Patent Abstract:
A method and apparatus for expanding a tubular below a restriction in a wellbore. An expandable tubular may comprise a first end having a first wall thickness, a second end having a second wall thickness, and a middle section disposed between the first and second ends and having a third wall thickness that is less than the first and second wall thicknesses. The first and second ends may include grooves. A method for expanding a tubular below a restriction in a wellbore may comprise running the tubular past the restriction, wherein the tubular comprises a first end and a second end, each end having a wall thickness greater than a wall thickness of a middle section disposed between the ends. The method may include expanding the tubular, wherein the first and second ends of the expanded tubular have outer diameters greater than the outer diameter of the middle section.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 12/429,823, filed Apr. 24, 2009, now U.S. Pat. No. 8,162,067 which is herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Embodiments of the invention generally relate to expanding tubulars in a wellbore. More particularly, embodiments of the invention relate to the expansion of tubulars below restrictions located in the wellbore. More particularly still, embodiments of the invention relate to an expandable tubular configured to be expanded below restrictions located in the wellbore. 
     2. Description of the Related Art 
     Oil &amp; gas and other types of wells are completed by drilling a borehole in the earth and then lining the borehole with tubulars, such as liners, casing, or well pipe, to form a wellbore. Using apparatus known in the art, the tubulars are cemented into the wellbore by circulating cement into the annular area defined between the outer wall of the tubulars and the borehole. The combination of cement and tubulars strengthens the wellbore and facilitates the isolation of certain areas of the formation behind the tubulars for the production of hydrocarbons. 
     Recent developments in the oil and gas exploration and extraction industries have included using expandable bore liners and casing. Apparatus and methods are emerging that permit tubulars to be expanded in situ. The most common expansion methods include the use of a cone, an expander tool with radially extendable members, or a hydraulic pressure introduced inside of the tubular, also know as hydroforming. 
     During the formation or after the completion of a wellbore, occasionally, a leak may develop at some point along a length of a tubular that permits the loss of well fluids into the surrounding environment behind the tubular or permits the introduction of unwanted fluids into the tubular and the wellbore. It is therefore sometimes necessary to seal or patch a hole or other defect in the tubular to prevent the loss or introduction of fluids through the wellbore. By utilizing the expansion techniques discussed above, an expandable patch or liner may be located adjacent a leak in the tubular and expanded into sealed engagement with the inside wall of the tubular to prevent further leakage. 
     There are several problems, however, associated with the expansion of tubulars in general. First, expandable tubulars are limited to an expansion of about 10%-25% of their original diameter using existing expansion practices. Second, as the expandable tubulars are subjected to higher pressures in the wellbore, the minimum wall thickness requirements for the expandable tubulars to resist collapse or burst forces exerted by these pressures significantly increase. Finally, the running tools and the expansion tools themselves continue to face strict dimensional limitations as the inner diameter of the wellbore typically decreases with increasing depth of the wellbore. 
     These problems are exacerbated when the expansion of tubulars may be utilized to address a defect below a restriction in the wellbore. A restriction may include downhole packers, safety valves, tool landing profiles, lubricators, etc. As mentioned above, these restrictions pose additional severe constraints in running standard expandable tools into the wellbore. These restrictions also demand the use of high expansion ratio expandable liners, which require high expansion forces. Further, smaller diameter wellbores require smaller diameter expandable tubulars, which geometrically leads to larger expansion ratios. Techniques like hydroforming or expandable packers require high pressure surface pumps or hydraulic intensifiers along with the high expansion ratio expandable liners. When using hydraulic pressure to expand a tubular, due to the high pressure required, weaknesses in the tubular are exploited limiting the amount of expansion that can be achieved before the tubular ruptures. 
     Scab liners and inflatable packers have been traditionally used to deal with leaks in a tubular since they can pass through restrictions and then expand to seal the leak area. The disadvantages of these devices include unreliable sealing and a considerable reduction in the flow area, which affects production of the well. Longitudinally corrugated pipes have also been proposed but connecting such pipes still remains a challenge. 
     Therefore, there is a need for a new and improved method and apparatus for expanding tubulars in a wellbore. There is also a need for a new and improved method and apparatus for expanding tubulars below restrictions in the wellbore. 
