Well Bore Casing Hanger Apparatus

Abstract

A casing hanger body is threadedly connected to a running tool secured to a running string, the tool being clutched or otherwise coupled to a seal structure, which is also threadedly connected to the body, the running string being used to lower the apparatus through a body of water to engage the hanger body with a seat in an underwater wellhead housing, and to locate its seal structure between the housing and body and in an initial position in which a fluid circulation path is open, the running string and running tool being rotated to thread the tool and seal assembly simultaneously along the hanger body to release the running tool from the body and place the seal structure in a position closing the circulation path, after which the running string and running tool may be retrieved. A plurality of such casing hanger apparatus can be placed or stacked one upon the other to support different sizes of concentric casing strings in the underwater well bore, the circulation path associated with each apparatus being closed by a seal structure. A tubing hanger may be landed on the uppermost hanger apparatus and locked to the threaded portion of the uppermost hanger body.

Description

The present invention relates to well bore apparatus, and more particularly to casing hanger apparatus adapted to be disposed in an underwater wellhead.

In most underwater or subsea casing hanger systems, the hanger and the pack-off assembly for closing the the circulation path through the hangar are lowered separately to the wellhead housing. In some systems, the hangar and pack-off assembly are run together. However, in both types of systems, after the casing string has been cemented in place, the pack-off assembly is moved downwardly into a sealing position closing the circulation path (See U.S. Pat. Nos. 3,335,799 and 3,492,026). Such downward movement requires that the pack-off assembly push the cement below it out of the way, or downwardly, so that the seal can be accomplished. Since there is normally a time delay between placing the cement into the well and energizing the pack-off assembly, the cement has a chance to set up and harden, making it very difficult to remove the cement from the path of the pack-off assembly or structure so that it can be energized into an appropriate sealed relation effectively shutting off or closing the circulation path.

Prior underwater casing hanger systems have been relatively costly, requiring the maintenance of substantial inventories because of the many different sizes of casing hangers required for the running-in and supporting of different sized casing strings. In addition, the running tool for lowering the casing hanger to the wellhead housing and for effecting the pack-off to close the circulation path has been comparatively complex, with its associated high costs.

By virtue of the present invention, the waiting time from the termination of the cementation operation until the energization of the pack-off seal is minimized considerably. Instead of the seal being effected by downward movement of the pack-off or seal structure to its circulation path closing position, such structure is moved upwardly to its circulation path closing position, thereby avoiding the necessity for pushing and pressing the cement ahead of the pack-off. Because of the minimizing of the waiting time from completion of cementation until energization of the pack-off seal, assurance is had that the cement is still in a fluent state, and this fact, coupled with the upward shifting of the pack-off or seal structure, renders it much easier to shift the structure to its circulation path closing position.

A further objective of the invention is to provide a casing hanger design which permits the easy conversion from one size casing thread to another, thereby reducing inventory problems and expenses. The outside profile of all casing hanger bodies may be made identical and interchangeable. It is only necessary to provide casing hangers of reduced inside profiles, and with the required size threads for supporting a different diameter casing string. The casing hangers can be easily stacked one upon the other in a wellhead housing in any combination, rather than being required to be landed in the wellhead housing in a predetermined sequence, as required by prior designs.

Another object of the invention is to provide a casing hanger combination in which a tubing hanger can be landed on the last casing hanger installed in the underwater wellhead, and be locked to such hanger in a simple and highly effective manner.

A further object of the invention is to provide a comparatively simple casing hanger apparatus and associated running tool, in which there is a direct drive between the running tool and the seal structure on the casing hanger body for shifting the latter to its position closing the fluid circulation path through the apparatus, the running tool being readily disconnected from the apparatus for retrieval. More particularly, the running tool is clutched or coupled directly to the seal structure threaded on the casing hanger body, so that rotation of the running tool not only moves the seal structure into its sealed or packed-off position closing the circulation path, but also places the running tool in a condition for disconnection from the seal structure and the casing hanger body, allowing the running tool and the running string connected thereto to be elevated from the casing hanger apparatus and removed to the drilling rig which may be located on a floating drilling vessel or platform.

