Well casing hanger assembly

Abstract

A well casing hanger assembly for releasably connecting first and second well casings to and from each other by a resiliently expandable and contractible locking means in which first and second locking shoulders are positioned to back up the locking means when it is expanded and which serve to positively guide the locking means into locking position and secure the locking means in the expanded position. One of the locking shoulders initially coacts with a receiving notch in the locking means for positively holding the locking means aligned and after the locking means is expanded and engaged between the first and second casings, the shoulder provides an additional backup adjacent the lower end of the locking means for maintaining the locking means in a secured position. Shearable holding means are provided for initially preventing the locking means from moving axially on the first member until the locking means expands and engages the second member. The shearable holding means may be positioned at the top, the bottom or intermediate the ends of the locking means.

Description

BACKGROUND OF THE INVENTION

It is generally old, as shown in U.S. Pat. No. 3,420,308 to support an inner casing in a well from an outer casing by means of a resilient expandable and contractible locking element. The present device is directed to various improvements in an assembly for connecting first and second tubular members together by means of a resilient expandable and contractible locking element which holds the locking element in an aligned position, guides the element to an expanded position, and provides shearable means which permits the locking element to move to a locked position and thereafter securely holds and locks the locking element without allowing the element to become misaligned or cocked out of position during the setting operation.

SUMMARY

The present invention is directed to a well hanger assembly for connecting first and second tubular members, such as casings together, which includes a resiliently expandable and contractible locking element radially and axially movable on the first member for engagement with the second member and locking shoulders between the first member and locking element positioned for aligning and guiding the locking element from a contracted non-engaging position into an expanded engaging position.

Yet a still further object of the present invention is the provision of first and second locking shoulders positioned in a recess on the first member and extending outwardly from the recess approximately the same distance and in which a receiving notch is provided in the locking means initially coacting with one of the locking shoulders for guiding the expanding and contracting movement of the locking means whereby when the one locking shoulder is moved out of the notch and the locking notch is moved axially, the locking shoulders act against upper and lower portions of the locking means for positively securing the first and second members together.

Still a further object of the present invention is the provision of providing shearable holding means for initially preventing axial movement of the locking means with respect to the first member until the locking means expands and engages the second members. The shearable means may be positioned above, below or intermediate the ends of the locking element.

Still other and further objects, features and advantages will be apparent from the following description of presently preferred embodiments of the invention, given for the purpose of disclosure and taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one type of resiliently expandable and contractible locking means, here shown as a plurality of spring-loaded dogs,

FIG. 2 is another type of resiliently expandable and contractible locking element, here shown as a split biased locking ring,

FIG. 3 is an elevational view, partly in cross section, of an inner expanding casing hanger in its collapsed position illustrating the connecting assembly of the present invention being run inside of a casing,

FIG. 4 is a view similar to that of FIG. 3 showing the inner hanger locking assembly in its outwardly biased position and in locked position in an outer casing hanger,

FIG. 5 is an elevational view, partly in cross section, illustrating another embodiment of the well casing hanger locking assembly of the present invention being run inside of a casing,

FIG. 6 is a view similar to that of FIG. 5 showing the locking mechanism locked in an outer casing hanger,

FIG. 7 is an elevational view, partly in cross section, illustrating a modified casing hanger locking assembly being run inside of a casing, and

FIG. 8 is a view similar to that of FIG. 7 showing the locking mechanism locked in an outer casing hanger.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, and particularly to FIG. 4, a first inner casing hanger 10 is shown which is desired to be connected and released from a second outer casing hanger 12, both of which are tubular members in which the casing hanger 10 is supported suspending a string of casing in a well from the outer casing hanger 12. The casing hanger assembly 10 includes an annular recess 14 in its outer peripheral surface for carrying an expandable biased and resiliently contracting locking means, generally indicated by the reference numeral 16.

