US2676788A - Rotary swivel - Google Patents

Description

April 27, 1954, H. E. DAVIDSON El AL 2,676,788

ROTARY SWIVEL 4 Sheets-'She et l Filed March 17, 1951 I, t Z I I/ [I], 7/ 2 3, II I u I l 36 I," j; (I, I, Q h I/ [/1 J2 if; X 66 67 u 34 I V 2/ 2r 1 56 h 25 /52? if J ' I'lb'enlgrg Harve lfliavlds'on Ap 1954 H. E. DAVIDSON r AL ROTARY SWIVEL 4 Sheets-Shet 2 Filed March 17, 1951' 25w 61110);- flarvey lffiauzdyan diiorne April 7 1954 l H. E. DAVIDSON El AL 2,676,788

ROTARY SWIVEL Filed March 17, 1951 44 Sheets-Sheet 3 6i I 37 36 0 5 J4 jg J5 l I 4:9 I J! J0 J5 L. I .53 v J I if; f/ W v 2 61' 6:? i 25 69 70 J41 2 6'1.- 65 6'0 J7 J4,

J39 lnve'nlans 45 41W OMEEaZO t April 7, 1954 H. E. DAVIDSON El AL 2,676,788

ROTARY SWIVEL Filed March 17, 1951 l-lllll Inc/61110115 azzdJafui Fl? 4 Sheets-Sheet 4 Patented Apr. 27, 1954 'liaiiygaeorp me eor Delaware I supply cemlappiicdiionii -eh-ii, 195 1; 'se1 ia1marshes 5 elaifiis. (elitest's) swee en. were i911??? sire I 55??? use'd in the petroleum industry for well i9 empl ria bih s er ici o. he. .19.? 1Q. ef t is .ie$l pi eupw r isr i' a lrelly fihe lgelly is suspended from atraveli'ii'g bloc}; n' eans ofa swivel and; is turned y a sewer-dorm rq a v table I io as bi'it th ut n s, nd i tim te, the bit, mana e the .i'd sired, 'ha te f s. Q lIi iWUSZ Qumped through the swivel and down thepipe under considerable pressure.

With so many oil wells no 7 depths of two n ilesor more, it is obvious that i i e era ng 1.

' being drilled to I Y :FhQfSWiYGLBlU-St be able to support tremendous loads, and is; required to be'massive in proportion. 'A swivel capable of supporting threehundred tons of pipe, for example, will weigh up-.

;wards of two tons. The drilling mud, particularly under high pressures, is abrasive and causes ;rapid..wear of the packing andother swivel parts. Even the slight degree of misalignment which; is normally found will aggravate this condition.

With usual typesof swivels it thus'becomesmecess ary, in order to prevent-leakage, to replace leaky-packing or'other worn-outelementsat-fairly 'irequent-intervals. In drilling-operations-it is not always safe or convenient to stop mud --circ ulation, however, and badly timed-attemptsto do s,o';may result in serious damage or eventheloss of; the hole. I

One object-of ourinvention-therefore, is to provide alternative packing means which may-be n put into use in; an emergency without "necessarily stopping mud circulation or even reducing pump pressure.

.q-Another vobject is to provide means for' 'con- "tinu'i'ng drilling past a critical point untilmud circulation can safely be stopped and permainent-repairs effected.

..;Anotherobject is to provide a swivel having :self-aligning conduit "means interposed between fthefixed and rotary mud conducting means.

Anothef'object' is to provide a" swivel *having rheansfor"selectively transferring the greatest "burden of stress and wear from" one "part to another: in order to lengthen the entire swivels "useful life.

*Another object is to provide a wash-pipe and ;pack ing assembly which may be very readily reversed or replaced under ordinary operating-con- 1 it Bil 9 le i grante s. a i .PWQQ Q of this invention 'wuiapeear hi'einafterin the specification anddrawings, and in the appended claims.

In theannex'edfoiirsheets of drawings:

7 Fig. "1 is a side'elev'ation of'th'e swivelofour invention; Y V

Fig. 2 isanother 'sideelevation of the swivel, but rotated from'Fig. 1;

I EigIB'is-a broken 'side elevation similar to Fig. 1, but sho'win'g theswivefpartlyin section and with the gooseneck turned to a'diiierent position;

FigLEi-isa horizontal transverse section taken on the line 4 '4' r Fig.6; v V

"Fl-g. 5 is seamen detail section showing the latch removed and the 'stiiffin'g boxes brought to- ;gether onthe wash pipe, ready for the wash pipe to be inserted into or removed fromthe swivel; d

Fig. 6 is a-broken side elevation, partly in :SGCtiQH, ShO WiIlg the assembly of the goose'rieck, bgnnet,- Stu-fling boxes, wash-pipe and adapter;

Fig. '1 is a transverse vertical section'of the upper stufiing box assembly, which is identical in'all respects with the lower stufiing box ase b y Fig. 8 is a fragmentary vertical sectionofthe upper oil seal assembly withinthe swivel'housnsr e Fig. 9 is-a. fragmentary vertical section of the lower oil-seal assembly.

