Patent Publication Number: US-11028657-B2

Title: Method of creating a seal between a downhole tool and tubular

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of co-pending U.S. patent application Ser. No. 13/398,829, filed Feb. 16, 2012, which claims benefit of U.S. provisional patent application Ser. No. 61/563,016 filed Nov. 22, 2011, and which aforementioned U.S. patent application Ser. No. 13/398,829 is also a continuation-in-part of U.S. patent application Ser. No. 13/029,022, filed Feb. 16, 2011, now U.S. Pat. No. 9,528,352. Each of the aforementioned related patent applications is herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     Embodiments of the present invention generally relate to a downhole expansion assembly. More particularly, embodiments of the present invention relate to seals for the downhole expansion assembly. 
     Description of the Related Art 
     In the oilfield industry, downhole tools are employed in the wellbore at different stages of operation of the well. For example, an expandable liner hanger may be employed during the formation stage of the well. After a first string of casing is set in the wellbore, the well is drilled a designated depth and a liner assembly is run into the well to a depth whereby the upper portion of the liner assembly is overlapping a lower portion of the first string of casing. The liner assembly is fixed in the wellbore by expanding a liner hanger into the surrounding casing and then cementing the liner assembly in the well. The liner hanger includes seal members disposed on an outer surface of the liner hanger. The seal members are configured to create a seal with the surrounding casing upon expansion of the liner hanger. 
     In another example, a packer may be employed during the production stage of the well. The packer typically includes a packer assembly with seal members. The packer may seal an annulus formed between production tubing disposed within casing of the wellbore. Alternatively, some packers seal an annulus between the outside of a tubular and an unlined borehole. Routine uses of packers include the protection of casing from pressure, both well and stimulation pressures, and protection of the wellbore casing from corrosive fluids. Packers may also be used to hold kill fluids or treating fluids in the casing annulus. 
     Both the liner hanger and the packer include seal members that are configured to create a seal with the surrounding casing or an unlined borehole. Each seal member is typically disposed in a groove (or gland) formed in an expandable tubular assembly of the liner hanger or packer. However, the seal member may extrude out of the groove during expansion of the expandable tubular assembly due to the characteristics of the seal member. Further, the seal member may extrude out of the groove after expansion of the expandable tubular assembly due to pressure differentials applied to the seal member. Therefore, there is a need for extrusion-resistant seals for use with an expandable tubular assembly. 
     SUMMARY OF THE INVENTION 
     The present invention generally relates to an anchor seal for an expandable tubular assembly. In one aspect, an anchoring seal assembly for creating a seal portion and an anchor portion between a first tubular that is disposed within a second tubular is provided. The anchoring seal assembly includes an expandable annular member attached to the first tubular. The annular member has an outer surface and an inner surface. The anchoring seal assembly further includes a seal member disposed in a groove formed in the outer surface of the expandable annular member. The seal member has one or more anti-extrusion spring bands embedded within the seal member, wherein the outer surface of the expandable annular member adjacent the groove includes a rough surface. The anchoring seal assembly also includes an expander sleeve having a tapered outer surface and an inner bore. The expander sleeve is movable between a first position in which the expander sleeve is disposed outside of the expandable annular member and a second position in which the expander sleeve is disposed inside of the expandable annular member, wherein the expander sleeve is configured to radially expand the expandable annular member into contact with an inner wall of the second tubular to create the seal portion and the anchor portion as the expander sleeve moves from the first position to the second position. 
     In another aspect, a method of creating a seal portion and an anchor portion between a first tubular and a second tubular is provided. The method includes the step of positioning the first tubular within the second tubular. The first tubular has an annular member with a groove and a rough outer surface, wherein a seal member with at least one anti-extrusion band is disposed within the groove and wherein a gap is formed between a side of the seal member and a side of the groove. The method further includes the step of expanding the annular member radially outward, which causes the at least one anti-extrusion band to move toward an interface area between the first tubular and the second tubular. The method also includes the step of urging the annular member into contact with an inner wall of the second tubular to create the seal portion and the anchor portion between the first tubular and the second tubular. 
     In another aspect, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface of the annular member. The seal assembly further includes a seal member disposed in the groove, the seal member having one or more anti-extrusion bands. The seal member is configured to be expandable radially outward into contact with an inner wall of the second tubular by the application of an outwardly directed force supplied to an inner surface of the annular member. Additionally, the seal assembly includes a gap defined between the seal member and a side of the groove. 
     In another aspect, a method of creating a seal between a first tubular and a second tubular is provided. The method includes the step of positioning the first tubular within the second tubular, the first tubular having a annular member with a groove, wherein a seal member with at least one anti-extrusion band is disposed within the groove and wherein a gap is formed between a side of the seal member and a side of the groove. The method further includes the step of expanding the annular member radially outward, which causes the first anti-extrusion band and the second anti-extrusion band to move toward a first interface area and a second interface area between the annular member and the second tubular. The method also includes the step of urging the seal member into contact with an inner wall of the second tubular to create the seal between the first tubular and the second tubular. 
     In yet another aspect, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface thereof. The seal assembly further includes a seal member disposed in the groove of the annular member such that a side of the seal member is spaced apart from a side of the groove, the seal member having one or more anti-extrusion bands, wherein the one or more anti-extrusion bands move toward an interface area between the annular member and the second tubular upon expansion of the annular member. 
     In a further aspect, a hanger assembly is provided. The hanger assembly includes an expandable annular member having an outer surface and an inner surface. The hanger assembly further includes a seal member disposed in a groove formed in the outer surface of the expandable annular member, the seal member having one or more anti-extrusion spring bands embedded within the seal member. The hanger assembly also includes an expander sleeve having a tapered outer surface and an inner bore. The expander sleeve is movable between a first position in which the expander sleeve is disposed outside of the expandable annular member and a second position in which the expander sleeve is disposed inside of the expandable annular member. The expander sleeve is configured to radially expand the expandable annular member as the expander sleeve moves from the first position to the second position. 
     In a further aspect, a downhole tool for use in a wellbore is provided. The tool includes a body having a bore. The tool further includes a seal assembly attached to the body. The seal assembly having an expandable annular member, a seal member and an expander sleeve, wherein the seal member includes one or more anti-extrusion spring bands embedded within the seal member. The tool further includes a slip assembly attached to the body. The slip assembly includes slips that are configured to engage the wellbore. 
     In a further aspect, downhole tool for use in a wellbore is provided. The tool includes a tubular having a tapered outer surface. The tool further includes an expandable annular member disposed on the tubular. The expandable member has an anchor portion. The tool further includes a seal member disposed in a groove of the expandable annular member. The seal member has one or more anti-extrusion bands, wherein the seal member and the anchor portion are configured to be expandable radially outward into contact with the wellbore as the expandable annular member moves along the tapered outer surface of the tubular. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.    
         FIG. 1  illustrates a view of an expandable hanger in a run-in (unset) position. 
         FIG. 2  illustrates a view of a seal assembly of the expandable hanger. 
         FIG. 3  illustrates a view of the seal assembly during expansion of the expandable hanger. 
         FIGS. 4A and 4B  illustrate a view of the seal assembly after expansion of the expandable hanger. 
         FIG. 5  illustrates an enlarged view of the seal assembly prior to expansion. 
         FIG. 6  illustrates an enlarged view of the seal assembly after expansion. 
         FIGS. 7-10  illustrate views of different embodiments of the seal assembly. 
         FIG. 11  illustrates a view of a downhole tool in a well. 
         FIG. 12  illustrates a view of the downhole tool in a run-in position. 
         FIG. 13  illustrates an enlarged view of a packing element in the downhole tool. 
         FIG. 14  illustrates a view of the downhole tool in an expanded and operating position. 
         FIG. 15  illustrates an enlarged view of the packing element in the downhole tool. 
         FIG. 16  illustrates a view of a hanger assembly in an unset position. 
         FIG. 17  illustrates a view of the hanger assembly in a set position. 
         FIG. 18  illustrates a view of an installation tool used during a dry seal stretch operation. 
         FIG. 19  illustrates a view of a loading tool with the seal ring. 
         FIG. 20  illustrates a view of the loading tool on the expandable hanger. 
         FIG. 21  illustrates a view of a push plate urging the seal ring into a gland of the expandable hanger. 
         FIGS. 22 and 22A  illustrate views of a pack-off stage tool. 
         FIGS. 23, 23A and 23B  illustrate the activation of slips in the stage tool. 
         FIGS. 24, 24A and 24B  illustrate the activation of a packing element in the stage tool. 
         FIGS. 25, 25A and 25B  illustrate the movement of an external sleeve in the stage tool. 
         FIGS. 26 and 26A  illustrate the closing of ports in the stage tool after the cementation operation is complete. 
         FIGS. 27 and 27A  illustrate views of a downhole tool in a run-in (unset) position. 
         FIGS. 28 and 28A  illustrate the setting of slips in the downhole tool. 
         FIGS. 29 and 29A  illustrate the setting of a packing element in the downhole tool 
         FIGS. 30 and 30A  illustrate views of a downhole tool in a run-in (unset) position. 
         FIGS. 31 and 31A  illustrate a downhole tool in a run-in (unset) position. 
         FIGS. 32 and 32A  illustrate the downhole tool in a set position. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention generally relates to extrusion-resistant seals for a downhole tool. The extrusion-resistant seals will be described herein in relation to a liner hanger in  FIGS. 1-10 , a packer in  FIGS. 11-15  and a hanger assembly in  FIGS. 16-17 . It is to be understood, however, that the extrusion-resistant seals may also be used with other downhole tools without departing from principles of the present invention. Further, the extrusion-resistant seals may be used in a downhole tool that is disposed within a cased wellbore or within an open-hole wellbore. To better understand the novelty of the extrusion-resistant seals of the present invention and the methods of use thereof, reference is hereafter made to the accompanying drawings. 
