|Publication number||USRE43198 E1|
|Application number||US 12/837,629|
|Publication date||Feb 21, 2012|
|Filing date||Jul 16, 2010|
|Priority date||Aug 8, 2007|
|Also published as||US7614449, US20090038808, WO2009020951A2, WO2009020951A3|
|Publication number||12837629, 837629, US RE43198 E1, US RE43198E1, US-E1-RE43198, USRE43198 E1, USRE43198E1|
|Inventors||Gary L. Anderson|
|Original Assignee||Baker Hughes Incorporated|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (6), Non-Patent Citations (2), Referenced by (1), Classifications (8), Legal Events (1)|
|External Links: USPTO, USPTO Assignment, Espacenet|
In the hydrocarbon exploration and recovery industry, it is often necessary to anchor equipment within a tubular structure such as a casing or tubing string. A common and long used apparatus for such duty is a set of slips with attendant support structure. In some embodiments, slips are utilized with conical structures that impart radially outwardly directed impetus on each slip as the slip is axially moved along the cone, usually under a compressive load. While such configurations have been extensively used, it is also known that this type of configuration can become stuck in the tubular structure in which it has been set, thereby rendering retrieval thereof difficult.
In another embodiment of a slip configuration, the slips are tangentially loaded to avoid the need for the conical portion. Depending upon the configuration of these tangentially loaded systems, there has been difficulty in retrieval or difficulty in creating acceptable holding strength.
As the art to which this disclosure pertains is always interested in improved technology, the disclosure hereof is likely to be well received.
A slip system includes a set of drive slips having wickers thereon, substantially all of which being truncated in cross-section; a set of gripping slips operatively interengagable with the set of drive slips; a drive slip end ring in operable communication with the set of drive slips; and a gripping slip end ring in operable communication with the set of gripping slips, the end rings capable of transmitting a load applied in an axial direction of the system to the set of gripping slips and the set of drive slips to tangentially load the set-of drive slips and the set of gripping slips against each other thereby increasing a radial dimension of the system and distributing stresses created in a target tubular.
A method for distributing stress in a target tubular imparted by a slip system includes embedding a plurality of sharp wickers of the slip system into the target tubular; and contacting an inside dimension of the target tubular with a plurality of truncated wickers.
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
In each of the rings 16 and 18, the position of slots 20, 22 or 24 are such, relative to each other, that slips 12 and 14 are alternately positioned when engaged with adjacent T-shaped slots in each ring. The alternate positioning of slips 12 and 14 is easily seen in
Finally, of note in
It is to be noted that the radial expansion of system 10 is affected entirely by tangential application of force through the slips 12 and 14; this means that the ID of the slip system can remain completely open and that conical structures previously used to radially displace slips are not necessary.
Referring now to
It should also be noted in passing that an angle of the mating surfaces 30, on each slip 12 and 14, is dictated by a radius extending from the axis of system 10. This angle ensures smooth and distributed contact along each face 30 to improve overall efficiency and strength of system 10.
Still referring to
Each one of the wickers 32 that is truncated, is so truncated to an extent about equal to the amount of penetration into the receiving tubular structure that is anticipated for pointed wickers on the gripping slips 14. The reason for this is so that when the pointed wickers are maximally embedded in the receiving tubular structure, the wickers 32 will be radially loaded against the receiving tubular structure without penetrating it into. This distributes the stresses of the receiving tubular structure more evenly about the tubular structure consistent with contact around the entirety of the slip system 10. One further benefit of the configuration of slips 12 is realized in the case of paraffin or other debris lining the inside dimension of the receiving tubular structure. Because wickers 32 are still above the surface of slips 12, those wickers are able to penetrate debris at the inside dimension of the receiving tubular structure and still ensure contact of truncation 34 with the inside dimension surface of the receiving tubular structure forming a frictional engagement therewith.
Each wicker 32, of course, possesses a pair of flanks 36, which in one embodiment, are positioned at 45°. It is to be understood that other angles are possible. It is also noted that in the system 10, it is not necessary to harden wickers 32, as they are not intended to bite into the receiving tubular structure. This is not to say that it is undesirable to harden wickers 32 but merely that it is not necessary to do so.
Addressing now the upright 42 of the key structure 48, and referring to both
It will be noted by the astute reader that ring 16 contains only T-shaped slot 20. The reason that the staggered T-shaped slots are not required on ring 16 is that all of the associated slips 12 substantially lack gripping wickers and therefore, the tensile force required to unseat them is substantially less than that of the slips 14. Therefore, there is no need to stagger the T-shaped slots in ring 16. This is by no means to say that it is inappropriate to stagger T-shaped slots 20, as it certainly is not only possible and functional, but rather merely to state that it is unnecessary.
While the figures in this application may suggest to one of ordinary skill in the art the existence of a clear uphole end and downhole end of slip system 10, based upon conventional illustration methods, it is to be understood that slip system 10 is usable with either end uphole. Generally, it will be desirable to impart a compressive setting force against ring 16 and the drive slips 12 while maintaining ring 18 and gripping slips 14 stationary. This is, however, not a requirement and the slip system 10 is to be understood to be actuable and retractable from either end. It is also to be understood that the system is actuable and retractable from a position downhole of the system of a position uphole of the system.
While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4311196||Jul 14, 1980||Jan 19, 1982||Baker International Corporation||Tangentially loaded slip assembly|
|US4576230||May 6, 1985||Mar 18, 1986||Tapp William T||Retrievable subsurface well casing slip and packer apparatus and method|
|US6119774||Jul 21, 1998||Sep 19, 2000||Baker Hughes Incorporated||Caged slip system|
|US6213204||Dec 7, 1998||Apr 10, 2001||Baker Hughes Incorporated||High load, thin slip system|
|US20040244966||Jun 6, 2003||Dec 9, 2004||Zimmerman Patrick J.||Slip system for retrievable packer|
|US20090014173 *||Oct 7, 2005||Jan 15, 2009||Iain Macleod||Well bore anchors|
|1||Halliburton; "Production Packers"; Jul. 2007; 6 pages.|
|2||International Search Report and Written Opinion Mailed Feb. 27, 2009, Written Opinion 7 pages, Ineternational Search Report 3 pages.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US20120160522 *||Jun 28, 2012||Texproil S.R.L.||Downhole packer tool with dummy slips|
|U.S. Classification||166/216, 166/382, 166/217|
|Cooperative Classification||E21B33/129, E21B23/01|
|European Classification||E21B33/129, E21B23/01|