     SUMMARY OF THE INVENTION 
     Embodiments of the invention generally relate to expanding tubulars in a wellbore. More particularly, embodiments of the invention relate to the expansion of tubulars below restrictions located in the wellbore. More particularly still, embodiments of the invention relate to an expandable tubular configured to be expanded below restrictions located in the wellbore. 
     In one embodiment, an expandable tubular comprises a first end having one or more grooves disposed along a length of the first end, a second end having one or more grooves disposed along a length of the second end, and a middle section coupled to the first and second ends. The middle section may include a wall thickness less than a wall thickness of the first and second ends. 
     In one embodiment, an expandable tubular comprises a first end having a first wall thickness and one or more grooves disposed along the length of the first end. The tubular further includes a second end having a second wall thickness and one or more grooves disposed along the length of the second end, wherein the one or more grooves on each end are separated by remaining portions of the first and second ends. The tubular further includes a middle section coupled to the first and second ends and having a third wall thickness, wherein the third wall thickness is less than the first and second wall thickness. 
     In one embodiment, a method for expanding tubulars below a restriction in a wellbore comprises running an expansion assembly beyond the restriction, wherein the expansion assembly comprises a tubular, wherein the ends of the tubular have a greater wall thickness than a section disposed between the ends of the tubular and an expansion tool coupled to the tubular. The method may include expanding the tubular using the expansion tool, wherein the ends of the expanded tubular have outer diameters greater than the section disposed between the ends of the expanded tubular. 
     In one embodiment, a method for expanding tubulars below a restriction in a wellbore comprises running an expansion assembly beyond the restriction. The expansion assembly comprises a tubular, wherein the ends of the tubular have a greater wall thickness than the middle section disposed between the ends of the tubular; an expansion tool coupled to the tubular; and a lifting device coupled to the expansion tool. The method further includes actuating the lifting device to move the expansion tool through the tubular and expanding the tubular, wherein the ends of the expanded tubular have outer diameters greater than the outer diameter of the middle section of the expanded tubular. 
     In one embodiment, an expandable tubular comprises a first end and a second end, wherein one or more grooves extends substantially along the length of the tubular from the first end to the second end to reduce an expansion force necessary to expand the tubular. The one or more grooves may include a helical shape. The one or more grooves may be disposed on the inner surfaces of the first end and the second end. 
     In one embodiment, a method for expanding a tubular below a restriction in a wellbore comprises running the tubular past the restriction, wherein the tubular comprises a first end, a second end, and one or more grooves that extend substantially along the length of the tubular from the first end to the second end and expanding the tubular, wherein the one or more grooves are configured to reduce an expansion force necessary to expand the tubular. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the 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  is a sectional view of a wellbore having a defect located below a restriction in the wellbore. 
         FIG. 2A  is a sectional view of an expandable tubular of an expansion assembly attached to a work string and disposed in the wellbore. 
         FIG. 2B  is a cross sectional view at one end of the expandable tubular according to one embodiment of the invention. 
         FIG. 2C  is a cross sectional view at one end of the expandable tubular according to an alternative embodiment of the invention. 
         FIG. 2D  is a cross sectional view at one end of the expandable tubular according to an alternative embodiment of the invention. 
         FIG. 3  is a sectional view of the expandable tubular during expansion. 
         FIG. 4  is a sectional view of the expandable tubular after expansion of the expandable tubular in the wellbore. 
         FIG. 5A  is a sectional view of the expandable tubular disposed in a casing before expansion. 
         FIG. 5B  is an isometric view of the expandable tubular disposed in the casing before expansion. 
         FIG. 5C  is an isometric view of one end of the expandable tubular disposed in the casing before expansion. 
         FIG. 5D  is a cross sectional view of one end of the expandable tubular disposed in the casing before expansion. 
         FIG. 6A  is a sectional view of the expandable tubular disposed in a casing after expansion. 
         FIG. 6B  is an isometric view of the expandable tubular disposed in the casing after expansion. 
         FIG. 6C  is an isometric view of one end of the expandable tubular disposed in the casing after expansion. 
         FIG. 6D  is a cross sectional view of one end of the expandable tubular disposed in the casing after expansion. 
         FIG. 7A  is a sectional view of the expandable tubular according to one embodiment of the invention. 