       FIG. 1  illustrates a view of an expandable hanger  100  in a run-in (unset) position. At the stage of completion shown in  FIG. 1 , a wellbore  65  has been lined with a string of casing  60 . Thereafter, a subsequent liner assembly  110  is positioned proximate the lower end of the casing  60 . Typically, the liner assembly  110  is lowered into the wellbore  65  by a running tool disposed at the lower end of a work string  70 . 
     The liner assembly  110  includes a tubular  165  and the expandable hanger  100  of this present invention. The hanger  100  is an annular member that is used to attach or hang the tubular  165  from an internal wall of the casing  60 . The expandable hanger  100  includes a plurality of seal assemblies  150  disposed on the outer surface of the hanger  100 . The plurality of seal assemblies  150  are circumferentially spaced around the hanger  100  to create a seal between liner assembly  110  and the casing  60  upon expansion of the hanger  100 . Although the hanger  100  in  FIG. 1  shows four seal assemblies  150 , any number of seal assemblies  150  may be attached to liner assembly  110  without departing from principles of the present invention. 
       FIG. 2  illustrates an enlarged view of the seal assemblies  150  in the run-in position. For clarity, the wellbore  65  is not shown in  FIGS. 2-6 . Each seal assembly  150  includes a seal ring  135  disposed in a gland  140 . The gland  140  includes a first side  140 A, a second side  140 B and a third side  140 C. In the embodiment shown in  FIG. 2 , a bonding material, such as glue (or other attachment means), may be used on sides  140 B,  140 C during the fabrication stage of the seal assembly  150  to attach the seal ring  135  in the gland  140 . Bonding the seal ring  135  in the gland  140  is useful to prevent the seal ring  135  from becoming unstable and swab off when the hanger  100  is positioned in the casing  60  and prior to expansion of the hanger  100 . In one embodiment, the side  140 A has an angle α (see  FIG. 5 ) of approximately 100 degrees prior to expansion, and side  140 A has an angle β (see  FIG. 6 ) between about 94 degrees and about 98 degrees after expansion of the seal assembly  150 . 
     As shown in  FIG. 5 , a volume gap  145  is created between the seal ring  135  and the side  140 A of the gland  140 . Generally, the volume gap  145  is used to substantially prevent distortion of the seal ring  135  upon expansion of the hanger  100 . The volume gap  145  is a free-space (empty space, clearance or void) between a portion of the seal ring  135  and a portion of the gland  140  prior to expansion of the hanger  100 . In other words, during the fabrication process of the hanger, the volume gap  145  is created by positioning the seal ring  135  within the gland  140  such that the seal ring  135  is spaced apart from at least one side of the gland  140 . Even though the volume gap  145  in  FIG. 5  is created by having a side of the gland  140  at an angle, the volume gap  145  may be created in any configuration (see  FIGS. 7-10 , for example) without departing from principles of the present invention. Additionally, the size of the volume gap  145  may vary depending on the configuration of the gland  140 . In one embodiment, the gland  140  has 3-5% more volume due to the volume gap  145  than a standard gland without a volume gap. 
     Referring back to  FIG. 2 , the seal ring  135  includes one or more anti-extrusion bands, such as a first seal band  155  (first anti-extrusion band) and a second seal band  160  (second anti-extrusion band). As shown, the seal bands  155 ,  160  are embedded in the seal ring  135  in an upper corner of each side of the seal ring  135 . In one embodiment, the seal bands  155 ,  160  are disposed on an outer circumference of the seal ring  135 . In another embodiment, the seal bands  155 ,  160  are springs. The seal bands  155 ,  160  may be used to limit the extrusion of the seal ring  135  during expansion of the seal assembly  150 . The seal bands  155 ,  160  may also be used to limit the extrusion of applied differential pressure after expansion of the seal assembly  150 . 
       FIG. 3  illustrates a view of the seal assemblies  150  during expansion and  FIGS. 4A and 4B  illustrate the seal assemblies  150  after expansion. As shown, an axially movable expander tool  175  contacts an inner surface  180  of the liner assembly  110 . Expander tools are well known in the art and are generally used to radially enlarge an expandable tubular by urging the expander tool  175  axially through the tubular, thereby swaging the tubular wall radially outward as the larger diameter tool is forced through the smaller-diameter tubular member. The expander tool  175  may be attached to a threaded mandrel which is rotated to move the expander tool  175  axially through the hanger  100  and expand the hanger  100  outward in contact with the casing  60 . It is to be understood, however, that other means may be employed to urge the expander tool  175  through the hanger  100  such as hydraulics or any other means known in the art. Furthermore, the expander tool  175  may be disposed in the hanger  100  in any orientation, such as in a downward orientation as shown for a top down expansion or in an upward orientation for a bottom up expansion. Additionally, a rotary expandable tool (not shown) may be employed. The rotary expandable tool moves between a first smaller diameter and a second larger diameter, thereby allowing for both a top down expansion and a bottom up expansion depending on the directional axial movement of the rotary expandable tool. 
     As shown in  FIG. 3 , the expander tool  175  has expanded a portion of the hanger  100  toward the casing  60 . During expansion of the hanger  100 , the seal ring  135  moves into contact with the casing  60  to create a seal between the hanger  100  and the casing  60 . As the seal ring  135  contacts the casing  60 , the seal ring  135  changes configuration and occupies a portion of the volume gap  145 . In the embodiment shown, the volume gap  145  is located on the side of the seal assembly  150  which is the first portion to be expanded by the expander tool  175 . The location of the volume gap  145  in the seal assembly  150  allows the seal ring  135  to change position (or reconfigure) within the gland  140  during the expansion operation. Additionally, the volume of the volume gap  145  may change during the expansion operation. As shown in  FIG. 4B , the expander tool  175  is removed from the hanger  100  after the hanger  100  is expanded into contact with the casing  60 . 
     The seal ring  135  changes configuration during the expansion operation. As shown in  FIG. 5 , the seal ring  135  has a volume which is represented by reference number  190 . Prior to expansion, a portion of the volume  190  of the seal ring  135  is positioned within the gland  140  and another portion of the volume  190  of the seal ring  135  extends outside of the gland  140  (beyond line  195 ). After expansion, the volume  190  of the seal ring  135  is repositioned such that the seal ring  135  moves into the volume gap  145  as shown in  FIG. 6 . In other words, the volume  190  of the seal ring  135  is substantially the same prior to expansion and after expansion. However, the volume of the seal ring  135  within the gland  140  increases after the expansion operation because the portion of the volume  190  of the seal ring  135  that was outside of the gland  140  (beyond line  195 ) has moved within the gland  140  (compare  FIGS. 5 and 6 ). Thus, the volume  190  of the seal ring  135  is substantially within the gland  140  after the expansion operation. In an alternative embodiment, the seal ring  135  does not extend outside of the gland  140  (beyond line  195 ) prior to expansion. The volume  190  of the seal ring  135  is repositioned during the expansion operation such that the seal ring  135  moves into the volume gap  145 . The volume  190  of the seal ring  135  is substantially the same prior to expansion and after expansion. In this manner, the seal ring  135  changes configuration during the expansion operation and occupies (or closes) the volume gap  145 . 
     The volume of the gland  140  and/or the volume gap  145  may decrease as the seal assembly  150  is expanded radially outward during the expansion operation. As set forth herein, the angle α ( FIG. 5 ) decreases to the angle β ( FIG. 6 ), which causes the size of the volume gap  145  to decrease. The height of the gland  140  may also become smaller, which causes the volume of the gland  140  to decrease. As such, the combination of the change in configuration of the seal ring  135  and the change of configuration of the volume of the gland  140  (and/or the volume gap  145 ) allows the seal ring  135  to create a seal with the casing  60 . In one embodiment, the volume of the gland  140  (including the volume gap  145 ) after the expansion operation may be substantially the same as the volume  190  of the seal ring  135 . In another embodiment, the volume of the gland  140  (including the volume gap  145 ) after the expansion operation may be equal to the volume  190  of the seal ring  135  or may be greater than the volume  190  of the seal ring  135 . 
     As shown in  FIG. 6 , the seal bands  155 ,  160  in the seal ring  135  are urged toward an interface  185  between the seal assembly  150  and the casing  60  during the expansion operation. The volume gap  145  permits the seal ring  135  to move within the gland  140  and position the seal bands  155 ,  160  at a location proximate the interface  185 . In this position, the seal bands  155 ,  160  substantially prevent the extrusion of the seal ring  135  past the interface  185 . In other words, the seal bands  155 ,  160  expand radially outward with the hanger  100  and block the elastomeric material of the seal ring  135  from flowing through the interface  185  between the seal assembly  150  and the casing  60 . In one embodiment, the seal bands  155 ,  160  are springs, such as toroidal coil springs, which expand radially outward due to the expansion of the hanger  100 . As the spring expands radially outward, the coils of spring act as a barrier to the flow of the elastomeric material of the seal ring  135 . In this manner, the seal bands  155 ,  160  in the seal ring  135  act as an anti-extrusion device or an extrusion barrier. 
     There are several benefits of the extrusion barrier created by the seal bands  155 ,  160 . One benefit of the extrusion barrier would be that the outer surface of the seal ring  135  in contact with the casing  60  is limited to a region between the seal bands  155 ,  160 , which allows for a high-pressure seal to be created between the seal assembly  150  and the casing  60 . In one embodiment, the seal assembly  150  may create a high-pressure seal in the range of 12,000 to 14,000 psi. A further benefit of the extrusion barrier would be that the seal assembly  150  is capable of creating a seal with a surrounding casing that may have a range of inner diameters due to API tolerances. Another benefit would be that the extrusion barrier created by the seal bands  155 ,  160  may prevent erosion of the seal ring  135  after the hanger  100  has been expanded. The erosion of the seal ring  135  could eventually lead to a malfunction of the seal assembly  150 . A further benefit is that the seal bands  155 ,  160  act as an extrusion barrier after expansion of the expandable hanger  100 . More specifically, the extrusion barrier created by the seal bands  155 ,  160  may prevent extrusion of the seal ring  135  when the gap between the expandable hanger  100  and the casing  60  is increased due to downhole pressure. In other words, the seal bands  155 ,  160  bridge the gap, and the net extrusion gap between coils of the seal bands  155 ,  160  grows considerably less as compared to an annular gap that is formed when a seal ring does not include the seal bands. For instance, the annular gap (without seal bands) may be on the order of 0.030″ radial as compared to the net extrusion gap between coils of the seal bands  155 ,  160  which may be on the order of 0.001/0.003″. 