The locking means 16 may be of any suitable type. One form of locking means is shown in FIG. 1, generally indicated by the reference numeral 18 consisting of a plurality of dogs 20 which are normally urged to an expanded position but yieldably contract or retract in the recess 14 when the casing hanger 10 is being run in the well casing 34. The dogs 20 are yieldably urged to an expanded position by suitable biasing means such as springs 22 and 24, as will be more fully described hereinafter for engagement with the casing hanger 12 for locking the casing hangers 10 and 12 together, and may thereafter be contracted back into the recess 14 for releasing the first and second casing hangers 10 and 12 from each other by suitable longitudinal movement of the casing hanger 10. Referring to FIG. 2, another suitable type of locking means 26 is illustrated consisting of a resilient biasing locking ring having a slot 28 for allowing the ring 26 to be expanded and contracted between the casing hangers 10 and 12.

Referring again to FIGS. 3 and 4, the casing hanger assembly 10 is provided with an upper radially extending stop shoulder 30 at the top of the recess 14 and a lower radial extending stop shoulder 32 at the bottom of the recess 14. The locking means 16 is axially slidable in the recess 14 between the upper stop shoulder 30 and the lower stop shoulder 32. The recess 14 supports the locking means 16 and allows the locking means 16 to contract inwardly into the recess 14 as the hanger assembly 10 is moved downhole through a casing 34 as best seen in FIG. 3. The locking means 16 includes an upper locking portion 36 and a lower key portion 38 for coacting with the locking notch 40 in the second casing hanger assembly 12, as best seen in FIG. 4. The locking notch 40 includes an upper locking portion 42 and a lower key receiving portion 44. The key portion 38 prevents the locking portion 36 of the locking means 16 from expanding outwardly and inadvertently engaging various shoulders in the well casing 34 until the key 38 is located adjacent the key receiving portion 44. The locking notch 42 includes a hanging shoulder 46 which extends inwardly towards the casing hanger 10 for coacting with the engaging shoulder 45 on the locking portion 36 of the locking means 16.

The recess 14 includes a locking shoulder 48 on the first casing hanger assembly 10 below and adjacent the stop shoulder 30 and a tapered shoulder 50 below the locking shoulder 48. The locking portion 36 of the locking means 16 includes a tapered surface 52 which coacts with the tapered shoulder 50 to assist in moving the locking ring 16 outwardly and into engagement with the locking notch 40 on longitudinal downward movement of the casing hanger assembly 10 relative to the locking means 16 when locking means 16 engages the casing hanger assembly 12. A locking surface 54 is provided on the backside of the locking means 16 adjacent its upper end for coaction with the locking shoulder 48 for maintaining the locking means 16 in the expanded and locked position in the locking notch 40 whereby the casing hanger assembly 10 may be connected to and suspended from the casing hanger assembly 12 so long as weight is exerted downwardly on the casing hanger assembly 10.

A second locking shoulder 56 is positioned in the recess 14 and connected to the casing hanger assembly 10 and positioned between the stop shoulders 30 and 32 and extends radially outward from the recess 14 approximately the same radial distance as the first locking shoulder 48 and includes a tapered surface 51. A receiving notch 58 is provided in the backside of the locking means 16 which initially coacts with the second locking shoulder 56 and/or shear rings 60 for allowing the locking means 16 to be retracted in the recess 14, but which also allows the locking means 16 to expand outwardly into the locking notch 40 and axially move towards the top of the recess 14. It is to be noted that the coaction between the second locking shoulder 56 and/or shear rings 60 and the receiving notch 58 restricts the axial movement of the locking means 16 as the casing hanger assembly 10 is moved downhole, but allows the expansion of the locking means 16 when the locking ring 16 becomes properly aligned with the locking notch 40. Because of the positive coaction between the second locking shoulder 56 and/or shear ring 60 and the notch 58, the locking means 16 may not move axially in the recess 14 until the locking notch 40 is reached and thereby avoids the possibility of the locking means 16 becoming cocked prior to and during actuation.