With respect to the threading of the seal structure on the casing hanger body, the movement of the seal structure to its position closing the circulation path leaves an upper portion of the threads of the body exposed, thereby enabling a tubing hanger to be locked down after being landed on the casing hanger by a coupling device which will thread onto the casing hanger body threads.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detail description is not to be taken in a limiting sense.

Referring to the drawings:

FIGS. 1a and 1b together constitute a quarter longitudinal section through casing hanger apparatus embodying the invention, the parts being illustrated with a circulating passage in open condition, FIG. 1b being a lower continuation of FIG. 1a;

FIGS. 2a and 2b are views similar to FIGS. 1a and 1b, with the circulating passage closed, FIG. 2b being a lower continuation of FIG. 2a;

FIG. 3 is a quarter longitudinal section, on a reduced scale, corresponding to FIGS. 2a and 2b, with the running tool removed;

FIGS. 4a and 4b together constitute a quarter longitudinal section illustrating a plurality of casing hangers disposed in an outer housing with circulating passages closed, the uppermost casing hanger supporting a tubing hanger and depending tubing, FIG. 4b being a lower continuation of FIG. 4a;

FIG. 5 is a cross section, on a reduced scale, taken along the line 5--5 on FIG. 2b;

FIG. 6 is an enlarged fragmentary longitudinal section through an upper portion of the apparatus illustrated in FIG. 4a.

As disclosed in the drawings, a casing hanger apparatus A is releasably connected to a running tool B secured to a tubular running string C, such as a casing string, by means of which the apparatus is run into a wellhead housing or body D previously installed above an ocean floor (not shown), with a suitable diameter pipe or casing string E secured to the housing and extending into the well bore drilled downwardly from the subsea or ocean floor. It is desired to land one or a plurality of casing strings 10, 11, 12 in the wellhead housing (see FIGS. 4a, 4b), cement each casing string in place, and then seal off the upper end of the circulation path disposed between the casing hanger apparatus and the wellhead housing.

As disclosed, a lower casing hanger body 13 is provided having a lower downwardly tapering terminal portion 14 adapted to engage a tapered seat 15 in the wellhead housing D, the latter having an inner cylindrical wall 16 extending upwardly from such seat. Above its lower terminal 14, the body is reduced in external diameter to provide an upwardly facing shoulder 17, the outer surface or wall 18 of the body above the shoulder being spaced from the inner wall 16 of the housing to provide an elongate annulus 19 therebetween in which a packing assembly or structure 20 is disposed. This structure comprises a tubular sleeve 21 having a lower head 22 provided with inner side seal rings 23 adapted to seal against the lower smooth periphery 18 of the casing hanger body and outer side seal rings 24 adapted to seal against the inner wall 16 of the wellhead housing. The pack-off or seal structure 20 has a reduced diameter portion 25 above its head 22 to provide an annular space 26 between it and the housing wall through which fluid can circulate. This reduced diameter portion terminates in an upper head 27 having internal left-hand threads 28 meshing with external left-hand threads 29 provided on the hanger body 13 and extending from the upper external seal portion 18 of the body to the upper end of the body.

Initially, the pack-off or seal structure 20 is disposed in a lower position along the hanger body, with its head 22 in engagement with the casing hanger body shoulder 17 with its upper threaded head 27 located at the lower threaded portion of the casing hanger body (FIGS. 1a, 1b). When in this position, circulation ports 30 in the seal body immediately above the seal head 22 are in alignment with circulation ports 31 extending through the hanger body 13, the hanger body immediately above its ports comprising a threaded box 32 to which the upper end of a casing string 10 is threadedly secured, the casing string extending downwardly into the well bore to the required extent when the body terminal 14 engages the housing seat 15. The lower portion 33 of the casing hanger body has a larger internal diameter than its threaded box 32 to provide an annular passage 34 communicating with the annulus 35 between the casing string 10 and the pipe or casing E depending from the wellhead housing D, the annular passage 34 being in communication with the body ports 31.

