US 3257130 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
June 21, 1966 J. D. WATTS ETAL 3,257,130
HANGER ASSEMBLY IMPROVEMENT Filed Oct. 26, 1960 2 Sheets-Sheet 1 INVENTORS JOHN D. Wms
ELwooD k. Dwcaflk ATTORNEYS June 21, 1966 J. D. WATTS ETAL 3,257,130
HANGER ASSEMBLY IMPROVEMENT Filed Oct. 26. 1960 2 Sheets-Sheet 2 Fig.2
I06 IOO/ 7 INVENTOR-S JOHN D. WATTS ELwooD k. PIEQQEJE.
ATTORNEYS United States Patent Filed Oct. 26, 1960, Ser. No. 65,064 2 Claims. (Cl. 285147) This invention relates to well completion equipment and more particularly to apparatus for effecting a permanent seal between a casing head and a tubing head and the exterior periphery of'a tubing string suspended in the casing head.
The invention may be employed in building safe oil wells by the methods described in US. Patents 2,117,444 issued May 17, 1938 and 2,082,413 issued June 1, 1937, to Mueller and Yancey. The description of applicable structure and steps in operation which appear in these patents is not repeated in detail herein, it being understood that they are referred to as showing equipment and methods which would be used with the present invention and to that extent they form a part of the present disclosure.
The use of slip type hanger assemblies to suspend a tubing string within a casing head is well-known. In the normal operation of such hanger assemblies, the tubing string is gripped by the slip segments of the hanger assembly at a position spaced below the upper end of the tubing string, the latter extending upwardly from the hanger assembly above the casing head within which the hanger assembly is landed. In most instances, the hanger assembly is provided with atemporary sealing means which is operable to-effect a pressure-tight seal between the inner periphery of the casing head bore and the outer periphery of the tubing string. There have been many proposals for effecting a permanent seal between the easin'g head bore, the tubing head bore mounted on the casing head and the exterior periphery of the upwardly extending end of the tubing string. For example, in some installations the hanger assembly itself has an upper extension which engages within the lower end of the tubing head bore and is arranged to be permanently sealed to the upper end of the tubing string. It has also been proposed to construct the hanger assembly of two sections, the lower section of which is utilized to land the tubing string within the casing head and provide a temporary seal while the upper section is arranged to effect the permanent seal being the casing head bore, tubing head bore and tubing string.
l An object of the present invention is the provision of apparatus of the type described including a casing head, ahangar assembly for suspending a tubing string within the casing head, a tubing head mounted on the casing head and an improved annular member arranged to be mounted between the casing head bore and the tubing head bore independent of the hanger assembly for providing a permanent seal between the latter and the exterior periphery of the upwardly'extending end of the tubing string. 1
Another object of the present invention is the provision of an apparatus of the type described having improved means for effecting a permanent seal between the casing head bore, a tubing head bore and the exterior periphery of a tubing string supported in the casing head.
Still another object of the present invention is the provision of apparatus of the type described which is simple in construction, efficient in operation, and economical to manufacture and maintain.
These and other objects of the present invention will become more apparent during the course of the following detailed description and appended claims.
The invention may best be understood with reference to the accompanying drawingswherein illustrative embodiments are shown.
In the drawings:
FIGURE 1 is a vertical sectional view of a casing head 7 I having a tubing head mounted thereon showing a hanger assembly, in elevation with parts broken away, landedin the casing head and supporting a tubing string and an annular member, in elevation with parts broken away, providing a permanent seal between the well heads and the tubing string, such apparatus embodying the principles of the present invention; and
FIGURE 2 is an enlarged, fragmentary, vertical crosssectional view of the apparatus shown in FIGURE 1 illustrating an annular sealing member of a modified form.
