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Publication numberUS3468558 A
Publication typeGrant
Publication dateSep 23, 1969
Filing dateOct 23, 1965
Priority dateOct 23, 1965
Publication numberUS 3468558 A, US 3468558A, US-A-3468558, US3468558 A, US3468558A
InventorsAhlstone Arthur G
Original AssigneeVentura Tool Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Casing hanger apparatus
US 3468558 A
Abstract  available in
Images(4)
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Claims  available in
Description  (OCR text may contain errors)

Sept. 23, 1969 A. G. AHLSTONE CASING HANGER APPARATUS 4 Sheets-Sheet 1 Filed Oct. 23. 1965 I vEN roe H1? 71/01? G. Hms TONE p 3, 1969 A. 5. AHLSTONE 3,468,558

CASING HANGER APPARATUS Filed Oct. 23, 1965 4 Sheets-Sheet 4 Hen/w? G. HHLSTONE United States Patent 3,468,558 CASING HANGER APPARATUS Arthur G. Ahlstone, Ventura, Califl, assignor to Ventura Tool Company, Ventura, Calif., a corporation of California Filed Oct. 23, 1965, Ser. No. 502,927 Int. Cl. F16] 55/00, 21/00; E21b 19/10 U.S. (ll. 285-18 14 Claims ABSTRACT OF THE DISCLOSURE Well bore casing hanger apparatus, including an outer hanger body supporting outer casing and an inner hanger body supporting inner casing and movable to a supporting shoulder on the outer body and locked thereto. A tu- 'bular string lowers the inner body and a packing structure as a unit into the outer body to locate the inner body on the supporting shoulder, at which time the packing structure is disposed above and spaced from the inner body. The tubular string and associated operating apparatus are then released from the inner body and suitably manipulated to shift the packing structure into a sealed position closing an annular passage between the bodies, whereupon the tubular string and associated apparatus are released from the packing structure and elevated to the drilling rig.

The present invention relates to casing hanger apparatus, and more particularly to apparatus for suspending casing from a well head, performing cementing or other operations in a well bore with respect to suspending casing, and effecting a pack-oil between the suspended casing and the well head.

In the drilling of oil and gas wells at an underwater site, different casing strings are hung to protect strata that have been drilled through from the pressures and fluids which may be required or encountered at greater depths. In many cases, a special housing or body is provided at or near the ocean bottom to support and seal ofi a casing string cemented in the well bore. With a drilling rig above water and the special housing below water, there are many problems faced in supporting a casing string, locking the casing hanger in place, verifying that the lock is operative, circulating fluid for conditioning, cementing the casing string, energizing an annular seal, testing the seal, and installing a protector which protects the seat and sealing area in the housing for the next casing hanger that is used in suspending another casing string to be lowered within the casing string or strings previously installed in the well bore. The problems are accentuated or made more difficult where the drilling rig is on a floating structure anchored in position, but still capable of moving up and down and from side to side or other lateral directions.

Heretofore, casing hanger assemblies have required several trips of a running string into the well bore to assemble all necessary parts to one another, and to perform all necessary operations in the running, landing, cementing, sealing and testing in connection with the easing string, and to protect the seat area for the next succeeding casing hanger to be installed in the well bore. A running string, which may be either casing or drill pipe,

and a running tool have been used for lowering the casing hanger body to its seat in a special housing at or near the ocean bottom. Fluid can be circulated down through the casing string suspended from the hanger body and up through the annular area therearound to the annular area above the hanger body to condition the well bore, after which cement is pumped down the running string, through the running tool, and down inside of the casing string, the cement returns moving up the annular area between the casing and the drilled hole or previously installed casing string, the returns passing back to the drilling rig through the annular area between the running string and the pipe which connects the drilling rig to the well bore. The running string and the running tool are then released from the hanger body and returned to the drilling rig.

With the aid of another running tool and running string, the seal assembly is then lowered to the location of the hanger, and by suitable manipulation of the running string, the seal assembly is installed in place. The running tool may have provision to seal 01f the bore of the well so that pressure applied above the seal assembly of the casing hanger will indicate if the seal will hold pressure. After the pressure test has been performed, the running string and running tool are brought back or retrieved to the drilling rig.

Another running tool is then used with a running string to lower a seat protector to the area just above or on the casing hanger just installed, which is the area or region for the next hanger to be seated or sealed. Following the installation of the seat protector, the running string and running tool are released therefrom and returned to the drilling rig.

In the performance of the above operations, three round trips with a running string are required, and three diiferent running tools, all at a very high cost, in view of the expense of operating offshore drilling rigs.

The main purpose or objective of the present invention is to reduce considerably the expense of performing the above-noted operations, which have, heretofore, been performed separately, by accomplishing them in a single trip. All of the necessary equipment or apparatus is lowered in the well bore on a running string after the parts have all been assembled to one another at the surface. The hanger body with the casing suspended therefrom, the packer assembly, and the seat protector are all run in the well bore in a single trip. The hanger body is landed on its companion seat, locked in place, fluid circulated for conditioning the well bore, the casing string cemented in place, the seal provided between the hanger and the previously installed hanger or casing, the effectiveness of the seal tested, and the seat protector installed, all in one trip in the well bore. The running string and the running tool can be disconnected from the assembly, leaving it in its place, including the placement of the seat protector at its proper location in the previously installed casing hanger.