The running tool B has an upper threaded box 36 secured to the lower end of the tubular running string C. An inner cylindrical sleeve 37 of the running tool is piloted within the upper portion of the casing hanger body 13, the lower portion of the sleeve carrying one or a plurality of side seal rings 38 for slidable sealing engagement with the inner wall 39 of the casing hanger body. The running tool B includes an outer sleeve 40 encompassing the upper threaded portion of the casing hanger body and having an upper left-hand threaded 41 portion meshing with the body threads 29, and lower axial teeth or drive lugs 42 meshing with companion axial teeth 43 at the upper end of the seal body 21. By virtue of the left-hand threaded connection 41, 29 between the outer running tool sleeve 40 and the casing hanger body 13, the casing string 10 and casing hanger assembly A may be lowered in the well bore, the running tool B being secured to the running string C, which moves downwardly until the casing hanger body terminal 14 engages the tapered seat 15, at which time the parts are in the relative position illustrated in FIGS. 1a, 1b.

Circulation can now be established down through the running string C and casing string 10, the circulating fluid passing upwardly between the casing string 10 and the pipe string E depending from the wellhead housing, and proceeding upwardly through the annulus 34 between the lower portion 33 of the hanger body and casing string, through the aligned ports 31, 30 in the hanger body and seal body, into the annulus 26 surrounding the latter, proceeding upwardly through such annulus and the annulus surrounding the outer sleeve 40 of the running tool into the annulus 50 between the running string C and wellhead housing, a continuation of which extends upwardly through a blowout preventer (not shown), or the like, surrounding the running string and the marine conductor pipe (not shown) extending upwardly to the drilling vessel. After circulation has been completed, the required charge of cement slurry is pumped down the running string C and through the casing string 10 for upward passage through the casing string-pipe string annulus 35, the uppermost portion of the cement slurry probably passing into the casing hanger circulation path 34, 31, 30, 26. After the required quantity of cement slurry has been displaced, the running string C is rotated to the right to rotate the running tool B to the right and thread its outer sleeve 40 upwardly along the casing hanger body 13. At the same time, the seal structure body is being threaded upwardly along the casing hanger body, since the rotary effort of the outer running tool sleeve 30 is transmitted to the seal body 21 through the clutch or drive lugs 42, 43. The running tool B unthreads from the body 13 after the requisite number of rotations have been taken, at which time the head 22 and seal rings 23, 24 are disposed above the circulation ports 31 of the body 13, effecting a pack-off or seal between the periphery 18 of the body above the ports 31 and the inner wall 16 of the wellhead housing D. The seals 38 on the inner sleeve 37 of the running tool still make a sealing engagement with the inner wall 39 of the hanger body (FIGS. 2a, 2b).

The blowout preventer (not shown) may then be closed on the casing running string C and pressure applied through a choke or kill line (not shown) to the fluid in the annulus 50 around the running string below the blowout preventer, so as to test the seal of the pack-off assembly 20. If no leak has been detected, the blowout preventer can be opened and the running string C and running tool B lifted to withdraw them to the drilling ring (FIG. 3).

A seat protector or wear bushing (not shown) may then be located in the wellhead housing to protect its inner cylindrical wall 16, and drilling of the well continued through the casing string 10.