Referring now to the drawings, andmore particularly to- Figs. 1 to "3 thereof,the numeral l designates the substantially ovoid bowl or body housing of the swivel, which in use is normally suspended ina stationaryposition from the hook of a traveling block (not shown) by means of a bail 2 pivotally mounted in the recess "3 of the body housing onthe bail pins 4. Said bail pins l-are provided with *Alemite lubricating'fittings- 5 and-welded end caps 6. An elevator bumper 1- also projects outwardly from the h'ousing I and serves as a guard against accidental impactsgwhilea breather. plug 3 permits escape -o f gas or fumesfrom the housing I.

Extending vertically -through the body-housing I is'arotary hollow spindle or stem 9, the lower end of which is adapted to be attached-to a kelly (not shown) by means of a'convent'ional coupling Ill. Said stem 9 has an integral circumferential flange H whereby the-drill pipe load on the stem is transmitted'through 'themain .thrust'bearings [2 'to the abutment l3'of the housing and the upward thrust of the stem 9 "is t'akn by' 'i 'pper "thrust bearings i 4. Radial and I8 and oil seal packing assemblies l8 and 20, and Alemite fittings 2| and 22, are also provided around the stem 9 inside the top and bottom of said housing I. Leakage of lubricant from the lower oil seal packing assembly 20 (Fig. 9) is prevented by the gasket 23 and retainer 24 which are attached to the housing by cap screws 25. The upper oil seal packing assembly l9 (Fig. 8) is held in place against the stop ring H by means of the depending skirt 26 of the bonnet 21 and the annular flange 28 having a raised circular sealing lip 29, with the aid of gaskets 3|] and 3| and bolts 32 and 33.

The bonnet 21 is integrally provided with opposite side apertures or windows 34 and a ringshaped top portion 35 which functions as a support on which a mud inlet fitting or gooseneck 3'5 having a pipe plug 31 is mounted above the stem 9 in spaced vertical alignment therewith for threaded attachment to the mud supply hose (not shown).

An annular adapter 38 having a circular bottom slot 39 and a depending skirt portion 4|), also stepped upper recesses 4| and 42, is secured by countersunk screws 43 to the top of the stem 9, which has stepped recesses 44 and 45 for receiving said adapter skirt portion 40 and a rubber gasket 45. The adapter slot 39 cooperates with the gasket 3| and flange lip 29 to complete the liquid seal.

The adapter recesses 4| and 42 receive the lower halves of a hardened steel wear ring 41 and rubber gasket 48. In similar manner, the bonnet top portion 35 is recessed to receive the packing ring 49 and rubber gasket 50 and the upper steel wear ring A small clearance is maintained between the lower wear ring 41 and the wash pipe 52, and between the upper wear ring 5| and the gooseneck 36, as in Figs. 3 and 6.

Interposed between the wear rings 41 and 5| is the wash pipe 52, being a symmetrical tube of heat treated alloy steel polished to give a smooth surface and close fit in the upper and lower stuiiing boxes 53 and 54, which encircle the wash pipe and are fastened by the bolts 55 and 56 to the bonnet top portion 35 and the adapter 38 respectively, as shown in Fig. 6.

The stufling boxes 53 and 54 are identical, each comprising a flanged exteriorly threaded tubular box portion 51, which box portion has associated therewith an inner packing retainer ring 58, a plurality of V-shaped packing rings 59 to hold the mud pressure, an Alemite fitting 50, a bronze spacer ring 6| to provide a grease space, a larger V-shaped packing ring 62 to retain the grease, and an outer packing retainer ring 53. A clamping nut 64 provided with a series of equally spaced peripheral notches 65 is screwed onto said tubular box portion 51.

Referring particularly to Figs. 4 and 6, a latch 66 consisting of a pair of substantially H-shaped members 61 having upwardly and downwardly extending end portions 68 is arranged to be clamped between the stuffing boxes 53 and 54 on the wash pipe 52 by means of the bolts 69 and. nuts 10, so that its end portions 58 may engage with the clamping nut notches 55 onv whichever stufling box is preferred.

The function of the latch 65 is to control selectively the wear in each of the two stufiing boxes 53 and 54. With the latch 66 either omitted or placed in inoperative central position between the stuffing boxes, the floating wash pipe 52 obviously will turn in the stuffing box having the looser packing and hence offering the less friction, unless 4 for some reason packing or wash pipe wear under the abrasive action of the drilling mud increases the friction in the acting stuffing box to the point where it causes rotation to begin in the other stufiing box. By setting the latch in either the upper or lower position, the relative rotation of the wash pipe is thereby restricted to the particular stufiing box desired and the other one is saved for future use, in accordance with operating conditions and personal preferences. In other words, the wash pipe 52 may be utilized either as a rotating extension to the stem 9 or as a fixed extension to the gooseneck 36, depending upon the position of the latch 66.