In effecting the pack-off, the packing element is subjected to compression only, inasmuch as torque or twisting action is not imposed thereon. The hanger body can be locked in place before the circulating and cementing operations commence, so that assurance is had that the hanger cannot be pumped from its companion seat. During such operations, the passage area through the apparatus is comtherethrough. The sealing effectiveness can be tested before the running tool and running string are elevated from the hole, so that additional pack-off force can be applied, and if the seal is still leaking, the running tool and running string can be removed and a suitable retrieving tool lowered for the purpose of retrieving the packing structure and then lowering a proper packing structure into place so that a proper seal can be secured.

This invention possesses many other advantages, and has other purposes 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 detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a combined side elevational view and longitudinal section of casing hanger and associated apparatus installed in and in connection with a well bore underlying a body of water;

FIGS. 2a and 2b together constitute a quarter longitudinal section through casing hanger apparatus embodying the invention and landed in a surrounding hanger body or housing, the parts being illustrated in the initial condition which they occupy in lowering the apparatus from the drilling rig, FIG. 2b being a lower continuation of FIG. 2a;

FIG. 3 is a cross-section taken along the line 33 on FIG. 2a;

FIG. 4 is a cross-section taken along the line 4-4 on FIG. 2a;

FIG. 5 is a cross-section taken along the line 5-5 on FIG. 2a;

FIGS. 6a and 6b together constitute views corresponding to FIGS. 2a and 2b, with the casing hanger locked in packed-off condition in a previously installed hanger, FIG. 6b being a lower continuation of FIG. 6a;

FIG. 7 is a section through the apparatus, parts being broken away, illustrating the casing hanger apparatus and a seat protector thereabove installed in a casing hanger body therearound and with the running tool removed;

FIG. 8 is a cross-section taken along the line 88 on FIG. 212;

FIG. 9 is an enlarged fragmentary, longitudinal section through the packer portion of the apparatus disclosed in FIG. 6b and FIG. 7 in sealed-off condition between the inner and outer casing hanger bodies.

A typical installation of apparatus embodying the invention is illustrated somewhat diagrammatically in FIG. 1, in connection with a well bore A underlying an ocean or other body of water and extending downwardly from the ocean floor F. A suitable base structure B is supported on the ocean floor and carries an outer casing C of relatively large diameter suspended from a casing hanger body D that rest upon an outer seat E on the base and is locked thereto by a suitable lock ring H. Disposed within the outer casing is an intermediate string of casing J extending down into the well bore and suspended from a suitable casing hanger body K resting upon a companion tapered seat L in the outer body D and suitably locked thereto by a lock ring M. One or more blowout preventers N are connected by means of a suitable connector P, such as a hydraulic connector illustrated in my application Ser. No. 476,417, filed Aug. 2, 1965, for Coupling Apparatus for Well Heads and the Like, now US. Patent No. 3,321,217, to the hanger body D, the blowout preventers being connected by a suitably hydraulic or other connector P to a flexible joint S, made of sections, secured to a marine conductor pipe T extending to the drilling rig, which may be located on a drilling platform or on a floating vessel or structure. An inner string of easing U is disclosed in FIG. 1 as having been locked in packed-off condition in the intermediate hanger body K and it is in connection with the casing hanger apparatus W for this inner casing to which the present invention is directed.

As disclosed in the drawings, the casing hanger assembly W is connected to a running tool V, the upper end of which is connected to a suitable tubular running string Y, such as drill pipe, extending through the blowout preventers N, connectors P, flexible joint S and marine conductor pipe T to the drilling rig. As shown in FIGS. 2a, 2b, the hydraulic connector P, which is secured to the outer casing hanger body D in the manner illustrated in the above-identified application Ser. No. 476,417, includes an adapter 10 above the hanger bodies, the inner end of the adapter clamping a suitable seal ring 11 between it and the upper end of the intermediate hanger body K, this seal ring having a groove 12 receiving a seal ring retainer 13 mounted in an internal circumferential groove 14 in the coupling adapter. The intermediate hanger body has a lower downwardly tapering seat or shoulder 15 above which is located an internal circumferential ring groove 16 containing a split inherently contractable lock ring 17 having an upper inner beveled surface 18. Above the lock ring groove 16 is an elongate internal seal surface 19 of cylindrical form extending to the seal ring 11 that has another internal circumferential groove 20 opening through it in spaced relation to the lower groove 16 and containing a split inherently contractable lock ring 21 having an upper inner beveled surface 22.