       FIGS. 7-10  illustrate views of different embodiments of the seal assembly. For convenience, the components in the seal assembly in  FIGS. 7-10  that are similar to the components in the seal assembly  150  will be labeled with the same number indicator.  FIG. 7  illustrates a view of a seal assembly  205  that includes the volume gap  145  on a lower portion of the seal assembly  205 . As shown, the volume gap  145  is between the side  140 C and the seal ring  135 . In this embodiment, a bonding material, such as glue, may be applied to sides  140 A,  140 B during the fabrication stage of the seal assembly  205  to attach the seal ring  135  in the gland  140 . Similar to other embodiments, the seal ring  135  will be reconfigured and occupy at least a portion of the volume gap  145  upon expansion of the seal assembly  205 . 
       FIG. 8  illustrates a view of a seal assembly  220  that includes the volume gap  145  on a lower portion and an upper portion of the seal assembly  220 . As shown, a first volume gap  145 A is between the side  140 A and the seal ring  135  and a second volume gap  145 B is between the side  140 C and the seal ring  135 . The first volume gap  145 A and the second volume gap  145 B may be equal or may be different. In this embodiment, the bonding material may be applied to the side  140 B during the fabrication stage of the seal assembly  220  to attach the seal ring  135  in the gland  140 . Similar to other embodiments, the seal ring  135  will be reconfigured and occupy at least a portion of the first volume gap  145 A and at least a portion of the second volume gap  1456  upon expansion of the seal assembly  220 . 
       FIG. 9  illustrates a view of a seal assembly  240  that includes the volume gap  145  with a biasing member  245 . As shown, the side  140 A of the gland  140  is perpendicular to the side  140 B. The biasing member  245 , such as a spring washer or a crush ring, is disposed in the volume gap  145  between the side  140 A and the seal ring  135 . The biasing member  245  may be used to maintain the position of the seal ring  135  in the gland  140 . In addition to seal band  160 , the biasing member  245  may also act as an extrusion barrier upon expansion of the seal assembly  240 . During the expansion operation, the seal ring  135  will be reconfigured in the gland  140  and compress the biasing member  245 . Additionally, in this embodiment, the bonding material may be used on sides  140 B,  140 C during the fabrication stage of the seal assembly  240  to attach the seal ring  135  in the gland  140 . 
       FIG. 10  illustrates a view of a seal assembly  260  that includes a volume gap  270  in a portion of a seal ring  265 . In this embodiment, the bonding material may be used on sides  140 A,  140 B,  140 C during the fabrication stage of the seal assembly  260  to attach the seal ring  265  in the gland  140 . Similar to other embodiments, the seal ring  265  will be reconfigured upon expansion of the seal assembly  260 . However, in this embodiment, the volume gap  270  in the portion of the seal ring  265  will be close or decrease in size when the seal ring  265  is urged into contact with the surrounding casing. In another embodiment, the seal ring  265  may include seal bands (not shown) embedded in the seal ring  265  similar to seal bands  155 ,  160 . In a further embodiment, an equalization vent (not shown) may be formed in the seal ring  265  to provide communication between the volume gap  270  and an external portion of the seal ring  265 . The equalization vent may be used to prevent the collapse of the seal ring  265  due to exposure of hydrostatic pressure. 
       FIG. 11  illustrates a view of a typical subterranean hydrocarbon well  90  that defines a vertical wellbore  25 . The well  90  has multiple hydrocarbon-bearing formations, such as oil-bearing formation  45  and/or gas-bearing formations (not shown). After the wellbore  25  is formed and lined with casing  10 , a tubing string  50  is run into an opening  15  formed by the casing  10  to provide a pathway for hydrocarbons to the surface of the well  90 . Hydrocarbons may be recovered by forming perforations  30  in the formations  45  to allow hydrocarbons to enter the casing opening  15 . In the illustrative embodiment, the perforations  30  are formed by operating a perforation gun  40 , which is a component of the tubing string  50 . The perforating gun  40  is used to perforate the casing  10  to allow the hydrocarbons trapped in the formations  45  to flow to the surface of the well  90 . 
     The tubing string  50  also carries a downhole tool  300 , such as a packer, a bridge plug or any other downhole tool used to seal a desired location in a wellbore. Although generically shown as a singular element, the downhole tool  300  may be an assembly of components. Generally, the downhole tool  300  may be operated by hydraulic or mechanical means and is used to form a seal at a desired location in the wellbore  25 . The downhole tool  300  may seal, for example, an annular space  20  formed between a production tubing  50  and the wellbore casing  106 . Alternatively, the downhole tool  300  may seal an annular space between the outside of a tubular and an unlined wellbore. Common uses of the downhole tool  300  include protection of the casing  10  from pressure and corrosive fluids; isolation of casing leaks, squeezed perforations, or multiple producing intervals; and holding of treating fluids, heavy fluids or kill fluids. However, these uses for the downhole tool  300  are merely illustrative, and application of the downhole tool  300  is not limited to only these uses. The downhole tool  300  may also be used with a conventional liner hanger (not shown) in a liner assembly. Typically, the downhole tool  300  would be positioned in the liner assembly proximate the conventional liner hanger. In one embodiment, the downhole tool assembly is positioned above the conventional liner hanger. After the conventional liner hanger is set inside the wellbore casing, a cementation operation may be done to secure the liner within the wellbore. Thereafter, the downhole tool  300  may be activated to seal an annular space formed between liner assembly and the wellbore casing. 
       FIG. 12  illustrates the downhole tool  300  in a run-in (unset) position. As shown in  FIG. 12 , the tubing string  50  includes a mandrel  305  which defines an inner diameter of the depicted portion of the tubing string  50 . An actuator sleeve  335  is slidably disposed about at least a portion of the mandrel  305 . The mandrel  305  and the actuator sleeve  335  define a sealed interface by the provision of an O-ring (not shown) carried on an outer diameter of the mandrel  305 . A terminal end of the actuator sleeve  335  is shouldered against a wedge member  325 . The wedge member  325  is generally cylindrical and slidably disposed about the mandrel  305 . An O-ring  310  seal is disposed between the mandrel  305  and the wedge member  325  to form a sealed interface therebetween. The seal  310  is carried on the inner surface of the wedge member  325 ; however, the seal  310  may also be carried on the outer surface of the mandrel  305 . In one embodiment, the seal  310  includes seal bands (i.e., anti-extrusion bands) in a similar manner as sealing element  450 A-B. Further, a volume gap may be defined between the seal  310  and a portion of the wedge member  325  in a similar manner as volume gap  470 A-B. 
     The downhole tool  300  includes a locking mechanism which allows the wedge member  325  to travel in one direction and prevents travel in the opposite direction. In one embodiment, the locking mechanism is implemented as a ratchet ring  380  disposed on a ratchet surface  385  of the mandrel  305 . The ratchet ring  380  is recessed into, and carried by, the wedge member  325 . In this case, the interface of the ratchet ring  380  and the ratchet surface  385  allows the wedge member  325  to travel only in the direction of the arrow  315 . 
     A portion of the wedge member  325  forms an outer tapered surface  375 . In operation, the tapered surface  375  forms an inclined glide surface for a packing element  400 . Accordingly, the wedge member  325  is shown disposed between the mandrel  305  and packing element  400 , where the packing element  400  is disposed on the tapered surface  375 . In the depicted run-in position, the packing element  400  is located at a tip of the wedge member  325 , the tip defining a relatively smaller outer diameter with respect to the other end of the tapered surface  375 . 
     The packing element  400  is held in place by a retaining sleeve  320 . The packing element  400  may be coupled to the retaining sleeve  320  by a variety of locking interfaces. In one embodiment, the retaining sleeve  320  includes a plurality of collet fingers  355 . The terminal ends of the collet fingers  355  are interlocked with an annular lip  405  of the packing element  400 . The collet fingers  355  may be biased in a radial direction. For example, it is contemplated that the collet fingers  355  have outward radial bias urging the collet fingers  355  into a flared or straighter position. However, in this case the collet fingers  355  do not provide a sufficient force to cause expansion of the packing element  400 . 
     The downhole tool  300  includes a self-adjusting locking mechanism which allows the retaining sleeve  320  to travel in one direction and prevents travel in the opposite direction. The locking mechanism is implemented as a ratchet ring  390  disposed on a ratchet surface  395  of the mandrel  305 . The ratchet ring  390  is recessed into, and carried by, the retaining sleeve  320 . In this case, the interface of the ratchet ring  390  and the ratchet surface  395  allows the retaining sleeve  320  to travel only in the direction of the arrow  330 , relative to the mandrel  305 . As will be described in more detail below, this self-adjusting locking mechanism ensures that a sufficient seal is maintained by the packing element  400  despite counter-forces acting to subvert the integrity of the seal. 
     In operation, the downhole tool  300  is run into a wellbore in the run-in position shown in  FIG. 12 . To set the downhole tool  300 , the actuator sleeve  335  is driven axially in the direction of the arrow  315 . The axial movement of the actuator sleeve  335  may be caused by, for example, applied mechanical force from the weight of a tubing string or hydraulic pressure acting on a piston. The actuator sleeve  335 , in turn, engages the wedge member  325  and drives the wedge member  325  axially along the outer surface of the mandrel  305 . The ratchet ring  380  and the ratchet surface  385  ensure that the wedge member  325  travels only in the direction of the arrow  315 . With continuing travel over the mandrel  305 , the wedge member  325  is driven underneath the packing element  400 . The packing element  400  is prevented from moving with respect to the wedge member  325  by the provision of the ratchet ring  390  and the ratchet surface  395 . As a result, the packing element  400  is forced to slide over the tapered surface  375 . The positive inclination of the tapered surface  375  urges the packing element  400  into a diametrically expanded position. The set position of the downhole tool  300  is shown in  FIG. 14 . In the set position, the packing element  400  rests at an upper end of the tapered surface  375  and is urged into contact with the casing  10  to form a fluid-tight seal which is formed in part by a metal-to-elastomer seal and a metal-to-metal contact. More generally, the metal may be any non-elastomer. 