If desired, additional casing hanger assemblies A2, A3 can be located in the wellhead housing, each assembly supporting its casing string 11 or 12 of an appropriate diameter, and being installed after the well bore has been drilled ahead to the desired depth. Each assembly is lowered on a running string and running tool and seated on the upper end of a previously installed casing hanger, after which each seal assembly is rotated to place it in its sealed position above the circulation ports of its casing hanger body. As disclosed in FIGS. 4a, 4b, a casing hanger body 13a is landed on a previously installed casing hanger body 13, being centered with respect thereto by a depending centering rib 51 piloted within the upper portion of the lower casing hanger body 13, the centering rib having a downwardly tapering surface 52 engaging a companion tapered surface 53 on the upper end of the lower hanger body 13.

As disclosed by way of example in FIG. 4a, a third casing hanger assembly A3 has been installed in the well bore and is centered in the intermediate body 13a by means of its depending rib 51 engaging a companion tapered surface 53 at the upper end of the hanger body, the seal structure 20 on the uppermost casing hanger body 13b having been rotated to elevate it to a position above the circulation ports 31 to close the latter, after the casing string 12 threadedly secured to the box 32 of the hanger body 13b has been appropriately cemented in place.

It will be apparent from FIGS. 4a, 4b that the external portions of the casing hanger bodies 13, 13a, 13b are identical and capable of using the same seal structure 20 threadedly attached to the exterior of each casing hanger body. The inner profile of each casing hanger body is dimensionally different, inasmuch as each body will accommodate a different diameter casing string 10, 11 or 12. The inner profile of each casing hanger body becomes smaller in diameter in upward sequence.

Each casing hanger body has an internal flange 60 provided with a downwardly tapering shoulder 61 on which a tubing hanger T is adapted to come to rest. In general, the tubing hanger is of a known specific design, including a main body 62 having a circumferential groove 63 on its upper portion and into which latch elements of a running tool (not shown) may be retained for lowering the tubing hanger and a string of tubing 64 secured to its lower threaded box 65 in the well bore and in the casing hanger assembly A3. The tubing hanger will be supported by the internal shoulder or seat 61 of the uppermost casing hanger body 13b. As disclosed, a lower abutment 66 having a downwardly tapering surface is adapted to engage this seat, this abutment being prevented from dropping downwardly along the body to any substantial extent by a split snap retainer ring 67 disposed in any external groove 68 in the body. An elastomer seal ring 69 rests upon the abutment ring, its upper end being engageable with a downwardly facing body shoulder 70. The tubing hanger body portion 71 above the seal ring and the abutment ring has a diameter closely approximating the inside diameter of the casing hanger body above its shoulder, the seal ring also having approximately the same diameter, or slightly less than the ID of the body wall 72. The casing hanger body has an outwardly directed head or flange 73 overlying the casing hanger body and provided with a depending centering rib 74 adapted to engage a companion downwardly tapering surface 53 at the upper end of the casing hanger body 13b.

Extending upwardly from the outer portion of its flange 73, the body comprises a sleeve portion 75 encircled by a coupling sleeve 76 having a lower internally threaded skirt 77 adapted to mesh with the left-hand body threads 29. The coupling 76 sleeve has a downwardly facing shoulder 78 adapted to engage an upwardly facing shoulder 79 on the flange externally of its upwardly projecting sleeve portion 75, so as to clamp the flange 73 and the tubular hanger body 62 between the coupling sleeve shoulder 78 and the upper portion of the casing hanger body 13b, as a result of rotation of the c coupling sleeve in the left-hand direction to mesh its skirt portion 77 with the external threads 29 on the upper portion of the hanger body 13b and thread it downwardly therealong to effect the clamping and retaining action of the tubing hanger body 62 against the casing hanger body 13b. Rotation of the coupling sleeve or nut 76 is performed by a suitable tool (not shown) which has projections fitting into axial recesses 80 opening through the upper end of the coupling nut, after the tubing hanger body 62 has been landed on the casing hanger body 13b. When such landing occurs, the abutment 66 comes to rest upon the hanger body shoulder 61, the tubing hanger body then moving downwardly to a slight extent to compress the seal ring 69 between the inner wall 72 of the casing hanger body and the opposed cylindrical external surface of the tubing hanger body 62.

