US3426848A - Remote hanger - Google Patents

Description

Feb. 11, 1969 E. w. KEARNS ET AL 3,426,848

REMOTE HANGER Filed Dec. 5, 1966 Sheet of 2 Feb. 11, 1969 Filed Dec;

E. w. KEARNS ET AL REMOTE HANGER Sheet 2 of 2 E. W ffea/vw Jfe a/ie/r 7. (of/00 INVENTORS United States Patent 3,426,848 REMOTE HANGER Edwin W. Kearns, Houston, and Stephen T. Cutlip,

Bellaire, Tex., assignors to Rockwell Manufacturing Company, Houston, Tex., a corporation of Pennsylvania Filed Dec. 5, 1966, Ser. No. 599,116 US. Cl. 166-214 Int. Cl. E2111 23/00, 33/03; F16! 37/18 Claims ABSTRACT OF THE DISCLGSURE The specification discloses a combination of wellhead with a hanger received within the wellhead for supporting a well pipe. The hanger disclosed is supported on a shoulder and has resilient arms which engage an annular groove in the bore of the wellhead and thereby hold the hanger down against any forces which may tend to push the hanger upwardly in the wellhead. A plug element is used to hold the arms in the groove.

vised to hold the casing or tubing down. Most of these methods do so by holding down the hanger to which the casing or tubing string is attached. Many of these methods require external means such as the lockscrew. Lockscrews are especially undesirable in underwater wellheads where they are not easily operable and are exposed to the sea environment.

The subject invention is a pipe hanger and a completely internal hold down means which are remotely installed in a wellhead. The hold down means comprises cantilevered springs integral with the hanger body which allow the hanger to pass through a valve of the same nominal size as the tubing or casing supported by the hanger. In its seated position within the wellhead, the hanger is locked down by an internal sleeve plug which holds a portion of the cantilevered springs in a groove within the wellhead. The hanger and attached pipe string may be easily removed by removing the plug.

It is, therefore, an object of the invention to provide a pipe hanger and completely internal hold down means which may be easily and remotely installed in a wellhead.

Another object is to provide a pipe hanger and internal hold down means which may be passed through a valve of the same nominal size as the pipe string supported by the hanger.

Still another object is to provide a pipe hanger and internal hold down means which may be easily retrieved from a remote wellhead.

Further objects and advantages will become apparent from the following drawings and description wherein:

FIGURE 1 is an elevation in partial section showing the invention employed in a tubing head;

FIGURE 2 is an elevational view in section of the hanger of the invention;

FIGURE 3 is an elevational view in section of the sleeve means used to lock the hanger of FIGURE 2 in place within the wellhead;

FIGURE 4 is an elevational view in section of the See tool used to run and pull the sleeve of FIGURE 3; and

FIGURE 5 is an elevational view in partial section showing the hanger of FIGURE 2 being lowered into its support position.

Referring first to FIGURE 1, there is shown a tubing string 4, supported in a tubing head 2 by hanger 6. Hanger 6 rests on an upwardly facing frusto-conical shoulder on the interior wall of tubing head 2. Hanger 6 has a plurality of spring fingers 12 integral with the body of hanger 6 extending upwardly therefrom. Spring fingers 12 have small lugs 14 which rest within a groove 16 machined on the interior of tubing head 2. A threaded sleeve 10 is connected to hanger 6 so that its exterior lies against the interior faces of spring fingers 12. Thus, spring fingers 12 are prevented from disengaging groove 16 and hold down tubing string 4 against excessive reservoir pressures.

Attached above tubing head 2 is production valve 18. As will be seen, hanger 6 may be lowered through valve 18 if it is of the same nominal size as tubing 4. Also attached to tubing head 2 is valve 20 which allows production through annulus 22. Although a single tubing string wellhead is shown, the hanger apparatus of the invention may be used with multiple tubing wells. In fact, it is very desirable in multiple tubing wells since no external hold down means is required and space requirements are relatively small.

