Patent Publication Number: US-9890603-B2

Title: Quarter turn tubing anchor catcher

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from Canadian Patent Application No. 2,854,409 filed Jun. 14, 2014 entitled Quarter Turn Tubing Anchor and Catcher. This application is also a continuation-in-part of United States patent application Ser. No. 14/311,322 filed Jun. 22, 2014 and entitled Quarter Turn Tubing Anchor and Catcher, which is itself a continuation-in-part of U.S. patent application Ser. No. 13/716,075 filed on Dec. 14, 2012 and entitled Quarter Turn Tension Torque Anchor. The entire disclosures of these priority documents and all related applications or patents are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a quarter turn tubing anchor catcher and its use in a system with a downhole reciprocating rod pump or progressive cavity pump, within in a well conduit. 
     BACKGROUND OF THE INVENTION 
     A tubing string is used for producing hydrocarbons and to position downhole tools proximal to one or more underground geological formations that contain petroleum fluids of interest. The tubing string may also be referred to as production tubing or a production string. The tubing string is made up of sections of individual pipe joints that are typically threaded together. The tubing string extends within a bore of the well. The well bore is typically completed with casing or liners. The completed well bore may also be referred to as a well conduit. The tubing string can carry various downhole tools into the well conduit. For example, downhole tools can be used for various purposes including anchoring the tubing string and reciprocating rod pump within the wellbore at a desired location and to limit movement of the tubing string. 
     Tubing anchor catchers are used to limit movement axially and radially in both directions. Prior art tubing anchor catchers comprise threads or helical bearings that require multiple full (i.e. 360 degree) rotations of the mandrel to either set or unset the tubing anchor catcher. Disadvantages of such tubing anchors catchers include the expense of manufacturing the threaded portions, the threads may be susceptible to corrosion and the threads may be difficult to, or unable to, unset if they become filled with sand or corroded. With the new technology of fracing, the industry has adopted a heavier weight casing to be able to handle the bends and ‘S’ curves that are drilled today. A heavier weight casing wall makes the interior diameter of the casing smaller. This change in diameter, combined with the wells drilled with deviations and horizontally, makes the setting of the older design (multiple revolutions) tubing anchor catchers difficult. 
     Applicant&#39;s U.S. application entitled Quarter Turn Tension Torque Anchor and assigned U.S. application Ser. No. 13/716,075 has improved on these designs by providing a means for transferring a short longitudinal movement into actuation of conical surfaces to extend the slips into gripping engagement with the well conduit. However the apparatus and method of U.S. Ser. No. 13/716,075 do not provide a means to stop downward movement of the tubing string and attached equipment downhole when tubing joints above such apparatus unexpectedly come apart. 
     It is therefore desirable to have a tubing anchor catcher that further improves on these prior designs. Particularly, there is a need for a tubing anchor catcher that avoids the prior art threads and helical bearing that require multiple full rotations of the tubing anchor catcher&#39;s mandrel to either set or unset the tool. The tubing anchor catcher should not need to translate rotational movement into linear movement to engage the slips with the well conduit, but rather should directly transfer a short longitudinal movement to extend the slips into gripping engagement with the well conduit. The tubing anchor catcher should requirement only a limited rotation. Also, the tubing anchor catcher should have a simple and effective means to stop the tubing string from downward movement if tubing joints above such apparatus unexpectedly come apart. 
     SUMMARY OF THE PRESENT INVENTION 
     The present invention provides a tubing anchor catcher that acts to stop movement of a tubing string within a wellbore in both directions axially and radially. The tubing anchor catcher may also catch the tubing string if a part of the tubing string above the tubing anchor catchers disconnects. 