The coupling nut 76 may be slipped over the tubular hanger body, with its lower shoulder 78 engaging a split retainer ring 82 located in an external groove 83 in the upper portion of the sleeve 75, the shoulder 75 contracting and riding past the ring, which will then snap into an elongate circumferential groove 84 in the coupling sleeve above its shoulder 78. The coupling sleeve cannot move upwardly off the tubing hanger body by virtue of engagement of its shoulder with the retainer ring 82. However, such retainer ring 82 does not interfere with downward feeding of the coupling sleeve member 76 along the tubular hanger body 62 upon being threadedly meshed with the casing hanger body threads 29.

The specific type of tubing hanger T forms no part of the present invention. As disclosed, it includes a valve sleeve 85 disposed therewithin adapted to be releasably retained in a lower position by a suitable spring 86 on the valve sleeve engaged within an internal groove 87 in the hanger body, in which fluid can flow through the space 88 surrounding the hanger body into ports 89 above an intermediate seal assembly 90 on the valve sleeve and then into longitudinal passages 91 through the hanger body opening through its upper end. The valve sleeve has an upper seal assembly 92 engaging the inner wall of the tubing hanger body 62 above the lower end of the upper passages 91 to confine the flow of fluid to the path just referred to. By means of a suitable tool (not shown) lowered on a wire line from the drilling rig, the sleeve 85 can be pulled upwardly, its spring 86 being forced out of its companion groove 87, the sleeve being moved upwardly within the body until the intermediate seal 90 is disposed above the lower tubing hanger body ports 89 and a lower seal 93 is disposed in sealed relation against the tubing hanger body below the ports, thereby closing such ports to the flow of fluid. The valve sleeve is releasably retained in this upper position by virtue of its spring 86 snapping into an upper internal groove 94 in the hanger body.

It is apparent that the same threaded portion 29 of the hanger body used for connecting the running tool thereto, and for effecting longitudinal shifting of the seal structure between circulation path opening and closing positions, is used for locking the tubing hanger body 62 downwardly in the casing hanger body 13b.

It is to be noted that the inner sleeve 37 and outer sleeve 40 of the running tool B appear to be integrated with the upper portion of the running tool. Such illustration is made merely in the interest of simplifying the drawings. Actually, the inner and outer sleeves are preferably threadedly secured to the upper portion of the running tool.

Claims

I claim:

1. In well bore casing apparatus: an outer body having a seat therein; an inner body for suspending a tubular string in a well bore and movable into engagement with said seat; passage means for allowing fluid flow between said inner and outer bodies; a seal structure on said inner body; first means for connecting said seal structure to the exterior of said inner body, whereby rotation of said seal structure in one direction moves said seal structure longitudinally of said inner body in one direction to a position closing said passage means; a running tool connectable to a running string; second means for releasably connecting said running tool to the exterior of said inner body, whereby rotation of said running tool in said one direction moves said first means in said one longitudinal direction and disconnects said running tool from the exterior of said inner body; and third means for releasably connecting said running tool to said seal structure, whereby rotation of said running tool in said one direction releases said second means to disconnect said running tool from the exterior of said inner body and move said seal structure along said body to its position closing said passage means.

2. In apparatus as defined in claim 1; wherein said first means comprises a threaded connection between said seal structure and inner body.

3. In apparatus as defined in claim 1; wherein said second means comprises a threaded connection between said running tool and inner body.

4. In apparatus as defined in claim 1; wherein said first and second means comprise an external thread on said inner body, an internal thread on said seal structure meshing with said external thread, and an internal thread on said running tool meshing with said external thread.

5. In apparatus as defined in claim 1; wherein said first and second means comprise an external thread on said inner body, an internal thread on said seal structure meshing with said external thread, and an internal thread on said running tool meshing with said external thread; said third means comprising clutch means on said running tool meshing with clutch means on said seal structure.