         FIG. 7B  is an isometric view of the expandable tubular according to one embodiment of the invention. 
         FIG. 8A  is a sectional view of the expandable tubular according to one embodiment of the invention. 
         FIG. 8B  is an isometric view of the expandable tubular according to one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a wellbore  10  having a casing  20  disposed in an earthen formation  15 . The casing  20  may be cemented in the formation  15  and may include multiple sections of casings coupled together to form the casing  20 . Located along the length of the casing  20  is a defect  25 , such as a leaking connection or a fracture in the wall of the casing  20 . The defect  25  may permit the loss of a fluid, such as a liquid or a gas, into the surrounding earthen formation  15  or permit the introduction of unwanted fluids into the casing  20  of the wellbore  10 . As a result, dangerous pressure fluctuations may occur during the formation or completion of the wellbore  10 . The defect  25  is located below a restriction  30  in the wellbore  10 . The restriction  30  may be a downhole packer, safety valve, landing profile, lubricator, tubular, or other obstruction which reduces the inner diameter of the wellbore  20  above the defect  25 . The restriction  30  may include a much smaller inner diameter than the area having the defect  25 . 
     In an alternative embodiment, the wellbore  10  may be uncased, such as an open hole disposed in the earthen formation  15 . The defect  25  may be located along a wall of the open hole that can be treated using embodiments of the invention described herein. The defect  25  may represent a zone that permits the loss of a fluid, such as drilling mud, into the surrounding earthen formation  15  or permit the introduction of unwanted fluids into the wellbore  10 . 
       FIG. 2A  illustrates an expansion assembly  100  lowered into the wellbore  10 . The expansion assembly  100  includes an expandable tubular  40 , an expansion tool  50 , and a lifting device  60 , each disposed on a work string  70 . The expansion assembly  100  may be run into the wellbore  10  on the work string  70  adjacent the defect  25 . The expansion assembly  100  is configured to be lowered beyond the restriction  30 . The expansion assembly  100  is configured to be lowered beyond the restriction  30  and adjacent the defect  25  in the wellbore  10 , operated to expand the expandable tubular  40  into engagement with the wellbore  10 , and removed from the wellbore  10  (leaving the expandable tubular  40  in the wellbore  10 ) during a single trip into the wellbore  10 . 
     The expandable tubular  40  may be used to patch, support, and/or seal the defect  25  in the casing  20  or the wall of the formation  15  in an uncased open hole. The expandable tubular  40  may include a cylindrical body having a bore therethrough. The expandable tubular  40  may be formed from a metal alloy, such as steel. The expandable tubular  40  includes a first and second end  41  and  43 , respectively, and a middle section  45 , such that the middle section  45  has an inner diameter greater than the inner diameters of the first and second ends  41  and  43 . The expandable tubular  40  has a greater wall thickness at the first and second ends  41  and  43  relative to the middle section of the expandable tubular  40 , while maintaining a substantially uniform outer diameter along the entire length of the expandable tubular  40 . The expandable tubular  40  may include a single tubular or multiple sections of tubulars coupled together. In an alternative embodiment, the first and second ends  41  and  43  may be separate pieces that are coupled to the middle section  45 , such as by welding or threaded connections. In one embodiment, the expandable tubular  40  may include only the first and second ends  41  and  43  without having a middle section  45 . In one embodiment, the expandable tubular  40  is about 6 feet to about 9 feet in length. In one embodiment, the expandable tubular  40  may include a solid wall. In one embodiment, the expandable tubular  40  may include one or more openings, such as holes or slots disposed in the wall of the expandable tubular  40 . In one embodiment, the expandable tubular  40  may include a screen, such as an expandable sand screen. In one embodiment, the expandable tubular  40  may include one or more layers disposed on the expandable tubular  40 . 