     One example embodiment of the present invention provides a tubing anchor catcher tool that is positionable within a well conduit for preventing movement of a tubing string. The tool comprises: a mandrel that is connectible at either end to the tubing string, the mandrel comprising a groove; a first cone element that is slidably mountable on to the mandrel, the first cone element comprising a first conical surface; a drag body that is slidably mountable on the mandrel, the drag body comprising a drag member that is sized for frictionally engaging an inner surface of the well conduit, a pin for engaging the groove, and a second conical surface; a biasing member that is slidably mountable on the mandrel adjacent the drag body for engaging the first cone element when the biasing member is compressed; and a slip cage that is slidably mountable on the mandrel, the slip cage comprising a slip or slips that are adapted for engaging the inner surface of the well conduit when one or more of the conical surfaces are disposed underneath the slip or slips. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: 
         FIG. 1  is an elevation side view of a first embodiment of a tubing anchor catcher; 
         FIG. 2  is a mid-line cross-sectional view taken along line  2 - 2  in  FIG. 1 ; 
         FIG. 3  is a mid-line cross-sectional view of  FIG. 1  showing the tubing anchor catcher with its slips extended; 
         FIG. 4  is a perspective view of an example embodiment of a mandrel for use as part of the tubing anchor catcher of  FIG. 1 ; 
         FIG. 5  is an enlarged view of an example embodiment of a groove that forms part of the mandrel of  FIG. 4 , showing a pin from the tubing anchor catcher engaged in the groove, in a run-in position; 
         FIG. 6  is the view of  FIG. 5  showing the pin in a set position; 
         FIG. 7  is a mid-line cross-sectional view of an example embodiment of a tubing anchor catcher, in the run-in position; 
         FIG. 8  is a mid-line cross-sectional view of the tubing anchor catcher of  FIG. 7 , in the set position; 
         FIG. 9  is a side elevation view of a second embodiment of a tubing anchor catcher; 
         FIG. 10  is a mid-line, sectional view of the tubing anchor catcher of  FIG. 9 ; and, 
         FIG. 11  is an exploded isometric view of parts of the tubing anchor catcher of  FIG. 9 . 
         FIG. 12  is a side elevation view of an example of the first embodiment of a tubing anchor catcher positioned within a well bore. 
         FIG. 13  is a cross-sectional view taken along line  13 - 13  in  FIG. 12 . 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIGS. 1 to 8  depict one example embodiment of a tubing anchor catcher  10 . The tubing anchor catcher  10  may be inserted within a well conduit  12  (see  FIGS. 13 and 14 ), such as a wellbore casing.  FIGS. 1 and 2  depict the tubing anchor catcher  10  in an unset, or “run-in”, orientation in which it can be run inside the well conduit  12  on a tubing string. Safety subs  14 A, B may be attached to a mandrel  20  of the tubing anchor catcher  10 , thus forming a lower pin end  10 B and an upper box end  10 A. In this embodiment, the tubing anchor catcher  10  may be run down the well conduit  12  while being threaded together within the tubing string in the downhole direction indicated by arrow  17 . Arrow  16  indicates the opposite direction within the well conduit  12 , namely the up-hole direction. It is noted, however, those terms such as “up”, “down”, “forward”, “backward” and the like are used to identify certain features of the tubing anchor catcher  10  when placed in a well conduit. These terms are not intended to limit the tubing anchor catcher&#39;s use or orientation. 
     The tubing anchor catcher  10  has an upper end  10 A and a lower end  10 B. The tubing anchor catcher  10  may comprise of a drag body  40 , a slip cage  60  and a biasing member  94 , all of which are mounted about the external surface of the mandrel  20 . The biasing member  94  can be for example, a coiled spring. The drag body  40  houses a drag means, in the form of one or more drag springs or drag blocks  42 , for spacing the tubing anchor catcher  10  away from the inner wall  13  of the conduit  12 . The drag blocks  42 , for example three or four drag blocks  42 , may be generally evenly spaced circumferentially about the tubing anchor catcher  10 . Each drag block  42  has a drag block spring  44  to urge the outer surface  46  of the drag block against the well conduit&#39;s inner wall. Upper and lower drag retaining rings  48 ,  50  keep the drag blocks  42  removably mounted within the drag body  40 . In addition to keeping the tubing anchor catcher  10  spaced from the well conduit  12 , the contact of the drag block surface  46  the well conduit&#39;s  12  inner wall or surface  13  causes friction that urges the drag body  40  to remain stationary while the mandrel  20  moves within the rest of the tubing anchor catcher  10 . 
     As will be discussed further, the drag body  40  is connected to the mandrel  20  by one or more drive pins  88  that extends inwardly from the drag body&#39;s  40  inner surface to engage an externally facing groove  80  that is on the outer surface of the mandrel  20 . As described further below, in one example embodiment, the drive pins  88  are made from a shearable material. 
