Abstract:
A method and assembly for reducing a radial gap between radially proximate components including a setting member having a first dimension that partially defines the radial gap, the setting member including a circumferential groove extending radially from the first dimension, and a first toroid having a second dimension, the setting member operatively arranged to engage with the first toroid, wherein increasingly engaging the setting member with the first toroid enables a boundary dimension of the assembly to be extended toward the radial gap for reducing the radial gap, the circumferential groove operatively arranged to catch the first toroid when the setting member is fully engaged with the first toroid.

Description:
BACKGROUND 
       [0001]    In the downhole drilling and completions industry packers or seal elements are ubiquitously used for a myriad of sealing and inhibition applications. There are many kinds of sealing elements available in the industry but since conditions encountered are ever changing, the industry is always receptive to new configurations providing sealing capability. 
       BRIEF DESCRIPTION 
       [0002]    An assembly for reducing a radial gap between radially proximate components including a setting member having a first dimension that partially defines the radial gap, the setting member including a circumferential groove extending radially from the first dimension, and a first toroid having a second dimension, the setting member operatively arranged to engage with the first toroid, wherein increasingly engaging the setting member with the first toroid enables a boundary dimension of the assembly to be extended toward the radial gap for reducing the radial gap, the circumferential groove operatively arranged to catch the first toroid when the setting member is fully engaged with the first toroid. 
         [0003]    A system including a pair of assemblies, each assembly including a setting member having a first dimension that partially defines the radial gap, the setting member including a circumferential groove extending radially from the first dimension, and a first toroid having a second dimension, the setting member operatively arranged to engage with the first toroid, wherein increasingly engaging the setting member with the first toroid enables a boundary dimension of the assembly to be extended toward the radial gap for reducing the radial gap, the circumferential groove operatively arranged to catch the first toroid when the setting member is fully engaged with the first toroid, and a plurality of subsequent toroids arranged in a sealing area between the first and second end assemblies. 
         [0004]    A method of reducing a radial gap between radially proximate components including engaging a first toroid with a setting member, the setting member at least partially defining the radial gap and having a radially extending circumferential groove, increasingly engaging the setting member with the first toroid, wherein increasingly engaging the first toroid enables a boundary dimension of the assembly to be extended toward the radial gap for reducing the radial gap, and locating the first toroid in the circumferential groove when the setting member becomes fully engaged with the first toroid. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
           [0006]      FIG. 1  is a quarter-sectional schematic view of an assembly for reducing an extrusion gap or the like, as described herein in a pre-deployment position; 
           [0007]      FIG. 2  is a quarter-sectional schematic view of the assembly of  FIG. 1  in a deployed position; 
           [0008]      FIG. 3  is a quarter-sectional schematic view of another embodiment of a gap reducing assembly as described herein in a pre-deployment position; 
           [0009]      FIG. 4  is a quarter-sectional schematic view of the assembly of  FIG. 3  in a deployed position; 
           [0010]      FIG. 5  is a quarter-sectional schematic view of the assembly of  FIG. 3  in an alternate deployed position; 
           [0011]      FIG. 6  is a quarter-sectional schematic view of an embodiment of a system including two end assemblies, each resembling the assembly of  FIGS. 3-5 , in a pre-deployment position; 
           [0012]      FIG. 7  is a quarter-sectional schematic view of the system of  FIG. 6  in a deployed position; 
           [0013]      FIG. 8  is perspective schematic view of two zones of a tubular or borehole isolated from each other according to an assembly resembling the assembly of  FIGS. 1 and 2 ; 
           [0014]      FIG. 9  is a quarter-sectional schematic view of the assembly of  FIG. 8  generally taken along line  9 - 9  in  FIG. 8 ; and 
           [0015]      FIG. 10  is a quarter-sectional schematic view of an assembly resembling the assembly of  FIG. 9 , but including a separate sealing element. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. Referring now to the drawings,  FIGS. 1 and 2  show a quarter-section of an assembly  10 . The assembly  10  includes a mandrel  12  having a setting member or wedge  14 . The assembly  10  is located in an annulus  16 , which is formed between an outer circumferential surface  18  of the mandrel  12  and a bore wall  20  of a borehole  22 . However, it is to be appreciated that the assembly  10  could be installed in an annulus formed between any set of tubulars and/or boreholes. As used herein the term “tubular” may generally include any tube-like structure, whether cylindrical or not, such as a tube, pipe, collar, casing, tubing, liner, etc. 