Now referring to FIGURE 2, hanger 6 and spring fingers 12 will be described in detail. Hanger 6 is generally cylindrical in shape. A smaller diameter lower portion 30 is joined to the larger diameter middle portion 32 by a downwardly facing frusto-conical shoulder 34 which cooperates with shoulder 8 within tubing head 2 to provide support means. (See FIGURE 1.) On the exterior of middle portion 32 two grooves are provided for O ring seals 34'. The exterior of lower portion 30 is provided with connection means 36 such as threads to receive a pipe string for suspension. The interior of middle portion 32 is provided with threaded connection means 38 to receive a pipe for lowering hanger 6 into a well or for inserting sleeve 10 as shown in FIGURE 1.

The upper portion of hanger 6 comprises spring fingers 12. Spring fingers 12 are conveniently formed by machining the upper portion of hanger 6 to the same outside diameter as middle portion 32, except for the extreme upper end which is machined with intersecting frustoconical surfaces 40 and 42. These bevelled surfaces allow the lugs to slide over obstructions and smaller diameter bores when the hanger is moved upwardly or downwardly in the wellhead equipment. The inside diameter of the upper portion is then machined to a greater dimension than the rest of the interior of hanger 6. Then longitudinal slots 44 are cut from the upper end of hanger 6 to its middle portion 32. Thus, cantilever acting spring fingers 12 are formed with lugs 14 at the free end therof. The ends of spring fingers 12 may be forced toward the axis of hanger 6 until lugs 14 lie completely within the outside diameter of middle portion 32. When such forces are removed, fingers 12 return to the position shown in FIGURE 2.

Referring also now to FIGURE 3, sleeve 10 will be described. Sleeve 10 is a tubular body with a reduced diameter lower exterior 50 which is threaded to fit threads 38 of hanger 6. The upper exterior 54 of sleeve 10 has a diameter slightly less than the inside diameter of hanger 6 at spring fingers 12. Thus, if sleeve 10 is connected to hanger 6 by threaded connection 38 and 50, upper exterior 52 will prevent fingers 12 from being forced inwardly. The upper interior of sleeve 10 is provided with a groove 54 formed by intersecting frusto-conical surfaces. Slots 56 are machined at degree intervals on the upper edge of sleeve 10. Slots 56 and groove 54 are for engage- 3 ment of a running and pulling tool 60 shown in FIG- URE 4.

The lower end of running and pulling tool 60 is a cylindrical extension 62 with a diameter slightly less than the inside diameter of sleeve 10. Spring loaded plungers or detents 63 are mounted in a hole drilled in extension 62 perpendicular to its axis. Plungers 63 are biased to partially project out of entension 62. Welded to extension 62 is cylindrical hub 64 which has two keys 66 machined at its base. Keys 66 and plungers 63 are so positioned that they may engage slots 56 and groove 54 respectively on sleeve 10. At the upper end of running and pulling tool 60, collar 68 is provided which is threaded on its interior 70 to receive a running pipe string for lowering into the well. Set screws 72 assure that tool 60 will not be accidentally separated from the running string. Collar 68 is attached to hub 64 by a joint of pipe 74.

Referring now to FIGURE 5, the installation of hanger 6 will be explained. Hanger 6 is first connected to tubing string 4. Then a string of tubing 3 is screwed into the threaded connection on the interior of hanger 6. Hanger 6 and tubing string 4 are then lowered into the well bore until shoulder 34 contacts support shoulder 8 within tubing head 2. As hanger 6 is lowered into the well bore spring fingers 12 may be forced inwardly allowing hanger 6 to pass through valve 18 or any bore which would allow the passage of the middle portion 32. When hanger 6 reaches its support position at shoulder 8, groove 16 receives lugs 14 of spring fingers 12 allowing the fingers to return to their normal position. Drill pipe 3 is then disconnected and removed from the well bore.