     The slip cage  60 , which may also be referred to as a slip retainer, is also mounted on the mandrel  20  adjacent the drag body  40 . In particular, the slip cage  60  is mounted on the mandrel  20  above the drag body  40  (i.e. in direction  16 ). The slip cage  60  may house one or more movable slips  62 . For example, three slips  62  are depicted as being evenly spaced about the slip cage  60 , although this is not intended to be limiting as the tubing anchor catcher  10  described herein may operate with one or more slips  62 . Each slip  62  has an outer surface with teeth  63  for gripping the inner wall  13  upon contact. The teeth  63  comprise upward gripping teeth  63 B and downward gripping teeth  63 A. One or more fasteners in the form of a cap pin or cap screw  65  is fastened to the drag body  40  and is each located within one of a plurality of associated elongate slots  66  that are defined by the slip cage  60  and spaced circumferentially thereabout, preferably between each slip  62 . The cap screw  65  is adapted to travel within associated slots  66 , to permit movement of the slip cage  60  relative to the drag body  40  and to prevent the slip cage  60 , and the drag body  40 , from longitudinally separating. 
     A cone element  70  is mounted about the mandrel  20  at an upper end of the slip cage  60 . The cone element  70  comprises an upper edge  70 A and a lower edge  70 B. The lower edge  70 B forms a first conical surface whose inclined surface wedges under the slip or slips  62  when the tubing anchor catcher  10  is moved into a set position. Likewise, an upper edge of the drag body  40  forms a second conical surface  54  whose inclined surface also wedges under the slip or slips  62  when the tubing anchor catcher  10  is moved into a set position. When the tool is in the unset position, the first and second conical surfaces  70 B,  54  do not actuate the slip or slips  62 . A slip spring  76  urges each slip  62  radially inwardly into the slip cage  60  and away from the well conduit  12  while in the unset position ( FIG. 2 ). 
       FIG. 3  depicts the tubing anchor catcher  10  in the set position with the slip or slips  62  extended outwardly from the slip cage  60  for engaging the inner surface  13  of the well conduit  12 . The slip or slips  62  are extended due to the conical surfaces  70 B,  54  moving underneath the slip or slips  62 . The biasing member  94  is compressed due to the movement down of the mandrel, which movement forces the first and second conical surfaces  70 B,  54  underneath the slip or slips  62 . 
       FIG. 4  depicts the mandrel  20  as including an upper end  20 A and a lower end  20 B. As described above, the upper and lower ends  20 A, B may each comprise threaded connections for connecting the mandrel  20  to the tubing string, optionally via safety subs  14 A and  14 B, thus providing an the upper end  10 A comprises a box threading and the lower end  10 B comprises a pin threading. At least one groove  80  is formed on the mandrel&#39;s outer surface  26 , as best seen in  FIGS. 4 to 6 . The groove  80  is dimensioned (width, depth) to slidingly accommodate a protruding portion of the drive pin  88  that extends therein threaded through a hole  56  in the drag body  40 . The lower retaining ring  50  retains the drag blocks  42  within the drag body  40 . The tubing anchor catcher  10  may comprise one or more sets of grooves  80  and drive pins  88 . For example, the tubing anchor catcher  10  may have three or four sets of grooves  80  and three or four sets of associated drive pins  88  that are generally evenly radially spaced about the mandrel  20 . 
     As depicted in  FIGS. 5 and 6 , the groove  80  may comprise a C-shape with shoulders  82  and  86  defining a first arm  80 A of the groove  80  and shoulders  84  and  92  defining a second arm  80 B of the groove  80 . The two arms  80 A, B of the groove  80  are connected by central portion  80 C that is defined by walls  86 ,  87 ,  89  and  90 . Wall  90  separates the first and second arms  80 A, B. 
     The operation of the tubing anchor catcher may now be described with reference to all figures, including  figures 5 and 6  showing the drive pin  88  positions of the groove  80 . As seen in  FIGS. 5 and 6 , which is an enlarged view of groove  80 , a portion  88   a  of the drive pin  88  protudes into the groove  80  and is seated against the shoulder  92  in the run-in (i.e. un-set) position with the slip or slips  62  retracted within the sip cage  60 . To move the drive pin  88  to the set position at shoulder  82 , the tubing string can be manipulated at surface so as to move axially, i.e. by pulling or pushing, and rotationally, i.e. by turning, so as to similarly manipulate the mandrel  20 . The manipulation at surface may articulate the tubing anchor catcher  10  between the run-in position and a set position. Due to the drag blocks  42  frictionally engaging the inner surface  13  of the well conduit  12 , the drag body  40  and the slip cage  60  remain relatively fixed as the mandrel  20  and the rest of the tubing string, are manipulated from surface. As manderel  20  is pulled, in direction  16 , the drive pin  88  becomes repositioned in mandrel  20  in direction A towards shoulder  84 . Thereafter, the mandrel  20  can be lowered, and turned, for example, a quarter turn to the right, or clockwise as viewed from above (i.e. about 90 degrees). As known in the art, anchor catchers are commonly right hand set/right hand release for reciprocating rod pumps. The turning is about the longitudinal axis of the tubing string and, therefore, the tubing anchor catcher  10 . This manipulation causes the drive pin  88  to be relocated from shoulder  84 , generally along walls  89 ,  87  and  86  to rest in shoulder  86  of the first arm  80 A. When the drive pin  88  is in shoulder  86 , the tubing anchor catcher  10  is in a pre-set position. Pulling the tubing string and, therefore, the mandrel  20  upwards, in direction  16  will cause the drive pin  88  to be relocated into shoulder  82 . When the drive pin  88  is in shoulder  82 , conical surfaces  54  and  70 B have moved under the slip or slips  62  and the tubing anchor catcher  10  is set with the slip or slips  62  extending outwards from the slip cage  60  to engage the inner surface  13  of the well conduit  12 . At this point, tension can be applied to the tubing string and the tubing string can be landed in a tubing hanger. 
