 having been released for movement downward relative to tubular body 30,

such downward movement is not only induced bygravity but will also be assured and motivated by a compression spring |08 disposed betweenrra collar I0, which is removably secured to the interior of tubular body 30, and an annular shoulder H2 immediately above wedge 18. downward thrust of the actuating member 1B and wedge 18 causes said wedge quickly and forcibly to move the gripping members 34 radially outward from the slots 32 in the body 30, whereupon the teeth 36 on the wedging members engage the inner surface of the casing I0 so as r to somewhat bite into said surface and effecta fixing of the gun positioning means 24 relative to the casing i0.

After the firing of the projectile 00 has taken place and the xing of gun positioning means 24 has been effected as aforesaid, the cablel 20 is slacked off. Inasmuch as the lower portion ||4 of cylindrical member I48 is smaller in diameter than the upper portion of said member, the lower end of portion |i4 abuts the upper surface of head 82 of actuating member 'i6 when said head is secured in elevated position by split clamp 84 as shown in dotted and full lines in the upper end of Fig. 3. However, after the actuating member l0 and head 82 have been moved to their lower full line position in Fig. 3 following the ring of projectile 60 and due to the cable 20 havingbeen slacked off, the member 48 and all of the interconnected mechanism including the gun i8 will quickly move by gravity downward so as to effect a sharp impact between the end of lower portion H4 of cylindrical member 48 and head 82 of actuating member 75. A very substantial heavy mass will thus be moved downward into impact with the actuating member 16 to drive said member farther downward andr force farther outward the gripping members 34 into very firm frictional engagement with the inner surface of casing i0, the teeth 36 of the gripping members being well-embedded within said inner surfaces vof the casingI as a result. Thus, the weight of the members which engagethe head 82 of wedging member T6, as well as the force exerted by spring |00, will serve toY maintain the gripping members 34 firmly in engagement with the inner surface of casing I0 and effectively fix the gun positioning means 24,l as well as the gun |8 and shifting units 26, relative to the casing i0.

Accurate positioning of auxiliary gun 60 relative to member 40, so as to axially align the barrel 64 of the auxiliary gun and hole 74 of member 48, is effected by any suitable means such as a positioning screw Ht in the auxiliary gun 60 which extends into a slot i8 formed in the upper end of member 48. Said positioning means thereby maintains said axial alignment while the gun 60 is being secured between the upper endV of member 48 and shoulder 62 of sleeve 50. Cylindrical member 48 is also prevented from rotating axially relative to tubulark body 30 during telescopic movement thereof by the provision of a plurality of slots |20 in the body 30 which receive the heads of guide bolts |22 secured to,

cylindrical member 48. The slots |20 are parallel to each other and theaxis of body 30. Any

The ends V02- Such.

lsuitablenumber of, suchslots; |20 and bolts |22 maybe provided'in circumferentially spaced relation. about the tubular body 3|).

The assembled gun I8, shifting unitsY 25, and gun positioning means 24 are now secured Within the casing I in position for having one or more of the charges within the barrel units 22 detonated in order to re the projectile in each gun so detonated` into the oil well casing so as to penetrate the same and the cement lining behind the casing. As stated hereinabove, either one projectile may be fired so as to penetrate the casing andV cement or a plurality of initial projectiles may be red simultaneously or in quick succession to penetrate the casing and cement at a plurality of spaced positions. The exemplary gun shown herein is illustrated as having twelve barrels or chambers 22. Assume that barrels 1, 4, 7 and 10, counting the barrels upward from the bottom of the gun, are fired initially. Four spaced penetrations are thereby formed through the casing and cement which may possibly extend into the strata Ie behind the cement. A greater depth of penetration may now. be eifected by selectively actuating the gun units 26 in a manner to be described so as to place additional loaded barrels 22 radially opposite-the penetrations effected by firing barrels 1, 4, 7 and l0 as described.

