US2689139A - Pipe hanger and sealing structure for well heads - Google Patents

Description

Sept? 1954 M. R. JONES ET AL 2,689,139

PIPE HANGER AND SEALING STRUCTURE FOR WELL HEADS Filed Oct, 20, 1950 2 Sheets-Sheet 1 43 30 61 -23; 2 k v 53 2 2/ 29 25 A? 26 //7 /7 I 24f" ZZ -Wr lll|| 20 C A20 M E. [l I M M 44 INVENTORS Sept. 14, 954 M. R. JONES ET AL 2,689,139

PIPE HANGER AND SEALING STRUCTURE FOR WELL HEADS Filed Oct. 20, 1950 2 Sheets-Sheet 2 INVENTOR.

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Patented Sept. 14, 1954 UNITED STATES PATENT OFFICE PIPE HANGER AND SEALING STRUCTURE FOR WELL HEADS poration of Texas Application October 20, 1950, Serial No. 191,198

7 Claims. (01. 285-22) This invention relates to a well head assembly and particularly to a pipe hanger and sealin unit for such assembly.

A principal object of this invention is to provide in a well head an improved type of pipe hanger and seal unit which may be installed on and about the pipe after the pipe has been inserted into the well through the usual casinghead.

Another object is to provide such a unit in which the seal member is actuated by downward pull exerted thereon by load-supporting members disposed below the seal member.

A further object is to provide a pipe hanger and seal unit comprising a bowl member, pipeengaging slips, and a sealing assembly for sealing between the pipe and the surrounding casinghead, the several elements being of segmented construction, and hinged to be closed about a pipe for movement along the pipe into place in the supporting well head.

A further object is the provision of such a unit in which the force employed to expand the sealing element is exerted through the slip bowl.

Still another object is the provision of such a unit in which the sealing assembly comprises a support ring engageable with a seat in the casinghead, a compressible resilient sealing ring disposed on the support ring, and a compression ring mounted on the sealing ring and adapted to be connected to the upper end of the slip bowl for axial movement thereby relative to the support ring in response to loads applied to the slip bowl.

An additional object is the provision of means for movably linking the slips to the slip bowl.

Other and more specific objects and advantages of this invention will become evident from the following detailed description when read in conjunction with the accompanying drawings which illustrate one useful embodiment in accordance with this invention.

In the drawings:

Fig. 1 is a longitudinal sectional view, taken generally along line ll of Fig. 2, of a well head assembly in accordance with an embodiment of this invention, showing the pipe hanger and seal unit in pipe-supporting and sealing position in a well head;

Fig. 2 is a top plan view of the upper end of the pipe hanger and seal unit; and

Fig. 3 is a view in perspective of the pipe hanger and seal unit shown in open position for mounting on a well pipe before insertion into the supporting well head.

Referring to the drawings, there is shown a casinghead, designated generally by the numeral It, mounted in the conventional manner on the upper end of an outer string of casing H, such as the usual surface casing of a well. Casinghead I is of generally conventional form, being composed of a generally tubular body l2 having an outwardly extending annular flange I3 at its upper end adapted for attachment of various upper well head fittings in the well-known mannor in completing the usual composite well head structure. The bore of body 12 has an axially straight portion [4 extending from a point somewhat below the upper end of the body to its lower end and merging at its upper end into an upwardly and outwardly tapering portion forming a tapered seat l5, which, in turn, terminates in a second axially straight portion l6 which extends to the upper end of body l2. A plurality of internally threaded openings 11 are provided in the wall of body 12 communicating with the interior of the body through straight portion I4 thereof.

A tubular casing or other well pipe [8 is shown inserted through the bore of casinghead ID to be supported therein by the pipe supporting and sealing unit, designated generally by the numeral 19, which is adapted to be inserted in the annular space between pipe 18 and the inner wall of the casinghead.

