Abstract:
An anchor tool has a body, a plurality of slips coupled to the body, each of the slips hingedly coupled to a link at a first end, each of the slips slidably retained in a channel at a second end and each of the slips operably moveable from a retracted orientation to an expanded orientation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not Applicable. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       BACKGROUND 
       [0003]    The present invention relates to tools for use in well drilling operations. More specifically, the present invention relates to an anchor for securing a tool within a well bore. 
         [0004]    Many operations performed in the course of exploration and production of oil and gas require that axial forces be applied to tools and other devices inside of a wellbore. In many instances the tool must be supported at a specific location inside the wellbore with an anchoring device. Downhole tool anchors and other isolation devices, comprising packers and plugs, have been extensively utilized in the industry. An exemplary application for an anchor involves a whipstock to be installed in a wellbore to facilitate drilling of additional wellbores in different directions off of the original or primary wellbore. 
         [0005]    “Dog” anchoring devices extend from within the envelope of the body of a tool into a pre-installed channel placed along the completion string within the wellbore. These types of anchors can withstand large forces, but require anchoring grooves at predetermined locations along the completion string. “Slip” anchors apply an anchoring force against the wellbore by extending small gripping plates, commonly known as slips, to the side of the surrounding wellbore. 
         [0006]    Other anchoring devices utilize pistons or rams which can be moved radially outward from the tool body to engage the circumference of a wellbore. Still other systems employ linkage systems to expand against a wellbore surface. Other types of anchors use fluid to lift anchoring surfaces which move vertically along a track or rail system. Other anchor types require an expansion or explosion of combustible materials to generate the required pressure to expand the anchoring surfaces against the side of the wellbore. 
         [0007]    Whipstocks are used to drill additional multi-directional wellbores from a primary wellbore. A whipstock is a long steel casing which contains an inclined plane to cause the drill bit to deflect from the original wellbore at an angle. It is often necessary that an anchor be placed to securely hold the whipstock in place. 
         [0008]    Prior art anchoring devices comprise, but are not limited to, the following: 
         [0009]    U.S. Pat. No. 4,153,109 discloses an anchor having annular slip sections for engaging a casing. Upper and lower expanders have frustoconical shaped ends to engage the slip structures. 
         [0010]    U.S. Application No. 20090071659 filed by Spencer, et al, published Mar. 19, 2009, discloses a technique for anchoring a tool in a wellbore. The technique utilizes one or more arms pivotally mounted to a structure for movement between a radially inward position and radially outward position that anchors the tool to a surrounding wall. A wedge component is positioned to selectively engage the arms. 
         [0011]    U.S. Pat. No. 5,350,016 issued to Thornton, Jr. on Sep. 27, 1994 discloses a wellbore anchor tool which employs at least one pair of individual slip segments which wrap at least partially around a mandrel passing through the tool, the individual slip segments carrying bearing surfaces and restraint members for holding the slip segments in the tool but at the same time in slidable engagement with the tool. 
         [0012]    U.S. Pat. No. 6,035,939 issued to Carter on Mar. 14, 2000 discloses a whipstock system having an anchor apparatus, the anchor apparatus incorporating a slip having an inclined surface and a toothed engaging surface for engaging a casing. 
         [0013]    U.S. Pat. No. 5,154,231 issued to Bailey, et al on Oct. 13, 1992 discloses a one-trip whipstock assembly incorporating a hydraulically set anchor which comprises an interlock for maintaining the anchor in its set position. An anchor is connected to the lower end of the assembly. Slip elements are expanded outwardly in response to the fluid pressure to engage the casing and set the anchor. 
         [0014]    U.S. Pat. No. 5,878,818 issued to Hebert, et al on Mar. 9, 1999 discloses a mechanically set anchor wherein a plunger extending from a base end of an anchor body activates a pin type trigger which releases a spring utilized to set multiple slips extending from the body of the anchor. Continued downward compressive forces fully set the slips into the borehole pipe casing. The anchor is mechanically released by upward pull to shear release pins. 
         [0015]    U.S. Pat. No. 5,829,531 issued to Hebert, et al on Nov. 3, 1998 discloses a mechanically set anchor, commonly used with a whipstock assembly, wherein a plunger extending from a base end of an anchor body activates a pin type trigger which releases a spring utilized to set multiple slips extending from the body of the anchor. 
         [0016]    U.S. Pat. No. 5,350,016 issued to Thornton, Jr. on Sep. 27, 1994 discloses downhole anchor tools. Individual slip segments are mounted about a mandrel with sloping surfaces engaging a sloping drive surface. 