The casing hanger apparatus W includes a body 23 having a lower portion 24 threadedly connected to the casing U suspended therebelow. This body has a downwardly facing tapered seat 25 adapted to engage the upwardly facing seat 15 in the surrounding hanger body K. Above this seat is a reduced external diameter portion 26 providing an upwardly facing shoulder 27 engageable with the lower end of the lock ring 17 when the hanger body 23 is moved past the lock ring, during which time the latter is expanded outwardly within its internal groove 16, then contracting partially inwardly across the shoulder 27 to lock the hanger body in place by preventing its upward movement.

Above the lock shoulder 27 is a reduced diameter, extemal, cylindrical seal surface 28 disposed opposite the internal seal surface 19 of the surrounding hanger body K and in spaced relation therewith when the hanger body comes to rest upon its companion seat 15 to form an annular passage 29. Above this seal surface, the hanger body has a reduced external diameter portion 30 provided with a right-hand thread 31 which is adapted to mesh with a packer actuating sleeve 32 having a companion internal thread 33. This packer actuator sleeve 32 supports and can exert an axial force against a pack-off assembly 34 to shorten the latter and compress it between the opposed sealing surfaces 19, 28, as described hereinbelow. The actuator sleeve 32 and packer assembly 34 are disposed initially above the upper end of the hanger body 23, as shown in FIGS. 2a, 2b.

The actuator sleeve 32 is connected to a seat protector 35 thereabove, which has a reduced diameter portion 36 piloted within the sleeve 32. The seat protector has a plurality of circumferentially spaced radial torque pins 37 extending into inverted T-shaped slots 38 in the sleeve. The seat protector 35 carries an external seal ring 39 at its upper portion, which is adapted to seal against the internal cylindrical surface 19 of the surrounding hanger body K, as described hereinbelow, and this seat protector is connected to a torque sleeve 40, forming part of the running and actuating tool V, by a plurality of circumferentially spaced coupling pins 41 on the lower portion of the sleeve disposed within companion J-slots 42 in the seat protector. The vertical legs 43 of the I-slots open upwardly through an upwardly facing shoulder 44 of the seat protector 35, the torque sleeve being welded, or otherwise suitably secured, to radial ribs 45 welded to the running tool mandrel 46, the upper end of which is threadedly secured to a tubular running string Y, such as drill pipe extending to the drilling rig above the body of water.

The mandrel 46 is releasably connected to the hanger body 23 by a hydraulically operated device 50. As disclosed most particularly in FIG. 2b, the hydraulically operable connection 50 includes a body 51 surrounding the lower portion of the mandrel 46 and having an inwardly directed flange 52 clamped between the upper end of a drill pipe joint 53 threadedly secured to the lower end of the mandrel 46, and a lower piston sleeve 54 above the flange, the upper end of which is engageable with and confined by a downwardly facing mandrel shoulder 55. The body 51 has a plurality of circumferentially spaced openings or slots 56 in which are disposed latches, locking segments or dogs 57 that have outer tapered fingers or lugs 58 adapted to fit within companion circumferential internal grooves 59 in the casing hanger body. With the latches 57 in the groove 59, a seal ring 60 on the body 51 seals against the casing string U. An annular expander and retainer cylinder 61 surrounds the running tool mandrel 46 and has a lower cylinder sleeve portion 62 adapted to move within an annular space 63 between the body 51 and the lower piston sleeve 54 to a position behind the locking segments or latches 57, to hold them outwardly with their fingers 58 within the hanger body grooves 59. The lower sleeve has a tapered nose 64 adapted to engage companion tapered surfaces 65 in the upper portion of the dogs or segments 57 for the purpose of shifting such segments outwardly into the grooves 59, the extent of outward movement of the segments being limited by engagement of their upper and lower terminals '66 with the upper and lower stop portions 67 provided on the body 51 on opposite sides of its slots 56.

The lower sleeve 62 is integral with a cylinder head 70, which is slidable along the periphery of the mandrel 46, and this cylinder head, in turn, is integral with an upper cylinder sleeve 71 slidable along an enlarged diameter portion 72 of the mandrel, which conforms in external diameter to that of the lower piston sleeve 54. The cylinder 61 is shiftable hydraulically along the mandrel 46 and within the body 51 surrounding it, between a lower position illustrated in FIG. 2b, in which the lower cylinder sleeve 62 is disposed behind the segments 57, to maintain them locked within the internal grooves 59 of the casing hanger body 23, and an upper position in which the lower cylinder sleeve is disposed above the lock segments 57, permitting them to retract inwardly fully from the internal body grooves 57, so as to eifect a disconnection between the mandrel 46 and the hanger body 23 (FIG. 6b).

The longitudinal shifting of the cylinder 61 along the mandrel 46 and with respect to the body 51 is accomplished hydraulically. Thus, fluid can flow through upper ports 73 extending from the central mandrel passage 74 into an annular cylinder space 75 between the cylinder head 70 and the upper piston head portion 72 provided by the mandrel 46 for the purpose of shifting the cylinder 61 in a downward direction along the mandrel. The annular cylinder member 61 is shifted in an upward direction by fluid passing from the central passage 74 in the mandrel through a plurality of ports 76 into a cylinder space 77 provided between the lower piston sleeve 54 and the periphery of the mandrel 46 for action upon the lower surface of the cylinder head 70, urging the cylinder 61 upwardly to a position in which the cylinder head engages the upper piston head 72, as disclosed in FIG. 6b, in which the lower sleeve 62 is above the dogs 57 which can be freed from the grooves 59.

