US2527225A - Means for controlling pressure in drilling wells - Google Patents

Description

06L 1950 c. A. LANGSTAFF ETAL 2,527,225

MEANS FOR CONTROLLING PRESSURE IN DRILLING WELLS Filed Aug. 20, 1945 2 Sheets -Sheet 1 \v, A TTOR/VEX out. 24, 1950 c, LANGSTAFF E 2,527,225

MEANS FOR CONTROLLING PRESSURE IN DRILLING-WELLS Filed Aug. 20, 1945 2 Sheets-Sheet 2 FIg 5 F.1- g 5.

F1 .4- J 82 W W 1 e7 Q Q 79 6f 57 I a INVENTOR. CLl/V70/V 'A.LA/VG.STAFE B BLAS/TO BRO/V214;

ATTGRIVEX Patented Get. 24, 1950 UNITED STATES MEANS FOR CONTROLLING PRESSURE IN DRILLING WELLS Application August 20, 1945, Serial No. 611,522

1 Claim.

The present invention relates to pressure control heads adapted to be utilized with rotary drilling apparatus to control well pressure while in the operation of drilling the well.

The present invention affords an effective and economical means whereby gas pressure within a well being drilled is effectively controlled. Most of the apparatus controlling the gas pressure during the rotary drilling of a well is of a complicated nature, exceedingly costly and requires skilled workmen to operate the same properly. Most blowout preventers' serving the same purpose as disclosed in this invention are situated in the cellar beneath the rotary table. To operate these blowout preventers it is necessary to remove the master bushings in the rotary table and to remove the packing element which forms the closure around the kelly. Furthermore, the arrangement of the prior devices is such as to hold the kelly in fixed alignment. As the kelly when it has drill pipe attached to it is under tension, any misalignment becomes a serious factor, particularly when the rotary table is misaligned relative to the packing unit of the blowout preventer. Such misalignment is common, even in the most carefully positioned rotary table, with the result that abnormal stresses are imposed on the kelly,

which results in wear and fatigue not only in the kelly but in the rotary table and the blowout preventer.

Another object is the provision of a blowout preventer wherein misalignment of the rotary table does not impose abnormal strains in the kelly.

Another object is the provision of a blowout preventer which has a direct connection with a rotary table, whereby it is easily contacted and serviced and may be readily removed or placed in positon of service.

With the above mentioned and other objects in view, the invention consists in the novel and useful provision, formation, construction, association and interrelation of parts, members and features, all as disclosed inone embodiment in the accompanying drawings, described generally and more particularly pointed out in the claim.

In the drawings:

Fig. 1 is a fragmentary elevation, partly in quarter vertical section, illustrating one embodiment of the invention;

Fig. 2 is a sectional view on the line 22 of Fig. 1;

Fig. 3 is a sectional view on the line 33' of Fig. 1;

Fig. 4 is a fragmentary elevation, partly in quarter vertical section, illustrating a modified form of the lowermost stuffing box;

Fig. 5 is a semicircumferential cross section on the line 5-5 of Fig. 4;

Fig. 6 is an elevation of one of the members shown in Fig. 4;

Fig. 7 is a fragmentary elevation of the base member shown in Fig. 4; and,

Fig. 8 is a fragmentary detail, partly in section, of a rotary table bushing lock.

Referring now to the drawings, and specifically to Figs. 1 to 3.inclusive:

l represents the conventional rotary table adapted to be driven in. any one of several ways, which table is formed with the usual central opening (a) which receives the master bushing (12). The master bushing is formed with a concentric square opening 2, which joins with a central tapered wall 3. lhe tapered wall 3 is adapted to receive slips whereby the drill pipe may be suspended, and square opening 2 in standard rotary equipment is adapted to receive kelly bushings whereby the kelly may be rotated. As is customary in rotary tables, some means such as indicated at 5 is provided for locking the kelly bushings against displacement from the rotary table. A similar means (not shown) is employed in retaining the master bushing in the rotary table. In the present instance the means contemplates an eccentric cam ii, mounted upon a pin 1, the cam being disposed within a pocket in the rotary table, the said pin 1 being provided with a socket type head whereby through a suitable wrench the pin may be rotated to turn the cam and position the cam either within the confines of the square opening or outwardly thereof.