         [0017]    U.S. Pat. No. 7,086,462 issued to Rutley, et al on Aug. 8, 2006 discloses an anchor assembly. Upper frictional members are spring-tensioned. Lower frictional engagement members slide along a conical engagement surface causing the lower frictional members to extend outwardly and engage the inner surface of the casing. 
         [0018]    U.S. Pat. No. 6,920,927 issued to Hirth on Jul. 26, 2005 discloses a wellbore anchoring device for anchoring a down-hole tool comprising an expandable cone having an annular integral shoulder, defining the large end of a conical annular recess on an outer surface of the cone, and a resilient slip positioned within the annular recess. Axial travel of the slip is limited by engagement with the shoulder. 
         [0019]    U.S. Pat. No. 7,431,080 issued to Wright, et al. on Oct. 7, 2008 discloses an anchor having slips at one end and a tapered opposite end for mating with a slip cone. The slip assembly  40  is slidingly connected to the mandrel outer surface and travels along this surface to the slip cone for actuation. A pin travels along a pattern on outer surface of the mandrel to advance the slip assembly and to retract the slip assembly. 
         [0020]    U.S. Pat. No. 7,588,078 issued to O&#39;Brien on Sep. 15, 2009 discloses an anchor having ramps that extend through apertures in slip structures giving the slips a ramp to ride out in a radial direction. 
         [0021]    U.S. Pat. Nos. 7,178,589, 7,377,328 and 7,448,446 to all disclose slips having angled extensions along the sides of the slips extending at an angle to the backs of the slips. Extensions fit within corresponding channels in recesses of the slip housings. 
       SUMMARY 
       [0022]    An anchor for securing a tool within a well bore comprises a plurality of slips connected to an anchor body, each slip hingedly connected to a link at a first end and each slip slidably retained in an anchor body channel at a second end, the slip connection arm hingedly connected to the anchor body. A piston contained within an annular opening is axially moveable on a mandrel toward the slips to force slips outward to engage a surrounding surface of a wellbore or casing. Inclined guide surfaces facilitate slip extension. Upon slip extension, slips are held in fixed orientation by the links and channels provided in the anchor. 
         [0023]    In some embodiments, an anchor tool includes a body, a plurality of slips coupled to the body, each slip hingedly coupled to a link at a first end, each slip slidably retained in a channel at a second end, each slip operably moveable from a retracted orientation to an expanded orientation. The link may be coupled to and selectively received within a complementary link recess of the body. The slip may be selectively at least partially received within a complementary slip recess of the body. The anchor tool may further comprise a mandrel coupled to the body and extending from the body, and a cap coaxially aligned with the mandrel and having an inclined surface to engage an inclined inner surface of each slip. The cap may be slidably received on the mandrel such that the inclined surface engages each slip inclined surface between the retracted and expanded orientations. Each link may hingedly couple each slip to the body between the retracted and expanded orientations. The cap may be movable in response to application of a fluid pressure to an exterior of the mandrel. In response to moving the cap toward the body, each slip may move between the retracted orientation and the expanded orientation. 
         [0024]    In some embodiments, an anchor tool includes a body including an outer diameter, the body being substantially coaxially aligned with a central axis of the anchor tool, a link coupled to the body, the link being both retractable relative to the body and rotatable relative to the body, a cap comprising an inclined surface, the cap being coaxially aligned with the central axis, and a slip, the slip being rotatably coupled to the link and the slip comprising an inclined surface configured for selective sliding engagement with the inclined surface of the cap. The link may be selectively received within a complementary link recess of the body. The slip may be selectively at least partially received within a complementary slip recess of the body. The anchor tool may further comprise a mandrel, the mandrel being rigidly coupled to the body and the mandrel being slidably received through the cap. The cap may be movable in response to increasing a fluid pressure supplied to the anchor tool. The cap may be movable in response to application of a fluid pressure to an exterior of the mandrel. In response to moving the cap, the slip may be moved radially relative to the central axis. The slip may be substantially prevented from rotating relative to the central axis. The mandrel may comprise a central passage and an associated flow orifice for receiving fluid. 
         [0025]    In some embodiments, an anchor tool includes a body including an outer diameter and a recess, a link pivotally coupled to the body in the recess and below the outer diameter, a slip pivotally coupled to the link, the slip comprising an engagement surface, and a cap moveably coupled to the body, wherein the slip is captured between the body and the cap, the cap moveable to engage a cap engagement surface with the slip engagement surface. The link may be translatable relative to the body. 