Details of the electrica1 means for detonating the` charges in the various barrels is not illustrated in detail herein as the same may be any conventional mechanism. For example, one means frequently employed involves only one electricalY conductor in thev cable 2l). discharge of individual projectiles from the perforator gun I8 may be effected by providing progressively greater resistances in series with the live wire used for detonating and placing all these, circuits in parallel with an insulating wire in the cable andthe cable itself. A source of current is connected in the circuit, together with an ammeter and a variable resistance. By manipulation of the mechanism in said circuit, selective firing of the charge in any desired barrel 22 of the perforator gun 8 may be effected.

Following the initial iii-ing of one or more projectiles into the casing initially to penetrate the same, one of the gun shifting units 2t may be actuated to dispose another loaded barrel and projectile opposite each initial penetration by the following mechanism:

Each of the gun shifting units 25 comprises a cylindrical. tube ft secured at its lower end to the upper end of the coupling. 52 asv shown in Fig. 2.

The tube 5t is provided intermediately of its ends with a plurality of circumferentially spaced slots |24' which extend parallel to each other and the axis of tube 54. The inner sleeve 55 is provided with radially extending bolts or threaded guide pins |25 which are sliclably disposed in slots |26, thus preventing axial rotation between the inner sleeve 56 and tube 54 and also limiting in at least one direction longitudinal movement between the sleeve 58 and tube 54.

In its initial position in which the gun shifting unit 25 is lowered into the casing l0, the guide pins |26 are disposed in the upper ends of slots |24 and are held in such position by locking means comprising a plurality of ball locks |28 disposed in holes |39 formed in inner sleeve 58. The ball locks |28 also extend into concavities |32. formed in the inner ends of threaded plugs |34.. The ball locks |28 are held in the locked positionl thereof illustrated in Fig. 2 by means of Selective a collapsible toggle |36 comprising a pair of members pivotally connected together at their inner ends by a pin |38 which also secures said members to the lower end of a vertically movable yoke ist. The yoke is provided with a longitudinally extending slot M2 Iwhich is disposed between the ends of the yoke, the slot accommodating a retaining bolt lili extending between opposite walls of inner sleve 55 as clearly shown in Fig. 2. In the locked position of the toggle l 355, the lower end of slot |42 is opposed adjacent retaining bolt |443.

Another auxiliary gun |56 is threadably xed to the upper end of inner sleeve 56, said auxiliary gun having a barrel opening extending vertically and containing a projectile |58 and a suitable charge of explosive. A firing cable |5t is connected to the detonating means of the gun E55, said cable extending upward so as to comprise part of or merge with supporting cable 20. The upper end of yoke |59 is provided with a central cavity |52. The charge within the auxiliary gun M5 is detonated by control means at the surface, the projectile ili thereby being discharged into cavity |52 of yoke It@ to move the same downward and eect collapsing of toggle 53S, whereupon ball locks l 28 may move out of the concavities |32 and permit telescopically slidable movement between the lower portion of inner sleeve 55 and the upper portion of tube 5e, such movement being guided by pins |26 within the slots |25.

Downward movement of the inner sleeve 56 and the perforating gun |3- connected thereto, as well as any other intermediate gun shifting units 26, is limited by engagement of the lower end li of inner sleeve 5S with the upper surface of a plug |55 threadably connected to the upper end of coupling 52. rlhe plug 56 has a flange portion i5? which seats on the upper rim 53 of coupling 52. rlhe thickness of flange |57 is made such that the upper surface thereof extends below the lower end |5 of sleeve 5t, 4when sleeve 5t is in its uppermost position a distance exactly equal to the space between the parallel axes of the barrels 2 in perforating gun I3. rEhe gun shifting units are thus capable of being used with various kinds of perforating guns in which the spacing between adjacent barrels may vary relative to the spacing between adjacent barrels of another gun. It is only necessary to provide a suitable substitute plug |55 within the gun shifting unit having a liange |51 of the required thickness, in order to be able to adjust the movement of inner sleeve 56 relative to tube 55 of the gun shifting unit to an amount equal to the spacing between the axes of adjacent barrels in the gun.