     One or more seal members  47  may be disposed on the outer surfaces of or partially disposed in a recess on the outer surfaces of the first and second ends  41  and  43  of the expandable tubular  40 . The seal members  47  may be formed from a metallic material or a polymeric material, such as rubber or an elastomer. The seal members  47  are adapted to sealingly engage the inner surface of the casing  20  above and below the defect  25  upon expansion of the expandable tubular  40 . The seal members  47  members may frictionally engage the casing, thereby holding the expandable tubular  40  axially within the casing. Alternatively or additionally, an anchor  49  may be disposed on the outer surface of or partially disposed in a recess on the outer surface of the first end  41  and/or second end  43 , in order to secure the expandable tubular  40  to the casing  20  and support the expandable tubular  40  in the wellbore  10 . Upon expansion of the expandable tubular  40 , the anchor  49  is adapted to engage the inner surface of the casing  20 . In one embodiment, the anchor  49  includes one or more gripping members for engaging the wellbore and securing the expandable tubular  40  in the wellbore. In one embodiment, the anchor  49  may include one or more gripping members, such wickers, slips, teeth, and/or gripping elements, such as carbide particles. 
     The expansion tool  50 , such as a solid expansion cone or mandrel, is used to support the expandable tubular  40  adjacent the second end  43  of the expandable tubular  40 . The expansion tool  50  may be in fluid communication with the work string  70 , which is disposed through the expandable tubular  40 . The expansion tool  50  is coupled to the lower end of the work string  70  and engages the lower end of the expandable tubular  40 . The expansion tool  50  may be directed through the expandable tubular  40  to expand the expandable tubular  40  into engagement with the surrounding casing  20 . In an alternative embodiment, the expansion tool  50  may include an expansion tool having radially expandable members, such as an expandable cone, expandable rollers, and/or having an inflatable bladder. 
     The lifting device  60  may be used to lift the expansion tool  50  through the expandable tubular  40 . The lifting device  60  may be a hydraulic jack that is coupled to the work string  70  above the expandable tubular  40  and operable to lift the expansion tool  50  relative to the expandable tubular  40 . In one embodiment, the lifting device is configured to lift the expansion tool  50  through the entire length of the expandable tubular  40  in a single stroke. In an alternative embodiment, the lifting device  60  is configured to lift the expansion tool  50  through a portion of the length of the expandable tubular  40  in a single stroke, and then may be reset to lift the expansion tool  50  again through the remaining length of the expandable tubular  40  in another stroke. In one embodiment, the lifting device  60  is configured to direct the expansion tool  50  through the entire length of the expandable tubular  40  using multiple actuations of the lifting device  60 . 
     The work string  70  is configured to lower the entire expansion assembly  100  adjacent the defect  25  in a single trip into the wellbore  20 . The work string  70  may include a tubular member having a flow bore therethrough with a seat  75  disposed at an end thereof. The work string  70  may be in fluid communication with the lifting device  60 , the expansion tool  50 , and/or the wellbore  10 . The work string  70  may be used to provide hydraulic fluid to the lifting device  60  and/or the expansion tool  50  to operate these devices. Fluid communication between the work string  70  and the lifting device  60 , expansion tool  50 , and/or the wellbore  10  may be controlled using the seat  75  and a device such as a ball or dart that is directed through the work string  70  to engage and seal against the seat  75 . In an alternative embodiment, the work string  70  may include one or more seats  75  disposed in the work string  70  to control fluid communication between the work string  70  and the devices coupled to the work string  70 . In an alternative embodiment, the work string  70  may include a solid rod without a flowbore therethrough, and the expansion tool  50  may include a solid expansion cone. 
     In operation, the expansion assembly  100  is run into the wellbore  10  on the work string  70  adjacent the defect  25  in the casing  20  and below the restriction  30 . The expansion assembly  100  is dimensioned to fit through one or more restrictions  30  located in the wellbore  10 . The seals  47  disposed on the ends  41  and  43  of the expandable tubular  40 , the anchor  49  disposed on the second end  43  of the expandable tubular  40 , and the expansion cone  50  may each include outer diameters that are smaller than the inner diameter of the restriction  30  before expansion of the expandable tubular  40 . The lifting device  60  may be located on the work string  70  above the restriction  30 , while the expandable tubular  40  is located adjacent the defect  25 . In an alternative embodiment, the lifting device  60  may also be dimensioned to be lowered beyond the restriction  30 . 
