US2122071A - Casing head - Google Patents

Description

June 28, 1938. c. A. RASMUSSEN ET AL 2,122,071

- CASING HEAD Filed May 22, 1936 3 Sheets-Sheet 1 Patented June 28 1938 CASING?v HEAD ijOhester A'. Basmussen and Charles. RhpButler, Long. Beach, Calif., assignors to Trobas, Inc., Long Beach, Galifl, a. corporation of -Galifornia Application May 22, 1936, Serial .No; 81,171

I 2,-Claims.

LOur;invention, relatesyto casing heads used at 'qr-the upper ends of .wells, for thepurpose of. closing -and supporting ,the; upper ends; of, separate strings of; pipe or-casinggwhich are extended downinto ethe well.

1. In the.drilling;ofoil wells andthe completion tofwthe well structure jafter drilling, strings of pipe or casing are; placed one within the. other, and after the-completion of the well it is generally customary topextendgan oil string down into the well structure through which'the production of the wellis-carried to-;the surface-ofthe'ground. vGur 'presentiinvention provides a simple and effective means, for hanging or. supporting-these ;various strings of easing, piping, or tubing in-the pwelland for. closing the upper ends thereof so that the; pressures withinthe. separate strings .;cemented in the well, andinsuch case the casing may 1 be 1 controlled; Some ,of' these strings are I, 20y hB8.d;:S81V(-3S l7he mere purpose of closing the upper ends of thespacesaroundthe, cemented strings.

1, It is an object of the invention to, provide a .casinghead of improved ,form by which-,theupper end of one pipe string may be supported'and sealed at or within the upper end of. anotherpipe string, this casing headhaving a simple duplex I sealing-means employingin combination a'gasket -,seal-of soft material and a'metal-to-metal seal.

,, Inthe preferred form of; the invention we employ a groovedfitting' at the upper end of the pipe string, a solid compressionand sealing ring, and a split ring for connecting the, solid ring to the -grooved ,fitting so", that the weight of the-inner 1-, string of pipe may betransmitted from the-fitting to the solid ring which not only compresses the soft packing, ring.1but..also=;makes.a metal-tometal seal with a sealing face provided for this purpose by the shell of the casing head. The sealingmeans above described not only-seals around the upper end of the inner string but also =sealsoff the space above" the sealing. ring.

A further object of the invention is to provide 1 a casing-head which may beused not only in the l. preferred embodiment of, our invention.

ordinary manner of easing heads, but also may be used, owing to the characteristic construction thereof, in connection with slips for the supporting of the inner string while it is being lowered or raised within the outer string.

,Further objects and advantages of the inventionwill be made evident throughout the following. part of the specification.

Referring to the drawings, which are for illustrative purposes only,

. Fig. 1' is a. vertically sectioned view showing a 2 is a cross section on a plane represented .by the line 2-,--2 of ,Fig. 1.

. Fig. 3 is a verticallylsectioned, view ofan'alterco native form. of our. invention. employing a, screw may be termed soft packing.

. an upper conical face 21., the ring 23 is-provided with an annular recess or counterbore 28 adapted to receive the outer cess I6 which receives the packing ring I1.

- cap for'closing the sealing means, instead of the :;b01tdl clamping ring shown in Fig. 1.

-ilF-ig. 4' is aviewtshowinghow the form of casing head or shell disclosed in Fig. 3 may be employed with slips tohold the pipe string during its installation or removal, or with a tubing supporting sleeve havingthe packing compressing ring integrally formed thereon.

Fig. 5- isan enlarged fragmentary section through. the compressor ring shown in Fig. 1.

Fig. 6 is a sectional view illustrating the manner ;inwhich a plurality'of the supporting and seal- ,ing units are associated in order tosupport three or more casings or tubings in a well.

. As shown in Figs. 1 and 2, the casing head provides a shell or body I0 having a cylindrical 7 wall II the lower end of which is provided with threads l2 whereby itmay be attached to a pipe or casing string I3 which extends within the well.