     In the set position, the collet fingers  355  are flared radially outwardly but remain interlocked with the lip  405  formed on the packing element  400 . This coupling ties the position of the retaining sleeve  320  and ratchet ring  390  to the axial position of packing element  400 . This allows the packing element  400  to move up the wedge member  325  in response to increased pressure from below, maintaining its tight interface with the casing inner diameter, but prevents relative movement of the packing element  400  in the opposite direction (shown by the arrow  315 ). The pressure from below the downhole tool  300  may act to diminish the integrity of the seal formed by the packing element  400  since the interface of the packing element  400  with the casing  10  and wedge member  325  will loosen due to pressure swelling the casing  10  and likewise acting to collapse the wedge member  325  from under the packing element  400 . One embodiment of the downhole tool  300  counteracts such an undesirable effect by the provision of the self-adjusting locking mechanism implemented by the ratchet ring  390  and ratchet surface  395 . In particular, the retaining sleeve  320  is permitted to travel up the mandrel  305  in the direction of the arrow  330  in response to a motivating force acting on the packing element  400 , as shown in  FIG. 15 . However, the locking mechanism prevents the retaining sleeve  320  from traveling in the opposite direction (i.e., in the direction of arrow  315 ), thereby ensuring that the seal does not move with respect to the casing  10  when pressure is acting from above, thus reducing wear on the packing element  400 . 
       FIG. 13  illustrates an enlarged view of the packing element  400  in the unset position. As such, the packing element  400  rests on the diametrically smaller end of the tapered surface  375 . The packing element  400  includes a tubular body  440  which is an annular member. The tubular body  440  includes a substantially smooth outer surface at its outer diameter, and defining a shaped inner diameter. In this context, a person skilled in the art will recognize that a desired smoothness of the outer surface is determined according to the particular environment and circumstances in which the packing element  400  is set. For example, the expected pressures to be withstood by the resulting seal formed by the packing element  400  will affect the smoothness of the outer surface. In one embodiment, the tubular body  440  may include a portion of the outer surface that includes knurling or a rough surface area which may be used as an anchor portion when the packing element  400  is set. 
     To form a seal with respect to the casing  10 , the packing element  400  includes one or more sealing elements  450 A-B. The sealing elements  450 A-B may be elastomer bands. In another embodiment, the sealing elements  450 A-B are swelling elastomers. The sealing elements  450 A-B are preferably secured in grooves  455 A-B formed in the tubular body  440 . For example, the sealing elements  450 A-B may be bonded to the grooves  455 A-B by a bonding material during the fabrication stage of the packing element  400 . Each groove  455 A-B includes a volume gap  470 A-B. As shown in  FIG. 13 , the volume gap  470 A-B is located on a lower portion of the groove  455 A-B. In other embodiments, the volume gap  470 A-B may be located at different positions and in different configurations in the groove  455 A-B (see volume gap in  FIGS. 5-10 , for example). Generally, the volume gap  470 A-B is used to substantially prevent distortion of the sealing element  450 A-B upon expansion of the packing element  400 . The size of the volume gap  470 A-B may vary depending on the configuration of the groove  455 A-B. In one embodiment, the groove  455 A-B has 3-5% more volume due to the volume gap  470 A-B than a groove without a volume gap. 
     Each sealing element  450 A-B includes a first seal band  460  and a second seal band  465 . The seal bands  460 ,  465  are embedded in the sealing element  450 A-B. In one embodiment, the seal bands  460 ,  465  are springs. The seal bands  460 ,  465  are used to limit the extrusion of the sealing element  450 A-B upon expansion of the packing element  400 . 
     The portions of the outer surface between the sealing elements  450 A-B form non-elastomer sealing surfaces  430 A-C. The non-elastomer sealing surfaces  430 A-C may include grip members, such as carbide inserts, knurling or a rough surface which allows the non-elastomer sealing surfaces  430 A-C to seal and act as an anchor upon expansion of the packing element  400 . For instance, the anchor portion (i.e., rough surface on the surfaces  430 A-C) would contact and engage with the surrounding casing  10  when the packing element  400  is set, as shown in  FIG. 15 . The anchor portion may be used to hold the packing sealing elements  450 A-B in place by preventing movement of the packing element  400 . In other words, the anchor portion ensures that the packing sealing elements  450 A-B do not move with respect to the casing  10  when subjected to high differential pressure, thus allowing the packing sealing elements  450 A-B to maintain the sealing relationship with the casing  10  while at the same time reducing wear on the packing element  400 . In one embodiment, the surfaces  430 A-C are induction hardened or similar means so that the surfaces  430 A-C penetrate an inner surface of the casing  10  to provide a robust anchoring means when the packing element  400  is activated. In this manner, the anchor portion may be used to help resist axial movement of the packing sealing elements  450 A-B relative to the casing  10  when the packing sealing elements  450 A-B are subjected to high differential pressure. 
     The anchor portion (i.e., rough surface on the surfaces  430 A-C) may be used in place of a gripping member (not shown) in the downhole tool  300 . Rather than having a separate gripping member, such as slips, on the downhole tool  300 , the anchor portion may be configured to hold the downhole tool  300  within the casing  10 , thus reducing the number of components in the downhole tool  300  and reducing the overall length of the downhole tool  300 . Other benefits of using the anchor portion (rather than separate slips) would be that the overall stroke length of the downhole tool  300  would be reduced; elimination of potential leak paths and manufacturing costs would be reduced without compromising performance. The length and/or the size of the surfaces  430 A-C may be arranged such that when the packing element  400  is set, a sufficient gripping force is created between the anchor portion and the surrounding casing  10  to support the downhole tool  300  within the wellbore. The surfaces  430 A-C may also be induction hardened so that the surfaces  430 A-C penetrate the casing  10  surface to provide a robust anchoring means upon activation of the packing element  400 . As discussed herein in relation to  FIGS. 13-15 , the wedge member  325  slides relative to the mandrel  305  to a position under the tubular body  440  to expand the packing element  400  radially outward into contact with the casing  10 . In another embodiment, the wedge member  325  and the mandrel  305  are formed as a single member (not shown) with a tapered surface, thus eliminating the need for the seal  310  and creating a thicker portion of the downhole tool  300  proximate the packing element  400 . Further, the tubular body  440  could be configured to move along the tapered surface of the single member to expand the packing element  400  radially outward into contact with the casing  10 . 
     The number and size of the sealing elements  450 A-B define the surface area of the non-elastomer sealing surfaces  430 A-C. It is to be noted that any number of sealing elements  450 A-B and non-elastomer sealing surfaces  430 A-C may be provided. The packing element  400  shown includes two sealing elements  450 A-B and defining three non-elastomer sealing surfaces  430 A-C. In general, a relatively narrow width of each non-elastomer sealing surface  430 A-C is preferred in order to achieve a sufficient contact force between the surfaces and the casing  10 . 
     The shaped inner diameter of the tubular body  440  is defined by a plurality of ribs  475  separated by a plurality of cutouts  480  (e.g., voids). The cutouts  480  allow a degree of deformation of the tubular body  440  when the packing element  400  is placed into a sealed position. Further, the cutouts  480  aid in reducing the amount of setting force required to expand the packing element  400  into the sealed position. In other words, by removing material (e.g., cutouts  480 ) of the tubular body  440 , the force required to expand the packing element  400  is reduced. In one embodiment, the volume of the cutouts  480  (voids) is between 25-40% of the volume of the tubular body  440 . The ribs  475  are annular members integrally formed as part of the tubular body  440 . Each rib  475  forms an actuator-contact surface  485  at the inner diameter of the tubular body  340 , where the rib  475  is disposed on the tapered surface  375 . In an illustrative embodiment, the tapered surface  375  has an angle γ between about 2 degrees and about 6 degrees. Accordingly, the shaped inner diameter defined by the actuator-contact surfaces  485  may have a substantially similar taper angle. 
     The tubular body  440  further includes an O-ring seal  495  in cutout  490 . The seal  495  is configured to form a fluid-tight seal with respect to the outer tapered surface  375  of the wedge member  325 . In one embodiment, the seal  495  includes seal bands (i.e., anti-extrusion bands) in a similar manner as sealing element  450 A-B. Further, a volume gap may be defined between the seal  495  and a portion of the cutout  490  in a similar manner as volume gap  470 A-B. It is noted that in another embodiment, the cutouts  480  may also, or alternatively, carry seals at their respective inner diameters. 
     In  FIG. 15 , the packing element  400  is shown in the sealed (set) position, corresponding to  FIG. 14 . During expansion of the packing element  400 , the sealing element  450 A-B moves into contact with the casing  10  to create a seal between the packing element  400  and the casing  10 . As the sealing element  450 A-B contacts the casing  10 , the sealing element  450 A-B changes configuration and occupies a portion of the volume gap  470 A-B. In the embodiment shown, the volume gap  470 A-B is located on the side of the packing element  400 , which is the last portion to be expanded by the wedge member  325 . The location of the volume gap  470 A-B in the packing element  400  allows the sealing element  450 A-B to change position (or reconfigure) within the groove  455 A-B during the expansion operation. Additionally, the volume of the volume gap  470 A-B may change during the expansion operation. In one embodiment, the volume of the volume gap  470 A-B may be reduced by 5-15% during the expansion operation. 