       FIG. 2B  illustrates a cross sectional view at the second end  43  of the expandable tubular  40  according to one embodiment of the invention. It is important to note that the cross-section view of  FIG. 2B  may be the same cross sectional view at the first end  41  of the expandable tubular  40 , and the embodiments described herein with respect to the second end  43  of the expandable tubular  40  are equally applicable to the first end  41 . The inner diameter at the second end of the expandable tubular  40  may include one or more grooves  42 , such as splines or flutes, located along the longitudinal length of the second end  43  of the expandable tubular  40 . The grooves  42  are configured to reduce the higher expansion forces necessary to expand the thicker wall section at the second end  43  of the expandable tubular  40 . The number, location, length, width, depth, and shape of the grooves  42  may be varied to adjust the expansion force necessary to expand the second end  43  of the expandable tubular  40 . In one embodiment, the grooves  42  may be straight, spiraled, angled, vertical, or combinations thereof. In one embodiment, the grooves  42  may extend along the entire length of the expandable tubular  40 . The grooves  42  may be disposed on the outer and/or inner surfaces of the expandable tubular  40 . The grooves  42  may extend from the first end  41  to the second end  43  of the expandable tubular  40 , including the middle section  45 . For example, the grooved expandable tubular  40  may be of substantially uniform configuration throughout its length. The grooves  42  may also be configured to uniformly distribute the stresses developed in the expandable tubular  40  during expansion. In one embodiment, the grooves  42  are separated by the remaining portions  44  of the inner diameter of the expandable tubular  40 . In one embodiment, the widths of the grooves  42  are about equal to the widths of the remaining portions  44  of the expandable tubular  40 . In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  may range from about 0.20 inches to about 0.35 inches. In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  may range from about 0.10 inches to about 0.55 inches. In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  from the outer diameter of the expandable tubular  40  to the surface of the groove  42  may be about 0.20 inches. In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  from the outer diameter of the expandable tubular  40  to the surface of the remaining portion  44  may be about 0.35 inches. In alternative embodiments, the inner diameter of the grooves  42  may be less than, equal to, or greater than the inner diameter of the middle section  45  of the expandable tubular  40 . 
     As shown in  FIG. 2A , one or more seals  47  may be disposed on the outer surface of the second end  43 . In one embodiment, a total thickness that includes the wall thickness at the second end  43  of the expandable tubular  40  and the thickness of the seal  47  disposed on the second end  43  may be about 0.35 inches. In one embodiment, a total thickness that includes the wall thickness at the second end  43  of the expandable tubular  40  and the thickness of the seal  47  disposed on the second end  43  may range between about 0.20 inches to about 0.35 inches. 
       FIG. 2C  is a cross sectional view at the second end  43  of the expandable tubular  40  according to an alternative embodiment of the invention. The second end  43  of the expandable tubular  43  may include a uniform outer diameter, a uniform inner diameter, and an expandable insert  48  disposed within the uniform inner diameter of the second end  43 . The insert  48  includes a tubular member having a uniform outer diameter that is coupled to the inner diameter of the second end  43 . The insert  48  has one or more grooves  42  separated by remaining portions  44  circumferentially disposed about the inner surface of the insert  48  and along the length of the second end  43 . In one embodiment, the widths of the grooves  42  are about equal to the widths of the remaining portions  44  of the insert  48 . In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  may range from about 0.20 inches to about 0.35 inches. In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  may range from about 0.10 inches to about 0.55 inches. In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  from the outer diameter of the expandable tubular  40  to the surface of the groove  42  of the insert  48  may be about 0.20 inches. In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  from the outer diameter of the expandable tubular  40  to the surface of the remaining portion  44  of the insert  48  may be about 0.35 inches. In alternative embodiments, the inner diameter of the grooves  42  of the insert may be less than, equal to, or greater than the inner diameter of the middle section  45  of the expandable tubular  40 . 
     As shown in  FIG. 2A , one or more seals  47  may be disposed on the outer surface of the second end  43 . In one embodiment, a total thickness that includes the wall thickness of the insert  48 , the wall thickness at the second end  43  of the expandable tubular  40 , and the thickness of the seal  47  disposed on the second end  43  may be about 0.35 inches. In one embodiment, a total thickness that includes the wall thickness of the insert  48 , the wall thickness at the second end  43  of the expandable tubular  40 , and the thickness of the seal  47  disposed on the second end  43  may range between about 0.20 inches to about 0.35 inches. 