The present invention includes a kelly drive means 8, which cooperates with the rotary table l and a stuning box 9. The stufling box 9 is located within the cellar beneath the rotary table and is secured to a drilling riser it This drilling riser is not detailed in the drawing, but one form of riser construction is illustrated and describedin United States patent to S. M. Kilmer, Jr., for Blowout Preventer, Patent No. 1,930,361, issued October 10, 1933, and reference is made thereto.

The kelly drive means 8 includes a bushing body I l, which is externally enlarged at IE to provide a square flange of such size and proportion as to fit readily within the square opening 2 of the master bushing I). Said flange i2 is formed with elongated grooves it within which may be received the cams 5 for locking the bushing body against displacement from the rotary table. The bushing body it is provided with .a

' a tube 38.

reduced diameter portion l4, below the flange I2. This construction provides for a tapered wall at 15. The external surface of that portion of the bushing body above the flange l2 may be cylindrical, while the inner curved wall I6 is formed with one or more equidistantly spaced apart longitudinally extending splines or keyways l1. Split reducer bushings l8 and [9, provided with complementary splines 28, are adapted to be received within the said body, with the splines 28 received within the splines or keyways 11. The bushings l8 and I9 are centrally notched at 2| and 22, to provide, when cooperating, a squared opening adapted to encompass the kelly 4. Obviously, if the kelly has other external shape, the notched openings 2| and 22 will be complementary thereto. The said bush-- ings rest upon an annular shoulder 23, included between the inclined surface l and the inner surface [6 of the body I l. Positioned immediately above the bushings is a split gland 24, and spaced from said split gland is a further split gland 25, there being chevron packing rings, designated generally as 26, interposed between said glands. The inner surface of the glands corresponds to the contour of the kelly 4.

The external surface of the body II is screwthreaded at 2! to receive a bonnet 28. This bonnet is provided with two spaced annular walls 29 and 30, interconnected by wall 3!. The inner surface of the annular wall 29 is screwthreaded I at 32 for engagement with the threads 21 of the body II. The annular wall 29 is of greater length than wall 39, and the end of said wall engages the top surface of the split gland 25.

The construction is such that the outer surface, to wit: surface 33 of wall 30 spacedly surrounds the kell 4. The outer wall 29 carries one or more set screws 34 for locking the bonnet against 7 movement after it has compressed the packing 26 to a selected degree, as hereinafter set forth in the statement of operation. To prevent mutilation of the threads of the bushing body H a 7 lead plug may be inserted at 35 in the threaded bore 36, against which the set screw bears, forcing the plug into engagement with threads 32.

" A jam nut 31 is employed to retain the set screw.

The body H has depending from the part I4 This tube is welded or otherwise secured to the part [4, as indicated at 39. Tube l4 normally surrounds the kelly, and in this sense acts either as a skirt or a sleeve, with the lower end thereof received within the stuffing box 9.

The stuffing box 9 includes an annular body having two portions 40 and 4| of different diameter, the portion 4| provided with a base flange 42. In the embodiment shown the internal diameter of portion 4| is the same as the internal diameter of the tube 38. The portion 49 is provided with an annular ledge or shoulder 43, upon which rests a gland 44, with chevron packing rings interposed between said gland 44 and a .top gland 46. The portion 40 is internally screwthreaded at 41 to receive an annular nut 48. The upper edge of said portion 40 is castellated or spacedly notched at 49, and the said nut 48 carries a swingable latch key 50, adapted to be received within any one of the selected notches to thereby lock the nut against rotation relative to the stufling box. Nut 48 is provided with one or more radial lugs or ears 5|, which are transversely bored at 52, whereby a. rod of other instrumentality may be inserted within said openings for the purpose of rotating the nut.

4 It is the intention that the nut when screwed within the body should compress the packing 46 between glands 44 and 46 to force the packing into engagement with the periphery of the tube 38.

An outlet means 53 communicates with the interior of the stufiing box, specifically at the zone below the packing, whereby gas may be discharged therethrough.

The drilling riser I0 is provided with an annular flange 54, to which base flange 42 is bolted by means 55, there being packing 56 between said flanges.