In View of the secure fixing of gun positioning means 25 relative to the casing il! as described hereinabove, the impact of inner sleeve against plug l of the gun shifting units will not effect movement of the gun positioning means 2li relative to the casing. The slots |25 and guide pins |25 Vwill insure axial alignment in a horizontal direction of another barrel or sets of barrels 22 with. the initially made penetrations in the casing l5, and the engagement of the lower end 255i of inner sleeve 55 with the plug 55 will insure such axial alignment in a vertical direction. The projectile in another barrel or projectiles in another set of barrels of the perforating gun |8 will thus accurately be aligned with the initially made penetrations in the casing |13, whereby the charges within said another barrel or set of barrels may now be detonated to discharge a second projec'tile'into each initially made penetration 1in the casing |0.

' The above-described gun shifting units will accurately position the barrels exactly opposite Ysuch initial penetrations, whereby the subsequent vdischarge of additional projectiles into said initially formed penetrations `will have greatest 'effect` for purposes of extending the penetration within the casing I or the cement lining |6 and VVthe stratum |4 as well as any additional casings or cement linings which may surround the innermost casing or lining. During such secondary ring, and assuming that barrels 1, 4, 7 and 10 are initially red, the barrels 2, 5, 8 and 11 can be red to effect such second penetrations.

Assuming that an additional gun shifting unit 26 is connected in the series of mechanisms and units illustrated in Fig.` l, said second gun shifting unit may now be actuated in order that a third barrel or set of barrels may be disposed radially opposite the penetrations which were initially made and through which second projectiles have been red. Such actuation of said second gun shifting unit 26 is effected by discharging the auxiliary gun |46 thereof in order to permit telescopic collapsing of rthe inner sleeve 56 relative to the tube 54 thereof until such telescopic movement is stopped by engagement of the lower end |54 of sleeve 56 with the plug |56 of said second 'gun shifting unit. The control for the detonating mechanism may then beoperated to discharge a third cartridge or set of cartridges through the aforementioned penetrations, thus still further ,extending or enlarging said penetration.

After all barrels of the gun have been discharged. as desired or as many of the barrels as Vdesired have been discharged, the gun and posi- Yshifting unit 26 relative to the tube 54 thereof -until the guide pins |26 are disposed at the upper ends of slots |24. While the positioning means 24 has been fixed relative to the casing I0 during Athe various flrings of the penetrating gun |8, the lower portion |14 of cylindrical member 48 adjacent the upper end of said positioning means has l been disposed against the upper surface of head `82 of the actuating member 16 as described above.

When said lower portion 4 moved downward into engagement with the head 82, it also moved downward relative to a vertical shaft |58 projecting upward from actuating member 16 and extending into a, central elongated aperture |60 'formed in said lower portion ||4 of member 48.

Intermediate the ends of the shaft |58 is a plurality of notches |62 which are disposed on opposite surfaces of the shaft |58. The lower portion I4 supports a pair of inwardly biased locking dogs |64 which are slidably disposed in transversely extending apertures |66 formed in said ,lower portion 4 and accommodating compression springs |68 which are held in operative position by threaded plugs |15. The locking dogs |64 l.will slide relative to the exterior surface of shaft Y|58 while the cylindrical member 48 is moving downward relative to tubular body 30. When the lower end of lower portion ||4 abuts the upper end of head 82, the locking dogs |64 will be disposed either opposite or below the notches |62 in shaft |58. Thus, during the removal of the mechanism from the well, when cylindrical member 48 is moved upward by the elevation of the gun shifting units 26, the guide bolts |22 will be moved against the upper ends of slots |20 and, during such movement of member 48, the locking dogs |64 will be disposed within notches |62 in shaft |58 and cause elevation of said shaft relative to tubular body 30.

