Abstract:
A tubular is an expandable compliant anchoring and sealing tubular. In one embodiment, the expandable complaint anchoring and sealing tubular is located on a cladding string, a liner hanger, a packer or a bridge plug. The expandable compliant anchoring and sealing tubular has grooves and protrusions both on external and internal surfaces of the tubular with external protrusions positioned against internal grooves and internal protrusions against external grooves in a radial direction. Upon radial expansion of the expandable compliant anchoring and sealing tubular, the external protrusions may be disposed in high interference contact with the surrounding casing or wellbore providing an anchoring and sealing relationship. This tubular configuration may be used when precise internal diameter of the surrounding casing or wellbore is unknown. The expandable compliant anchoring and sealing tubular may provide dimensional adjustability by bending of the groove spans in a radial direction.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a non-provisional application that claims the benefit of U.S. Application Ser. No. 61/462,190 filed on Jan. 31, 2011, which is incorporated by reference herein in its entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    This invention relates to the field of tubular systems, and more specifically to tubular systems that can be expanded against surrounding casing or wellbore to provide an anchoring and sealing relationships. 
         [0005]    2. Background of the Invention 
         [0006]    Frequently an anchoring/sealing tubular, which may be inserted in casing or an open hole and expanded into a sealing and supporting relationship with the surrounding casing or open hole, is needed to act as a liner hanger, a packer, or to isolate worn casing, or to provide a zonal isolation in a wellbore. Drawbacks to conventional designs include a compliance to adjust to the variability in inside dimensions to be encountered with the surrounding casing or wellbore while at the same time to provide adequate support for loads and/or sealing relationships. 
         [0007]    Consequently, there is a need for improved tubular systems. Additional needs include an expandable, compliant, integrated anchoring and sealing tubular system. 
       BRIEF SUMMARY OF SOME OF THE PREFERRED EMBODIMENTS 
       [0008]    An expandable, compliant, integrated, anchoring and sealing tubular system located on a cladding string, a liner hanger, a packer or a bridge plug. The expandable, compliant, integrated, anchoring and sealing tubular system comprises grooves and protrusions both on external and internal surfaces of the tubular with external protrusions positioned against internal grooves and internal protrusions against external grooves in a radial direction. Upon radial expansion of the tubular, the external protrusions may be disposed in high interference contact with the surrounding casing or wellbore and may provide an anchoring and sealing relationship. Without limitation, this tubular configuration may be particularly useful when a precise internal diameter of the surrounding casing or wellbore is unknown. In embodiments, the system provides dimensional adjustability by bending of the groove spans in the radial direction. 
         [0009]    These and other needs in the art are addressed in one embodiment by an expandable tubular defining an internal wall and an external wall. The tubular includes a plurality of external grooves and external protrusions on the external wall and a plurality of internal grooves and internal protrusions on the internal wall. The external grooves are positioned against internal protrusions, and internal grooves positioned against external protrusions in a radial direction. The external grooves providing support and/or sealing relationship with the surrounding casing or wellbore upon expansion of said tubular. 
         [0010]    These and other needs in the art are addressed in another embodiment by an expandable tubular system that includes a first expandable tubular and a second expandable tubular. The tubular system having said first expandable tubular defining an internal wall and an external wall. Said first tubular having a plurality of external grooves and external protrusions on the exterior wall and a plurality of internal grooves and internal protrusions on the interior wall. Said external grooves are positioned against internal protrusions, and internal grooves positioned against external protrusions in a radial direction. The first expandable tubular positioned as a sleeve over the second expandable tubular and attached by at least one end to the second expandable tubular preventing sliding of the first expandable tubular over the second expandable tubular in a longitudinal direction. Said expandable tubular system providing sealing/anchoring relationships with the surrounding casing or wellbore upon radial expansion thereof against the surrounding casing or wellbore. 