         [0026]    In some embodiments, a method of operating an anchor tool includes locating the anchor in a well bore, altering a fluid pressure supplied to the anchor tool, moving a cap of the anchor tool toward a body of the anchor tool, wherein a slip of the anchor tool is connected to the body via a rotatable link and wherein the cap includes an inclined surface, and in response to moving the cap toward the body, radially moving the slip relative to the central axis while substantially preventing rotation of the slip relative to the central axis. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    Referring now to the figures, wherein like elements are numbered alike in the several drawings: 
           [0028]      FIG. 1  is a schematic cross-sectional view of the anchor tool depicting a connection link and slip extended; 
           [0029]      FIG. 2  is a view of the anchor tool with connection links and slips retracted; 
           [0030]      FIG. 3  is a view of the anchor tool with connection links and slips extended; 
           [0031]      FIG. 4  is a partial cross-sectional view of the anchor tool with slips extended; 
           [0032]      FIG. 5  is a partial cross-section, isometric view of a segment of the anchor tool with slips extended; 
           [0033]      FIG. 6  is a side view of an anchor tool segment with slips extended. 
           [0034]      FIG. 7  is a partial cross-section, isometric view of a segment of the anchor tool segment with slips retracted; 
           [0035]      FIG. 8  is a cross-sectional view of the anchor tool; 
           [0036]      FIG. 9  is a detail of the anchor tool depicting a slip and link; 
           [0037]      FIG. 10  is a detail of the anchor tool depicting a piston and connector; 
           [0038]      FIG. 11  is a detail of the anchor tool depicting a shear pin; 
           [0039]      FIG. 12  is an oblique side view of an anchor tool according to an alternative embodiment of the disclosure showing the anchor tool with slips in a near fully retracted state; 
           [0040]      FIG. 13  is an oblique side view of the anchor tool of  FIG. 12  showing the anchor tool with slips in a partially extended state; 
           [0041]      FIG. 14  is an oblique side view of the anchor tool of  FIG. 12  showing the anchor tool with slips in an extended state to contact a casing wall; 
           [0042]      FIG. 15  is a schematic view of an anchor tool according to another alternative embodiment of the disclosure; and 
           [0043]      FIG. 16  is a partial oblique view of a slip according to an alternative embodiment of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0044]    Referring to  FIGS. 1-3 , schematic representational views of anchor  10  are depicted. Anchor  10  generally comprises subassembly  22 , upper mandrel  24 , lower mandrel  26 , slips  28 , links  34 , piston  30 , cylinder  32  and cylinder cap  38  having inclined channels  88 . Anchor  10  is depicted in  FIGS. 1 and 3  with a slip  28  expanded for engagement with a casing wall  60  while  FIG. 2  depicts slips  28  retracted into subassembly  22 . 
         [0045]    Referring again to  FIG. 1 , subassembly  22  comprises assembly body  40 . In some embodiments, a link receiver  35  comprising a longitudinal link slot  36  may be intermediate the link  34  and the body  40 . In some embodiments, a receiver bolt  41  may be used to join the link receiver  35  to the body  40 . Body  40  comprises a hollow cylinder having a central passage  42 . Body  40  defines a central axis  100 . Passage  42  extends along axis  100 . Threading  44  is provided at the upper end  46  of body  40  for attachment to a pipe string (not shown). 
         [0046]    Body  40  is attached at its lower end  47  to upper mandrel  24 . In the embodiment depicted, body  40  is attached by threading to upper mandrel  24 . Upper mandrel  24  is a tubular structure coaxially aligned with body  40 . Upper mandrel  24  has a central passage  48  extending therethrough. Central passage  48  is aligned with passage  42  of body  40 . 
         [0047]    Referring to  FIGS. 1 and 9 , upper mandrel  24  is attached at its lower end to connector  52 . Connector  52  is connected to lower mandrel  26 . Connection of connector  52  to upper mandrel  24  and lower mandrel  26  may be accomplished by threads carried by each. In the embodiment depicted central passage  48  terminates at connector  52 . Accordingly, fluid flow may be provided from body  40  through lower mandrel  26  by way of central passages  42  and  48 , but not through connector  52 . Body  40 , upper mandrel  24 , connector  52  and lower mandrel  26  are aligned with central axis  100 . 