     Groove  80  is in the shape of a “C”, although this is not intended to be a literal graphical description of shapes that will work, as other shapes will work other than exact C-shapes as may mirror images of the groove  80 . 
     To release the slip or slips  62 , the tubing string and, therefore, the mandrel  20  can be manipulated at surface. For example, the mandrel  20  can be moved relative to the rest of the tubing anchor catcher  10 , so that the drive pin  88  is relocated out of shoulder  82 . As shown in  FIG. 6 , the mandrel  20  can be pushed down so that the drive pin  88  is relocated along line F toward shoulder  86 . With a quarter turn to the right the drive pin  88  will be repositioned along line H and then a straight pulling up of the tubing string and mandrel  20  will cause the mandrel  20  to move so that the drive pin  88  ends up in shoulder  84 . When the drive pin  88  has been relocated out of the first arm  80 A of the groove  80 , the conical surface  54  moves out from under the slip or slips  62  and the spring  76  will cause the slip or slips  62  to retract back into the slip cage  60 . 
     When the tubing anchor catcher  10  is in the set position and in the event of a break in the tubing string, etc, which may cause the tubing string to fall down into the well (i.e., in direction  17 ), the tension in the tubing string is lost. This causes the weight of the tubing string to bear on the upper safety sub  14 A, which will bear on the biasing member  94 . The biasing member  94  will compress, from the weight of the tubing string above, and act against the upper edge  70 A of the cone  70 . This action causes the downwardly gripping upper teeth  63 A to more directly engage and bite into the inner surface  13  of the well conduit  12 . For example, the greater the amount of tubing string weight that compresses the biasing member  94 , the harder, or more directly, the upper teeth  63 A will engage the inner surface  13  of the well conduit  12 . When the upper teeth  63 A are more directly engaged into the inner surface  13  of the well conduit  12 , the upper teeth  63 A can hold the weight of the tubing string above the tubing anchor catcher  10 , for example, until such time that the tubing string can be recovered from the well. The drag blocks  42  are still in frictional contact with the inner surface  13  of the well conduit  12  and the lower conical surface  54  is still wedged under the slip or slips  62 . 
     An alternate means of un-setting the tubing anchor catcher is now described. If it is not possible to relocated drive pin  88  in a location in the groove  80  so as to unset the slip or slips  62 , for example due to packing of sand or other materials into the groove  80 , the slip or slips  62  may be unset by applying a sufficient upward tension on the tubing string and the mandrel  20 . In one embodiment, the upward tension is of a sufficient amplitude to shear the drive pins  88 , which form the primary connection between the drag body  40  and the mandrel  20 . Then the mandrel  20  may then move upward (i.e. in the direction of arrow  16 ), relative to the drag body  40 , which causes upper cone  70  to move up and out from under the slip or slips  62 , which then allows slip or slips  62  to move inwardly as they move away from the second conical surface  54  of the drag body  40 . This allows the slip or slips  62  to retract from contacting the inner surface of the well conduit. When the slip or slips  62  are retracted, the tubing anchor catcher  10  may be pulled out of the well conduit  12 . At this time the cap  65  may engage the lower shoulder  68 B of the slot  66  so that, even though the slip cage  60  is furthest away from the drag body  40 , the slip cage  60  and the drag body  40  do not separate. Alternatively, or additionally, the lower edge of the drag body  40  may engage the lower safety sub  14   b  as the tubing string is pulled upwards towards the surface (i.e. in direction  16 ). 