The running tool V is connected to the hanger body 23 and the parts of the apparatus disposed therearound. The seat protector 35 is connected to the upper portion of the packing actuator sleeve 32 by virtue of the torque pins 37 being disposed in the T-slots 38, and the seat protector is connected to the torque sleeve 40 by reception of the torque pins 41 of the latter within the J-slots 42. At the drilling rig, the running tool V is lowered into the hanger body 23 until the locking dogs 57 are opposite the circumferential grooves 59, at which time the dogs are retracted and the cylinder 61 is disposed in its upper position along the mandrel 46. By suitable means, such as disclosed in my application for Apparatus for Hanging Well Bore Casing, Ser. No. 503,047, filed Oct. 23, 1965, fluid under pressure is directed from the mandrel passage 74 through the upper ports 73 into the upper cylinder space 75 to shift the cylinder 61 downwardly and its sleeve 62 downwardly behind the dogs 57 to move them outwardly and place their fingers or lugs 58 fully into the circumferential lock grooves 59 in the casing hanger body 23, the sleeve 62 remaining behind the dogs and holding them locked within the body grooves. With the mandrel 46 latched to the hanger body, the lower end of the packer assembly 34 is spaced above the upper end of the hanger body 23.

It will be evident from the drawings that leakage of fluid under pressure between the various parts to which it is applied is prevented by a suitable seal ring 80 on the cylinder head engaging the periphery of the mandrel 46, by an upper seal ring 81 on the mandrel slidably engaging the inner surface of the upper sleeve 71, by an external seal ring 82 on the lower piston sleeve 54 engaging the inner surface of the lower cylinder sleeve 62 and by a seal ring 83 on the mandrel below the lower ports 76 engaging the inner surface of the lower piston sleeve 54. The inwardly directed body flange 52 is sealed to the mandrel by seal rings 84 on the latter engaging the flange, leakage of fluid between the lower end of the mandrel and the drill pipe joint 53 therebelow being prevented by seal rings 85 on the mandrel engaging the inner surface of the drill pipe.

When the hanger apparatus W and the casing U suspended therefrom is connected to the running tool V and lowered through the marine conductor pipe T and the equipment connected thereto therebelow by means of the drill pipe Y to a position illustrated in FIGS. 2a and 2b, in which the hanger body 23 rests upon its seat 15 and the lock ring 17 has contracted over the upwardly facing shoulder 27, a by-pass circulating passage exists between the hanger apparatus W and the surrounding hanger body K. As shown, this by-pass apparatus communicates with the annulus in the well bore surrounding the susupended casing U and includes a plurality of circumferentially spaced longitudinal fluid passages 91 extending through the hanger body 23 to the annular passage 29 between the opposed seal surfaces 19, 28. Fluid can then pass upwardly through the annular space 92 between the inner seal surface 19 and the threaded portion 30 of the hanger body and through the wide open space 93 between the upper end of the hanger body 23 and the lower end of the packer assembly 34, then passing upwardly through an annular passage 94 between the mandrel 46 and the packer assembly, actuator sleeve 32 and seat protector 35, the by-pass path then continuing through a plurality of circumferentially spaced longitudinal openings 95 in the torque sleeve and into the annulus 96 between the tubular running string Y and the surrounding apparatus to the drilling rig.

The packing assembly 34 includes an upper abutment ring 100 secured to the lower portion of the threaded packing actuator sleeve 32 by means of a swivel. Such swivel includes a split snap retainer ring 101 mounted in an external groove 102 in the nut or sleeve 32 and an internal groove 103 in the upper abutment ring 100. A thrust bearing 104 is provided between the actuator sleeve 32 and the upper abutment ring 100, so that the sleeve can be rotated without rotating the ring. As shown, the thrust bearing includes an upper race 105 in the threaded sleeve and a lower race 106 in the upper end of the upper abutment ring 100, ball bearings 107 being disposed in these races to allow the sleeve 32 to rotate without rotating the upper abutment ring 100.

The lower end of the upper abutment ring 1% engages an initially retracted packing element ring 108 made of an elastomer material, such as rubber or a rubber-like material, the lower end of this packing ring being engaged by a lower abutment 109 adapted to engage an upwardly facing shoulder 110 on the hanger body 23 below its external surface 28. The packing ring 108 and the lower abutment ring 109 are assembled to the upper abutment ring 100 by a plurality of cap screws 111 extending through the lower ring and packing ring and threaded into the upper abutment ring, the screws having heads 112 received within counterbores 113 in the lower abutment ring 109 and adapted to engage the upper ends 114 of the counterbores.