         [0048]    Referring back to  FIGS. 1 and 2 , each slip  28  has an exterior surface  60  for selectively engaging casing wall  58  or unfinished bore hole. Each slip  28  has an interior surface  62  aligned with exterior surface  60 . Each slip  28  has an upper guide surface  64  and a lower guide surface  66 . 
         [0049]    Referring to  FIGS. 1 and 8 , each slip  28  is connected by a hinge pin  68  to a link  34  lower end  70 . Each link  34  is also connected by a hinge pin  72  at a link upper end  74  to body  40 . In embodiments where links  34  are associated with a link receiver  35 , the link upper end  74  may be associated with a link slot  36  along which the link upper end  74  may translate when an associated slip  28  is moved. 
         [0050]    Referring to  FIG. 5  a partial cross-section of slips  28  is shown. In the embodiment depicted three (3) slips  28  are spaced in an angular or radial array at 120 degrees radial intervals. Each slip  28  comprises a unitary block with a defined link channel  76  for receiving a corresponding link  34 . Links  34  are not depicted in  FIG. 5 . Still referring to  FIG. 5 , inner surface  62  is depicted. Inner surface  62  comprises an arc segment  78 . Arc segment  78  is curved to conform with outer surface  80  of upper mandrel  24 . Upper mandrel  24  is not depicted in  FIG. 5 . Inner surface  62  further comprises beveled edges  82  on each side of arc segment  78 . Beveled edges  82  of each slip inner surface  62  are sized and positioned to abut a beveled edge  82  of an adjacent slip  28  when anchor  10  is in a slip-retracted orientation. In alternative embodiments, the inner surfaces  62  may comprise any other shape or profile configured to allow the slips  28  to compactly be centrally located and, in some cases, abut outer surface  80 . 
         [0051]    Referring to  FIG. 4 , a body guide surface  84  is provided in body  40 . Body guide surface  84  is sized and positioned for sliding engagement with upper guide surface  64  of slip  28 . Each of body guide surface  84  and upper guide surface  64  is inclined at an angle to axis  100 . In the embodiment illustrated body guide surface  84  extends at a 45 degree angle to axis  100  and slip upper guide surface  64  extends at a 135 degree angle to axis  100  (in relation to the y axis of an x-y grid with the axis  100  corresponding to y). In some embodiments, body guide surface  84  may be a feature of the link receiver  35 . Further, in alternative embodiments, the angles of incline may be different while still allowing actuation without unduly restrictive friction forces. 
         [0052]    Referring to  FIGS. 1 ,  2 ,  4 , and  8 , cylinder cap  38  and cylinder  32  comprise attached cylindrical structures each extending around upper mandrel  24 . 
         [0053]    Referring to  FIGS. 6 ,  7 , and  8 , upper casing  110  comprises a hollow cylindrical structure surrounding cylinder cap  38 . Channels  88  are provided in upper casing  110 . Each channel  88  is sized and positioned to receive at least a portion of the lower segment of slip  28  when anchor  10  is in a slip-retracted orientation. 
         [0054]    The exterior surface of the cylinder cap  38  comprises a guide surface  90 . Each guide surface  90  is sized and positioned for sliding engagement with lower guide surface  66  of slip  28 . Each of lower guide surface  66  and guide surface  90  are inclined at angle to axis  100 . In the embodiment illustrated guide surface  90  extends at a 150 degree angle to axis  100  and slip lower guide surface extends at a 30 degree angle to axis  100  (in relation to the y axis of an x-y grid with the axis  100  corresponding to y), but the angle may be different in alternative embodiments. 
         [0055]    Referring to  FIGS. 1 ,  8  and  10 , a piston  30  is depicted. Piston  30  has an interior surface  94  that slidingly engages exterior surface  80  of upper mandrel  24 . Piston  30  comprises a piston head  96  and flange  98 . Piston head  96  is fixedly attached to lower housing  102 . In the embodiment depicted, such attachment is by threading. Lower housing  102  is a tubular structure surrounding at least a portion of upper mandrel  24  and surrounding at least a portion of lower mandrel  26 . As piston  30  is slidable on and in relation to upper mandrel  24  and lower housing  102  is fixedly attached to piston head  96 , lower housing  102  is also slidable in relation to upper mandrel  24 . Lower housing  102  and upper mandrel  24  define an upper annular opening  104  therebetween. 
         [0056]    A flow orifice  106  is provided in upper mandrel  24 . Flow orifice  106  is sized and positioned to allow flow of fluid from passage  48  into annular opening  104 . Connector  52  comprises connector flange  111 . Connector flange  111  sealingly engages lower housing  102 . Piston head  94  sealingly engages lower housing  102 . Accordingly, fluid transmitted from passage  48  into annular opening  104  is retained intermediate connector flange  111  and piston head  94 . 