     During the expansion operation, the seal bands  460 ,  465  in the sealing element  450 A-B are urged toward an interface  415  between the packing element  400  and the casing  10 , as shown in  FIG. 6 . The volume gap  470 A-B permits the sealing element  450 A-B to move within the groove  455 A-B and position the seal bands  460 ,  465  at a location proximate the interface  415 . In comparing the volume gap  470 A-B prior to expansion ( FIG. 13 ) and after expansion ( FIG. 15 ), a small volume gap remains after the expansion operation. It is to be noted that the small volume gap is optional. In other words, there may not be a small volume gap (see volume gap  470 A-B on  FIG. 15 ) after the expansion operation. 
     The seal bands  460 ,  465  are configured to substantially prevent the extrusion of the sealing element  450 A-B past the interface  415 . In other words, the seal bands  460 ,  465  expand radially outward with the packing element  400  and block the elastomeric material of the sealing element  450 A-B from flowing through the interface  415  between the packing element  400  and the casing  10 . In one embodiment, the seal bands  460 ,  465  are springs, such as toroidal coil springs, which expand radially outward due to the expansion of the packing element  400 . As the spring expands radially outward during the expansion operation, the coils of spring act as a barrier to the flow of the elastomeric material of the sealing element  450 A-B. After the expansion operation, the seal bands  460 ,  465  may prevent extrusion of the sealing element  450 A-B when a gap between the packing element  400  and the casing  10  is increased due to downhole pressure. In other words, the seal bands  460 ,  465  bridge the gap between the packing element  400  and the casing  10  and prevent extrusion of the sealing element  450 A-B. In this manner, the seal bands  460 ,  465  in the sealing element  450 A-B act as an anti-extrusion device or an extrusion barrier during the expansion operation and after the expansion operation. 
     There are several benefits of the extrusion barrier created by the seal bands  460 ,  465 . One benefit of the extrusion barrier would be that the outer surface of the sealing element  450 A-B in contact with the casing  10  is limited to a region between the seal bands  460 ,  465 , which allows for a high pressure seal to be created between the packing element  400  and the casing  10 . In one embodiment, the packing element  400  may create a high-pressure seal in the range of 12,000 to 15,000 psi. A further benefit of the extrusion barrier would be that the packing element  400  is capable of creating a seal with a surrounding casing that may have a range of inner diameters due to API tolerances. Another benefit would be that the extrusion barrier created by the seal bands  460 ,  465  may prevent erosion of the sealing element  450 A-B after the packing element  400  has been expanded. The erosion of the sealing element  450 A-B could eventually lead to a malfunction of the packing element  400 . 
     The packing element  400  rests at the diametrically enlarged end of the tapered surface  375  and is sandwiched between the wedge member  325  and the casing  10 . The dimensions of the downhole tool  300  are preferably such that the packing element  400  is fully engaged with the casing  10 , before the tubular body  440  reaches the end of the tapered surface  375 . Note that in the sealed position, the sealing elements  450 A-B and the non-elastomer sealing surfaces  430 A-C have been expanded into contact with the casing  10 . 
     As such, it is clear that the tubular body  440  has undergone a degree of deformation. The process of deformation may occur, at least in part, as the packing element  400  slides up the tapered surface  375 , prior to making contact with the inner diameter of the casing  10 . Additionally or alternatively, deformation may occur as a result of contact with the inner diameter of the casing  106 . In any case, the process of deformation causes the sealing elements  450 A-B and the non-elastomer sealing surfaces  430 A-C to contact the inner diameter of the casing  10  in the sealed position. In addition, the non-elastomeric backup seals prevent extrusion of the sealing elements  450 A-B. 
       FIG. 16  illustrates a hanger assembly  500  in an unset position. At the stage of completion shown in  FIG. 16 , a wellbore has been lined with a string of casing  80 . Thereafter, the hanger assembly  500  is positioned within the casing  80 . The hanger assembly  500  includes a hanger  530 , which is an annular member. The hanger assembly further includes an expander sleeve  510 . Typically, the hanger assembly  500  is lowered into the wellbore by a running tool disposed at the lower end of a work string (not shown). 
     The hanger assembly  500  includes the hanger  530  of this present invention. The hanger  530  may be used to attach or hang liners from an internal wall of the casing  80 . The hanger  530  may also be used as a patch to seal an annular space formed between hanger assembly  500  and the wellbore casing  80  or an annular space between hanger assembly  500  and an unlined wellbore. The hanger  530  optionally includes grip members, such as tungsten carbide inserts or slips. The grip members may be disposed on an outer surface of the hanger  530 . The grip members may be used to grip an inner surface of the casing  80  upon expansion of the hanger  530 . 
     As shown in  FIG. 16 , the hanger  530  includes a plurality of seal assemblies  550  disposed on the outer surface of a tubular body of the hanger  530 . The plurality of seal assemblies  550  are circumferentially spaced around the hanger  530  to create a seal between hanger assembly  500  and the casing  80 . Each seal assembly  550  includes a seal ring  535  disposed in a gland  540 . A bonding material, such as glue (or other attachment means), may be used on selective sides of the gland  540  to attach the seal ring  535  in the gland  540 . Bonding the seal ring  535  in the gland  540  is useful to prevent the seal ring  535  from becoming unstable and swab off when the hanger  530  is positioned in the casing  80  and prior to expansion of the hanger  530 . Bonding the seal ring  535  in the gland  540  is also useful to resist circulation flow swab off as installation of liners typically require fluid displacements prior to sealing and anchoring of the hanger assembly  500 . 
     The side of the gland  540  creates a volume gap  545  between the seal ring  535  and the gland  540 . As set forth herein, the volume gap  545  is generally used to minimize distortion of the seal ring  535  upon expansion of the hanger  530 . The volume gap  545  may be created in any configuration (see  FIGS. 7-10 , for example) without departing from principles of the present invention. Additionally, the size of the volume gap  545  may vary depending on the configuration of the gland  540 . The seal ring  535  includes a first seal band  555  and a second seal band  560 . The seal bands  555 ,  560  are embedded in opposite sides of the seal ring  535 . The seal bands  555 ,  560  are used to limit the extrusion of the seal ring  535  during and after expansion of the seal assembly  550 . 
     The hanger assembly  500  includes the expander sleeve  510  which is used to expand the hanger  530 . In one embodiment, the expander sleeve  510  is attached to the hanger  530  by an optional releasable connection member  520 , such as a shear pin. The expander sleeve  510  includes a tapered outer surface  515  and a bore  525 . The expander sleeve  510  further includes an end portion  505  that is configured to interact with an actuator member (not shown). The expander sleeve  510  optionally includes a self-adjusting locking mechanism (not shown) which allows the expander sleeve  510  to travel in one direction and prevents travel in the opposite direction. 
     To set the hanger assembly  500 , the actuator member is driven axially in a direction toward the hanger  530 . The axial movement of the actuator member may be caused by, for example, applied mechanical force from the weight of a tubing string or hydraulic pressure acting on a piston. The actuator member, in turn, engages the end portion  505  of the expander sleeve  510  in order to move the expander sleeve  510  axially toward the hanger  530 . At a predetermined force, the optional releasable connection member  520  is disengaged, which allows the expander sleeve  510  to move relative to the hanger  530 . The hanger  530  is prevented from moving with respect to the wedge expander sleeve  510 . As the tapered outer surface  515  of expander sleeve  510  engages the inner surface of the hanger  530 , the hanger  530  is moved into a diametrically expanded position. 
     The set position of the hanger assembly  500  is shown in  FIG. 17 . In the set position, the expander sleeve  510  is positioned inside the hanger  530 . In other words, the expander sleeve  510  is not removed from the hanger  530 . This arrangement may allow the expander sleeve  510  to apply a force on the hanger  530  after the expansion operation. The bore  525  of the expander sleeve  510  permits other wellbore tools to pass through the hanger assembly  500  prior to expansion of the hanger  530  and after expansion of the hanger  530 . In comparing the hanger assembly  500  in the unset position ( FIG. 16 ) and the hanger assembly  500  in the set position ( FIG. 17 ), it is noted that the expander sleeve  510  is disposed substantially outside of the hanger  530  in the unset position and the expander sleeve  510  is disposed inside the hanger  530  in the set position. The expander sleeve  510  remains inside the hanger  530  after the expansion operation is complete. As such, the expander sleeve  510  is configured to support the hanger  530  after the expansion operation. 
     As shown in  FIG. 17 , the hanger  530  is urged into contact with the casing  80  to form a fluid-tight seal which is formed in part by a metal-to-elastomer seal and a metal-to-metal contact. More specifically, the seal ring  535  moves into contact with the casing  80  to create a seal between the hanger  530  and the casing  80 . As the seal ring  535  contacts the casing  80 , the seal ring  535  changes configuration and occupies a portion of the volume gap  545 . In the embodiment shown, the volume gap  545  is located on the side of the seal assembly  550  which is the first portion to be expanded by the expander sleeve  510 . The location of the volume gap  545  in the seal assembly  550  allows the seal ring  535  to change position (or reconfigure) within the gland  540  during the expansion operation. Additionally, the seal bands  555 ,  560  in the seal ring  535  are urged toward an interface between the seal assembly  550  and the casing  80  to block the elastomeric material of the seal ring  535  from flowing through the interface  585  between the seal assembly  550  and the casing  80 . In one embodiment, the seal bands  555 ,  560  are springs, such as toroidal coil springs, which expand radially outward due to the expansion of the hanger  530 . As the spring expands radially outward during the expansion operation, the coils of spring act as a barrier to the flow of the elastomeric material of the seal ring  535 . In addition, after expansion of the hanger  530 , the seal bands  555 ,  560  may prevent extrusion of the seal ring  535  when the gap between the hanger assembly  500  and the casing  80  is increased due to pressure. In other words, the seal bands  155 ,  160  bridge the gap, and the net extrusion gap between coils of the seal bands  155 ,  160  grows considerably less as compared to an annular gap that is formed when a seal ring does not include the seal bands. In this manner, the seal bands  555 ,  560  in the seal ring  535  act as an anti-extrusion device or an extrusion barrier during the expansion operation and after the expansion operation. 