         [0017]    Wedge  14  has an outer dimension  24  and borehole  22  has a dimension  26 , with a gap  28  formed between the outer dimension  24  of the wedge  14  and wall  20  of the borehole  22 . For example, the dimensions  24  and  26 , or any other dimension referred to herein, could be radii, major radii, minor radii, diameters, distances from a reference point, etc. As described in more detail below, a toroid  30  (or a plurality of toroids  30 ) is included to seal, block, obstruct, close, or otherwise alleviate or prevent extrusion of a sealing element through the gap  28 . It is to be appreciated that with reference to the embodiments described herein, the term “toroid” as used herein relates generally to any annular, ring, or donut shaped body, regardless of cross-sectional geometry, and that the body may be solid, hollow, or otherwise hollow, but packed or filled with another material. The toroids described herein are generally stretchable, compressible, durable, resilient, and/or otherwise able to change in shape, size, thickness, etc. When applicable, the term “toroid” is to be interpreted broader than “torus” or “ring”, which both imply circumferential continuity. For example, as used herein, the term “toroid” encompasses bodies that are not only circumferentially continuous, but also bodies which contain a split, break, or open end, for example resembling a ‘c’ shape, such as is common with piston rings or the like. Thus, a toroid may be formed by rotating a cross-sectional shape at least partially about a line, where the line is in the same plane as the shape and does not intersect the shape. For example, the cross-sectional shape of each of the toroids  30  in  FIG. 1  is a circle having a diameter  34 , with the diameter  34  defining the thickness of each of the toroids  30 , with toroid arranged coaxially with the borehole, mandrel, tubulars, etc. It is also to be understood however that toroids with varying cross-sectional shapes and varying dimensions may be used together in embodiments contemplated herein. That is, any assembly described herein could utilize consistently shaped and sized toroids, or have toroids of various shapes and sizes. For example, although each toroid shown herein has a generally circular cross-sectional shape, other shapes, such as ellipses, rings, etc. could be used. Furthermore, “toroid” could also refer to a body that is wound or coiled or woven, such as a coil spring or garter spring. For example, each toroid  30  could be a coil of a coil spring. 
         [0018]    The term “wedge” is used herein to refer to the setting member and components or portions of the setting member, because the setting member is illustrated throughout the drawings as having a conical or frustoconical wedge shape. However, it is to be appreciated that the setting member could take various other shapes and arrangements. For example, in lieu of a tapered wedge, the setting member could include: discrete tiers or steps; a rounded bump or bulge; a lever; an inflatable portion, etc., for engaging under, in, or with the toroids in order to pry, stretch, expand, compress, or otherwise alter the shape, size, and/or position of the toroids (i.e., to set the toroids). Furthermore, it is to be appreciated that the setting member does not need to be circumferentially continuous, for example, the setting member could include a plurality of discrete portions (e.g., each having a wedge-shaped cross-section) spaced about a circumference of a mandrel. 
         [0019]    The toroids  30  could act alone as a seal in order to isolate between zones of a borehole, or the toroids  30  could act as a backup for preventing a separate sealing element from extruding through the gap  28 . In the embodiment of  FIGS. 1 and 2 , a material  32  is associated with the toroids  30 , e.g., the material  32  could be packed inside the toroids, surrounding the toroids, etc. The material  32  could be, for example, a filler material, an elastomer, a stainless steel mesh containing the toroids  30 , etc. 