At this point hanger 6 is fully supporting tubing string 4. However, nothing is preventing the string from moving upwardly if excessive bottom hole pressures arises since fingers 12 may spring inwardly due to the sloped surfaces of groove 16 and lugs 14. To remedy this situation sleeve 10 is attached to running and pulling tool 60 by keys 66 and plungers 63 engaging slots 56 and groove 54. (See FIGURES 3 and 4.) Tool 60 and sleeve 10 are then lowered on a pipe string until sleeve 10 is within hanger 6. Tool 60 and consequently sleeve 10 are then rotated until sleeve 10 has fully engaged the threaded connection on the interior of hanger 6. Tool 60 is now removed from the well bore by simply pulling it upwardly. The apparatus now appears as shown in FIGURE 1. As can be seen, the outside diameter of sleeve 10 is only slightly less than the inside diameter of hanger 6 at the inner faces of fingers 12. Thus, finger lugs 14 are prevented from being forced inwardly of groove 16 and hanger 6 and tubing string 4 are positively held down against excessive bottom hole pressures.

The present invention also allows hanger 6 to be retrieved along with tubing 4. To do this, tool 60 is lowered into engagement with sleeve 10. Sleeve 10 is then unscrewed from hanger 6 and removed from the well. A pipe string is then lowered into the well and rotated to engage the threaded connection on the interior of hanger 6. Hanger 6 and tubing string 4 are then pulled upwardly. Finger springs 12 are forced inwardly due to the cooperating fnusto conical surfaces of lugs 14 and groove 16 thereby releasing hanger 6 for upward travel.

Thus, it can be seen from the preceding description that effective hold down of a pipe string has been attained by completely internal means. The apparatus used may be easily installed by remote control and may likewise be easily removed.

Although only a single preferred embodiment of the invention has been described many modifications thereof can be made by one skilled in the art Without departing from the spirit of the invention and it is intended that the invention be limited only by the scope of the following claims.

We claim:

1. Internal means for holding down a pipe hanger and its supported pipe string within a wellhead comprising:

spring fingers extending upwardly from said hanger around its upper periphery, said fingers being longitudinal strips separated by slots opened at the upper end to allow said fingers to be forced inwardly at their upper ends, lugs projecting radially outward from the upper ends of said fingers engageable with an annular groove in said wellhead when said fingers are in a non-deflected position; and

sleeve means remotely engageable with said pipe hanger to prevent disengagement of said hanger from said wellhead by maintaining said non-deflected position of said fingers. 2. The combination of claim 1 wherein the inner surfaces of said finger means substantially define a portion of a cylinder in said non-deflected position and the outer surface of said sleeve means is a cylindrical surface in close proximity to said fingers throughout their length.

3. The combination of claim 1 wherein said sleeve means and said hanger are connected by connection means preventing relative axial movement therebetween.

4. Internal means for holding down a pipe hanger and its supported pipe string within a wellhead comprising:

cantilevered spring fingers extending upwardly from said pipe hanger, the outer faces of which define a portion of a cylinder of a diameter slightly less than the bore of said wellhead, the inner faces of which define a portion of a smaller diameter cylinder, the extreme upper end of said fingers being provided with outwardly projecting lugs engageable with annular groove means on the interior of said wellhead when said fingers are in a non-deflected position; and

tubular sleeve means remotely insertable within said hanger means having threads thereon engageable with threads on the interior of said hanger to prevent relative axial movement therdbetween, the upper exterior of said sleeve means comprising a cylindrical surface of a diameter slightly less than the diameter of said finger inner faces and adjacent to said fingers throughout their length to prevent deflection thereof.

5. The combination of claim 4 wherein said lugs are provided with upwardly facing and downwardly facing inwardly converging surfaces to inwardly deflect said fingers when said sleeve means is removed and said hanger is moved upwardly or downwardly through diameters less than the diameter of said wellhead annular groove means.

References Cited UNITED STATES PATENTS 3,292,717 12/1966 Hall et al. 166-217 3,339,944 9/1967 Poague 285-319 3,361,212 1/1968 Page 166224 JAMES A. LEPPINK, Primary Examiner.

U.S. Cl. X.R.

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