       FIG. 18  illustrates a view of an installation tool  600  for use in a dry seal stretch operation. The seal ring  135  is installed in the gland  140  during the fabrication process of the hanger  100  by the dry seal stretch operation. The installation tool  600  generally includes a taper tool  675 , a loading tool  625  and a push plate  650 . A low-friction coating may be used in the dry seal stretch operation to reduce the friction between the seal ring  135  and the components of the installation tool  600 . In one embodiment, the low-friction coating may be applied to a portion of a taper  610  of the taper tool  675  and a portion of a lip  630  on the loading tool  625 . In another embodiment, the low-friction coating may be applied to a portion of the seal ring  135 . The low-friction coating may be a dry lubricant, such as Impregion or Teflon®. 
     As shown in  FIG. 18 , the seal ring  135  is moved up the taper  610  of the taper tool  675  in the direction indicated by arrow  620 . The taper tool  675  is configured to change the seal ring  135  from a first configuration having a first inner diameter to a second configuration having a second larger inner diameter (e.g., stretch the seal ring). As illustrated, the loading tool  625  is positioned on a reduced diameter portion  640  of the taper tool  675  such that the lip  630  can receive the seal ring  135 . The loading tool  625  is secured to the taper tool  675  by a plurality of connection members  615 , such as screws. After the seal ring is in the second configuration, the seal ring  135  is moved to the lip  630  of the loading tool  625 . 
       FIG. 19  illustrates a view of the loading tool  625  with the seal ring  135 . The loading tool  625  and the push plate  650  are removed from the end  615  of the taper tool  600  in the direction indicated by arrow  645 . Generally, the loading tool  625  is an annular tool that is configured to receive and hold the seal ring  135  in the second configuration (e.g., large inner diameter).  FIG. 20  illustrates a view of the loading tool  625  and the push plate  650  on the expandable hanger  100 . The loading tool  625  is positioned on the hanger  100  such that the lip  630  of the loading tool  625  (and seal ring  135 ) is located adjacent the gland  140 . Thereafter, the loading tool  625  is secured to the hanger  100  by the plurality of connection members  615 . Prior to placing the seal ring  135  in the gland  140 , a bonding material, such as glue, is applied to the selective sides of the gland  140 . 
       FIG. 21  illustrates a view of the push plate  650  and the loading tool  625 . During the dry seal stretch operation, the push plate  650  engages the seal member  135  as the push plate  650  is moved in a direction indicated by arrow  665 . The push plate urges the seal ring  135  off the lip  630  of the loading tool  625  and into the gland  140  of the hanger  100 . This sequence of steps may be repeated for each seal ring  135 . 
     As mentioned herein, the packing element  400  may be used with different downhole tools. For instance, the packing element  400  may be used as a back-up for a compression or inflatable element, or in conjunction with a stage tool, or integral with a pack-off stage tool.  FIGS. 22 and 22A  illustrate an example of the packing element with a pack-off stage tool  700 . For convenience, the components in the stage tool  700  that are similar to the components in the downhole tool  300  will be labeled with the same number indicator. The stage tool  700  is attached to casing  85  and lowered into the wellbore  75 . The stage tool  700  is used during a cementing operation to inject cement into an annulus  795  formed between the casing  85  and the wellbore  75  at specified locations in the wellbore  75 . As shown, the stage tool  700  includes the packing element  400 , the expansion cone  325 , a mechanical piston assembly  725  and slips  705 . 
     As shown in  FIG. 22 , the stage tool  700  includes slips  705  and a gauge ring  755 . The slips  705  are configured to travel along the gauge ring  755  upon activation of the slips  705 . The stage tool  700  further includes a self-adjusting locking mechanism which allows the slips  705  to travel in one direction and prevents travel in the opposite direction. The locking mechanism is implemented as a lower locking ring  760 . Upon activation, the slips  705  are configured to grip the wellbore  75  to support the stage tool  700  in the wellbore  75 . 
     In another embodiment, an anchor portion (i.e., rough surface on the surfaces  430 A-C on the packing element  400 ) may be used in place of the slips  705  to support the stage tool  700  in the wellbore  75 , thus reducing the number of components in the stage tool  700  and reducing the overall length of the stage tool  700 . As set forth herein, the length and/or the size of the surfaces  430 A-C may be arranged such that when the packing element  400  is set, a sufficient gripping force is created between the anchor portion and the surrounding wellbore  75  to support the downhole tool  300  within the wellbore  75 . The surfaces  430 A-C may also be induction hardened so that the surfaces  430 A-C penetrate the surface of the wellbore  75  to provide a robust anchoring means upon activation of the packing element  400 . 
       FIG. 22A  illustrates a view of an upper end of the stage tool  700 . As shown, the stage tool  700  includes an inner sleeve  710  with ports  745  and a body member  730  with ports  750 . As will be described herein, the inner sleeve  710  is configured to move relative to the body member  730  to align the ports  745 ,  750  and thus create a fluid pathway between an inside portion and an outside portion of the stage tool  700 . The stage tool  700  further includes a closing seat  715  and an opening seat  720 . The stage tool  700  also includes an upper lock ring  740  that is attached to a housing via shear screws  735 . Additionally, the stage tool  700  includes an external sleeve  790 . 
     As shown in  FIG. 22A , a plug  775  is disposed in the stage tool  700 . After the stage tool  700  is located in the wellbore  75 , the plug  775  is dropped into the stage tool  700 . The plug  775  moves through a bore  765  of the stage tool  700  until it contacts the opening seat  720  in the inner sleeve  710 . The plug  775  is configured to block fluid communication through the bore  765  of the stage tool  700 . 
       FIGS. 23, 23A and 23B  illustrate the activation of the slips  705  in the stage tool  700 . After the plug  775  blocks fluid communication through the bore  765  of the stage tool  700 , the fluid pumped from the surface creates a fluid pressure within the bore  765  of the stage tool  700 . At a predetermined pressure, the inner sleeve  710  moves relative to the body member  730  until the ports  745  in the inner sleeve  710  align with the ports  750  in the body member. 
     After the ports  745 ,  750  are aligned, fluid in the bore  765  may flow through the ports  745 ,  750  into a fluid passageway  770  to set the packing element  400  and the slips  705 . The fluid moving through the fluid passageway  770  generates a fluid pressure which causes the mechanical piston assembly  725  to apply a force on the wedge member  325  which is subsequently applied to the retaining sleeve  320 . The force on the retaining sleeve  325  causes shear pin  785  to break and allows the slips  705  to move along the gauge ring  755 . The movement of the slips  705  in a first direction relative to the gauge ring  755  causes the slips  705  to move radially outward and engage the wellbore  75 , as shown in  FIG. 23B . The self-adjusting locking mechanism (i.e., locking ring  760 ) prevents travel in the slips  705  in a second opposite direction. The slips  705  and the packing element  400  are configured such that the force to break the shear pin  785  is less than the force to move the packing element  400  along the expansion cone  325 . As a result, the shear pin  785  breaks and the slips  705  move along the gauge ring  755  prior to the movement of the packing element  400  along the expansion cone  325 . After the slips  705  have been set, the retaining sleeve  325  moves under the packing element  400 , as set forth herein. 
     The packing element  400  may be configured such that a force of a preselected magnitude is required in order to radially expand it during the packer setting process. This radial expansion is effected by the axial movement of wedge member  325  with respect to the packing element  400 . Therefore, because of the angle of inclination of the wedge member  325  and friction between the wedge member  325  and packing element  400 , the radial force required to radially expand packing element  400  can be correlated to a corresponding axial force which must be applied to the wedge member  325  in order to achieve relative movement between wedge member  325  and packing element  400 . Hence, there exists a threshold axial force which must be applied to the wedge member  325  in order to radially expand packing element  400 . 
     In operation, an axial force may be applied to the wedge member  325  (and therefore onto the packing element  400 ) which is less than this threshold axial force. In such instances, the applied axial force is communicated from the wedge member  325  to the packing element  400 , and from the packing element  400  to collet fingers  355 , and the retaining sleeve  320  without the packing element  805  experiencing any radial expansion (or any substantial radial expansion). Therefore, such an applied axial force less than the threshold axial force may be applied through the packing element  400  in order to effect the operation of another tool and/or another part of the same tool, such as setting slips  705  as described herein. 
     Furthermore, in operation, an axial force may be applied to the wedge member  325  (and therefore onto the packing element  400 ) which is greater than the aforementioned threshold axial force. In such instances, if there exists little or no available space for the packing element  400 , collet fingers  355 , and the retaining sleeve  320  to move axially, then the wedge member  325  may move axially with respect to the packing element  400 . In this way, the wedge member  325  is forced further under the packing element  400 , resulting in radial expansion of the packing element  400 , which may continue until the packing element  400  has been moved to its set position in the wellbore. 
     In another embodiment, the aforementioned threshold axial force may be preselected by including a latch and/or a shearable fastening between the wedge member  325  and the packing element  400 . This threshold axial force may be preselected by the configuration and (for example) selection of construction materials of the packing element  400  alone, or in combination with the configuration and selection of a suitable latch and/or shearable fastening between the wedge member  325  and the packing element  400 . 
     In practice, by way of example, the aforementioned threshold axial force may be circa 10,000 lbs, though other magnitudes above and below this figure are contemplated, and may be tailored to suit specific applications. 
       FIGS. 24, 24A and 24B  illustrate the activation of the packing element  400  in the stage tool  700 . After the slips  705  have engaged the wellbore  75 , the fluid pressure generated by the fluid moving through the fluid passageway  770  causes the mechanical piston assembly  725  to activate the packing element  400 . In a similar manner as described herein, the wedge member  325  is urged under the tubular body  440  of the packing element  400 . As a result, the packing element  400  moves radially outward into contact with the wellbore  75 , and a seal is formed between the stage tool  700  and the wellbore  75 . 