Suitable shear means may be provided connected to the first casing hanger assembly 10 for initially restricting the longitudinal or axial movement of the locking means 16 relative to the recess 14. In the embodiment shown in FIGS. 3 and 4, a ring 60 is connected to the locking shoulder 56 by a shear means such as pin 62. When the locking means 16 is brought into alignment with the locking notch 40 on the second casing hanger 12, the locking means 16 is expanded and downward movement of the first casing hanger assembly 10 relative to the locking means 16 causes the surface 53 of receiving notch 58 to bear on ring 60 and shear the pin 62. Upon further downward movement of the casing hanger assembly 10, the tapered shoulders 50 and 51 on assembly 10, respectively, contact and engage the tapered surface 52 and on the back of the locking means 16 and the bottom surface 53 of notch 58, forcing the locking portion 36 further into the locking portion 42 of the locking notch 40. Still further downward movement of the casing hanger assembly 10 brings the locking shoulder 48 against the locking surface 54 of the locking means 60 holding the upper end of the locking means 16 in a securely locked position after the top of locking means 16 contacts stop shoulder 30 of recess 14 on hanger 10. It is also to be noted that the second locking shoulder 56 engages and contacts a lower locking surface 64 on the back of the locking means 16 and prevents the locking means 16 from cocking and additionally locks the locking means 16 into the locked position.

The shear ring 60 is protectively positioned in the notch 58 and therefore will not catch on shoulders in the well tubing and accidentally shear at an undesired position. After being sheared, it remains captive in the notch 58 eliminating the possibility of falling off into the casing.

The casing hanger assembly 10 may be easily released and removed from the casing hanger assembly 12 by an upward longitudinal movement of the casing hanger 10 which will allow the locking means 16 to be moved axially downward until the lower end of the locking means 16 contacts the stop shoulder 32 and the notch 58 is thereby aligned with the second locking shoulder 56 and the top locking surface 54 is removed to a position below the first locking shoulder 48. Thus upward movement of the casing hanger assembly 10 allows the locking means 16 to be retracted into the recess 14 and the assembly 10 is moved uphole.

Other and further modifications may be provided as best seen in FIGS. 5, 6, 7 and 8 where like character references refer to like parts with the addition of the suffix "a", and "b".

Referring now to FIGS. 5 and 6, an outwardly biased and resiliently contracting locking means 16a which is shown as the type shown in FIG. 1, is carried in a recess 14a in the casing hanger assembly 10a and is retracted therein when moving through a a casing 34a, as best seen in FIG. 5, and is expandable for engaging a locking notch 40a in the casing hanger assembly 12a, as best seen in FIG. 6. As the locking means 16a is of the resilient dog type shown in FIG. 1, suitable means are provided for retaining the ends of the locking means 16a in the recess 14a. A first ring 70 is provided secured to the casing hanger 10a by a plurality of pins 72 for encircling the lower end of the recess 14a and thus the lower end of the locking means 16a for retaining the lower ends of the dogs in the recess 14a. An upper ring 74 is provided secured to the casing hanger 10a by a plurality of pins 76 for encircling the upper end of the recess 14a and retaining the upper ends of the locking means 16a in the recess 14a. In the embodiment shown in FIGS. 5 and 6, the second locking shoulder 56a is initially positioned in the receiving notch 58a in the locking means 16a in the retracted positioned for holding and aligning the locking means 16a in the recess 14a. In the embodiment shown in FIGS. 5 and 6, the shear means may be provided at the top of the locking means such as by making the pins 76 shear pins. When the locking means 16a is brought into alignment with the locking notch 40a, the locking means 16a is resiliently urged outwardly to engage the locking notch 40a. Further downward movement of the casing 10a shears the pins 76 and moves the top locking shoulder 48a behind the locking surface 54a on the locking means 16a adjacent the top end of the locking means 16a, and slides the ring 74 upwardly and moves the lower locking shoulder 56a to a position behind the lower locking surface 64a on the locking means 16a.