         [0011]    The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which: 
           [0013]      FIG. 1  illustrates a cross-sectional view of an embodiment of an expandable compliant anchoring and sealing tubular; 
           [0014]      FIG. 2A  illustrates a partial cross-sectional view of an embodiment of the expandable compliant anchoring and sealing tubular shown in  FIG. 1  being inserted inside the surrounding casing before expansion; 
           [0015]      FIG. 2B  is a partial cross-sectional view of an embodiment of the expandable compliant anchoring and sealing tubular shown in  FIG. 1  being expanded against surrounding casing having a maximum inside diameter; 
           [0016]      FIG. 2C  is a partial cross-sectional view of an embodiment of the expandable compliant anchoring and sealing tubular shown in  FIG. 1  being expanded against surrounding casing having a minimum inside diameter; 
           [0017]      FIG. 3  is a cross-sectional view of another embodiment of an expandable compliant anchoring and sealing tubular; 
           [0018]      FIG. 4A  is a partial cross-sectional view of an embodiment of the expandable compliant anchoring and sealing tubular shown in  FIG. 3  being inserted inside the surrounding casing before expansion; 
           [0019]      FIG. 4B  is a partial cross-sectional view of an embodiment of the expandable compliant anchoring and sealing tubular shown in  FIG. 3  being expanded against surrounding casing having a maximum inside diameter; 
           [0020]      FIG. 4C  is a partial cross-sectional view of the expandable compliant anchoring and sealing tubular shown in  FIG. 3  being expanded against surrounding casing having a minimum inside diameter; 
           [0021]      FIG. 5  is a partial cross-sectional view of an embodiment of an expandable compliant anchoring and sealing tubular with sealing and elastomeric elements; 
           [0022]      FIG. 6  is a cross-sectional view of an embodiment of an expandable compliant anchoring and sealing tubular system; 
           [0023]      FIG. 7A  is a partial cross-sectional view of an embodiment of the expandable compliant anchoring and sealing tubular system shown in  FIG. 6  being inserted inside the surrounding casing before expansion; 
           [0024]      FIG. 7B  is a partial cross-sectional view of an embodiment of the expandable compliant anchoring and sealing tubular system shown in  FIG. 6  being expanded against surrounding casing having a maximum inside diameter; and 
           [0025]      FIG. 7C  is a partial cross-sectional view of an embodiment of the expandable compliant anchoring and sealing tubular shown in  FIG. 6  being expanded against surrounding casing having a minimum inside diameter. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]      FIG. 1  illustrates an embodiment of expandable compliant anchoring and sealing tubular  10  having a plurality of external grooves  12  and external protrusions  13  on exterior surface  34  and a plurality of internal grooves  14  and internal protrusions  15  on internal surface  27 . In embodiments as shown, internal grooves  14  are positioned against external protrusions  13 , and external grooves  12  are positioned against internal protrusions  15  in a radial direction. In embodiments, each external groove  12  is disposed between two external protrusions  13 . In an embodiment, each internal groove  14  is disposed between two internal protrusions  15 . In embodiments as shown, on opposing ends of each internal groove  14  are internal protrusion angled sides  16 ,  17 , which extend to the corresponding internal protrusion apex  22 . In other embodiments as shown, on opposing ends of each external groove  12  are external protrusion angled sides  18 ,  19 , which extend to the corresponding external protrusion apex  11 . 
         [0027]    In an embodiment for cladding a casing or wellbore  35 , which internal diameter may vary between IDmax and IDmin, the depths of external groove  12  and internal groove  14  are each not less than 0.5*(IDmax−IDmin) (as shown in  FIGS. 2B ,  2 C). Without limitation, the expected variations in internal diameter of casing may be estimated using API Specification 5CT, Specification for Casing and Tubing. For instance, the variation in internal diameter, (IDmax−IDmin), for 7⅝ inch, 39 lb/ft casing, according to API Specification, may be as much as 0.239 inches. Further, without limitation, the expected variations in wellbore diameter may be estimated using the caliper measurements, for instance as disclosed in SPE/IADC 67769 publication, which is incorporated herein by reference in its entirety. 
         [0028]    Expansion of expandable compliant anchoring and sealing tubular  10  may be accomplished by any expansion means suitable for use with tubular systems. In an embodiment (not illustrated), a method of expansion of expandable compliant anchoring and sealing tubular  10  includes moving a solid or variable expansion mandrel (not illustrated) within passage  28  or by applying pressure in passage  28 . 