' Fixed to the lower end of shaft |58 is a yoke |12, the lower end of which is pivotally connected to another collapsible toggle |14 comprising a pair of members pivotally connected at their inner ends and extending outward in opposite directions to hold one or more locking balls |16 within radially extending holes |18 formed in collar I0. The outermost locking balls |16 are disposed in concavities formed in screw plugs |82 which are threadably connected to the walls of tubular body 30. The toggle |14 thus holds the locking balls |16 in engagement with the concavities |80 of plugs |82 releasably to secure the collar ||0 relative to the inner surface of tubular body 30. Said collar H8 serves as an abutment as aforesaid for the upper end of compression spring |08 which maintains the actuating member 16 in its lower or depressed position for purposes of maintaining the gripping members 34 in their extended position illustrated in Fig. 3.

Upward movement of shaft |58 by the means described above therefore serves to collapse toggle |14 so as to remove it from engagement with the innermost locking balls-|16 and thereby permit the outermost balls to be removed from the locking concavities |80. Thereupon, the force ofthe compression spring |08 moves the collar ||0 upward within body 30 until the energy of the spring is expended. Continued movement of shaft |58 will bring the upper end |84 of yoke |12 into abutting relation with the lower end of head 82 fixed to the upper end of actuating member 16. Further upward movement of shaft |58 will therefore effect corresponding upward movement of actuating member 16 so as to withdraw the wedge 18 from locking engagement with gripping members 34. Springs 38 then operate to retract the gripping members 34 from their locked position illustrated in Fig. 3 to their retracted position shown in Fig. 7.

The foregoing retraction of actuating member 16 takes place while the guide bolts |22 are being moved upward into slots |20. Upon the bolts |22 reaching the end of slots |20, the tubular body Y 30 will be moved upward as the other mechanism is elevated by cable 20. In the event the teeth 36 of the gripping members 34 are embedded within the well casing to such an extent that the springs 38 cannot readily retract the gripping members 34, the shape of the teeth 36 is such that upward movement of the gripping members 34 by the tubular body 30 will cam the teeth out of their gripping notches formed upon the embedding of the teeth within the inner surface of the casing I6 and thus free the gripping members 34 from the casing. The gun andits attached mechanisms are then free to be entirely removed from the casing i0.

The entire assembly of gun and mechanism illustrated in Fig. 1 is completely removed from the casing |0 for purposes of reloading the barrelS Of the gun and resetting-.the various locking Y and holding meansv such as clamp 84, toggle 136 and toggle |14-, as Well as replacing all of the other relatively movable members in their initial position'so as to place the gun in readiness for again being lowered into the well to effect further penetration where and when desired.

It will thus be seen that the present mechanism comprises a relatively simple, accurate and effective means for securing a multi-barrelled perforating gun at any desired position within an oil well casing, said means being operable to establish and hold the gun at a predetermined initial position where an initial penetration or set of penetrations may be made in the casing, the cement lining, and the stratum behind said lining as well as any other casings and linings which might surround the innermost casing and lining. The positioning means of the present invention comprises gripping members which are projectible outward from a supporting body, such outward projection being effected by means which will effectively cause teeth on the gripping members to bite into the inner surface of the casing suiciently to firmly anchor the positioning means to the casing. The projection of said gripping members is effected by foolproof mechanism comprising an auxiliary gun from which a light powered projectile is red to release locking mechanism which normally holds the gripping member projecting device in retracted position. Thereafter, simply by discharging another single light powered projectile from another auxiliary gun, one of the gun shifting units in the string of mechanism lowered into the Well casing is operated to eiTect movement of the multi-barrelled gun longitudinally within the well exactly the distance between two adjacent barrels of the gun so as to dispose a second cartridge or set of cartridges opposite the penetration or set of penetrations initially made within the casing Il). Then, said second cartridge or set of cartridges may be discharged into or through the initially made penetrations to extend the same. Such second discharge or discharges may be followed by even additional discharges, dcpending upon the number of barrels in the gun and the number of gun shifting units connected in the string of units attached to the gun.