       FIGS. 9 to 12  depict an alternative or second embodiment of a tubing anchor catcher  100  with an upper end  100 A and a lower end  100   B . The tubing anchor catcher  100  may comprise many of the same features as tubing anchor catcher  10 . For example, one difference between the two tubing anchor catchers  10 ,  100  is that the drive pin  88  of the tubing anchor catcher  10  may be sheared as a secondary release mechanism, as described above. In contrast, the tubing anchor catcher  100  may comprise a drive pin or drive pins  188  that are not designed to shear as a secondary release mechanism. The lower cone  41  is formed as a separate piece to the drag body  40 . The tubing anchor catcher  100  may comprise one or more shear pins  72  that connect the lower end of the lower cone  41  to drag body  40 . The shear pins  72  are made of a material that will shear in response to a lower shearing force than the shear force required to shear the pin  188 . In this embodiment, the second conical surface  54  is formed on an upper end of the lower cone  41  (see  FIG. 12 ). Lower cone  41  slidably mounts about the external surface of the mandrel  20  so that conical surface  54  in combination with conical surface  70 B on cone  70  compress together along mandrel  20  to force the slip or slips  62  into the set position, as described above. The shear pins  72  provide a secondary release of slip or slips  62  by the application of a sufficient pulling force to the tubing string so as to shear the shear pins  72 . When the shear pins  72  are sheared, the lower cone  41  is released from connection with the stationary drag body  40  and can move downwardly away from its position under the slip or slips  62 . The slip or slips  62  can then retract away from the inner surface  13  of the well conduit  12 . 
     The tubing anchor catchers  10 ,  100  are thus designed to anchor the tubing string from movement longitudinally along the well (in both directions, up and down the well) and from rotating. The anchoring is achieved by simple setting and release procedures that require relatively little movement of the tubing string. In this instance, setting is achieved by a small pull and right hand rotation of the mandrel  20  (via the tubing string) that is adequate for the drive pins  88 ,  188  to travel the short distances within the groove  80 . Further, both tubing anchor catchers  10 ,  100  can prevent a broken tubing string from falling into the well bore by the compression of the biasing member  94  causing the downward gripping teeth  63 A to grip the inner surface  13  of the well conduit  12 , as described above. 
     The slip or slips  62  and the diameter of the anchor cathcer  10 ,  100  may be configured to provide one or more by-pass spaces  78  between the tubing anchor catchers  10 ,  100  and the inner surface  13  of the well conduit  12 , which may create high flow areas for fluids (e.g. gas) and solids (e.g. sand) to pass by the tubing anchor catchers  10 ,  100 . 
     This optional embodiment of the tubing anchor catchers  10 ,  100  configured with by-pass spaces  78  may permit lines, tubes and cables such as capillary cable to be carried downhole via the large by-pass spaces  78 . In particular, the fact that the tubing anchor catchers  10 ,  100  is set and unset by longitudinal motion and a quarter turn, permits its use with the capillary cable since the tubing anchor catchers  10 ,  100  may avoid wrapping of the cable around the tubing anchor catchers  10 ,  100 . In contrast, prior art anchors require multiple full (360 degree) rotations—between two to nine full rotations for setting and unsetting—and cause an undesirable wrapping of the cable around the tubing anchor catcher as it is set, which can damage the cable. Alternately, the cables must be pre-wrapped when installed with these prior art tubing anchors catchers, so that they unwrap as the tubing anchor catcher is rotated during setting, which is tedious and undesirable. Also, if cable is required to be pre-wrapped then on setting the tool, the unwrapped extra cable becomes available to jam between the tool and the well conduit and it may be damaged, break or otherwise interfere with reliable wellbore operations. 
     Optionally, the drag blocks  42  may be hardened, in comparison to prior art drag springs, for a longer operational life. The slip or slips  62  may optionally be made with carbide inserts for teeth for superior durability and grip on the well conduit wall  13 , and Inconel™ type springs  76  are employed for improved resistance to H 2 S and CO 2 . Further, the surface of the mandrel  20  may optionally be coated with Teflon® for improved resistance to H 2 S and CO 2 , and to help maintain mandrel strength. 
     While the above disclosure describes certain examples of the present invention, various modifications to the described examples will also be apparent to those skilled in the art. The scope of the claims should not be limited by the examples provided above; rather, the scope of the claims should be given the broadest interpretation that is consistent with the disclosure as a whole.