6. In well bore casing apparatus: an outer body having a seat therein; an inner body for suspending a tubular string in a well bore and movable into engagement with said seat; passage means for allowing fluid flow between said inner and outer bodies; a seal structure disposed initially in a lower position on said inner body with said passage means open when said inner body engages said seat; a running tool connectable to a running string; means for releasably connecting said running tool to said inner body for lowering said inner body and seal structure and to engage said inner body with said seat; and means for elevating said seal structure along said inner body to a position closing said passage means.

7. In apparatus as defined in claim 6; said elevating means comprising a threaded connection between said seal structure and inner body, and means for transmitting rotation of said running tool to said seal structure to thread said seal structure upwardly along said inner body to the position closing said passage means.

8. In apparatus as defined in claim 6; said elevating means comprising a left-hand threaded connection between said seal structure and inner body, and means for transmitting right-hand rotation of said running tool to said seal structure to thread said seal structure upwardly along said inner body to the position closing said passage means.

9. In apparatus as defined in claim 6; said passage means comprising first port means in said inner body, second port means in said seal structure communicable with said first port means when said seal structure is in said lower position on said inner body; said seal structure comprising seal means below said second port means and located initially below said first port means and movable to a position above said first port means upon elevation of said seal structure to a position closing said passage means.

10. In apparatus as defined in claim 6; said elevating means comprising a left-hand threaded connection between said seal structure and inner body, and means for transmitting right-hand rotation of said running tool to said seal structure to thread said seal structure upwardly along said inner body to the position closing said passage means; said passage means comprising first port means in said inner body, second port means in said seal structure communicable with said first port means when said seal structure is in said lower position on said inner body; said seal structure comprising seal means below said second port means and located initially below said first port means and movable to a position above said first port means upon elevation of said seal structure to a position closing said passage means.

11. In well bore casing apparatus: an outer body having a seat therein; an inner body for suspending a tubular string in a well bore and movable into engagement with said seat; passage means for allowing fluid flow between said inner and outer bodies; a seal structure on said inner body; first means for mounting said seal structure on the exterior of said inner body for movement of said seal structure longitudinally of said inner body to a position closing said passage means; a running tool connectable to a running string; second means above said first means for releasably connecting said running tool to the exterior of said body; and third means for releasably connecting said running tool to said seal structure, whereby manipulation of said running tool releases said second means and moves said seal structure along said inner body to its position closing said passage means.

12. In apparatus as defined in claim 11; wherein said first means comprises a threaded connection between said seal structure and inner body.

13. In apparatus as defined in claim 11; wherein said second means comprises a threaded connection between said running tool and inner body.

14. In apparatus as defined in claim 11; wherein said first and second means comprise an external thread on said inner body, an internal thread on said seal structure meshing with said external thread, and an internal thread on said running tool meshing with said external thread.

15. In apparatus as defined in claim 11; wherein said first and second means comprise an external thread on said inner body, an internal thread on said seal structure meshing with said external thread on said running tool meshing with said external thread; said third means comprising clutch means on said running tool meshing with clutch means on said seal structure.

16. In apparatus as defined in claim 11; wherein said first and second means comprise an external left-hand thread on said body, an internal left-hand thread on said seal structure meshing with said external thread, and an internal left-hand thread on said running tool meshing with said external thread.

17. In well bore casing apparatus: an outer body having a seat therein; an inner body for suspending a tubular string in a well bore and movable into engagement with said seat; passage means for allowing fluid flow between said inner and outer bodies; a seal structure disposed initially in a lower position on said inner body with said passage means open when said inner body engages said seat; first means for mounting said seal structure on the exterior of said inner body for upward movement of said seal structure along said inner body to a position closing said passage means; a running tool connectable to a running string; second means above said first means for releasably connecting said running tool to the exterior of said inner body; and third means for releasably connecting said running tool to said seal structure, whereby manipulation of said running tool releases said second means and elevates said seal structure along said inner body to its position closing said passage means.