Referring now more particularly to FIGURE 1, there i is shown therein well head apparatus embodying the principles of the present invention, which includes a casing head 10 which is utilized in the well in the usual manner and has connected therewith a casing pipe 12 of conventional construction. The well head 10 is provided with a through here 14, the lower end of which is threaded to receive the upper end of the casing pipe 12 and the central portion of which communicates with the usual radially extending lateral flow openings 16. The upper end of the casing head bore 14 has a first counter-bore 18 formed therein which defines with the bore 14, an
annular shoulder 20 providing an upwardly facing annular seat for receiving and supporting a hanger assembly, generally indicated at 22. The hanger assembly is arranged to engage and support a tubing string 24 within the casing head 10 with the upper end portion of the tubing string extending above the hanger assembly and the casing head 10. t
The well head apparatus of the present invention also includes a tubing head 26 having a through bore 28 formed therein, the lower end of which is provided with a downwardly facing frusto-conical seating surface 30. The casing head bore 14 is formed with a second counterbore 32 adjacent the upper end thereof which forms with the counterbore 18 an upper annual seat 34. Mounted between the seats 30 and 34 is an annular sealing element or member 36 having an upwardly facing frusto-conical surface 38 formed on the upper periphery thereof for engaging the downwardly facing frusto-conical surface 30 and an annular shoulder or seat 40 formed on the lower periphery thereof for engaging the annular seat 34. Preferably, a sealing ring 41 is mounted within a suitable annular groove formed in the surface 30.
Any suitable means may be employed for mounting the tubing head 26 on the casing head -10, and, as shown, the casing head 10 includes an upper annular flange 42 and the tubing head '26 is provided with a generally corresponding lower annular flange '44, the flanges being suitably apertur'ed at circumferentially spaced positions to receive conventional bolt assemblies 46 which may be tightened to secure the two flanges together. Preferably, an annular sealing ring 48 is provided between the flanges 42 and 44 of the Well heads adjacent their inner peripheries. The annular sealing element 48 is preferably of the type disclosed in Watts et al. Patent 2,766,829, and includes a generally flat ring arranged to be disposed between the opposed horizontal surfaces of the flanges 42 and 44 and having lips 50 extending from the inner end thereof. The lips 50 provide exterior frusto-conical surfaces for engaging frusto-conical surfaces 52 and 54 formed in the bores of the heads 10 and 26 respectively. It will be understood that the sealing element 48 is of metal and the frusto-conical surfaces of the lips 50 have an angle somewhat steeper than the frusto-conical surfaces 52 and 54, these surfaces being brought into par- 3 allelism when the bolt assemblies 46 are tightened, thus providing an effective seal between the bores of the heads and 26.
While the hanger assembly 22 may be of any suitable construction which preferably embodies slip segments for engaging and supporting the tubing string, there is shown in the drawings a slip type hanger assembly which is also of the wrap around type such as disclosed in our co-pending application Serial No. 798,708, filed March 11, 1959, now Patent No. 3,051,513. Thehanger assembly 22 includes a pair of upper arcuate segmental members 56 of semicircular configuration, which members, when disposed in cooperating relation with respect to each other, form a slip bowl providing an exterior cylindrical surface arranged to closely fit within the counterbore 18 of the casing head 10. The interior surface of the segmental members 56 are provided with a series of vertically spaced downwardly and inwardly inclined frustoconical surfaces 58. Disposed within the slip bowl formed by the segmental members 56 is a plulower segmental member on opposite sides of the tongue rality of segmental slips 60, each having a series of vertically-spaced exterior frusto-conical wedging surfaces 62 engageable with the surfaces 58. Each segmental slip also includes an interior serrated surface 64 of generally arcuate configuration for engaging the exterior surface of the tubing string 24 to support the latter.
As shown in FIGURE 1, there are four segmental slip-s provided, each segmental member 56 having a pair of slips associated therewith. In order to maintain the proper relation between the slips so that in operation they will move radially inwardly in response to downward movement relative to the members 56, each slip has a pin 66 extending tangentially from one longitudinal edge thereof and the opposite longitudinal edge has a tangentially extending bore 68 formed therein for receiving the pin 66 of the adjacent slip. It will be understood that suitable means (not shown) is provided for selectively maintaining the slips in their upper position with respect to the members 56 so that the slips can be properly assembled and then released for operative engagement with the tubing string.