         [0057]    Anchor  10  components are sized and structured such that fluid flow into annular opening  104  first fills annular opening  104  with fluid (not shown), then biases piston head  94  upward toward body  40 . As cylinder  32  and cylinder cap  38  are each slidable on upper mandrel  26 , continued injection of fluid into annular opening  104  pushes all of piston  30 , cylinder  32 , and cylinder cap  38  upward toward body  40 . Such force causes slips  28  to extend outwardly. Interaction of inclined slip upper guide surface  64  with body guide surface  84  facilitates outward movement of slip  28  at slip  28  upper end  70 . Interaction of inclined slip lower guide surface  66  with each cylinder cap inclined surface  90  facilitates outward movement of each slip  28  at the slip lower end. In some embodiments, the outward extension of slips  28  occurs without rotating the slips  28  relative to the central axis  100 . 
         [0058]    When sufficient fluid is introduced into annular opening  104 , slips  28  will be extended until exterior surfaces  60  of slips  28  engage casing wall  58  or portions of an uncased bore, anchor  10  will be set in a fixed position in relation to casing wall  58  or an uncased bore. 
         [0059]    Hinged link  34  retains slip  28  in its radially extended orientation at slip upper end  70 . Channels  88  provided in upper casing  110  retain the lower end of each slip  28  in its radial orientation at the slip lower end. Additionally, the links  34  and channels  88  provide rotational and/or angular stability to the slips  28  relative to the central axis  100 . 
         [0060]    Referring to  FIG. 10 , outer ratchet ring  114  is connected to housing  102 . Accordingly, when housing  102  is forced upward by fluid flow into annular opening  104 , ratchet ring  114  is drawn upward to engage inner ratchet ring  115 . Inner ratchet  115  is fixedly attached to lower mandrel  26 . Ratchet ring  114  and inner ratchet ring  115  accordingly lock housing  102  in a fixed position in relation to lower mandrel  26 , and consequently lock slips  28  in a fixed position. 
         [0061]    To pull the anchor  10  from its locked position within the casing  58 , it is necessary to exert upward tension on mandrels  24  and  26  until shear pins  118  are severed from shear sleeve  122 . Upon such severance, housing  102  will be free to slide in relation to mandrel  26 , allowing piston  30  to drop along the upper mandrel  24  and to allow slips  28  and links  34  to retract back within the tool, and in some embodiments, radially inward beneath an outermost diameter of the body  40 . 
         [0062]    Referring to  FIGS. 1 through 6 , a plurality of apertures  130  are provided through slips  28 . Among other things, apertures  130  allow reduction in weight of anchor  10 . 
         [0063]    Referring now to  FIGS. 12-14 , oblique side views of an alternative embodiment of an anchor tool  10  are shown with slips  28  mostly retracted, slips  28  partially extended, and slips  28  sufficiently extended to engage a casing  58  wall, respectively. In operation, the anchor tool  10  may be deployed down hole, either inside a casing  58  or in an unfinished or open bore. Such deployment may take place while the slips  28  are in a mostly retracted or fully retracted state as shown in  FIG. 12 . 
         [0064]    In the mostly and/or fully retracted state, in some embodiments, the exterior surface  60  of slips  28  may either collectively form an outer diameter substantially similar to or less than an outer diameter of the body  40  and/or the remainder of subassembly  22 . In other words, in some embodiments, the slips  28  may be configured not to protrude radially outward more than a remainder of the subassembly  22  when the slips  28  are in a mostly and/or fully retracted state. As such, the slips  28  may be less likely to present surfaces and/or edges that may undesirably catch or hang on casing  58  features and/or debris within casing  58  and/or an uncased bore. Once the anchor tool  10  is at its desired depth and/or location within the casing  58  and/or bore, fluid pressure may be applied to the anchor tool  10 .  FIGS. 12-14  also more clearly show that cylinder cap  38  may be connected to cylinder  32  using a cap bolt  50 . 
         [0065]    As fluid pressure is increased and as the annular opening  104  is increasingly filled with fluid, the piston  30  may be forced to move along the length of the upper mandrel  24 . With sufficient movement of the piston  30  and its associated cylinder  32  and cylinder cap  38 , the inclined guide surface  90  of the cylinder cap  38  may contact the complementary inclined lower guide surfaces  66  of the slips  28 . With continued movement of the cylinder cap  38  toward the body  40 , the slips are increasingly forced radially outward away from the central axis  100 . Even when slips  28  are significantly extended radially outward away from the central axis  100 , and in some embodiments so far as to contact casing  58 , anchor tool  10  is configured to ensure that the slips  28  are robust and resistant to any angular rotation of the anchor tool  10  about the central axis  100 . 