V The body I0 is enlarged at its upper end to provide an enlarged portion I4 from which a circular flange-i 5 extends radially. The enlarged portion -14 is provided with a-counterbore I6 forming a packing recess for receiving a ring I! of what This ring Il may be made from a material somewhat plastic in its nature which will expand in radial direction when placed under axial compression. A material suitable for this purpose is rubber or rubber compound. The-counterbore I6 is defined by a cylindrical wall I8 and a bottom wall I9, a portion of which bottom wall is relieved so as to provide a conical face 2|. At the upper end of the cylindrical wall I8 a conical seat 22 is formed. To compress the packing ring I! a compressor ring 23 is provided which has a lower portion 24 of substantially thesame radial dimension as the counterbore I6 and is adapted to project downwardly into the upper end of the counterbore I6 so as to. compress the packing ring I'I. Above the lower portion the ring 23 is provided with aradial rib 25 having a lower conical face 26 and The upper portion of portions of split ring segments 29 which are adapted to engage an annular groove 3I in a sleeve coupling -32. coupling '32 is provided with internal threads 33 The lower end of the sleeve for-engagement with threads .34 on-the upper --end of a pipe string .35 which extends downwardly through the bore of. the body I 0 and within the casing string I3 to which the body ID is secured, as shown in Fig. 1. ch36 of the supporting member or coupling 32 is 0t such diameter that it will. just pass within the The external face .bore .31 of the body 10. The face 36 therefore defines the inner wall of the counterbore or re- The ring segments 29 form a separable flange for the coupling 32 through which the downward load carried by the coupling 32 is transmitted to the compressor ring 23. The downward movement of the compressor ring 23 produces a compression of the packing ring I! so that it will be expanded against the outer face 36 of the coupling 32, before the conical face 26 comes into engagement with the conical seat 22 of the body H]. The weight of the inner string 35 is transmitted to the coupling 32 through the threads 34 and 33, and the load of the inner string is then imparted through the shoulder 38 of the coupling 32 to the ring segments 29 which in turn engage the upwardly faced shoulder 39 at the lower end of the counterbore 28 of the compressor ring 23. Threaded into the body 18 below the packing l! are lateral outlet pipes 40 which communicate with the interior of the outer casing l3 through the space 53 of the body III.

The compressor ring 23 is forced downwardly with positive pressure against the seat 22 by means of a clamping ring 4! having a flange 42 which is forced toward the flange E of the body H) by bolts 43. The member M has an upstanding cylindrical wall 44, and at the inner edge of the lower face 45 of the flange 42 a conical seat 46 is formed for engagement with the upper conical face 27 of the compressor ring 23. The downward pressure of the bolts 43 is transmitted through the conical seat 46 of the clamping member M to the conical face 2? of the compressor ring 23. Within the lower part of the cylindrical wall 44 above the compressor ring 23 is an inwardly extending rib ll having a downwardly faced shoulder 48 for limiting the upward movement of the ring segments 29 should the coupling 32 be moved upwardly. The upwardly extending cylindrical wall 44 of the clamping member 4| is provided with threads 49 and 5| to which additional elements of the Well structure may be secured, such, for example, as a nipple 52 which may be employed to support an additional casing head of the type shown in Fig. l, or as shown in Figs. 3 and 4, for carrying another string of pipe which is to extend downwardly within the pipe string 35.

The space between the compressor ring 23 and the outer face of the coupling 32 is effectively sealed by the soft packing ring ll. The space around the exterior of the ring 23 is sealed by the engagement of the face 26 with the seat 22 and the face 21 with the seat 46. Accordingly, the upper end of the space 53 is sealed not only by the soft ring l! but by the metal-to-metal engagement of the face 26 with the conical seat 22. The lower end of the space 54 within the nipple 52 is sealed by the packing ring H and by the metal-to-metal engagement of the. face 21 with the seat 46. The packing ring Il when compressed in place as shown in Fig. 1, has a lip 55 projecting downwardly into the conical space formed between the conical wall 2| and the outer face 36 of the coupling 32. This lip may be formed by the material of the packing ring flowing into the conical space, or where the ring is molded from rubber the lip 55 may be formed thereon.