- The hanger assembly 22 also includes a pair of lower segmental members 70 which, when positioned in cooperating relation, form a compression ring having a downwardly facing frusto-conical surface 72 providing a seat for engaging the seat 20 of the casing head 18. Each of the lower segmental members 70 is connected with a corresponding upper segmental member 56 for relative a-rcuate movement with respect thereto so that when each cooperating pair of upper and lower segmental members is in co-extensive alignment, the hanger assembly can be separated for removal or mounting around the tubing string 24 between the ends thereof and then secured in position therearound by effecting a relative arcuate movement between the lower members and upper members during which the separation between the lower members and upper members are bridged by the respective upper and lower members.
To this end, the lower portion of each upper segmental member 56 has formed therein an upwardly extending ancuate slot 74 of generally inverted L-shaped configuration to receive an arcuate tongue 76 extending upwardly from the associated lower segmental member 70, the tongue being of corresponding general inverted L-shaped configuration. The tongue and groove connection 74 and '76 provided between the upper and lower segmental members serves to afford radial rigidity to the members when in operative position and yet provide a limited amount of relative vertical movement therebetween. This relative vertical movement is provided in order to compress a sealing means, generally indicated at 78, which is mounted between the upper and lower members.
The sealing means comprises a segmental sealing ring 80 having inner and m ter portions mounted on each 76, one end of the inner and outer sealing ring portions 60 being interconnected by an integral portion providing a tongue 82 and the opposite ends thereof being interconnected by an integral portion providing a corresponding groove 84.
It will be seen that during the landing of the hanger assembly 22, seat 72 thereof will engage seat 28 of the casing head and slip-s 60 will move downwardly within the slip bowl thus effecting radial movement of the serrated surfaces 64 thereof into supporting engagement with theperiphery of the tubing string 24. As the weight of the tubing string is transferred to the seat 72, sealing ning will be compressed respectively into engagement with the counterbore 18 and exterior periphery of the tubing string 24 to provide a temporary seal therebetween.
The annular member 36 is formed with a through bore 86 for receiving the upper end of the tubing string 24 and means is provided in the bore 86 for effecting a permanent seal between the annular member 36 and the exterior periphery of the tubing string. As shown in FIGURE 1, the permanent sealing means of the annular member 36 is in the form of welding material 88 deposited between the upper extremity of the tubing string and an annular groove 90 formed in the upper extremity of the bore 86. In order to test the effectiveness of the seal provided by the welding material 88, a resilient annular sealing ring 92 is mounted within a suitable groove formed in the bore 86 in a position spaced below the groove 90. A radially extending test port 94 is formed in the annular member between the resilient sealing element 92 and the bore 90. In accordance with the usual practice, after the welding material 88 has been deposited between the annular member 36 and tubing string 24, test pressure is applied through the test port 94 to deter mine the effectiveness of the weld, the resilient sealing ring 92 serving to hold such test pressure against leakage in the opposite direction.
Referring now more particularly to FIGURE 2, there is shown therein an annular member 96 which may be utilized in place of the annular member 36 previously described. The annular member 96 has its upper outer periphery provided with a frusto-conical seating surface 98 for engaging the frusto-conical surface 30 of the tubing head. The lower exterior periphery of the annular member 96 is formed with a downwardly facing frustoconical seating surface 100 which is arranged to engage an upwardly facing frusto-conical seating surface 102 formed in the casing head'counterbore 18 in lieu of the shoulder 34 previously described. Both the seating surface 98 and the seating surface 100 are preferably provided with sealing elements 184 and 106 respectively, which are mounted within appropriate grooves formed in the respective surfaces.