         [0020]    In order to obstruct the gap  28  for inhibiting or preventing extrusion, the wedge  14  is moved axially in the direction indicated by arrows  35 . This axial movement results in the toroids  30  engaging with the wedge and expanding as the wedge is inserted further into the toroids  30 . Effectively, this interplay between the wedge  14  and the toroids  30  enables a maximum outer dimension  36  of the assembly  10  to increase in order to block or obstruct the gap  28 . In  FIG. 2 , the maximum outer dimension equals dimension  26  of the borehole  22 . The maximum outer dimension  36  is defined by the radially outermost point of the assembly  10 , which in  FIG. 2  is the outer portion of a lead toroid  30   a , and in  FIG. 1  is the outer dimension  24  of the wedge  14 . That is, the lead toroid  30   a  is expanded as the wedge  14  is inserted until the lead toroid  30   a  becomes lodged between the wedge  14  and the wall  20  of the borehole  22 . It is to be appreciated that the lead toroid  30   a  is marked with an identifier ‘a’ for sake of discussion only, and otherwise any description of toroids  30  applies generally to lead toroid  30   a . Expansion of the lead toroid  30   a  creates a blockage in gap  28  for, as noted above, isolating zones of the borehole  22  on opposite sides of the gap  28  or providing a backup function for a separate sealing element that seals and isolates the zones of the borehole  22 . In one embodiment, the sealing element takes the form of a plurality of toroids  30  behind the lead toroid  30   a , with the other toroids  30  lodging together behind the lead toroid  30   a . In addition to the toroids  30 , the material  32  may also assist to obstruct or seal the gap  28  and/or annulus  16  by further impeding passage of sediment, hydrocarbons, debris, or any other substance or particles present in the borehole  22 . 
         [0021]    Wedge  14  also includes a circumferential groove  38  extending radially inwardly from the outer dimension  24  of the wedge  14 . In the event that one of the toroids  30  traverses the entirety of the tapered portion of the wedge, and expands over the outer dimension  24  of the wedge, the groove  38  is included to catch that toroid. This locks the toroid to the wedge so that the toroid essentially becomes a part of the wedge, and further toroids that traverse the entirety of the wedge  14  may engage with, and expand around, the locked toroid. This is described in more detail below with respect to  FIG. 5 . 
         [0022]    Referring to  FIGS. 3-5 , a second embodiment is shown, designated generally as an assembly  40 . The assembly  40  resembles the assembly  10  in several respects, and unless otherwise noted, any description of elements of assembly  10  applies generally to corresponding elements of the assembly  40 . The assembly  40  includes a mandrel  42  having a wedge device  44  made up of an inner wedge  46  and an outer wedge  48 . That is, the inner wedge  46  is generally positioned radially inwardly from the outer wedge  48 . In the embodiment of  FIG. 3 , the assembly  40  is located in an annulus  50  between a wall  52  of a borehole  54  and an outer surface  56  of the mandrel  42 . The inner wedge  46  and the outer wedge  48  are substantially conical or frustoconical in shape, and include tapered shoulders  58  and  60 , respectively. In the currently described embodiment, a toroid  62  is located axially in front of the wedge device  44  and has an outer dimension  64 , which is approximately equal to an outer dimension  66  of the wedge device  44 . 
         [0023]    Initially, as shown in  FIG. 3 , the inner wedge  46  and the outer wedge  48  are arranged such that the inner wedge  46  is located radially inwardly of the outer wedge  48 . This initial arrangement deters the toroid  62  from engaging with the shoulder  58  of the inner wedge  46  until the wedge device  44  is set. The toroid  62  is also deterred from engaging with the shoulder  60  of the outer wedge  48  because a minimum outer dimension  68  of the shoulder  60  of the outer wedge  48  of the wedge device  44  is located radially outwardly from a center  70  of the cross-sectional shape that forms the toroid  62  (e.g., in  FIG. 3  a circle is the cross-sectional shape that forms the toroid). 