         [0029]    In an embodiment, after expandable compliant anchoring and sealing tubular  10  is positioned at a desired location inside surrounding casing or wellbore  35  as shown in  FIG. 2A , free expansion of expandable compliant anchoring and sealing tubular  10  (i.e., before it comes in contact with the casing or wellbore  35 ) occurs without flattening of expandable compliant anchoring and sealing tubular  10 . It is to be understood that without flattening refers to without plastic bending of groove spans  37  and  38 , which for selected tubular wall thickness  29  and depth of grooves  20  and  21  defines the minimum value of groove shoulder angles  23 ,  24 ,  25  and  26 . In an embodiment as shown in  FIGS. 2B and 2C  when external protrusions  13  come into contact with the surrounding casing or wellbore  35 , the additional pressure is exerted on external protrusions  13 , which may lead to an increase in the bending moments applied to groove spans  37 ,  38 . In embodiments as shown in  FIG. 2C , plastic bending may be the result. In embodiments, selecting the maximum value of pressure between external protrusions  13  and the surrounding casing or wellbore  35  may define the maximum value of groove shoulder angles  23 ,  24 ,  25 , and  26  to allow plastic bending of internal protrusion angled sides  16 ,  17  and external protrusion angled sides  18 ,  19  to accommodate for differences in surrounding casing inner diameter (ID). In an embodiment as shown in  FIG. 1 , expandable compliant anchoring and sealing tubular  10  has substantially equal widths of external protrusions  13  and internal protrusions  15 ; external grooves  30  and internal apexes  32 ; and internal grooves  33  and external apexes  31 . In such an embodiment, plastic bending of the groove spans  37 ,  38  may result in longitudinal elongation of the expandable compliant anchoring and sealing tubular  10 . 
         [0030]    In an embodiment as shown in  FIG. 3 , the widths of external groove  41  and internal groove  42  selected are significantly larger than the widths of external protrusion  43  and internal protrusion  44 . In embodiments, the depths of internal and external grooves  46  and  47  are each not less than the expected radial variance of 0.5*(IDmax−IDmin) of the surrounding casing or wellbore  35  (shown in  FIGS. 4A-4C ). For selected tubular wall thickness  45  and widths of external protrusion  43  and internal protrusion  44  of expandable compliant anchoring and sealing tubular  10 , the widths of external groove  41  and internal groove  42  are defined from the condition that during free expansion of expandable compliant anchoring and sealing tubular  10  (i.e. before external protrusions  55  come into contact with the surrounding casing or wellbore  35 ), internal groove span  48  and external groove span  49  do not exhibit plastic bending. When external protrusions  55  come into contact with the surrounding casing or wellbore  35 , the additional pressure is exerted on external protrusions  55 , which may lead to an increase in the bending moments applied to internal groove span  48  and external groove span  49 . In embodiments as shown in  FIGS. 4A-4C , selecting the maximum value of the pressure between external protrusions  55  and the surrounding casing or wellbore  35  defines the minimum lengths of width of external groove  41  and internal groove  42  to allow plastic bending of the internal groove span  48  and external groove span  49  to accommodate for differences in surrounding casing or wellbore  35  inner diameter (ID). In such embodiments, plastic bending of the groove spans  48 ,  49  may result in longitudinal shrinkage of expandable compliant anchoring and sealing tubular  10 . 
         [0031]    Both minimum and maximum values of groove shoulder angles (i.e., groove shoulder angles  23 ,  24 ,  25 ,  26 ) for expandable compliant anchoring and sealing tubular  10  may be estimated based on boundary conditions described above using standard formulas of Strength of Materials, for instance as disclosed in SRENGTH OF MATERIALS by S. Timoshenco (which is incorporated by reference herein in its entirety), or using Finite Element Analysis. 
         [0032]    In another embodiment as shown in  FIG. 5 , one or more advantages may be achieved through expandable compliant anchoring and sealing tubular  10  comprising some of the external protrusions  54  or both external protrusions  54  and internal protrusions  56  comprising sealing elements  50 . Sealing elements  50  may include wickers or teeth of triangular or circular profile or any other suitable sealing profile  53 . In an embodiment, at least one of the protrusions of expandable compliant anchoring and sealing tubular  10  does not include sealing elements. Instead, embodiments include this protrusion having a substantially smooth surface. In an embodiment, smooth surface protrusion  51  acts as a wear pad during run-in of expandable compliant anchoring and sealing tubular  10  to facilitate removal of debris or other materials that may interfere with the interface of sealing elements  50  with the inner wall surface of surrounding casing or wellbore  35 . 