Prior to lowering the casing hanger apparatus and the casing U suspended therefrom into the well bore, the casing hanger apparatus has its parts in their relative positions illustrated in FIGS. 2a and 2b, in which the packing element or ring 108 is retracted and with the actuator sleeve 32 and packing assembly 34 occupying their upper positions spaced above the hanger body 23, the actuator sleeve 32 being connected to the seat protector 35 by the pin and T-slot connections 37, 38 and the seat protector being connected to the torque sleeve 40 through the pin and J-slot connections 41, 42. The lower portion of the mandrel 46 is secured to the hanger body by means of the hydraulically actuatable connection 50.

The casing U is lowered from the drilling rig through the equipment disposed above the ocean floor and into the well bore A, the uppermost portion of the casing string being secured to the hanger apparatus W which has its parts in the relative relationship illustrated in FIGS. 2a and 2b. The tapered shoulder 25 of the hanger body 23 will move past the upper lock ring 21 and shift it outwardly out of its way and will then move downwardly into engagement with the lower lock ring 17, expanding it more fully into its groove 16 out of its way until the hanger body engages its companion seat 15 in the surrounding hanger body K, whereupon the split lock ring 17 will contract inherently across the body shoulder 27 and lock the hanger body and the casing suspended therebelow in place. At this time, the packing abutment 100, or the seat protector 35 or actuator sleeve 32, is disposed across the upper lock ring 21 and the seal ring 39 on the seat protector may be out of sealing relation to its cornpanion cylindrical seal surface 19 at the upper portion of the outer hanger body K. An upward pull can now be taken on the running string Y to insure that the hanger body 23 is locked in place.

Circulating fluid can now be pumped down through the tubular running string Y and through the mandrel 46, continuing on down through the casing U and then passing around its lower end or suitable casing ports (not shown) into the annulus 90 between the suspended casing string and the well bore, and also between the casing string U and whatever casing string J is surrounding it. The circulating fluid flows upwardly through the body passages 91 and through the annular passage 29 between the internal and external seal surfaces 19, 28, flowing upwardly between the packing assembly 34 and the hanger body 23 and also upwardly through the annulus 94, continuing through the by-pass openings in the torque sleeve 41) into the annulus 96 around the running string Y to the drilling rig.

The circulating fluid can be followed by the pumping of a suitable charge of cement down through the running string Y, the apparatus and the suspended casing string U. This charge of cement passes from the casing string and moves upwardly through the annulus 90 around the casing string to the desired height, in a known manner, the fluid in advance of the charge of cement slurry passing upwardly through the by-pass path through and around the casing hanger apparatus W.

After the cement has been displaced around the suspended casing U, the running string Y and the mandrel 46 are disconnected from the hanger body 23, such disconnection being effected hydraulically. As disclosed in FIG. 6b, a dart or plug 134 is lowered down through the running string and into the mandrel passage 74, this plug including a body 131 having an upper head 132 which will come to rest upon an upwardly facing seat 133 in the mandrel. When the head engages the seat, an upper side seal ring 134 on the body sealingly engages the wall of the mandrel passage above the upper ports 73, an intermediate seal ring 135 on the body engages the wall of the mandrel passage between the upper and lower ports 73, 76, and a lower seal ring 136 on the body engages thewall of the mandrel passage below the lower ports 76. A stem 137 is disposed within the central passage 138 through the mandrel body, this stem including an upper portion 139 having an upper fishing head 140 which is threadedly secured to a main stem portion disposed within the body. An upper seal ring 141 on the stem engages the wall of the body bore 138 above a plurality of upper ports 142 extending from the central passage of the body to its exterior, communicating with the upper mandrel ports 73. An intermediate seal ring 143 is disposed on the stem and sealingly engages the wall of the body bore 138 above a set of lower ports 144 in the stem, extending from a central passage 145 running upwardly through the stem and communicating with a central passage in the upper stem portion 146 open at its upper end, the stern ports 144 communicating with side ports 147 extending through the body 131 in communication with the mandrel ports 76. A lower seal ring 148 is mounted on the lower portion of the stem and sealingly engages the wall of the body passage below the stem ports 144. A helical spring 149 surrounds a reduced diameter portion of the stem 137, its upper end bearing against a body shoulder 150 and its lower end against a stem shoulder 151, urging the stem in the downward position illustrated in FIG. 6b, limited by engagement of a stem flange 152 with the upper end of the body 131.

When the dart 130 is disposed in the position shown in FIG. 6b, fluid pumped down the running string Y and into the mandrel 46 can flow through the stern passages 146, 145 and out through the ports 144, 147 of the dart and through the mandrel ports 76 into the lower annular space 77 between the lower piston 54 and the mandrel, the fluid under pressure acting in an upward direction on the cylinder head 70 and shifting the annular cylinder 61 upwardly along the mandrel to a position in which the locking dogs or latches 57 are free to shift inwardly from the hanger body grooves 59. The fluid or liquid in the cylinder space 75 above the head 70 can pass outwardly through the upper mandrel ports 73 and the body ports 142 into the annular spring space 153, then continuing downwardly through a discharge passage 154 extending through the lower stem, the exhausting fluid then flowing out of the lower end of the lower stem and into the mandrel below the dart.

