US2758891A - Non-rotatable retaining devices - Google Patents

Description

Aug. 14, 1956 A. w. KAMMERER NON-ROTATABLE RETAINING DEVICES Filed Aug. so, 1952 INVENTOR. ec//Ee WKAMMEQEQ,

#will z Y. 2/ 2 ..3 l 4 5 z 2 2 J J nited States Patent O N N -R'OTATABLE RETAINING DEVICES Archer W. Kammerer, Fullerton, Calif. Application August 30, '1952, Serial No. 307,276

3 Claims. (Cl. 308-4) The present invention relates to retaining or lock devices, and more particularly to devices for securing operative parts of a mechanism in appropriate assembled relation.

An object of the present invention is to provide a retaining device capable of being readily and non-rotatably secured to a member on which it is mounted.

Another object of the invention is to provide a retaining device that can be easily mounted on a supporting member and dismantled therefrom, and which has a high load transmitting capacity.

In the drilling of wells, it is sometimes desirable to use a stabilizing or centering device near the drill bit to stabilize or center the equipment in the hole. Diiiiculties are sometimes encountered in retaining the device in place, and in drilling or washing over it in the event the equipment becomes stuck in the well bore.

Accordingly, a further object-of the invention is to provide a device for retaining stabilizing and centering equipment in appropriate position on a tubular string disposed in a well bore, and in which the device can be milled or drilled away readily when the equipment becomes stuck in the well bore;

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best dened by the appended claims.

Referring to the drawings:

Figure 1 is a longitudinal section, with parts shown in elevation, of a device embodying the invention applied to drilling equipment disposed in a well bore;

Fig. 2 is a longitudinal section, on an enlarged scale, taken along the line 2*2 on Fig. l;

Fig. 3 is a cross-sectiony taken along the line 3 3 on Fig. 2.

The invention is disclosed in the drawings as applied to a device for stabilizing or centering a rotatable drilling string A in a well bore B. As is well known, the drill pipe A extends to the top of the hole, where it is rotated by suitable equipment. The lower portion of the drill string A may be constituted by a drill collar sub having an upper box 11 threaded onto the lower pin end 12 of an adjoining drill pipe section 13, the lower pin 14 of the sub being threaded into the box portion 15 of a suitable rotary drill bit 16, for drilling the hole. During the drilling operation, suitable circulating uid is pumped down the drill pipe A, which passes out through one or more nozzles or orifices 17 in the drill bit, the circulating iluid carrying the cuttings up through the annulus 18 between the drill string A and the well bore B to the top of the hole.

For the purpose of appropriately stabilizing and centering the drill bit 16 in the well bore, a suitable device may 2,758,891 Patented Aug. 14, 1956 be mounted on the drill collar section 10. As shown in the drawings, this centering device may consist of an elongate rubber or rubber-like sleeve 19 having an outside diameter slightly less than the diameter of the bore hole B being produced by the drill bit 16. This sleeve 19 is not secured on the drill collar 10, but functions as a bearing, the drill collar rotating therewithin. However, to permit the cuttings to be circulated out of the hole, the sleeve may be provided with a plurality of circumferentially spaced and longitudinally extending inclined grooves 2t) through which both the cuttings and the drilling uid may pass in an upward direction.

As shown in the drawings, the centering or stabilizing device 19 is prevented from moving longitudinally along the drill collar member 10 by upper and lower retaining devices or structures 21 now to be described. Since the structures are identical, although oppositely arranged, a description of the upper structure will su'lce for both. An annular retaining member 22, in the form of a ring, is disposed around the upper portion of the drill collar member 10, and extends outwardly from the periphery of the latter to a certain extent. However, the diameter of the ring 22 is still substantially less than the diameter of the Well bore B, to avoid interference with the upward passage of fluid through the annulus 18 between the drill pipe string A and the wall of the well bore. The retaining member 22 is held in position on the drill collar member 10 by a plurality of rollable retaining elements 23, in the form of balls, that are disposed within an external raceway 24 provided in the periphery of the drill collar member 10, and also in an internal raceway 25 in the retaining ring 22. It is evident from the figures that each ball 23 extends partially into both raceways or grooves 24, 25, which are of toroidal shape, and serves to lock the retaining ring 22 to the drill collar or tubular member 10 against longitudinal movement with respect thereto.

For reasons pointed out hereinafter, it is desired to prevent rotation of the retaining member 22 with respect to the drill collar 10. In the present instance, such rotation is precluded by one or more longitudinally extending keys 26, which are inserted in opposed keyways 27, 28 formed in the drill collar 10 and within the ring 22. Following insertion of the one or more keys 26 in the opposed keyways 27, 28, each key 26 is prevented from being removed by a transversely extending set screw 29 threaded into the drill collar 10 at the base of the keyway 27 and extending across the upper end of the key 26 itself. The key 26 is prevented from moving downwardly by engaging the bottom 30 of the keyway 27.

In assembling the non-rotatable retaining device 21, the ring 22 is slipped over one end of the drill collar or sub 10, and is placed in a position in which its raceway 25 is opposite the external raceway 24 of the drill collar member. The keys 26, which are disclosed as located diametrically opposite each other, can then be placed in the upper ends of the drill collar keyways 27 and slipped downwardly into the ring or sleeve keyways 28. Between the locking keys 26, the ring 22 is provided with threaded holes 31 that are large enough to allow the balls 23 to be inserted therethrough and into the raceways 24, 25. When a plurality, such as two, keys 26 are used, then a pair of transversely extending threaded holes or bores 31 are employed, one group of balls 23 being inserted through one hole until the raceway spaces between the keys 26 are substantially completely filled, and another group of balls being inserted through the other threaded hole 31 to substantially completely lill the raceway spaces between the keys on the other side of the device. Following insertion of the balls, plugs 32 are threaded into the holes to prevent the balls 23 from dropping out of place. The transveresly extending set screws 29 are then threaded into the drill collar, to retain the keys 26 in place.