18. In apparatus as defined in claim 17; said first means comprising a threaded connection between said seal structure and inner body; said third means transmitting rotation of said running tool to said seal structure to thread said seal structure upwardly along said inner body to its position closing said passage means.

19. In apparatus as defined in claim 17; wherein said second means comprises a threaded connection between said running tool and inner body.

20. In apparatus as defined in claim 17; wherein said first and second means comprise an external thread on said inner body, an internal thread on said seal structure meshing with said external thread, and an internal thread on said running tool meshing with said external thread.

21. In apparatus as defined in claim 17; said passage means comprising first port means in said inner body, second port means in said seal structure communicable with said first port means when said seal structure is in said lower position on said inner body; said seal structure comprising seal means below said second port means and located initially below said first port means and movable to a position above said first port means upon elevation of said seal structure to a position closing said passage means.

22. In apparatus as defined in claim 17; wherein said first and second means comprise an external thread on said inner body, an internal thread on said seal structure meshing with said external thread, and an internal thread on said running tool meshing with said external thread; said passage means comprising first port means in said inner body, second port means in said seal structure communicable with said first port means when said seal structure is in said lower position on said inner body; said seal structure comprising seal means below said second port means and located initially below said first port means and movable to a position above said first port means upon elevation of said seal structure to a position closing said passage means.

23. In apparatus as defined in claim 17; wherein said first and second means comprise an external left-hand thread on said inner body, an internal left-hand thread on said seal structure meshing with said external thread, and an internal left-hand thread on said running tool meshing with said external thread.

24. In apparatus as defined in claim 17; wherein said first and second means comprise an external left-hand thread on said inner body, an internal left-hand thread on said seal structure meshing with said external thread, and an internal left-hand thread on said running tool meshing with said external thread; said passage means comprising first port means in said inner body, second port means in said seal structure communicable with said first port means when said seal structure is in said lower position on said inner body; said seal structure comprising seal means below said second port means and located initially below said first port means and movable to a position above said first port means upon elevation of said seal structure to a position closing said passage means.

25. In apparatus as defined in claim 1; a tubing hanger in said inner body; and means for securing said tubing hanger to the exterior of said inner body.

26. In apparatus as defined in claim 1; wherein said second means comprises a threaded connection between said running tool and inner body; a tubing hanger in said inner body; and means for securing said tubing hanger to the upper body threaded portion of said threaded connection.

27. In well bore casing apparatus: an outer body having a seat therein; an inner body for supporting a tubular string in a well bore and movable into engagement with said seat; passage means for allowing fluid flow between said inner and outer bodies; a seal structure on said inner body; means for connecting said seal structure to the exterior of said inner body for movement of said seal structure along said body to a position closing said passage means; a tubing hanger seated in said inner body; and coupling means connected to the exterior of said inner body and engaging said tubing hanger for securing said tubing hanger to said inner body.

28. In apparatus as defined in claim 27; said connecting means comprising a threaded connection between said seal structure and exterior of said inner body; said coupling means being connected to the inner body threaded portion of said threaded connection.

29. In well bore casing apparatus: an outer body having a seat therein; an inner body for supporting a tubular string in a well bore and movable into engagement with said seat; passage means for allowing fluid flow between said inner and outer bodies; a seal structure on said inner body; means for connecting said seal structure to the exterior of said inner body for movement of said seal structure along said body to a position closing said passage means; a tubing hanger in said inner body; and coupling means connected to the exterior of said inner body for securing said tubing hanger to said inner body; said connecting means comprising a threaded connection between said seal structure and exterior of said inner body, the upper portion of the external thread of said threaded connection on said inner body being exposed when said seal structure is in its position closing said passage means; said coupling means being threadedly connected to said exposed thread on said inner body.