The pipe supporting and sealing unit 19 is composed of a tubular bowl 20 the outer wall 2| of which is axially straight and dimensioned to be freely but snugly slidable in straight portion M of the bore of the casinghead. The bore of bowl 20 is somewhat larger in diameter than the external diameter of pipe is and has a downwardly and inwardly inclined surface 22. The upper end of bowl 2G is provided with an inwardly extending annular flange 23, the inner diameter of which is larger than the external diameter of pipe 18 whereby the bowl will be freely movable along and about the pipe. A plurality of arcuate pipe-gripping slips 24 are mounted in the bore of bowl 2!] and are provided on their inner faces with pipe-gripping teeth 25, the rear faces of the slips being tapered, as at 26, to complement the taper of inclined surface 22 of the slip bowl. With this arrangement, it will be understood that when the toothed faces of slips 24 are engaged with the outer wall of pipe l8, the load of the pipe will produce a wedging action between the slips and the inclined surface of the slip bowl to thereby cause the slips to firmly grip and support the pipe, the slip bowl being supported against substantial downward movement in the casinghead in the manner to be subsequently described. The slips 24 are held in place in bowl 23 by means of bolts 21, the lower ends of which screw into, or are otherwise suitably connected to, outwardly extending shoulders 29 on the rear faces of the slips and extend upwardly through apertures 28 provided in flange 23. Apertures 28 are made appreciably larger in diameter than bolts 27 to provide a loose sliding fit for the bolts, which are provided at their upper ends with enlarged heads 30 so that they will not pull through apertures 28. Thus the slips may be retained in the slip bowl by means of a relatively loose linkage which will allow some degree of movement of the slips relative to the slip bowl so as to permit the slips to adjust themselves relative to the pipe and bowl during assembly and setting of the structure. Shoulders 29 form abutments which are spaced from but engageable with the lower edges of flanges 23 to prevent the slips from being pulled upwardly out of the slip bowl.

The sealing assembly includes a metal support ring 3|, the inner diameter of which is such as to provide a loose fit about pipe l8. Ring 3| has an outer surface 32 which is tapered to complement the slope of seat I in the bore of easinghead It]. Seat i5 thereby serves as an abutment or shoulder to engage support ring 3| and resist any substantial downward movement thereof in the bore of the casinghead. A resilient compressible sealing ring 33 is mounted on the upper end of support ring 3| and is dimensioned, in its normal uncompressed condition, to fit slidably in the annular space between the exterior of pipe [8 and straight portion |6- of the casinghead bore. A metal follower or compression ring 34 is seated on top of sealing ring 33 and is also dimensioned to'be freely slidable in the annular space between pipe I8 and straight portion l6 of the casinghead bore. A plurality of angularly spaced, axially registering holes 36, 37, and 38 are provided respectively in support ring 3|, sealing ring 33, and compression ring 34, through which bolts 39- extend, the lower ends of the bolts being screwed into registering threaded sockets 43 provided in the upper end of bowl 20. The upper ends of bolts 39 are provided with conventional hollow heads 4| which are adapted to seat in sockets 42 i formed by counterboring the upper ends of holes 38' in compression ring 36. The diameters of the several holes 36, 3?", and 38 are made somewhat larger than that of the bolts 39' whereby the latter may slide freely through the several rings inresponse to the axial movement of the slip bowl relative to the sealing assembly, the