         [0024]    By moving the inner wedge  46  axially toward the toroid  62  in the direction indicated by arrows  72  in  FIG. 4 , the inner wedge  46  of the wedge device  44  is inserted radially inwardly of the toroid  62 , and the toroid  62  engages with the shoulder  58  of the inner wedge  46 . The inner wedge  46  could be moved, for example, via an electrical, hydraulic, and/or mechanical actuating configuration that in one embodiment applies a load on a radially extending projection or flange  74  of the inner wedge  46 . As the inner wedge  46  is loaded further, the toroid  62  expands radially outwardly around the wedge device  44 , effectively enabling an increase in the maximum outer dimension of the assembly  40  in order to close or block a gap  76  formed between the wedge device  44  and the wall  52  of the borehole  54 . A lead toroid  62   a  is shown in  FIG. 4  engaged with, and expanded by, the shoulder  60  of the outer wedge  48  to the extent that the lead toroid  62   a  has also engaged the wall  52  of the borehole  54 . In other words, since the gap  76  is smaller than a dimension  78  of the cross-section of the toroid  62   a , the wedge device  44  has lodged the lead toroid  62   a  in the gap  76  between the outer wedge  48  and the wall  52  of the borehole  54 . Similarly to the lead toroid  30   a , the identifier ‘a’ is used with lead toroid  62   a  for the sake of discussion only, and any description generally to toroids  62  is applicable to lead toroid  62   a . Thus, as can be seen by comparing  FIGS. 3 and 4 , the maximum outer dimension of the assembly  40  has shifted from the outer dimension  66  of the wedge device  44  to the outer dimension of the lead toroid  62   a , which equals a dimension  80  of the borehole  54  because the lead toroid  62   a  has contacted the wall  52  of the borehole  54 . 
         [0025]    Relative movement between the inner wedge  46  and the outer wedge  48  is possible, for example, by the lead toroid  62   a  blocking forward movement of the outer wedge  48 . The radially extending flange  74  of the inner wedge  46  acts as a stop for limiting the amount of relative movement between the inner wedge  46  and the outer wedge  48  by receiving a radially extending flange  82  of the outer wedge  48 . Relative movement is also prevented in the opposite direction because the inner wedge  46  and the outer wedge  48  include complementary ratcheting teeth  84 . The complementarily arranged ratchet teeth  84  restrict the axial movement of the inner wedge  46  relative to the outer wedge  48  to only the direction indicated by the arrows  72 . Thus, once the flange  82  of the outer wedge  48  has contacted the flange  74  of the inner wedge  46 , the two wedge portions are essentially locked together such that the shoulders  58  and  60  form a single ramp for expanding the toroids  62  (as shown in  FIGS. 4 and 5 ). 
         [0026]    In  FIG. 5 , the borehole  54  is illustrated having a dimension  80 ′ greater than the dimension  80  as shown in  FIGS. 3 and 4 . For example, this could occur if the borehole  54  later became washed out. As a result, a gap  76 ′ in  FIG. 5  is larger than the gap  76  in  FIGS. 3 and 4 , and also larger than the dimension  78  of the cross-sectional shape of the toroids  62 . As a result, the lead toroid  62   a  is able to completely traverse the shoulder  60  of the outer wedge  48 . Similar to groove  38 , a circumferential groove  86  is included in the outer wedge  48 . Also similar to the groove  38 , if one of the toroids  62 , such as lead toroid  62   a , traverses the entirety of the shoulder  60  of the outer wedge  48 , that toroid will become locked in the groove  86 . For example, lead toroid  62   a  is shown locked in groove  86  in  FIG. 5 . 