Referring now to FIGS. 7 and 8, an outwardly biased and resiliently contractible locking means 16b is shown carried in a recess 14b in a casing hanger 10b, which locking means 16b may be of the locking ring type shown in FIG. 2. The embodiment shown in FIGS. 7 and 8 is identical to that shown in FIGS. 3 and 4 with the exception of the shear means. The shear means is positioned at the lower end of the locking means 16b and consists of a locking ring 80 connected to the casing hanger 10b by shear pins 82. The ring 80 includes a downwardly directed shoulder 84 arranged to engage in upwardly directed shoulder 86 on the locking means 16b when the locking means 16b is expanded. When the casing hanger 10b is lowered into the casing hanger 12b, and the locking means 16b is brought into alignment with the locking notch 40b, the shoulders 84 and 86 are brought into engagement. Further downward movement of the casing hanger 10b shears the shear pins 82 and moves the locking shoulders 48b and 56b downwardly behind the locking means 16b and against the locking surfaces 54b and 64b, respectively, securing the locking means 16b in the locked position.

The embodiments of FIGS. 5, 6, 7 and 8 are released similar to the embodiment of FIGS. 3 and 4 by a longitudinal upward movement of the casing hanger 10a and 10b, relative to the casing hangers 12a and 12b, respectively.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as others inherent therein. While presently preferred embodiments of the invention are given for the purpose of disclosure, numerous changes in the details of construction and arrangement of parts may be made which will readily suggest themselves to those skilled in the art and which are encompassed within the spirit of the invention and scope of the appended claims.

Claims

What is claimed is:

1. In an assembly for connecting first and second tubular members to and from each other in a well by longitudinal movement of the first member, said first member including an annular recess in its peripheral surface adjacent the second member, a radially extending stop shoulder on the first member at each of the top and bottom ends of the recess, resiliently expandable and contractible locking means positioned in said recess and axially slidable therein between said stop shoulders, a locking shoulder on the first member below and adjacent the stop shoulder at the top end of the recess, a locking notch on the second member in its peripheral surface adjacent the first member for receiving the expanded and locked means, the improvement comprising,

a second locking shoulder positioned in the recess intermediate the ends of the recess, said second locking shoulder extending outwardly from the recess approximately the same distance as the first locking shoulder,

a receiving notch in the locking means initially coacting with the second locking shoulder for allowing the locking means to be retracted in the recess, but when the locking means is expanded and axially moved toward the top end of the recess and into the locking notch the second locking shoulder is moved out of the notch and acts against the lower end of the locking means for holding the lower end of the locking means in the locked position, and

shear means to limit axial movement of the locking means on the first member until the locking means engages the locking notch in the second member.

2. The apparatus of claim 1 wherein the shear means is connected between the lower end of the locking means and the first member.

3. The apparatus of claim 1 wherein the shear means is intermediate the ends of the locking means.

4. The apparatus of claim 3 wherein the shear means is positioned in the receiving notch of the locking means.

5. The apparatus of claim 1 wherein the shear means is positioned above the locking means.

6. In an assembly for connecting first and second tubular members to and from each other in a well by longitudinal movement of the first member, said first member including an annular recess in its peripheral surface adjacent the second member, a radially extending stop shoulder on the first member at each end of the recess, a resiliently expandable and contractible locking means positioned in said recess and axially slidable therein between said stop shoulders, locking shoulder on the first member for locking said locking means in an expandable position, a locking notch on the second member in its peripheral surface adjacent the first member for receiving the expanded and locked locking means, the improvement comprising,

shearable holding means intermediate the ends of the resiliently expandable and contractible locking means said shearable holding means acting to prevent axial movement of said expandable and contractible locking means on the first member until said locking means engages said locking notch and the shearable holding means which when sheared by downward longitudinal movement of the first member allows the upper portion of the locking means to releasably lock the first anad second members together.