slip bowl being thus dependingly connected to follower ring 34 by the engagement of bolt'heads 4|- with the edge of holes 38; The lower end of support ring 3| is provided with upwardly extending sockets 43 to receive the upper end of bolts 2! and are of sumcient depth so that the latter may move freely longitudinally therein in response to relative axial movement between slips 24* and slip bowl 23'. It will be understood that sockets 43 will be angularly' interspersed in support ring 3| with holes 36, so as to avoid any interference between the respective relative movementsof bolts 29 and 33 Aswill be seen particularly in Fig. 3 slip bowl support ring 3|: and compression ring 34' are split diametrically to divide these members into two complementary semi-circular segments. Slips= 24. are likewise segmented in. a. corresponding manner. Sealing ring 33 is split on only one side whereby the sealing ring will serve as a flexible hinge, indicated at 35, connecting the segments of the hanger and sealing unit at the opposite side to provide an articulated connection between the several segments which will allow the unit to be opened and closed for application to, and removal from, pipe I 8. The split in sealing ring 33 is preferably oifset somewhat with respect to the split between adjacent metallic' members of the unit, thereby forming a tongue 43 protruding from one side of one of the adjacent metallic members of the unit and adapted to enter the space between support ring 3| and compression ring 34 in the opposing side of the other adjacent member. The split in sealing ring 33 is so positioned that tongue 44 will include one of the holes 31. With this arrangement when the unit is closed about the pipe, tongue 44 will enter the adjacent space between the support and compression rings and hole 31 in tongue 44 will be brought automatically in registration with the corresponding holes 36 and 33 in support ring 3| and compression ring 34, respectively. Thus, a bolt 33 may then be inserted through these registering holes and when screwed into its corresponding socket will serve to lock together the open ends of the segmentsof the complete unit about the pipe. It will be under stood that the pipe hanger and assembly unit may be formed from any desired number of ar ticulated segments, and that other suitable arrangements may be employed for hinging the segments to each other and for locking the open ends together when closedab'out a pipe.

The adjacent side edges of adjoining slips 24 are provided with cooperating sets of tongues and slots 46, which are adapted to be engaged when the segments of the unit are closed about a pipe, in. order' to prevent relative axial movement between the slip segments, in order toassure centering of the pipe in the hanger structure.

In operation, the above-described pipe hanger" and sealing unit |9, assembled as described, will be opened as illustrated in Fig. 3, one of the bolts 33 being withdrawn, as shown, for this purpose; The opened unit is then placed about a portion of pipe l8 which extends above the upper end of casinghead I0 and closed about the pipe, after which the previously withdrawn bolt 38 will beinserted through the registering holes incom-- pression ring 34, tongue 44' and support ring 3| and screwed into registering socket 40 in the upper end of slip bowl 20'. It will be understood that pipe |8' will previously have been inserted into the well through casinghead l0, and usually through a series of conventional well head fittings such. as blowout preventors and master gates (not shown) which will ordinarily be in position onv top ofv the casinghead. At this stage pipe I3 will ordinarily be suspended in a derrick from the usual hoisting and lowering equipment. (Not shown.)

When the unit hasbeen: looked around the pipeitwillbe allowed to slide down the-pipe into the annular space between the pipe and casinghead. Asv the unit enters: the bore of the casinghead, slip bowl 20 will descend therein until-support ring 3| engages seat |5= in the casinghead, thereby arresting further downward. movementof the unit. Slips24will then tend to slide downwardly and inwardly along inclined surface 22 of the slip bowl and engage the; exterior of: pipe' |8. Any downward movement of-the latter rela ace-9,139

tive to the casinghead, as by slacking off of, the derrick line by which it is suspended, will tend to set the slips firmly in the pipe wall, thereby anchoring the pipe against further downward movement. The load of the pipe will be transferred to the slip bowl by the wedging action of the slips on inclined surface 22. At the same time, the slip bowl will tend to move downwardly in the casinghead under the load thus'applied thereto. This load will, in turn, be transferred through bolts 39 to compression ring 34 which will thus be drawn downwardly toward support ring 3|, which remains stationary because of its engagement with seat [5. The resulting downward movement of compression ring 34 relative to support ring 3| will compress and radially expand sealing ring 33, thereby tightly sealing the annular space between the pipe and the inner wall of the casinghead.

In the structure, above described, the slip bowl will normally be dimensioned to provide a close sliding fit in the straight portion I4 of the casinghead bore. As a result upon application of the load of the pipe, the lateral forces developed by the wedging action of the slips on the sides of the slip bowl will tend to expand the latter into strong frictional engagement with the surrounding wall of the casinghead bore, whereby a very substantial part of the load on the hanger will be supported by friction, the remainder of the load being taken on bolts 39 and support ring 3| and utilized to actuate sealing ring 33.