         [0027]    Once one of the toroids  62  becomes locked in the groove  86 , that toroid effectively becomes part of the wedge device  44 . That is, the lead toroid  62   a  that becomes locked may act like a ramp to essentially increase the size of the wedge device  44 , for subsequent toroids, such as a secondary toroid  62   b , to engage with and expand around. Similar to the identifiers ‘a’ discussed above, it is to be appreciated that the identifier ‘b’ is used for the sake of discussion only, and any description of toroids  62  generally applies to secondary toroid  62   b . Thus, in the embodiment depicted in  FIG. 5 , it is the secondary toroid  62   b , not the lead toroid  62   a , that obstructs the gap  76 ′ by engaging with the wall  52  of the borehole  54 . It is to be appreciated that up to three toroids can stack themselves in a stable arch in order to bridge a gap, such as the gap  76  or  76 ′. Therefore, the gap  76  or  76 ′, measured between the outer dimension  66  of the wedge device  44  (which could be measured as shown in any of  FIGS. 3-5 ), and the wall  52  of the borehole  54 , can equal up to three times the dimension  78  of the cross-sectional shape of the toroids  62 . 
         [0028]    A packer device  90  is shown in  FIGS. 6 and 7 . The device  90  includes a mandrel  92  having a first end assembly  94  and a second end assembly  96 . The end assemblies  94  and  96  both generally resemble the wedge device  44  in that they include two conical or frustoconical wedge portions that can be arranged into single ramp by way of relative movement between the two portions. Specifically, the first end assembly  94  includes an inner wedge  98  and an outer wedge  100 , while the second end assembly  96  includes an inner wedge  102  and an outer wedge  104 . Similar to the wedge device  44 , each of the first and second end assemblies  94  and  96  may include complementarily arranged ratcheting teeth between their corresponding inner and outer wedges, and/or radially extending projections, for limiting the relative movement between their corresponding inner and outer wedges, as described above. 
         [0029]    Also similar to the assemblies discussed above, the device  90  is located in an annulus  106  formed between a wall  108  of a borehole  110  and an outer surface  112  of the mandrel  92 . Additionally, the device  90  is included to engage with toroids  114  in order to cause the toroids  114  to seal, block, obstruct, or close a set of gaps  116  and  118 , located between the wall  108  of the borehole  110  and the first and second end assemblies  94  and  96 , respectively. A first lead toroid  114   a  is positioned in front of first end assembly  94  and a second lead toroid  114   b  is positioned in front of second end assembly  96 , with a plurality of other toroids  114  located between the lead toroids  114   a  and  114   b.    
         [0030]    The first end assembly  94  operates similarly to the wedge assembly  44 . A setting device presses the first end assembly  94  axially in the direction of arrows  120  in order to move the first end assembly  94  along the mandrel  92 . Unlike the wedge assembly  44 , the first end assembly  94  includes a dog  122  that restricts relative movement between the inner wedge  98  and the outer wedge  100 , for example, by being held in an opening  124  of the inner wedge  98  and a notch  126  in the outer wedge  100 . Then, when the first end assembly  94  passes over a receiving area  128 , the dog  122  can drop out, thereby enabling relative movement between the inner wedge  98  and the outer wedge  100  (at least until the relative movement is restricted again, for example by ratcheting teeth and/or radially extending flanges, as described above with respect to  FIGS. 3-5 ). 
         [0031]    The inner wedge  98  of the first end assembly  94  is connected to the outer wedge  104  of the second end assembly  96  via a connecting element  130 , which could be, for example, a fixed length of stainless steel mesh. Movement of the inner wedge  98  will exert a force on the lead toroid  114   a , which will transfer to the outer wedge  104  via the toroids  114  and  114   b . Since the inner wedge  98  is fixed to the connecting element  130 , movement of the inner wedge  98  will result in the connecting element  130  also moving, which will in turn enable the outer wedge  104  to move in the direction of the arrows  120 . The movement of the outer wedge  104  exposes the tapered shoulder of the inner wedge  102  so that second lead toroid  114   b  can engage with the shoulder of the inner wedge  102  and expand. The inner wedge  102  does not move because it is fixed to the mandrel  92  at an anchor point  132 . 