         [0066]    Referring now to  FIG. 14 , the robust nature of the anchor tool  10  is more clearly seen. For example, even though the slips  28  are extended far enough to contact casing  58 , the links  34  and the slips  28  remain sufficiently angularly captured between robust adjacent components to prevent any significant angular displacement and/or damage to the links  34  and the slips  28 . It may be important to prevent such damage to the links  34  and the slips  28  so that they are maintained in a retractable condition that promotes the above-described selective retraction and subsequent removal of the anchor tool  10 . Specifically, even when substantially radially extended, the slips are angularly bounded by adjacent walls of both inclined channels  88  and body walls  89 . As such, during the course of extending the slips  28  from a retracted position to an extended position, any forces applied to the slips  28  that may promote an angular displacement of the slips  28  may be transferred to the body  40 , the cylinder  32 , and/or the cylinder cap  38 . Similarly, the links  34  are protected against significant angular deflection by link receiver walls  91  of link receiver  35 . 
         [0067]    Referring now to  FIG. 15 , a schematic of an alternative embodiment of an anchor tool  200  according to the disclosure is shown. Anchor tool  200  may be substantially similar to anchor tool  10  in the composition of its components and operation, but the actuation mechanism of the anchor tool  200  is different. Specifically, instead of the body  40  being longitudinally fixed relative to the upper mandrel  24  so that cylinder cap  38  can be moved along the upper mandrel  24  toward the body  40 , the cylinder cap  38  is fixed relative to the upper mandrel  24  and the body  40  is movable along the upper mandrel  24 . More specifically, in some embodiments, an actuation mechanism  202  may be provided and associated with the body  40  so that fluid pressures may selectively actuate the body  40  toward and/or away from the cylinder cap  38 . In some embodiments, controlling movement of the body  40  in both directions along the upper mandrel  24  may require multiple and/or selectable fluid paths and/or fluid cavities within actuation mechanism  202 . As such, anchor tool  200  may be operable in substantially the same manner as anchor tool  10  with the exception that it may be the body  40  and associated links  34  and slips  28  (only one shown) that are translated along the length of the upper mandrel  24  to accomplish extension and/or retraction of slips  28 . 
         [0068]    Referring now to  FIG. 16 , a partial oblique bottom view of alternative embodiment of a slip  28  is shown. In this embodiment, slip  28  comprises a retainer channel  67  formed along the lower guide surface  66 . Retainer channel  67  may comprise a so-called “T-channel” configured to receive a complementary rail that may be formed lengthwise along guide surface  90  of cylinder cap  38 . In some cases, such a retainer channel  67  may provide improved strength and/or positional stability to the slips  28  as they are retracted. Additionally, the retainer channel  67  and associated complementary rails may further promote the ability for the anchor tools  10 ,  200  to selectively and/or partially retract the slips  28  in a controlled manner without fully removing the anchor tools  10 ,  200 . Still further, in much the same way retainer channel  67  is provided on lower guide surface  66 , retainer channels  67  may be provided on upper guide surfaces  64  of slips  28 . In cases where retainer channels  67  are provided on upper guide surfaces  64 , body guide surfaces  84  may be provided with the complementary rails for interaction with the retainer channels  67  of the upper guide surfaces  64 . 
         [0069]    At least one embodiment is disclosed and variations, combinations, and/or modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of the disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to comprise iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 comprises, 2, 3, 4, etc.; greater than 0.10 comprises 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, RI, and an upper limit, Ru, is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=RI+k*(Ru−RI), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . 50 percent, 51 percent, 52 percent, . . . 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed. Use of the term “optionally” with respect to any element of a claim means that the element is required, or alternatively, the element is not required, both alternatives being within the scope of the claim. Use of broader terms such as comprises, comprises, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above but is defined by the claims that follow, that scope comprising all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present invention. Further, while the claims herein are provided as comprising specific dependencies, it is contemplated that any claims may depend from any other claims and that to the extent that any alternative embodiments may result from combining, integrating, and/or omitting features of the various claims and/or changing dependencies of claims, any such alternative embodiments and their equivalents are also within the scope of the disclosure.