The device is also provided with .simple and rugged means for effectively withdrawing the gripping members of the positioning means as well as the entire mechanism attached to and including the gun from the well at the completion of a penetration operation, regardless of whether it is a single or sequential penetration operation. The various movable parts and members of the mechanism may quickly and easily be restored to their initial operative position so as to render the positioning and gun shifting units reuseable at another position within a previously penetrated well or in another well. When elevated to the surface, the gun may be reloaded in accordance with conventional practice.

The gun shifting units are also provided with means which may variably be calibrated in order to adapt the gun positioning means for use with guns having uniform distances between barrels which are different from the uniform distances between barrels of another gun. The gun shifting units and positioning means are also useable in a wide range of diameters of oil well casings, the gripping members of the holding means being capable of a relatively wide range of lateral movement so as to be engageable with the inner surface of oasings of diierent diameters. However, in. the-event anI unusuallyl` small orfflarge diameter casing. is to be; penetrated, additional gripping members of appropriate length maybe substituted for those presentlyv in the positioningV means in order to permitV the positioning means to be operable within said casings.y The entire mechanism for positioning and shifting a multi-barrelled gun within a well is of such nature that it is rugged and effective yet of a slender, elongated nature so as readily to adapt the mechanism to the inherently limited spaces within Well casings and particularly oil wellv casingssin wide use at the present time.

Whilethe invention has been illustrated and described in its preferred embodiment and'has included certain details, it should be understood that the invention is not to be limited to the preoise details herein illustrated and described since the same may be carried out in other ways, falling within the scope of the invention as claimed;

I claim as my invention:

1. Mechanism for use with a multi-barrelled casing perforating gun and tiring means capable of operation to discharge selectively a casing penetrating cartridge from each barrel of said gun, said mechanism comprising in combination, positioning means arranged to be disposed at a predetermined position within. av well casing and including locking members movable into rm engagement with the interior of said casing to position said gun for discharging the initial' cartridge in a barrel of the gun to effect a penetration of said casing, gun shifting means attachable to said gun and having a portion telescopicaily and slidably associated with a portion of said positioning means, slots extending longitudinally oi one of said portions and pins xed to the other portion and slid'able Within said slots to guide the relative movement of said means in one direction, a calibrated stop member carried by one of said means and engageable by the other means to limit the relative movement thereof in the other direction, releasable locking mechanism carried by one of said means and engageable with the other means releasably to hold one of said means so that the pins are clisposed in one of the ends of said slots, and means operable to release said locking mechanism to permit movement of saidv gun and telescoping portion of said shifting means downward longitudinally oi said casing and relative to said positioning meansand into engagement with said calibrated stop member and position another barrel and cartridge of the gun opposite said casing penetration to permit discharge of said another cartridge into said penetration.

2. Mechanism for use with a multi-barrelled casing perforating gun and ring means capable of operation to discharge selectively a casing penetrating cartridge from each barrel of said gun, said mechanism comprising in combination, positioning means arranged to be disposed at a predetermined position within a well casing and including locking members movable into rm engagement with the interior `oi said casing' to position said gun for discharging the intial c'artridge in a barrel of the gun to effect a penetration of said casing, gun shifting means associated with said positioning means and attachable to said gun, releasable locking mechanism interengaging said positioning and shifting means and operable to hold them in one position relative to each other during the discharge of said initial cartridge, and an auxiliary gun carried by one of said means and operable to discharge a projectile into contact with said locking mechanism to release it to permit said shifting means to effect movement of said gun longitudinally of said casing and relative to said positioning means accurately to position another barrel and cartridge of the gun opposite said casing penetration to permit the discharge of said another cartridge into said penetration.