       FIGS. 25, 25A and 25B  illustrate the movement of the external sleeve  790  of the stage tool  700 . After the packing element  400  and the slips  705  have engaged the wellbore  75 , the fluid pressure generated by the fluid moving through the fluid passageway  770  causes the external sleeve  790  to move relative to the body member  730 . The movement of the external sleeve  790  exposes the ports  745 ,  750 , as shown in  FIG. 25A . The exposure of the ports  745 ,  750  opens a fluid passageway between the bore  765  of the stage tool  700  and the annulus  795  formed between the stage tool  700  and the wellbore  75 . Cement may be pumped through the bore  765 , the ports  745 ,  750  and into the annulus  795  during the cementing operation. After the cementation operation is complete, the closing plug  780  is dropped into the stage tool  700 . 
       FIGS. 26 and 26A  illustrate the closing of the ports  745 ,  750  of the stage tool  700  after the cementation operation is complete. The closing plug  780  moves through the bore  765  of the stage tool  700  until it contacts the closing seat  715  attached to the inner sleeve  710 , as shown in  FIG. 26A . The closing plug  780  is configured to block fluid communication through the bore  765  of the stage tool  700 . The fluid pumped from the surface creates a fluid pressure within the bore  765  of the stage tool  700 . At a predetermined pressure, the inner sleeve  710  moves relative to the body member  730  until the ports  745  in the inner sleeve  710  misalign with the ports  750  in the body member  730 . At this point, fluid in the bore  765  may no longer flow through the ports  745 ,  750 ; thus the fluid passageway between the bore  765  and the annulus  795  is closed. 
       FIGS. 27 and 27A  illustrate a downhole tool  800  in a run-in (unset) position. The downhole tool  800  may be used to seal a desired location in a wellbore. For convenience, the components in the tool  800  that are similar to the components in the tool  300  will be labeled with the same number indicator. The tool  800  includes a slip assembly  850  and a packing element  805 . 
     The slip assembly  850  includes slips  840  and a wedge member  845 . The wedge member  845  is generally cylindrical and slidably disposed about the mandrel  305 . The downhole tool  800  includes a locking mechanism which allows the wedge member  845  to travel in one direction (arrow  865 ) and prevents travel in the opposite direction (arrow  870 ). In one embodiment, the locking mechanism is implemented as a ratchet ring  390  is disposed on a ratchet surface  395  of the mandrel  305 . The ratchet ring  390  is recessed into, and carried by, the sleeve  320 . In this case, the interface of the ratchet ring  390  and the ratchet surface  395  allows the sleeve  320  and the wedge member  845  to travel only in the direction as indicated by arrow  865 . As shown, the sleeve  320  is attached to the wedge member  845  by a dog  890 , and the sleeve is attached to the mandrel  305  by a shear pin  875 . 
     The packing element  805  includes a tubular body  440 , which is an annular member. The tubular body  440  includes an optional grip member  810  with a grip surface  815 . The grip member  810  is configured to engage the casing  10  upon activation of the packing element  805 . In a similar manner as described herein, the wedge member  325  is configured to move axially along the outer surface of the mandrel  305 . The packing element  805  is prevented from moving with respect to the wedge member  325 . As a result, the packing element  805  is forced to slide over the tapered surface of the wedge member  325 . The positive inclination of the tapered surface urges the packing element  805  into a diametrically expanded position. 
     The packing element  805  may be configured such that a force of a preselected magnitude is required in order to radially expand it during the packer setting process. This radial expansion is effected by the axial movement of wedge member  325  with respect to the packing element  805 . Therefore, because of the angle of inclination of the wedge member  325  and friction between the wedge member  325  and packing element  805 , the radial force required to radially expand packing element  805  can be correlated to a corresponding axial force which must be applied to the wedge member  325  in order to achieve relative movement between wedge member  325  and packing element  805 . Hence, there exists a threshold axial force which must be applied to the wedge member  325  in order to radially expand packing element  805 . 
     In operation, an axial force may be applied to the wedge member  325  (and therefore onto the packing element  805 ) which is less than this threshold axial force. In such instances, the applied axial force is communicated from the wedge member  325  to the packing element  805 , and from the packing element  805  to collet fingers  355 , and retaining sleeve  320  without the packing element  805  experiencing any radial expansion (or any substantial radial expansion). Therefore, such an applied axial force less than the threshold axial force may be applied through the packing element  805  in order to effect the operation of another tool and/or another part of the same tool, such as setting slips  840  as described hereafter. 
     Furthermore, in operation, an axial force may be applied to the wedge member  325  (and therefore onto the packing element  805 ) which is greater than the aforementioned threshold axial force. In such instances, if there exists little or no available space for the packing element  805 , collet fingers  355 , and retaining sleeve  320  to move axially, then the wedge member  325  may move axially with respect to the packing element  805 . In this way, the wedge member  325  is forced further under the packing element  805 , resulting in radial expansion of the packing element  805 , which may continue until the packing element  805  has been moved to its set position in the wellbore. 
     In another embodiment, the aforementioned threshold axial force may be preselected by including a latch and/or a shearable fastening between the wedge member  325  and the packing element  805 . This threshold axial force may be preselected by the configuration and (for example) selection of construction materials of the packing element  805  alone, or in combination with the configuration and selection of a suitable latch and/or shearable fastening between the wedge member  325  and the packing element  805 . 
     In practice, by way of example, the aforementioned threshold axial force may be circa 10,000 lbs, though other magnitudes above and below this figure are contemplated, and may be tailored to suit specific applications. 
       FIGS. 28 and 28A  illustrate the setting of the slips  840  in the tool  800 . In the embodiment shown, the setting sequence for the tool  800  is to set the slip assembly  850  ( FIG. 28A ) and then set the packing element  805  ( FIG. 29A ). In another embodiment, the packing element  805  may be set, and then the slip assembly  850  may be set. 
     To set the slip assembly  850 , an actuator sleeve (not shown) is driven axially in the direction of arrow  865 . The axial movement of the actuator sleeve may be caused by, for example, applied mechanical force from the weight of a tubing string or hydraulic pressure acting on a piston. The actuator sleeve applies a force on the wedge member  325 , which drives the wedge member  325  axially along the outer surface of the mandrel  305 . The movement of the sleeve  320  along the outer surface of the mandrel  305  toward the wedge member  845  causes the shear pin  875  to break. Thereafter, the sleeve  320  moves along the mandrel  305  thereby allowing the dog  890  to be released. The sleeve  320  moves until a surface  880  of the sleeve  320  contacts an end surface  885  of the wedge member  845  (compare  FIGS. 27A and 28A ). At this point, the sleeve  320  urges the wedge member  845  under the slips  845 . As a result, the slips  840  expand radially outward and engage the casing  10 . 
       FIGS. 29 and 29A  illustrate the setting of the packing element  805  in the tool  800 . After the slip assembly  850  has been set, the packing element  805  is set. To set the packing element  805 , the actuator sleeve drives the wedge member  325  axially along the outer surface of the mandrel  305  in a similar manner as described herein. With continuing travel over the mandrel  305 , the wedge member  325  is driven underneath the packing element  805 . The packing element  805  is prevented from moving with respect to the wedge member  325  by the provision of the ratchet ring  390  and the ratchet surface  395 . As a result, the packing element  400  is forced to slide over the tapered surface  375 . The positive inclination of the tapered surface urges the packing element  805  into a diametrically expanded position. As the packing element  805  expands radially outward, the gripping surface  815  of the gripping member  810  engages the wellbore. The gripping member  810  may be used to hold the packing sealing elements  450 A-B in place by preventing movement of the packing element  805 . In other words, the gripping member  810  ensures that the packing sealing elements  450 A-B do not move with respect to the casing  10  when subjected to high differential pressure, thus allowing the packing sealing elements  450 A-B to maintain the sealing relationship with the casing  10 . In one embodiment, the gripping surface  815  is induction hardened or similar means so that the gripping surface  815  penetrates an inner surface of the casing  10  to provide a robust anchoring means when the packing element  805  is activated. In this manner, the gripping member  810  may be used to help resist axial movement of the packing sealing elements  450 A-B relative to the casing  10  when the packing sealing elements  450 A-B are subjected to high differential pressure. 
       FIGS. 30 and 30A  illustrate views of a downhole tool  980  in a run-in (unset) position. For convenience, the components in the tool  980  that are similar to the components in the tool  300  and tool  800  will be labeled with the same number indicator. The tool  980  includes a biasing member  985 , such as a spring, between the sleeve  320  and the sleeve  855 . A sleeve  990  is attached to sleeve  855  via a lock screw  995 . The tool  980  operates in a similar manner as tool  800 . The biasing member is configured to apply a biasing force on the wedge member  845  after the slips  840  are set (see  FIG. 28A ). In other words, after the shear pin  875  breaks and the dogs  890  are released, the movement of the sleeve  320  along the mandrel  305  causes the biasing member  985  to be compressed between sleeves  320 ,  855 . The sleeve  320  is locked in one direction and is able to move in the other direction due to the locking mechanism  390 ,  395 . Thus, the compressed biasing member  985  applies a biasing force on the wedge member  845  (via the sleeve  855 ). The biasing force may be used to maintain the wedge member  845  under the slip  840  after the slips  840  have been set. 
       FIGS. 31 and 31A  illustrate a downhole tool  900  in a run-in (unset) position. For convenience, the components in the tool  900  that are similar to the components in the tool  300  will be labeled with the same number indicator. The tool  900  includes a packing element  905  that may be used to seal a desired location in a wellbore. The packing element  905  is held in place by the retaining sleeve  320 . The packing element  905  may be coupled to the retaining sleeve  320  by a variety of locking interfaces. In one embodiment, the retaining sleeve  320  includes a plurality of collet fingers  355 . The terminal ends of the collet fingers  355  are interlocked with the annular lip  405  of the packing element  905 . 