Following the hydraulic disconnection of the mandrel 46 from the hanger body 23, the dart 130 can be removed, as by lowering a fishing tool (not shown) on a wire line (not shown) through the drill pipe into coupling engagement with the stem head 140, the wire line and dart then being pulled through the drill pipe Y to the drilling rig. The running string Y and running tool V are now lowered to lower the packing assembly 34 over the hanger body 23 and to bring the actuator sleeve 32 against the upper portion of the hanger body. The drill pipe and mandrel are then rotated to thread the actuator sleeve 32 downwardly along the threaded body portion 30, shifting of the packing assembly downwardly until the lower abutment 109 engages the body shoulder 110, at which time the retracted packing sleeve 108 is disposed between the internal and external seal surfaces 19, 28. A continuation of the rotation of the running string and mandrel will effect a continued downward threading of the actuator sleeve 32 along the body, moving the upper abutment 100 toward the lower abutment 109 and shortening the packing sleeve or ring 108 and expanding it outwardly and inwardly into firm sealing engagement with the internal and external sealing surfaces 19, 28 on the outer and inner hanger bodies K, 23. A suflicient torque is imposed on the apparatus to insure the firm sealing of the packing sleeve 108 against its companion surfaces. However, it is to be noted that during the entire rotation of the actuator sleeve on the hanger body, torque is not transmitted to the packing structure, because of the swivel 100107, so that no twist is imparted to the packing, but only an axial compressive force inveifecting its pack-off against the inner seal surface and the external seal surface.

The effectiveness of the packed-off seal 108 can now be tested with all of the apparatus remaining in place. A suitable pressure is imposed on the fluid in the annulus 96 surrounding the tubular running string, as, for example, by closing a blowout preventer N thereagainst and then subjecting the fluid in the annulus below the blowout preventer to adequate pressure. If no pressure loss occurs, assurance is had that the seal is effective. If a leak is detected, which is determined to be due to the packing 108, an additional compression of the packing sleeve can be undertaken by turning the running string Y and the mandrel 46, which will effect an additional downward threading of the actuator sleeve 32 along the anchor body 23.

Assuming the seal does not leak, the running tool V can now be disconnected from the seat protector 35 merely by partially turning the running string Y to the right to be assured that the torque sleeve pins41 are disposed against the ends of the J-slots 42 and in alignment with its vertical legs 43, whereupon the tubular running string is moved upwardly to move the pins 41 out of the J+slots 42, which permits the running tool V to be removed from the casing hanger apparatus W and elevated through the equipment thereabove to the .drilling rig, the parts of the casing hanger apparatus then being in the position illustrated in FIG. 7, with the seat protector 35 in place and with an effective pack-off existing between the hanger body 23 and the hanger body K, or other device there around. At this time, it is to be noted that the downward movement ofthe seat protector will have shifted its seal ring 39 into sealing engagement with the cylindrical surface 19 of the surrounding hanger body K.

When the seat protector 35 is no longer required, it is easily removed by lowering a suitable retrieving tool on a running string. This retrieving apparatus may be of the type disclosed in my application for Well Bore Running- In and Retrieving Tool, Ser. No. 503,563, filed Oct. 23, 1965, now Patent No. 3,350,130. This tool becomes coupled to the seat protector, as by latching under a downwardly facing shoulder 170 of an internal groove 171 in the upper portion of the seat protector, with suitable pins entering the J-slots 42 so as to be coupled to and transmit torque to the seat protector. The retrieving tool (not shown) can then be appropriately turned, by turning the running string Y, to turn the seat protector 35 relative to the packing actuator sleeve 32 and align the torque pins 37 with the vertical legs of the inverted T-slots 38, which will then allow an upward pull to be taken on the apparatus to shift the pins 37 from the T-slots and thereby effect a full disconnection of the seat protector from the actuator sleeve 32, the seat protector being withdrawn with the running string and retrieving tool to the drilling rig above the body of water.

In the event that a leakproof seal is not effected between the packing ring 108 and the inner and outer hanger bodies 23, K, the packer assembly 34 can be removed. The retrieving tool shown in the above application, Ser. No. 503,563, is connected to a tubular string and lowered from the drilling rig into a position in which pins of the retrieving tool, corresponding to the torque pins 37 of the seat protector 35, move into the T-slots 38, whereupon the running string and retrieving tool are rotated to the left, to unthread the entire packer assembly 34 upwardly of the body and completely disconnect the actuator sleeve 32 from the body, whereupon the packer assembly can be elevated to the drilling rig and a new pack-off assembly substituted in its place, which is then run, with a seat protector 35 connected thereto, through the equipment above the floor of the ocean and threadedly connected to the packer body 23, continued right-hand rotation of the running string Y, running tool and the packer actuating sleeve 32 again shifting the latter downwardly and effecting a pack-off of the packing ring 108 against the internal and external sealing surfaces 19, 28, the packer assembly then being in the condition illustrated in FIGS. 6b and 9. The running tool preferably seals against the internal cylindrical surface of the casing U in essentially the same manner as disclosed in FIG. 6b, allowing the liquid in the annulus 96 around the running string to be subjected to pressure to test the effectiveness of the seal.