         [0032]    Once the dog  122  is released into the receiving area  128  and relative movement between the inner wedge  98  and outer wedge  100  is possible, the inner wedge  98  will move away from the toroids  114 , exposing the tapered shoulder of the inner wedge  98  to the toroids  114 , thereby enabling the lead toroids  114   a  to engage with the shoulder of the inner wedge  98  and expand as the inner wedge  98  is inserted therethrough. Inner wedge  98  will be pressed in the direction of the arrows  120  until the gaps  116  and  118  are obstructed by toroids  114   a  and  114   b , respectively, as shown in  FIG. 7 . Also, the outer wedges  100  and  104  may include circumferential grooves  134  and  136 , respectively, which are included for the same purpose as grooves  38  and  86 . Thus, additional toroids  114  may expand over the lead toroids  114   a  or  114   b  if the lead toroids become locked in their respective grooves  134  or  136 , with up to three of the toroids  114  able to bridge in a stable arch in order to obstruct the gaps  116  and  118 . 
         [0033]    From  FIGS. 8 and 9  it can be better appreciated how a system according to the current invention could be used in order to isolate zones of a borehole, or tubular, from each other. For example, an assembly  140  is shown including a plurality of toroids  142  in a sealing area  144 , with the sealing area  144  separating a first zone  146  from a second zone  148  in a sealed manner. In  FIGS. 8 and 9 , the toroids  142  are shown specifically in the form of garter springs located between a first wedge  150  and a second wedge  152 . The toroids  142  are arranged to obstruct extrusion gaps located between the sealing area  144  and the zones  146  and  148 . For example,  FIG. 9  shows a gap  154 , located between the wedge  150  and a wall  156  of a borehole  158 , being obstructed by a plurality of the toroids  142 . The wedges  150  and  152  may include grooves  160  and  162 , respectively. Grooves  160  and  162  resemble grooves  38  and  86 , and are included for the same reasons. In view of  FIGS. 8 and 9 , it is to be appreciated that sealing of an annulus  164 , located between a mandrel  166  and the borehole  158 , is accomplishable by packing and lodging many of the toroids  142  together. 
         [0034]      FIG. 10  illustrates an alternate embodiment for the assembly  140 , generally designated as an assembly  140 ′. Specifically with respect to the embodiment of  FIGS. 8 and 9 , many of the toroids  142  in the sealing area  144  have been replaced with a sealing element  168 . The sealing element  168  could be any suitable sealing element used with packer assemblies. As is further appreciable in view of  FIG. 10 , the toroids  142  are acting as a backup to prevent extrusion of the sealing element  168  through the gap  154 , so that the sealing element  168  can seal the annulus  164  between the mandrel  166  and the borehole  158 . 
         [0035]    It is of course to be appreciated that the components of the various embodiments discussed herein could be interchanged with corresponding or similar components in other discussed variants, or with any other equivalents or substitutes, and that such modifications are within the intended scope of the current disclosure. For example, first and second wedges  150  and  152  could be replaced by any of the other assemblies discussed herein, or the sealing area  144  could be filled with, or surrounded by, stainless steel mesh, steel wool, elastomers, filler material, etc. Furthermore, it is to be appreciated that any of the assemblies described herein could be used as both a backup and a sealing element, or as a backup for a separate sealing element. 
         [0036]    It is also to be understood that while the above-described embodiments refer to expanding the toroids to obstruct radially outwardly located gaps, these dimensions could be reversed or inverted. That is, for example, instead of a conical wedge, the setting member could take the form of a funnel arranged radially outwardly from the toroids, for compressing the toroids to obstruct a radially inwardly located gap. For example, the toroids could be made from a partially compressible material, or could take the form of a pre-stretched or plastically deformed garter spring. It is to be noted that illustrations for such inverted embodiments would virtually identically resemble the Figures disclosed herein, as the cross- or quarter-sections would be essentially mirror images of each other. Thus, generally according to the embodiments of the current invention, increasingly engaging a toroid with a suitable setting member (regardless of expansion or compression) results in the setting member altering the toroid (e.g., enlarging or compressing) in order to change a boundary dimension (e.g., a maximum outer dimension, a minimum inner dimension, etc.) of an assembly by extending the boundary dimension of the assembly radially toward the gap to be obstructed. 
         [0037]    While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.