An important advantage resulting from the described construction is that it provides a compact structure by means of which the load will be supported near the upper end of the casinghead thereby permitting the use of much shorter casingheads than those generally in use heretofore.

The pipe hanger and sealing unit in accordance with this invention, because of its compact construction, will readily pass through the bores of the usual well head fittings, such as blow-out preventors, master gates, and the like, which will normally be mounted on the casinghead during the operation of running and setting casing. The unit may thus be installed quickly and with a minimum of disturbance to the well head structure already in place.

It will be understood that in the described structure, the sealing ring may also be expanded into sealing engagement with the pipe and the surrounding casinghead independently of the weight of the pipe suspended therein. This may be done by screwing down bolts 39 in sockets 40 of the slip bowl sufiiciently to compress and expand sealing ring 33 between follower ring 34 and support ring 3! to the desired extent. Or a combination of weight applied to the slips and tightening of bolts 39 may be employed to provide the desired degree of compression of sealing ring 33. i

It will be understood the various alterations and modifications may be made in the details of the illustrative embodiment within the scope of the appended claims and without departing from the spirit of the invention.

What we claim and desire to secure by Letters Patent is:

1. A pipe hanger structure for supporting a well pipe which'extends axially through a tubular well head member having an internal seat, comprising, a bowl member insertible within the well head member about the pipe, the exterior of said bowl member being axially straight and dimensioned to slide freely through said seat, pipe supporting means within the bowl member, and an annular sealingassemblyinsertible in the annular space between the pipe and the well head member above said bowl member, said sealing assembly comprising a support ring engageable with said seat, a follower ring disposed above said support ring, .a compressible resilient sealing ring disposed between said support ring and said follower ring, and a plurality of angularly spaced connection members slidably extending through said sealing assembly dependingly connecting said bowl member to said follower ring.

2. A structure according to claim 1, wherein said bowl member and said sealing assembly comprise articulated segments adapted to be wrapped around the pipe.

3. A structure according to claim 1, wherein said bowl member and said sealing assembly comprise a plurality of articulated arcuate segments having a separable connection at one point between adjacent segments.

4. A structure according to claim 1, wherein said bowl member and said support and follower rings comprise a plurality of arcuate segments, and said sealing ring is split only at one point between adjacent segments whereby to form articulating connection between said segments at the other junctures thereof.

5. A pipe hanger structure for supporting a well pipe which extends axially through a tubular well head member having an internal seat, comprising, a bowl member insertible within the well head member, the exterior of said bowl member being axially straight and dimensioned to slide freely through said seat, pipe supporting means within the bowl member, connection elements connecting said pipe supporting means for longitudinal movement relative to said bowl member, and an annular sealing member insertible in the annular space between the pipe and the well head member above said bowl member, said sealing assembly comprising, a support ring engageable with said seat, a follower ring disposed above said support ring, a compressible resilient sealing ring disposed between said support ring and said follower ring, and a plurality of angularly spaced connection members slidably extending through said sealing assembly dependingly connecting said bowl member to said follower ring.

6. A pipe hanger structure for supporting a well pipe which extends axially through a tubular well head having an internal seat and an axially straight portion below said seat, comprising, a bowl member insertible within the well head member about the pipe, the exterior of said bowl member being axially straight and slidable in the axially straight portion of said well head member, pipe supporting means within the bowl member, and an annular sealing assembly insertible in the annular space between the pipe and the well head member above said bowl member, said sealing assembly comprising a support ring engageable with said seat and separate from said bowl member, a follower ring disposed above said support ring, a compressible resilient ring disposed between said support ring and said follower ring, and a plurality of angularly spaced connection members slidably extending through said sealing assembly dependingly connecting said bowl member to said follower ring.

7. A pipe hanger structure for supporting a well pipe which extends axially through a tubular well head member having an internal seat, comprising, a support ring engageable with said seat to limit its downward movement in said well sesame said connection members for longitudinal movement therewith relative to said support ring.

References Cited in the file of this patent UNITED STATES PATENTS N mbe Name Date Eckel Dec. 5, 1950 Allen May 22, 1951

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