It is therefore optional whether the latch 66 is initially engaged with either the upper or the lower stuffing box, but if we assume for the sake of example that the swivel has been operated with the latch 56 engaged in the lower position until leakage caused by the rotating wash pipe has developed past the upper packing, the operation is as follows: Drilling is temporarily stopped until the latch is shifted to the upper position and fibrous grease is injected into the leaking upper stuflin-g box packing through the Alemite grease connection 6%. This will usually stop the leakage, because the latch prevents further rotation of the wash pipe in the worn stufing box and transfers the rotation to the other box having unused packing. If leakage still occurs past the worn stuffing box it may be stopped by tightening the clamping nut i l to compress the packing if suflicient packing remains, or by inserting an additional ring or two of packing under said nut and then tightening the nut to compress the packing tightly. Should the latch 55 be initially engaged in the upper position, it may similarly be transferred to the opposite position to counteract leakage in the lower packing. The important fact is that since no further rotation is necessary in the worn packing, a seal between this packing and the stationary end of the wash pipe, even though the latter may be worn quite rough and. grooved also, can be obtained, which seal will be at least sufhcient for temporary operation until it is convenient for drilling to be stopped, mud pressure cut ofi, circulation stopped, and the wash pipe assembly removed for complete replacement of the pipe and both sets of stufling box packing.

With conventional swivel design it is generally necessary to remove the wash pipe assembly through the top of the swivel. This is a. considerable disadvantage because the rotary hose and the gooseneck 35, which interfere with such removal and therefore must usually be removed first, are heavy and difficult to handle. Our invention renders the wash pipe assembly very accessible and allows it to be removed through either of the bonnet side windows 34, without having to remove any of the top structure.

Thus, to remove the wash pipe assembly from the swivel of this invention, the latch 55 is removed from th wash pipe 52, the clamping nuts 64 are loosened but not completely unscrewed from the stuffing boxes 53 and 54, the bolts 55 and 56 are removed, and the stuffing boxes 53 and 54 are slid toward the center of the wash pipe 52 as in Fig. 5, So that the stuiiing boxes 53 and 54 will clear the wear rings 41 and 5|. The wash pipe assembly may then be removed as a unit from the swivel, and a completely or partly new assembly may be substituted.

Although we have illustratedand described our invention herein in considerable detail, we do not wish to be limited to the exact and specific details so shown and described, but we may use such modifications, substitutions or equivalents thereof as are embraced within the scope of the invention or pointed out in the appended claims.

We claim:

1. In a rotary swivel, the combination of a substantialiy stationary housing, a support on said housing, a gooseneck mounted on said support, bearings within the housing, a hollow stem rotatably supported on said bearings in vertical alignment with the gooseneck, a pair of separate stufi'ing boxes secured to the stem and to the support respectivel a wash pip-e rotatably fitted within said stuifing boxes so as to provide a fluid conduit between the gooseneck and the stem, and a latch slidably mounted on the wash pipe for selectively preventing relative rotation between said wash pipe and one or the other of the stuifing boxes.

2. In a rotary swivel, the combination of a bowl-shaped housing, a bail thereon for suspending said housing in a fixed position, a hollow bonnet having apertures on opposite sides and mounted on said housing, a gooseneck mounted on the bonnet, a rotary stem vertically supported on bearings within the housing assembly, an adapter mounted on said stem, a wash pipe adapted to be inserted laterally into the bonnet between the adapter and the upper part of the bonnet, a pair of stufiing boxes encircling the wash pipe, one of said stuffing boxes being secured to the adapter and the other to the bonnet, and latch means adapted to lock the wash pipe into the preferred engagement with either of said stufling boxes.

3. In a rotary swivel, the combination of a housing, a support on said housing, a gooseneck on said support, a hollow stem rotatably supported in said housing in spaced vertical alignment with the bottom of the gooseneck, a wash pipe interposed between said stem and the bottom of the gooseneck, stufling boxes supporting the ends of the wash pipe, and a vertically slidable latch on the wash pipe for causing said wash pipe to engage one of said stuifing boxes and thereby to function alternatively as an extension afiixed to the stem or to the gooseneck.

4. In 'a rotary swivel, the combination of a housing, a support on said housing, a gooseneck on said support, a hollow stem rotatably supported in said housing in vertical alignment with the gooseneck, a wash pipe and wear rings at each end thereof between the stem and the gooseneck, stufiing boxes encircling the wear rings and wash pipe, a separate slidable latch member for selectively preventing relative rotation between said wash pipe and one or the other of said stufiing boxes, and means for injecting lubricant into each stufiing box.

5. In a rotary swivel, the combination of a housing, a support on said housing, a gooseneck mounted on said support, a hollow stem rotatably supported in said housing in alignment with the gocseneck, a wash pipe interposed between the stem and the gooseneck, a pair of stuffing boxes encircling the wash pipe and secured in fixed relation to the stem and to the support respectively, each stufiing box having its outer portion provided with a series of peripheral notches, and a latch movable on the wash pipe to engage one ormore of said notches on either stufiing box alternatively to prevent rotation of the wash pipe therein.

References Cited in the file of this patent

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