     The insert  48  may be coupled to the second end  43  using methods known by one of ordinary skill, such as by a threaded connection, a dovetail joint, a weld joint, or a shrink or interference fit. In an alternative embodiment, the insert  48  may be disposed in a groove machined in the inner circumference of the second end  43 . In an alternative embodiment, the insert  48  may comprise a spring having expansion portions movably disposed on the spring that are configured to expand the expandable tubular  40  upon engagement with the expansion tool  50 . 
       FIG. 2D  a cross sectional view at the second end  43  of the expandable tubular  40  according to an alternative embodiment of the invention. The second end  43  includes a uniform inner diameter and an outer diameter having one or more grooves  42  separated by remaining portions  44  circumferentially disposed along the length of the second end  43 . The one or more seals  47  coupled to the outer surface of the second end  43  may be disposed within the grooves  42  and surround the remaining portions  44 . In one embodiment, the widths of the grooves  42  are about equal to the widths of the remaining portions  44  of the expandable tubular  40 . In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  may range from about 0.20 inches to about 0.35 inches. In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  may range from about 0.10 inches to about 0.55 inches. In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  from the inner diameter of the expandable tubular  40  to the surface of the groove  42  may be about 0.20 inches. In one embodiment, the wall thickness at the second end  43  of the expandable tubular  40  from the inner diameter of the expandable tubular  40  to the surface of the remaining portion  44  may be about 0.35 inches. In alternative embodiments, the outer diameter of the grooves  42  of the insert may be less than, equal to, or greater than the outer diameter of the middle section  45  of the expandable tubular  40 . In one embodiment, a total thickness that includes the wall thickness at the second end  43  of the expandable tubular  40  and the thickness of the seal  47  disposed on the second end  43  may be about 0.35 inches. In one embodiment, a total thickness that includes the wall thickness at the second end  43  of the expandable tubular  40  and the thickness of the seal  47  disposed on the second end  43  may range between about 0.20 inches to about 0.35 inches. 
       FIG. 3  is a sectional view of the expandable tubular  40  during expansion with the expansion assembly. To begin expansion of the expandable tubular  40 , the lifting device  60  may be actuated to direct the expansion tool  50  through the expandable tubular  40 . In one embodiment, a ball  79  may be seated on the seat  75  disposed within the work string  70  to close fluid communication between the work string  70  and the wellbore  10 . Fluid pressure may then be increased in the work string  70  to actuate the lifting device  60 . The lifting device  60  may utilize the top surface  46  of the expandable tubular  40  as a reaction surface to move the expansion tool  50  relative to the expandable tubular  40 . The lifting device  60  may engage the top surface  46  of the expandable tubular  40 , lift the work string  70 , and thereby lift the expansion tool  50  through the expandable tubular  40  and expand the expandable tubular  40 . The expansion tool  50  expands the second end  43  of the expandable tubular  40 . Upon expansion, the seals  47  and the anchor  49  engage the inner surface of the casing  20 . The seals  47  sealingly engage the inner surface of the casing  20  below the defect  25 . The anchor  49  engages the inner surface of the casing  20  and is operable to support the expandable tubular  40  in the wellbore  10 . In one embodiment, the lifting device  60  may include one or more selectively extendable gripping members, such as slips, for securing the lifting device  60  in the wellbore to function as a reaction point against which the lifting device  60  may move the expansion tool  50  relative to the expandable tubular  40  to expand the expandable tubular  40 . 