The centering or stabilizing device 19 may then be slipped over the other end of the drill collar member 10, its upward movement being limited by engagement of its upper end with the upper retaining ring 22, The, lower retaining device 2.1 is then assembled in place, its ring 22 being engageable with the lower end of the Sleeve 19. The drill bit 16 can then be threaded onto the pin end 14 of the drill collar member and the latter then threaded onto the drill pipe, the entire assembly then being lowered into the well bore B to its bottom. During the drilling operation, the drill collar 10 will rotate inside the centering or stabilizing device 19, which functions as a bearing. Any tendency for the centering device 19 to move substantially -in a longitudinal direction with respect to the sub 10 is precluded by its engagement with the upper and lower retaining rings 22, the longitudinal force being transmitted from each ring 22 through the balls 23 to the drill collar 10 itself. in view of `the large number of balls 23 employed, and the fact that the balls, in eifect, function as an axial type of bear-ing, thrusts o-f large amounts can be transmitted between the stabilizing device 19 and the drill collar or pipe 10.

In the event the drill bit 16 becomes stuck in the hole, and it is necessary to wash over and mill away the centering device 19, for the purpose of freeing the bit and retrieving it from the hole, the necessary wash-over or milling -tool can be lowered in the well bore B, and will pass over the box end 11 of the drill collar member 10, to engage `the upper retaining ring 22, which is preferably made of readily drillable material, such as brass, so as to disintegrate under the action of a cutting tool. Since the drill bit 16 and drill collar 10 are stuck in the hole, they are prevented from rotating. The keys 26 effectively couple 'the retaining ring 22 to the drill collar, thereby preventing rotation of the ring. Accordingly, the washover tool can be rotated, to operate upon the upper stationary retaining ring 22 and disintegrate it. Following its disintegration, the wash-over tool can continue to disintegrate the centering device 19, then operating upon the lower drillable ring 22, moving -on down beyond the latter, if need be, for the purpose of freeing the equipment in the well bore and allowing it to be withdrawn to the top of the hole,

It is, accordingly, apparent that a retaining device 21 has been provided which is easily assembled and dismantled. 1n Athe event disassembly is required, it is merely necessary to unthread the plugs 32 and withdraw the balls 23, which allows the ring 22 to be moved longitudinally off the drill pipe member 10. In addition to this advantageous feature, the device is non-rotatable, thereby facilitating its drilling away, and it also has a very great 'load transmitting capacity, since longitudinally directed forces can be transmitted through the large surfaces provided by the raceways 24, 25 and through the balls 23.

The inventor claims:

l. In apparatus for stabilizing a tubular string in a well bore: a one-piece cylindrical tubular member; a stabilizing device on said tubular member engageable with ,the wall of the well bore to substantially center the tubular member therein; means for preventing substantial longitudinal movement of said stabilizing device on said tubular member in one direction, including an annular member on said tubular member engageable with said stabilizing device, said tubular member and annular member having opposed circumferential grooves, rollable elements in said grooves locking said annular member to said tubular member against substantial longitudinal movement with respect thereto, opposed longitudinal` keyways in said tubular member and annular member, a key in said keyways, said annular member having a hole arcuately displaced from said keyways through which said rollable elements are insertable in said grooves, and means closing said hole, said key in said tubular member extending lengthwise beyond the end of said annular member to allow said key to be inserted in an endwise direction into said opposed keyways, and means engaging said key to prevent its endwise removal from said keyways.

2. In apparatus for stabilizing a tubular string in a well bore: a one-piece cylindrical tubular member; a stabilizing device on said tubular member engageable with the wall of the well bore to substantially center the tubular member therein; means for preventing substantial longitudinal movement of said stabilizing device on said tubular member in one direction, including an annular member on said tubular member engageable with said stabilizing device, said tubular member and annular member having opposed circumferential grooves, balls in said grooves locking said annular member to said tubular member against substantial longitudinal movement with respect thereto, opposed longitudinal keyways in said tubular member and annular member, a key in said keyways, said annular member having a hole arcuately displaced from said keyways through which said balls are insertable in said grooves, and means closing said hole, said keyway in said tubular member extending lengthwise beyond the end of said annular member to allow said key to be inserted in an endwise direction into said opposed keyways, and means engaging said key to prevent its endwise removal from said keyways.

3. In apparatus for stabilizing a tubular string in a well bore: a one-piece cylindrical tubular member; a stabilizing device on said tubular member engageable with the wall of the well bore to substantially center the tubular member therein; means for preventing substantial longitudinal movement of said stabilizing device on said tubular member in both directions, including an annular member on said tubular member engageable with the upper end of said stabilizing device, an annular member on said tubular member engageable with t-he lower end of said stabilizing device, said tubular member and each of said annular members having opposed circumferential grooves, balls in said grooves locking said annular members to said tubular member against substantial longitudinal movement with respect thereto, opposed longitudinal keyways in said `tubular member and each of said annular members, a key in said opposed keyways, each of said annular members having la hole arcuately displaced from said keyways through which said 'balls are insertable in said grooves, and means closing said holes, said key-ways in said tubular member extending lengthwise beyond the ends of said annular members to allow said 'keys to be inserted in an endwise direction into said opposed keyways, and means engaging said keys to prevent :their endwise removal from said keyways.

References Cited in the `file of Vthis patent UNITED STATES PATENTS

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