In many instances it may be desirable to provide auxiliary sealing means consisting of a packing ring 56, the lower and upper portions of which extend respectively into annular grooves 5'! and 58 in the confronting faces of the flanges l5 and 42. This packing ring 56 is disposed in the space between the compressor ring 23 and the bolts 43.

In Fig. 1 we have shown the form of our invention especially adapted for use Where it is desired to mount an additional casing head thereon. As shown in Fig. 3, the same principles of construction may be embodied in a casing head having a screw-type clamping means instead of a bolted clamping means, which casing head is especially suitable for supporting the final piping or tubing string. In this form of the invention a casing or body 68 is provided which is similar to the body l8 shown in Fig. 1 with the exception that it has, instead of the flange I5, external threads 6| adapted to be engaged by the internal threads 62 of a screwtype clamping ring 63 comprising a cylindrical Wall 64 having an inwardly extending flange or lip 65 for engaging the ring segments 29 by which a coupling 32 is supported so as to carry an inner pipe string 35. The ring 63 may be provided with a pair of extending arms or lugs 66 by which it may be turned for the purpose of tightening it down on the threads Si or unscrewing it. The inwardly extending lip 65 engages the upper faces 61 of the ring segments 29, and the downward pressure exerted by the clamping ring 63 is transmitted through the ring segments to a compressor ring 68 which differs from the compressor ring 23 in that it has only one conical face 69 for metal-to-metal engagement with the conical seat H formed in the counterbore [6a intermediate the upper and lower ends of the counterbore. The lower part 12 of the counterbore is of smaller diameter than the upper part 13 of the counterbore, and the lower part 12 forms the recess for the soft packing ring ll. In this form of the invention the piping which extends upwardly from the packing head is screwed into threads 14 in the upper part of the coupling 32.

As shown in the left half of Fig. 4, the ring segments 29 and the compressor ring 68 shown in Fig. 3 may be replaced by a solid ring 80 which is formed integrally with a sleeve or fitting Bl adapted to support a tubing string 82. The ring or flange 80 of the fitting 8! extends downwardly into an upper counterbore 83 in a body or shell 84, and compresses a soft packing member 85 into a lower counterbore 86. Between the upper and lower counterbores 83 and 86 a conical seat 81 is formed against which the ring 88 finally comes to rest after compression of the packing ring 85. The screw-type clamping ring 63, shown in Fig. 4, bears downwardly against the upper face of the ring 89 and positively presses the same downwardly into its proper position of use shown in Fig. 4. The upper end of the fitting 8| has external threads 88 and 89 to which either an outer pipe 9| or an inner pipe 92 may be connected as shown. The invention also provides, in combination with the counterbored body disclosed in Figs. 1 to 4, a means whereby slips may be used to support the inner pipe string during the lowering and raising thereof. As shown in Fig. 4, a plurality of socket segments 93 are provided which, when fitted together in the counterbore consisting of the upper and lower counterbores 83 and 86, will form a conical socket face 94 for receiving tapered slips 95. Preferably, there need be only two of the socket segments, which may in this case be made semi-cylindrical in form. Each of the segments 93 has an upper, large diametered, arcuate wall 96 with a downwardly faced shoulder 9'! at the lower end thereof for engaging the bottom wall 98 of the lower counterbore 86 so that the weight of the tubing indicated at 82a, which is transmitted through the slips 95 to the socket segments 93, will be in turn transmitted through the shoulder 91 to the body or shell 84 of the casing head. It will be readily seen that such socket segments can be applied to the counterbore I6 disclosed in Fig. 1 and to the counterbores I2 and I3 of Fig. 3.

This final part of the invention is especially suited for use with a casing head adapted to carry the pump tubing of a well structure, which pump tubing is ordinarily pulled at frequent intervals in order to replace worn parts of the pump supported at the lower end thereof. The structure shown in Fig. 4 not only provides means for hanging the tubing 82 in the well during the operation of the pump but also provides for the pulling of the tubing without necessity of procuring a separate spider and jacks to hold the tubing, since the slips 95 and the required socket means therefor may be readily applied to the upper end of the casing head body.