In the event of removal of the seat protector 35, the upper lock ring 21 is in position to lock another hanger body (not shown) from which another casing string is suspended, the hanger body resting upon the upper end of the hanger body 23 previously installed, and having a shoulder that will be disposed below the lock ring 21 that will contract partially out of its internal groove 20 to overlie the shoulder of the added hanger body in essentially the same manner as the lower lock ring 17 overlies the shoulder 27 of the previously installed hanger body. A pack-off can be effected between a packing ring against the seal surface 19 above the upper lock ring 21 in essentially the same manner as with the packing assembly 34 described above, there being a by-pass area around and through the apparatus for circulating fluid that passes upwardly through the annulus between the subsequently run casing string (not shown) and the casing string U described above.

It is, accordingly, apparent that well bore casing hanger apparatus has been provided which requires only a single trip into the well bore to run, land, lock the hanger in place, test the lock, circulate fluid, pump cement for sealing and supporting the suspended casing in the drilled hole, actuate the area of the seal, test the seal, and install the seat protector. All necessary apparatus is appropriate- 1y assembled at the drilling rig and is run simultaneously into the well bore. A large circulation area is present in and around the apparatus. The packing element 108 is packed off by being subject to longitudinal compression only, there being no torque or twisting action imposed upon it. The hanger 23 is locked in place before the cementing operation begins so that it cannot be pumped off its supporting seat 15. The effectiveness of the pack-off of the packing 108 can be tested before the running string Y is removed from the hole, and, if necessary, a defective pack-off can be remedied by retrieving the packing structure 34, in view of the ability to couple into the packing actuator sleeve 32 and reversely rotate and unthread it completely from the hanger body 23. The running string Y is released from the hanger body 23 before the pack-off operation commences, which eliminates the necessity for substantial turning of the running string in order to retrieve the running tool- V from the apparatus that is left connected to the casing hanger body, including the seat protector 35 for a hanger apparatus to be installed subsequently.

I claim:

1. In well bore casing apparatus: an outer body connectible to an outer casing; an inner body supportable by said outer body for suspending an inner casing within the outer casing; said inner and outer bodies providing a fluid passage therebetween communicating with the annular space between the inner and outer casings; a packing structure for closing said passage; a mandrel adapted for connection to a running string; means releasably connecting said mandrel to said inner body; means releasably connecting said packing structure to said mandrel for support solely by said mandred and positioning said packing structure above and spaced from said inner body; said inner body with the inner casing suspended therefrom and said packing structure being movable as a unit with said mandrel and running string to a position of support of said inner body on said outer body and with said packing structure in open relation to said passage; and means for shifting said packing structure from said position above and spaced from said inner body to a position closing said passage after support of said inner casing on said outer body.

2. In well bore casing apparatus as defined in claim 1; said means releasably connecting said mandrel to said body being constructed and arranged for release prior to shifting of said packing structure to said position closing said first-mentioned passage to allow said mandrel to move downwardly and move said packing structure downwardly therewith around said inner body and toward said position closing said first-mentioned passage.

3. In well bore casing apparatus as defined in claim 1; and means for releasing said means releasably connecting said mandrel to said inner body prior to shifting of said packing structure from said position above and spaced from said inner body.

4. In well bore casing apparatus as defined in claim 1; and hydraulically operable means for eifecting release of said mandrel from said inner body.

5. In well bore casing apparatus as defined in claim 1; wherein said means for shifting said packing structure to a position closing said first-mentioned passage is operative in response to rotation of said mandrel by the running string.

6. In well bore casing apparatus as defined in claim 1; wherein said means for shifting said packing structure includes a threaded portion on said inner body and a threaded actuator sleeve disposed initially above said inner body and shiftable downwardly into engagement with said inner body, and means responsive to rotation of said mandrel by the running string for threading said sleeve downwardly of said inner body to shift said packing structure downwardly to said position closing said first-mentioned passage.

7. In well bore casing apparatus: an outer body connectible to an outer casing; an inner body supportable by said outer body for suspending an inner casing within the outer casing; said inner and outer bodies providing a fluid passage therebetween communicating with the annular space between the inner and outer casings; said inner and outer bodies having opposed sealing surfaces spaced from each other to provide an annular passage therebetween constituting a portion of said flow passage; one of said bodies having an upwardly facing shoulder; a packing structure adapted to be moved into said annular passage; a mandrel adapted for connection to a running string; means releasably connecting said mandrel to said inner body; means releasably connecting said packing structure to said mandrel for support solely by said mandrel and positioning said packing structure above and spaced from said inner body and annular passage; said inner body with the inner casing suspended therefrom and said packing structure being movable downwardly as a unit with said mandrel and running string to a position of support of said inner body on said outer body and with said packing structure in open relation to said annular passage; and means for moving said packing structure from said position above and spaced from said inner body downwardly into said annular passage and against said shoulder to compress said packing structure against said sealing surfaces to close said annular passage.