FIGURE 2 also illustrates a seal between the flanges 42 and 44 of the heads 10 and 26 in the form of an API ring 168 which is engaged within an annular groove formed in the opposed surfaces of the flanges. The API ring may be used in lieu of vthe sealing ring 48 described in connection with the embodiment shown in FIGURE 1. The annular member 96 is provided with a permanent sealing means for engaging the exterior periphery of the tubing string which is utilized in lieu of the welding material 88 previously described. As shown, the annular member 96 is formed with a bore 110 to receive the tubing string and a counterbore 112 is formed in the upper portion of the bore 110. Mounted in the bottom of the counterbore is an annular packing end ring 114 having annular packing 116 engaged thereagainst. Mounted within the counterbore and in engagement with the packing 116 is a packing spacer ring 118 which also engages at its upper end packing 120. The packing 120 is engaged by an upper packing end ring 122 which, in turn, is engaged by a packing gland sleeve 124 threadedly mounted within the upper end of the counterbore 112. It will be seen that by turning the packing gland sleeve 124 within the counterbore, packing 116 and 122 will be compressed into sealing engagement between the packing end rings and the packing spacer ring and into pressure-tight engagement with the counterbore 112 and adjacent periphery of the tubing string. The packing spacer ring 118 is provided with an opening through which test pressure may be applied through a test port 128 to insure the eflz'ectiveness of the seal provided by the packing 116 and 122.
In a like manner, in order to insure that the seal between the bores of the heads and 26 is effective, there is provided a test port 130 which extends through the flange 42 of the casing head and communicates with the horizontal surface thereof at a position spaced inwardly from the API ring 108. After the two heads have been secured together, test pressure may be applied to the test port 130 to test the effectiveness of the seal between the inner engaging sealing surfaces 30 and 98, 100 and 102, and the effectiveness of the seal provided by the API ring, 108.
It will be understood that in the embodiment shown in FIGURE 2 the loading from the upper to the lower head is carried by the member 96 and the API ring 108. In some installations it is possible to eliminate the API ring 108 and thus eliminate the necessity of the grooves in the flanges of the upper and lower heads as well as the test port 130. In this arrangement the annular member 96 serves as the sole means for transmitting the load between the upper and lower heads. It will be noted, however, that the load of the casing is supported independently of the annular member.
It thus Will be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing specific embodiment has been shown and described only for the purpose-of illustrating the principles of this invention and is subject to extensive change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the folon said first conduit head, means defining aligned through bores in said first and second conduit heads, a hanger assembly supported in the through bore of said first conduit head, a string of well conduit supported by said hanger assembly with its upper end extending into the lower end of the through bore of said second conduit head, and an annular member separate from said hanger assembly, said annular member supported solely on said first conduit head within said first head through bore, said annular member extending within both of said through bores and sealingly engaging the interior surface of each through bore, said annular member also sealingly engaging the outer surface of said well conduit adjacent the upper end of said conduit.
2. The combination as set forth in claim 1 wherein said hanger assembly comprises a plurality of complementary segmental members each having at least one upper segmental element interengaging a lower segmental element, said upper and lower elements being arcuately movable with respect to one another between a first position wherein the upper and lower segmental elements on each segmental member are substantially coextensive and said complementary segmental members are separable from one another and a second position wherein at least one upper segmental element and lower segmental element on each segmental member interengage and arcuately extend with at least one upper segmental element and lower segmental element of each adjacent complementary segmental member, so that said hanger assembly comprises a radially rigid unit when said elements are disposed in said second position.
References Cited by the Examiner UNITED STATES PATENTS 2,097,615 11/1937 Burns 285-144 2,313,169 3/1943 Penick et al. 285-133 I 2,402,723 6/1946 Bean 285-144 2,485,497 10/1949 Lemley 285-444 2,491,598 12/1949 Allen 285-343 3,051,513 8/1962 Watts 285146 CARL w. TOMLIN, Prirrtary Examiner.
R. L. MCLEAR, R. V. PARKER, JR., S. R. MILLER,
D, W. AROLA, Assistant Examiners,