       FIG. 4  illustrates the expandable tubular  40  after expansion. As described above, the lifting device  60  may be configured to direct the expansion tool  50  through the entire length of the expandable tubular  40  in a single actuation, thereby expanding the expandable tubular  40  in a single actuation. In an alternative embodiment, the lifting device  60  may be direct the expansion tool  50  through a portion of the length of the expandable tubular  40  in a single actuation. Initially, the top surface  46  of the expandable tubular  40  may be used as a reaction surface against which the lifting device  60  may engage to lift the expansion tool  50  relative to the expandable tubular  40 . Upon expansion of the second end  43  of the expandable tubular  40 , the anchor  49  may secure and support the expandable tubular  40  in the wellbore  10 . The lifting device  60  on the work string  70  may be reset while the anchor  49  supports the expandable tubular  40  in the wellbore  10 . Subsequent actuation (s) of the lifting device  60  may utilize the engaged anchor  49  as a reaction point against which the lifting device  60  may move the expansion tool  50  relative to the expandable tubular  40  to expand the expandable tubular  40 . In an alternative embodiment, after initial expansion of the expandable tubular  40  using the lifting device  60  and engagement of the anchor  49  to the casing  20 , the expansion tool  50  may be pulled through the remaining portion of the expandable tubular  40  by applying a pull force on the work string  70  from the surface of the wellbore  10  to expand the remaining portion of the expandable tubular  40 . Upon expansion of the first end  43  of the expandable tubular  40 , the seals  47  may sealingly engage the inner surface of the casing  20  above the defect  25 . The seals  47  effectively seal off the defect  25  and prevent fluid communication between the earthen formation  15  and the inside of the casing  20  via the defect  25 . After expansion of the expandable tubular  40 , the lifting device  60 , the expansion tool  50 , and the work string  70  may be raised through the restriction  30  and removed from the wellbore  10 . 
     In an alternative embodiment, the expansion assembly  100  may be configured to expand the expandable tubular  40  in a top-down approach. The expansion tool  50  may be initially coupled to the work string  70  adjacent the first end  41  of the expandable tubular  40 . The first end  41  of the expandable tubular  40  may include the anchor  49  to secure the expandable tubular  40  in the wellbore upon expansion of the first end  41 . Actuation of the expansion tool  50  may direct the expansion tool  50  through the expandable tubular  40  from the first end  41  to the second end  43  of the expandable tubular  40 . After expansion, the expansion tool  50  and the work string  70  may be removed from the wellbore  10  through the expanded expandable tubular  40  and the restriction  30 . 
     As shown in  FIG. 4 , since the first and second ends  41  and  43  of the expandable tubular  40  have thicker wall sections relative to the middle section  45 , the expansion of the first and second ends  41  and  43  result in these ends having larger outer diameters compared to middle section  45 . The thicker wall sections allow the expansion assembly  100  to pass through the restriction  30  while expanding to a large outer diameter without adversely affecting the expandable tubular  40  and the expansion forces necessary to expand the expandable tubular  40 . 
       FIGS. 5A-5D  illustrate the expandable tubular  40  disposed in a casing  20  before expansion.  FIGS. 6A-6D  illustrate the expandable tubular  40  disposed in a casing  20  after expansion. As described above, the expandable tubular  40  includes first and second ends  41  and  43  having thicker wall sections than the middle section  45  of the expandable tubular  40 . The expandable tubular  40  includes one or more grooves  42  separated by remaining portions  44  circumferentially disposed along the inner surface of the expandable tubular at the first and second ends  41  and  43 . One or more seals  47  are disposed on the outer surface of the first and second ends  41  and  43  of the expandable tubular  40  to sealingly engage the casing  20  upon expansion of the expandable tubular  40 . The first and/or second ends  41  and  43  may also include one or more anchors  49  as described above. 
       FIGS. 7A-B  and  8 A-B illustrate alternative embodiments of the expandable tubular  40 . The expandable tubular  40  may include a substantially uniform outer diameter and inner diameter along the longitudinal length of the expandable tubular  40 . The inner surface of the expandable tubular  40  may include one or more helical grooves  42  disposed along the longitudinal length of the expandable tubular  40 . The helical grooves  42  may help reduce the expansion forces necessary to expand the expandable tubular  40 . In one embodiment, the expandable tubular  40  may include two helical grooves formed in the inner surface of the expandable tubular  40  and that extend the longitudinal length of the expandable tubular  40 . In one embodiment, the expandable tubular  40  may include four helical grooves formed in the inner surface of the expandable tubular  40  and that extend the longitudinal length of the expandable tubular  40 . A helical groove  42  may continuously extend from one end of the expandable tubular  40  to the opposite end of the expandable tubular  40 . The helical grooves  42  may intersect with one or more other helical grooves  42 . The number and pitch of the one or more helical grooves  42  may be vary. The expandable tubular  40  may include one or more seals and/or anchors as described above for engagement with the wellbore. The substantially uniform outer and inner diameters may assist in providing a better seal and uniform profile after expansion of the expandable tubular  40 . 
     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.

Technology Classification (CPC): 4