Referring to Fig. 6 we illustrate the manner in which three or more casings, such as the outer casing I3 and the inner string 35, illustrated in Fig. 1, and an auxiliary string I00, may be supported and sealed ofi in a well. In this embodiment of the invention we show an auxiliary shell or body IOI adapted for positioning directly above the body I0, the shell IOI having a lower flange I02 and an enlarged portion I03 similar to the symmetrical with the counterbore I6 of body I0,

so that the opposed conical seats 22 and I06 respectively engage the lower and upper conical faces 26 and 21 of the ring 23 to form a metalto-metal seal between the body I0 and the auxiliary body IOI.

The internal diameter of the shell or body IOI is such that when the tubing shown threaded to the upper end of the sleeve coupling 32 in Fig. 1 is removed, the body IOI extends downwardly over the upper end of the coupling 32 in the manner shown.

Directly above the sleeve coupling 32 lateral outlet pipes I0'I are threaded into the body It", so as to communicate with the interior of the tubing 35 through the coupling 32.

The upper end of the body IOI is provided with a radially extending flange I08 and an enlarged portion I09, in which is formed a counterbore IIO having a relieved portion forming a conical face I I I.

The auxiliary casing or pipe I00 extends through the coupling 32 and is threaded into the lower end of a sleeve coupling II2, which coupling is identical in form to the coupling 32 except as to diameter, and has associated therewith a ring II 3 and split ring segments I I4 which are identical in form to the ring 23 and segments 29 associated with the coupling 32.

The ring H3 is adapted to compress a packing II6 within the counterbore IIO to sealthe space between the coupling I I2 and the body I 0|.

The ring II3 seats on a conical seat II'I provided on the body and is compressed thereon by a cap member II8 bolted thereto in the manner shown and having a conical seat II9 engaging the ring to provide a metal-to-metal seal between the body IOI, the ring H3, and the cap II8.

In this embodiment of our invention the packing ring 56 of Fig. 1 has not been shown but may be included in installations where it is deemed desirable to provide packing means in addition to the packing I1 and H6 and the metal-tometal seals afforded by the rings 23 and H3 and their associated seating surfaces.

We claim as our invention:

1. A casing head of the character described, including; a body having means for connecting it to the upper end of a casing, said body having a vertical bore therethrough with a counterbore in the upper end of said bore and an upwardly and outwardly flared conical seat in the upper part of said counterbore; a tubular member substantially completely filling said bore of said body and extending within said bore past said counterbore so that a packing recess substantially closed at the bottom is formed at the lower part of said counterbore; a soft packing ring in said recess; a compressor ring extending downwardly into the upper part of said counterbore to compress said soft packing ring, said compressor ring having a conical face for sealing engagement with said conical seat after said soft ring has been compressed, and said compressor ring having an upwardly faced conical sealing face; and a clamping ring adapted to be secured to the upper end 9f said body, said clamping ring having an inwardly and downwardly faced conical seat adapted to make sealing engagement with said upwardly faced conical face of said compressor ring and to force the same positively downwardly to compress said soft packing and press said downwardly faced conical face thereof into sealing engagement with said upwardly faced conical seat of said body.

2. A casing head of the class described for use with an outer well casing and an inner string of tubing, said casing head having: a body adapted for connection to the upper end of the casing, said body having a vertical bore therethrough with a counterbore in the upper end of said bore, the bottom of said counterbore being beveled to taper downward toward said bore, and the upper edge of said counterbore being beveled to provide a conical seat; a tubular member adapted for connection with the inner string of tubing, said tubular member extending within said bore past said counterbore with sufficient closeness of fit with the bore to form a packing recess having a closed bottom at the lower part of said counterbore; a soft packing ring in said recess; a compressor ring extending downwardly into the upper part of said counterbore to compress said soft packing ring and wedge the ring into the beveled lower end of the counterbore, said compressor ring having a conical face for sealing engagement with said conical seat after said soft ring has been compressed, said compressor ring being dimensioned to fit said tubular member sufficiently close to completely close said recess, thereby entrapping the soft ring; and a clamping ring adapted to be secured to the upper end of said body and to force the compressor ring positively downward.

CHESTER A. RASMUSSEN. CHARLES R. BUTLER.

Images