         [0033]    In embodiments as shown in  FIG. 5 , one or more advantages may be achieved through incorporation of elastic elements  52  in some of the external grooves  57 . Elastic elements  52  may include O-ring type elements of different cross-sectional profiles provided that upon radial expansion of expandable compliant anchoring and sealing tubular  10  elastic elements  52  are compressed between the surrounding casing or wellbore  35  and expandable compliant anchoring and sealing tubular  10 . Without limitation, such elastic elements  52  may provide additional sealing capability (i.e., for instance, in the case of corroded or damaged internal surface surrounding casing or wellbore  35 ). 
         [0034]    In an embodiment as shown in  FIG. 6 , one or more of the advantages may be achieved by utilizing expandable compliant anchoring and sealing tubular  10  as a seal/anchor between an expandable tubular and surrounding casing or wellbore  35 . As shown in  FIG. 6 , an expandable compliant sealing/anchoring system  60  comprising a first expandable tubular  61  (i.e., expandable compliant anchoring and sealing tubular  10 ) and a second expandable tubular  62 . First expandable tubular  61  is positioned over second expandable tubular  62  as a sleeve and attached at one end or at both ends  63 ,  69  to second expandable tubular  62  preventing sliding of first expandable tubular  61  over second expandable tubular  62  in a longitudinal direction. This may be achieved by any suitable method such as by welding, gluing, crimping, encapsulation or by threadable engagement. First expandable tubular  61  comprises a plurality of external protrusions  66  and external grooves  67  and a plurality of internal grooves  68  and internal protrusions  64 . Internal grooves  68  are positioned against external protrusions  66 , and external grooves  67  are positioned against internal protrusions  64  in a radial direction. In embodiments, internal protrusions  64  are positioned into contact or a near contact relationship with external surface  65  of second expandable tubular  62 . The geometry of first expandable tubular  61  is selected using the same principles as for expandable compliant anchoring and sealing tubular  10  taught above. In an embodiment, the depths  73 ,  72  of external and internal grooves  67 ,  68 , respectively, are not less than the half of the expected variance in diameter of the surrounding casing or wellbore  35 . The widths  71 ,  70  of external protrusions  66  and internal grooves  68 , respectively, may be selected substantially equal or the widths  70  of internal grooves  68  may be selected substantially larger than the widths  71  of external protrusions  66 , provided that upon radial expansion of the expandable compliant sealing/anchoring system  60  the groove spans  74 ,  75  do not exhibit plastic bending until the external protrusions  66  come into contact with the surrounding casing or wellbore  35 . 
         [0035]      FIG. 7A  shows schematically an embodiment of expandable compliant sealing/anchoring system  60  being deployed at the desirable location inside the surrounding casing or wellbore  35 . The expansion swage diameter (not illustrated) is selected such that expansion to the diameter Dexp of the expandable compliant sealing/anchoring system  60  against the surrounding casing or wellbore  35  with maximum expected internal diameter, IDmax, may result in minimal plastic bending of groove spans  74 ,  75  (as shown in the embodiment of  FIG. 7B ), while when expanded against the minimal internal diameter, IDmin, the additional bending of groove spans  74 ,  75  may compensate for the variance in internal diameter of the surrounding casing or wellbore  35  (as shown in the embodiments of  FIG. 7C ). 
         [0036]    First expandable tubular  61  and second expandable tubular  62  may be formed of any suitable material. In an embodiment, the material is a malleable metal. Without limitation, examples of suitable malleable metals include steel or alloys thereof. 
         [0037]    It is to be understood that embodiments of expandable compliant anchoring and sealing tubular  10  may have protrusions and/or grooves of different widths. In other embodiments, the protrusions may be hardened or may be coated to increase friction with surrounding coating. Also, embodiments of the internal surface of the expandable tubular may be coated with a lubricant to reduce friction with an expansion swage. Moreover, embodiments of expandable compliant anchoring and sealing tubular  10  may have variable internal and external diameters. For instance, the diameter of the smooth external protrusions may be larger than the diameter of the external protrusions comprising sealing elements to protect sealing elements during deployment operation. 
         [0038]    Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the invention as defined by the appended claims.