The form of the invention depicted in Figs. 4-7 inclusive contemplates a modification of the stuffing box structure. The type, of stuifing box 9 shown in Fig. 1 is not large enough in internal diameter to accommodate a drilling bit of the size which would normally be utilized with a kelly of the proportions shown in this figure. In Fig. 4 we have illustrated a stufling box 5'! formed in three parts, to wit: a body 58, a base 59 and a, collar 60 interconnecting the base and the body. The body is illustrated separately in Fig. 6, and comprises an annulus formed with an internal shoulder or ledge 6| and an external flange 82. That portion of the body which lies beneath the flange 62 is externally reduced in diameter at 63, and this reduced diameter portion is screwthreaded inwardly from the end, as indicated at 54. The upper edge of the body at 65 and the lower edge of the flange 62 at 66 are castellated or notched. The body 58 is likewise provided with internal threads 6! inwardly extending from the castellated area 65.

The base 59 includes an annular wall 68 terminating in a flange 69. The top of the annular wall 68 is provided with spaced castellations or notches 10 which extend to the inner surface H of said, wall. The periphery of the wall 68 is provided with stepped threaded sectors I2, thus forming slots or ways 13 between contiguous ends of the teeth.

The collar 66 is provided at one end with an internal flange l4, and the internal surface of said collar inward from the opposite end thereof is provided with threaded sectors 15 similar to the threads 12, whereby the collar may be locked to the base upon rotation of the collar in one direction. It is of course obvious that the threaded areas for the base and collar are of the breech type, and constitute a quick detachable means for locking or unlocking the elements. To aid in turning the collar, the external surface thereof is provided with spaced projections 16. A gland nut 11 similar to the gland nut 48 engages the threads 61. This gland nut compresses the packing designated generally as T8. The gland nut is locked in position and against rotation by means of a latch key 19 which may be swung downwardly for reception between certain of the castellations 65. Annular packing rings 88 are positioned in the space included between inner surfaces H of the base, the periphery 63 of the body, the base of flange 62, and a gland nut 8| secured to threads 64. It is apparent that a turning of the gland nut will compress the packing between the surfaces just mentioned. The nut 8| may be adjusted to compress the packing prior to securing the flange '69 to the drilling riser by means of the bolts 86. A skirt or sleeve '82, which corresponds to the skirt or sleeve 38 of Fig. l, surrounds the kelly. The bottom of said skirt or sleeve 82 is provided with an external flange 83, the periphery of which is adjacent the inner surface 84 of the body. Between the bottom surface of flange SI and the top surface of flange 83 at 85 may be placed antifriction thrust bearings. It is intended that the diameter of thecollar measured from the periphery of the projection 16 shall be smaller than the opening in the rotary'table when the master bushings have been removed. As shown in Fig. 4, dance 59 is bolted or otherwise secured to the drilling riser by bolts or equivalent means 36.

The operation, uses and advantages of the invention just described are as follows:

That form of the invention shown in Figs. 1-3 inclusive will first be considered.

The kelly drive means is carried on the kelly i being slid-ably mounted thereon, said sliding movement being limited between upper kelly upset as and the lower kelly. upset 9!. The kelly drive means is lowered for engagement with the squared opening of the rotary table as the kelly is lowered into the well. When the squared portion of said kelly drive means is within the squared opening of the master bushing, it is locked thereto against movement by the cams 6, which enter grooves l3 in the squared portion. The tube 38 will be received in the stuffing box 9, passing in its downward travel with the kelly through the annular gland nut to be surrounded by the packing 45. When the parts aforesaid are so received in the table and the stuifing box 9, the bonnet 28 and the gland nut 48 are turned so as to compress the packing 26 in one instance and 45 in the other. to thereby move the same into engagement with the kelly and the tube 38 and to seal on well pressure. The blowout preventer, which is included in the drilling riser I9 and seals off the space between the casing and the drill pipe, is then opened so that gas pressure in the well is admitted within the stufiing box 9 and upwardly through the tube 38 to the kelly drive means. The equipment is then ready for use and drilling may proceed in the usual manner, the kelly being lowered as the hole is made. It is obvious in equipment of this character'that the rotary table will drive the kelly through the kelly drive means *3, and that the tube 38 will rotate within the stuffing box 9. It is for this reason that the gland nut 43 is arranged so as to be locked to the stufling box body, otherwise rotation of the tube 39 might produce rotation of the nut and unduly compress packing '45. As drilling proceeds, the upper kelly upset 99 will reach a point Where it is adiacent the bonnet 28, and when this occurs additional lengths of drill pipe must be added if drilling is to proceed.

