Patent Grant
8678083
The field of the invention is expandable liner hangers and more particularly a spiral slip design disposed in a groove with tapered side walls to uniformly move the spiral slip member out as expansion reduces the groove width to enhance a grip on a surrounding tubular.
Spiral patterns have been used in downhole tools as passages for cement in the context of expansion such as in hangers for liners that are set by expansion. Examples of such spiral paths for flow of displaced fluids during cementing are U.S. Pat. Nos. 6,899,181, see FIG. 9, and 7,055,597, see FIG. 7.
Another design uses grooves to reduce stress during expansion and as a location for metal displacement under inserts as the inserts engage the surrounding tubular. The stress relieving zones 885 are taught to be spiral in one alternative for the purpose of reducing expansion stress as discussed in paragraph 82 of U.S. Publication 2010/0089591.
The reality of longitudinal shrinkage during expansion of tubulars has been deployed in liner hangers to drive out slip rings 36 and 38 that are described as a cylindrical shape with a longitudinal split, a cylinder that separates into segments on expansion or a series of segments retained with a band spring in column 3 lines 52-58 of U.S. Pat. No. 7,096,938. The same description is found in the continuation U.S. Pat. No. 7,367,390.
What has yet to be developed and addressed by the present invention is a slip design that takes advantage of the longitudinal shrinkage during expansion of the hanger and configures the slip design to evenly load the surrounding tubular despite any shape irregularities it may have over an extended length of the hanger. The open nature of the slip design allows for circumferential coverage over a longer length than a longitudinally split cylinder. Beyond that a spiral design can be threaded on during assembly and provides negligible resistance to expansion. The retaining groove not only radially extends a spiral shape but also winds up gripping the slip shape more tightly as the mandrel is radially expanded and the differential longitudinal growth from mandrel expansion cocks the slip member slightly in its retaining groove to prevent shifting until the surrounding tubular wall is engaged. These and other advantages of the present invention will be more apparent to those skilled in the art from a review of the detailed description of the preferred embodiment and the associated figures while recognizing that the full scope of the invention is to be determined by the appended claims.
A liner hanger uses a spirally shaped slip member that makes at least one revolution about the mandrel being expanded. The slip member is disposed in a groove with tapered end walls that approach each other during radial mandrel expansion due to shrinkage of said mandrel in the longitudinal direction. The shrinkage binds the slip to the mandrel as the slip member approaches the surrounding tubular. The tapered side walls of the groove moving together cam out the slip member into enhanced contact with the surrounding tubular to support the liner or other string below the hanger. The slip member and groove have preferably the same pitch to allow easy mounting with an applied rotational force.
Referring to
The groove 10 is defined by a recessed radial surface 22 flanked by outwardly tapering side walls 24. While all the surfaces are illustrated as flat, other configurations are envisioned. The side walls 24 or bottom 22 can be arcuate. The bottom surface can be undulating and match a similar shape on the face 26 of the slip member 16 shown in
Optionally the connectors can also be designed to release on one or opposed ends, the segments to which they were initially attached. If this is designed into the assembly it is preferred that the connectors 44 or 46 release at a time when the segments are already in contact with the surrounding tubular so that the release will not facilitate sliding of the released segments in the groove 10. To prevent such sliding, schematically illustrated travel stops 48 and 50 can be placed in the adjacent groove 10 to prevent such sliding motion.
The spiral windings can be left hand or right hand oriented. Installation of the spiral slip member can be by a simple threading action. The assembly has enough flexibility to work its way onto the mandrel groove 10 with an applied rotational movement. The entrance at the leading end of the groove 10 can be sloped to aid the slip member 16 in getting started into the groove 10 under the force of a rotational movement applied to the slip member 16 to get it into position for running to a subterranean location.
Those skilled in the art will appreciate that the spiral orientation of the slip member makes it simple to assembly to the mandrel and allows slip contact with the surrounding tubular over a longer length of the surrounding tubular than a ring structure. The slip material usage is minimized relative to known designs by using a spiraling elongated element instead of a more complex ring structure that employs an array of open areas to minimize resistance to expansion that also has the result of increasing part cost. Simple vertically split cylindrical shapes cannot by definition cover for a full 360 degrees of supporting the tubular string load. Rather, the split by design opens in the expansion mode leaving more load on the balance of the circumference of the now open ring structure thus limiting the capacity of the slip system.
The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below.
| Number | Name | Date | Kind |
|---|---|---|---|
| 2174076 | Bowen | Sep 1939 | A |
| 2670797 | Armentrout | Mar 1954 | A |
| 3714984 | Read | Feb 1973 | A |
| 3779314 | Read | Dec 1973 | A |
| 3851707 | Jett | Dec 1974 | A |
| 4488595 | Akkerman | Dec 1984 | A |
| 4498534 | Lindsey, Jr. | Feb 1985 | A |
| 4583590 | Greenlee et al. | Apr 1986 | A |
| 6752216 | Coon | Jun 2004 | B2 |
| 6899181 | Simpson et al. | May 2005 | B2 |
| 6968896 | Coon | Nov 2005 | B2 |
| 7055597 | Lauritzen | Jun 2006 | B2 |
| 7096938 | Carmody et al. | Aug 2006 | B2 |
| 7306034 | Garcia | Dec 2007 | B2 |
| 7360592 | McMahan | Apr 2008 | B2 |
| 7367390 | Carmody et al. | May 2008 | B2 |
| 7607476 | Tom et al. | Oct 2009 | B2 |
| 8443881 | Thomson et al. | May 2013 | B2 |
| 20030037931 | Coon | Feb 2003 | A1 |
| 20070039161 | Garcia | Feb 2007 | A1 |
| 20100089591 | Thompson et al. | Apr 2010 | A1 |
| 20120012305 | Yokley | Jan 2012 | A1 |
| 20120261116 | Xu | Oct 2012 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20120261116 A1 | Oct 2012 | US |