8. In well bore casing apparatu as defined in claim 7; said means releasably connecting said mandrel to said body being constructed and arranged for release prior to shifting of said packing structure to said position closing said annular passage to allow said mandrel to move downwardly and move said packing structure downwardly therewith around said inner body and toward said position closing said annular passage.

9. In well bore casing apparatus as defined in claim 7; and means for releasing said means releasably connecting said mandrel to said inner body prior to shifting of said packing structure from said position above and spaced from said inner body. I

10. In well bore casing apparatus as defined in claim 7; and hydraulically operable means for effecting release of said mandrel from aid inner body.

11. In well bore casing apparatus as defined in claim 7; wherein said means for shifting said packing structure to a position closing said annular passage is operative in response to rotation of said mandrel by the running string.

12. In well bore casing apparatus as defined in claim 1; wherein said means for shifting said packing structure includes a threaded portion on said inner body and a threaded actuator sleeve disposed initially above said inner body and shiftable downwardly into engagement with said inner body, and means responsive to rotation of said mandrel by the running string for threading said sleeve downwardly of said inner body to shift said packing structure downwardly to said position against said sealing surfaces closing said annular passage.

13. In well bore casing apparatus: an outer body connectible to an outer casing; an inner body supportable by said outer body for suspending an inner casing within the outer casing; said inner and outer bodies providing a fluid passage therebetween communicating with the annular space between the inner and outer casings; a packing structure for closing said passage; a mandrel adapted for connection to a running string; means releasably connecting said mandrel to said inner body; means releasably connecting said packing tructure to said mandrel for support solely by said mandrel and positioning said packing structure above and spaced from said inner body; said packing structure being spaced laterally from said mandrel to provide a fluid passage therebetween communicating with said other fluid passage; said inner body with the inner casing suspended therefrom and said packing structure being movable as a unit with said mandrel and running string to a position of support of said inner body on said outer body and with said packing structure in open relation to said first-mentioned passage; means for shifting said packing strutcure from said position above and spaced from said inner body to a position closing said first-mentioned fluid passage after support of said inner body on said outer body; and means retaining said packing structure in said closed positions.

14. In well bore casing apparatus: an outer body connectible to an outer casing; an inner body supportable by said outer body for suspending an inner casing within the outer casing; said inner and outer bodies providing a fluid passage therebetween communicating with the annular space beeen the inner and outer casings; said inner and outer bodies having opposed sealing surfaces spaced from each other to provide an annular passage therebetween constituting a portion of said flow passage; one of said bodies having an upwardly facing shoulder; a packing structure adapted to be moved into said annular passage; a mandrel adapted for connection to a running string; means releasably connecting said mandrel to said inner body; means releasably connecting said packing structure to said mandrel for support solely by said mandrel and positioning said packing structure above and spaced from said inner body and annular passage; said packing structure being spaced laterally flom said mandrel to provide a fluid passage therebetween communicating with said other fluid passage; said inner body with the inner casing suspended therefrom and said packing structure being movable downwardly as a unit with said mandrel and running string to a position of support of said inner body on said outer body and with said packing structure in open relation to said annular passage; means for moving said packing structure from said position above and spaced from said inner body downwardly into said annular passage and against said shoulder to compress said packing structure against said sealing surfaces to close said annular passage; and means retaining said packing structure in said closed position.

References Cited UNITED STATES PATENTS 10 CARL W. TOMLIN, Primary Examiner DAVE W. AROLA, Assistant Examiner US. Cl. X.R.

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3688841 *Mar 15, 1971Sep 5, 1972Vetco Offshore Ind IncOrienting tubing hanger apparatus
US3797864 *Oct 28, 1971Mar 19, 1974Vetco Offshore Ind IncCombined metal and elastomer seal
US3837684 *Oct 30, 1972Sep 24, 1974Vetco Offshore Ind IncSubsea casing hanger pack-off apparatus and method
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US8678093 *Apr 14, 2011Mar 25, 2014Aker Subsea LimitedInsertion of a pack-off into a wellhead
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Classifications
U.S. Classification285/18, 285/123.2, 166/348, 285/321, 285/334.2, 166/340
International ClassificationE21B33/03, E21B33/043
Cooperative ClassificationE21B33/043
European ClassificationE21B33/043
Legal Events
DateCodeEventDescription
May 1, 1986ASAssignment
Owner name: VETCO OFFSHORE INDUSTRIES, INC., 7135 ARDMORE ROAD
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:VETCO OFFSHORE, INC., A CORP. OF DE.;REEL/FRAME:004572/0533
Effective date: 19860421
Sep 29, 1982ASAssignment
Owner name: VETCO OFFSHORE, INC. 5740 RALSTON ST.VENTURA,CA.93
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:VETCO INC.;REEL/FRAME:004056/0858
Effective date: 19820922