If drilling is to continue after the kelly has been lowered through the rotary table to where the top kelly upset 99 is adjacent the bonnet, another joint is placed in the string. To accomplish this, the kelly is raised in the well to a point where the lower kelly upset 9| is positioned below the kelly drive bushings l8 and 9. The blowout preventer i9 is then closed around the drill pipe, the kelly drive bushing locks, to wit: the cams B, are released from the kelly drive means 8 and the kelly is withdrawn from the well. As the kelly is withdrawn the lower upset of the kelly, not shown in the drawings, engages the lower face of the bushings l8 and 19 to remove the kelly drive means 8 from the table. When the joint connecting the kelly with the drill pipe is elevated above the rotary table, slips are inserted in the master bushin which is carried in the table to support the drill pipe while the joint is disconnected. An'added length of drill pipe is then coupled at this point, the

described sequence is repeated as drilling continues.

It is to be observed that there is no rigid connection between the rotary table and the stufiing box 9. The kelly is held suspended by the kelly drive means, and it is not essential that the rotary table be centered with the stuiilng box 9, for the reason that the arrangement shown does not impose any bending stress on the kelly. The kelly packing 26 is carried by the kelly drive means, and the lower end of the tube 38 is packed by the means 45. This arrangement permits the tube 38 to gyrate as the tube is rotated, if vertical alignment of the rotary tablebushing openin and stuffing box is not maintained. It is further to be observed that the stufiing box 9 does not incorporate any rollers or other antifriction means such as are universally used in the average rotary blowout preventer. Any upward thrust of the kelly drive assembly caused by well pressure is counteracted through the antifriotion bearings in the rotary table. Consequently, the present invention saves manufacturing costs as to this item, for the reason that auxiliary antifriction means need not be provided.

The master bushings may remain in place in the rotary table in the practice of the present invention during a removal of the drill pipe from the well, provided of course that the inside diameter of the casing is equal to or smaller than the bore through the master bushing.

As heretofore pointed out, the form of the invention shown in Fig. 1 does not permit the passage of a large drilling bit through the stuffing box 9, and specifically through the bore 4| thereof. The form of the invention shown in Fig. 4 will permit such bit passage therethrough. The internal diameter of the bore of the base 59 may be of a size equal to that of the well casing, and, as is shown, is of greater diameter than that of the sleeve or skirt 82. Viewing the parts in the position shown in Fig. 4, a turning of the colla 60 in one'direction will position the sector type teeth 15 thereof within the ways 13 of the base 59, and as the kelly is lifted upwardly the parts may be separated. Initially, the base member 59 is attached to the drilling riser, and the bit is lowered therethrough in the customary manner, whereupon the body 58 and collar 60 are locked in position of service through the simple expedient of turning the collar 66. It is to be observed that this collar has a flange 85 which engages the top of flange 62 carried by the body and effectively holds the body and base together, the castellations 6B entering the notches or castellations 10 of the base. The pressure to be exerted by the packing element 18 against the skirt or sleeve is regulated by the nut 11. The pressure of packing against the surface 63 of the body is regulated by the nut 8|. The body and the collar may be lifted upwardly when the collar is released from the base, as the skirt flange 83 has engagement with flange 6|. Such a construction likewise permits the lowering of these elements within the cellar of the Well.

We claim:

The combination with control equipment for preventing blowouts during the drilling of a well,

utilizing a rotary table, of a stuifing box secured to said control equipment, the said stuffing box having a housing, a packing within said housing, and means for regulating compression of said packing, the said stuffing box being in direct communication with the hole being bored; said rotary table positioned above said stuffing box; and a kelly drive means for cooperating with said rotary table, the said kelly drive means being in axial alignment with the stuffing box; said kelly drive means including a bushing body formed to fit within the opening of the rotary table, drive bushings Within said bushing body and formed to fit about the kelly, packing surrounding the kelly and confined within said REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,484,786 Johnston Feb. 26, 1924 2,105,754 Otis Jan. 18, 1938 2,180,680 Hild Nov. 21, 1939 2,222,082 Leman et a1 Nov. 19, 1940 2,222,207 Teis et al Nov, 19, 1940 2,333,847 Deely Nov. 9, 1943

Images