     The packing element  905  includes the tubular body  440 , which is an annular member. The tubular body  440  has an anchor  910  with a grip surface  915 . The anchor  910  is configured to engage the casing  10  upon activation of the packing element  905 . The anchor  910  may be used in place of a gripping member (not shown) in the downhole tool  900 . Rather than having a separate gripping member, such as slips, on the downhole tool  900 , the anchor  910  may be configured to hold the downhole tool  900  within the casing  10 , thus reducing the number of components in the downhole tool  900  and reducing the overall length of the downhole tool  900 . Other benefits of using the anchor  910  (rather than separate slips) would be that the overall stroke length of the downhole tool  900  would be reduced; elimination of potential leak paths and manufacturing costs would be reduced without compromising performance. The length and/or the size of the grip surface  915  may be arranged such that when the packing element  905  is set, a sufficient gripping force is created between the anchor  910  and the surrounding casing  10  to support the downhole tool  900  within the wellbore. 
     The downhole tool  900  includes a self-adjusting locking mechanism which allows the retaining sleeve  320  to travel in one direction and prevents travel in the opposite direction. The locking mechanism is implemented as a ratchet ring  390  disposed on a ratchet surface  395  of a mandrel  950 . The ratchet ring  390  is recessed into, and carried by, the retaining sleeve  320 . In this case, the interface of the ratchet ring  390  and the ratchet surface  395  allows the retaining sleeve  320  to travel only in the direction of the arrow  965 , relative to the mandrel  950 . 
     As shown in  FIG. 31 , the mandrel  950  has an outer tapered surface  955 . As such, the mandrel  950  has a first portion  950 A with a first thickness and a second portion  950 B with a greater second thickness. As will be described herein, the packing element  905  is urged along the tapered surface  955  of the mandrel  950  during the setting process. The use of the tapered surface  955  of the mandrel  950  to activate the packing element  905 , rather than having a separate wedge member, reduces the number of components in the downhole tool  900  and reduces the overall length of the downhole tool  900 . Other benefits of using the tapered surface  955  of the mandrel  950  (rather than a separate wedge member) would be the elimination of potential leak paths between the separate wedge member and the mandrel, and manufacturing costs would be reduced without compromising performance. Another benefit of using the tapered surface  955  of the mandrel  950  would be that the added thickness of the mandrel  950  provides ultra high pressure body integrity below the packing element  905 . 
       FIGS. 32 and 32A  illustrate the downhole tool  900  in a set position. To set the downhole tool  900 , an actuator sleeve  935  is driven axially in the direction of the arrow  965 . The axial movement of the actuator sleeve  935  may be caused by, for example, applied mechanical force from the weight of a tubing string or hydraulic pressure acting on a piston. The actuator sleeve  935 , in turn, drives the retaining sleeve  320  and the packing element  905  axially along the tapered surface  955  of the mandrel  950 . The ratchet ring  390  and the ratchet surface  395  ensure that the retaining sleeve  320  and the packing element  905  travel only in the direction of the arrow  965 . With continuing travel over the mandrel  950 , the packing element  905  moves along the tapered surface  955  into a diametrically expanded position. The set position of the downhole tool  900  is shown in  FIG. 32A . 
     In the set position, the packing element  905  is urged into contact with the casing  10  to form a fluid-tight seal and the gripping surface  915  of the anchor  910  engages the casing  10 . The anchor  910  may be used to support the tool  900  in the casing  10 . Additionally, the anchor  910  may be used to hold the packing sealing elements  450 A-B in place by preventing movement of the packing element  905 . More specifically, the anchor  910  ensures that the packing sealing elements  450 A-B do not move with respect to the casing  10  when subjected to high differential pressure, thus allowing the packing sealing elements  450 A-B to maintain the sealing relationship with the casing  10 , while at the same time reducing wear on the packing element  905 . In one embodiment, the gripping surface  915  of the anchor  910  is induction hardened or similar means so that the gripping surface  915  penetrates an inner surface of the casing  10  to provide a robust anchoring means when the packing element  905  is activated. In this manner, the anchor  910  may be used to support the tool  900  within the casing  10  and also help resist axial movement of the packing sealing elements  450 A-B relative to the casing  10  when the packing sealing elements  450 A-B are subjected to high differential pressure. 
     In one embodiment, an anchoring seal assembly for creating a seal portion and an anchor portion between a first tubular that is disposed within a second tubular is provided. The anchoring seal assembly includes an expandable annular member attached to the first tubular. The annular member has an outer surface and an inner surface. The anchoring seal assembly further includes a seal member disposed in a groove formed in the outer surface of the expandable annular member. The seal member has one or more anti-extrusion spring bands embedded within the seal member, wherein the outer surface of the expandable annular member adjacent the groove includes a rough surface. The anchoring seal assembly also includes an expander sleeve having a tapered outer surface and an inner bore. The expander sleeve is movable between a first position in which the expander sleeve is disposed outside of the expandable annular member and a second position in which the expander sleeve is disposed inside of the expandable annular member, wherein the expander sleeve is configured to radially expand the expandable annular member into contact with an inner wall of the second tubular to create the seal portion and the anchor portion as the expander sleeve moves from the first position to the second position. 
     In another embodiment, a method of creating a seal portion and an anchor portion between a first tubular and a second tubular is provided. The method includes the step of positioning the first tubular within the second tubular. The first tubular has an annular member with a groove and a rough outer surface, wherein a seal member with at least one anti-extrusion band is disposed within the groove and wherein a gap is formed between a side of the seal member and a side of the groove. The method further includes the step of expanding the annular member radially outward, which causes the at least one anti-extrusion band to move toward an interface area between the first tubular and the second tubular. The method also includes the step of urging the annular member into contact with an inner wall of the second tubular to create the seal portion and the anchor portion between the first tubular and the second tubular. 
     In one embodiment, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface of the annular member. The seal assembly further includes a seal member disposed in the groove, the seal member having one or more anti-extrusion bands. The seal member is configured to be expandable radially outward into contact with an inner wall of the second tubular by the application of an outwardly directed force supplied to an inner surface of the annular member. Additionally, the seal assembly includes a gap defined between the seal member and a side of the groove. 
     In one aspect, the gap is configured to close upon expansion of the annular member. In another aspect, the gap is configured to close completely upon expansion of the annular member. In a further aspect, a portion of the seal member is used to close the gap. In an additional aspect, the one or more anti-extrusion bands comprise a first anti-extrusion band and a second anti-extrusion band. In yet a further aspect, the first anti-extrusion member is embedded on a first side of the seal member and the second anti-extrusion band is embedded on a second side of the seal member. In another aspect, the first anti-extrusion band and the second anti-extrusion band are springs. In a further aspect, the first anti-extrusion band and the second anti-extrusion band are configured to move toward a first interface area and a second interface area between the annular member and the second tubular upon expansion of the annular member. In an additional aspect, the first interface area is adjacent a first side of the groove and the second interface area is adjacent a second side of the groove. 
     In one aspect, the seal member is configured to move into the gap upon expansion of the seal member. In another aspect, a second gap is defined between the seal member and another side of the groove. In a further aspect, a biasing member disposed within the gap. In an additional aspect, a plurality of cutouts formed on an inner surface of the annular member. In another aspect, the annular member is a liner hanger. In yet a further aspect, the annular member is a packer. 
     In another embodiment, a method of creating a seal between a first tubular and a second tubular is provided. The method includes the step of positioning the first tubular within the second tubular, the first tubular having a annular member with a groove, wherein a seal member with at least one anti-extrusion band is disposed within the groove and wherein a gap is formed between a side of the seal member and a side of the groove. The method further includes the step of expanding the annular member radially outward, which causes the first anti-extrusion band and the second anti-extrusion band to move toward a first interface area and a second interface area between the annular member and the second tubular. The method also includes the step of urging the seal member into contact with an inner wall of the second tubular to create the seal between the first tubular and the second tubular. 
     In one aspect, the gap is closed between the seal member and the groove upon expansion of the annular member. In another aspect, the gap is closed by filling the gap with a portion of the seal member. In a further aspect, an expander tool is urged into the annular member to expand the annular member radially outward. In an additional aspect, the expander tool is removed from the annular member after the expansion operation. In yet another aspect, the expander tool remains within the annular member after the expansion operation. 
     In yet another embodiment, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface thereof. The seal assembly further includes a seal member disposed in the groove of the annular member such that a side of the seal member is spaced apart from a side of the groove, the seal member having one or more anti-extrusion bands, wherein the one or more anti-extrusion bands move toward an interface area between the annular member and the second tubular upon expansion of the annular member. 
     In one aspect, the one or more anti-extrusion bands comprise a first anti-extrusion band and a second anti-extrusion band. In another aspect, the first anti-extrusion band and the second anti-extrusion band are configured to move into an annular gap formed between the annular member and the second tubular after expansion of the annular member due to downhole pressure. In a further aspect, at least one side of the seal member is attached to the groove via glue. 
     In a further embodiment, a hanger assembly is provided. The hanger assembly includes an expandable annular member having an outer surface and an inner surface. The hanger assembly further includes a seal member disposed in a groove formed in the outer surface of the expandable annular member, the seal member having one or more anti-extrusion spring bands embedded within the seal member. The hanger assembly also includes an expander sleeve having a tapered outer surface and an inner bore. The expander sleeve is movable between a first position in which the expander sleeve is disposed outside of the expandable annular member and a second position in which the expander sleeve is disposed inside of the expandable annular member. The expander sleeve is configured to radially expand the expandable annular member as the expander sleeve moves from the first position to the second position. 
     In one aspect, a gap formed between a side of the seal member and a side of the groove which is configured to close as the expander sleeve moves from the first position to the second position. In another aspect, a second seal member disposed in a second groove formed in the inner surface of the expandable annular member, the second seal member having one or more anti-extrusion spring bands embedded within the seal member. In another aspect, the second seal member is configured to create a seal with the expander sleeve. 
     While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.