3. Mechanism for use with a multi-barrelled casing perforating gun and firing means capable of operation to discharge selectively a casing penetrating cartridge from each barrel of said gun, said mechanism comprising in combination, positioning means including a body and a plurality of grip-ping members supported by said body for guided movement laterally outward therefrom into gripping engagement with the interior of said casing to position said gun for discharging a cartridge in a barrel of the gun to effect a penetration of said casing, an actuating. member movable longitudinally relative to said body and engageable with said gripping members to effect lateral outward movement thereof into engagement with the interior of said casing,

latching means operable releasably to hold said actuating member in its elevated position, an auxiliary gun supported relative to and aimed at said latching means and operable to discharge a projectile against said latching means and vrelease it from said actuating member to permit determined Xed distance to position another barreland cartridge of the gun opposite said casing penetration to permit the discharge of said another cartridge into said penetration.

4. Mechanism for use with a multi-barrelled casing perforating gun andiiring means capable of operation to discharge selectively a casing penetrating cartridge from each barrel of said gun, said mechanism comprising in combination, positioning means arranged to be disposed at a predetermined position Within a Well casing and including locking members movable into rm engagement with the interior of said casing to position said gun for discharging a cartridge in a barrel of the gun to effect a penetration of said casing, and a series of Ygun shifting units connected in longitudinal alignment within said casing and one end of said series being connectedV to said positioning means and the other end of 4said series being attachable to said gun, said shifting units being operable selectively to move said gun longitudinally of said casing and relative to said positioning means to position in sequence other barrels and cartridges of the gun radially opposite said casing penetration to permit the successive discharge of said other cartridges into said penetration.

5. Mechanism for use with a multi-,barrelled casing perforating gun and ring means capable of operation to discharge selectively a casing penetrating cartridge from each barrel of said gun, said mechanism comprising in combination,

positioning means arranged to be disposed at a predetermined position Within a Well casing and including locking members movable into firm engagement with the interior of said casing to position said gun for discharging a cartridge in a barrel of the gun to effect a penetration of said casing, a series of gun shifting units connected in longitudinal alignment Within said casing and one end of said series being connected to the upper end of said positioning means and the other end of said series being attachable to the lower end of said gun, control means associated With each of said units and selectively operable from the upper end of said casing to actuate sequentially said units to effect movement of said gun longitudinally of said casing and relative to said positioning means to position in sequence other barrels and cartridges of the gun radially opposite said casing penetration to permit the successive discharge of said other cartridges into said penetration.

6. Mechanism for use with a multi-barreled casing perforating gun and ring means capable of operation to discharge selectively a casing penetrating cartridge from each barrel of said gun, said mechanism comprising in combination, positioning means including a body and a plurality of gripping members supported by said body for guided movement laterally outward therefrom into griping engagement with the inside surface of a casing to position said gun for discharging a cartridge in a barrel of the gun laterally to effect a penetration of said casing, an actuating member movable longitudinally relative to Said body and engageable with said gripping members to effect lateral outward movement thereof into said gripping engagement With the interior of said casing, means urging said actuating member to move longitudinally into forceful engagement with said gripping members, latching means operable releasably to hold said actuating member from forceful engagement with said gripping members, combustion means operable When ignited to actuate said latching means to release said actuating member to permit movement of the actuating member into' forceful engagement With said gripping members as aforesaid, and gun shifting means including movement limiting means interconnecting said gun and said positioning means and operable to permit longitudinal movement of said gun relative to said positioning means a predetermined fixed distance such as to position another barrel and cartridge of the gun opposite said casing penetration to permit the discharge of said another cartridge into said penetration.

References cited in the sie of this patent UNITED sTATEs PATENTS Number Name Date 2,076,307 Wells Apr. 6, 1937 2,266,382 Quintrell Dec. 16, 1941 2,330,509 McCullough Sept. 28, 1943 2,436,503 Cleveland Feb. 24, 1948 2,587,723 Githens et al Mar. 4, 1952

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