Patent Publication Number: US-2019178047-A1

Title: Annular blowout preventer packing element

Description:
TECHNICAL FIELD 
     Embodiments of the present disclosure relate generally to annular blowout preventers, and more specifically, to an improved packing element for an annular blowout preventer. 
     BACKGROUND 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light and not as admissions of prior art. 
     Blowout preventers are used extensively throughout the oil and gas industry. Typical blowout preventers include a main body to which are attached various types of ram units or packing units. The two categories of blowout preventers that are most prevalent are ram blowout preventers and annular blowout preventers. Blowout preventer stacks frequently utilize both types, typically with at least one annular blowout preventer stacked above several ram blowout preventers. A blowout preventer stack may be secured to a wellhead and may provide a means for sealing the well in the event of a system failure. 
     Annular blowout preventers generally include annular packing units or packing elements made at least partially from elastomeric material. Upon activation of the annular BOP, the packing element seals the wellbore. The annular blowout preventer typically includes a piston that is actuated (e.g., through pressurized air or fluid) into engagement with the elastomeric packing element. Such activation of the annular packing element compresses the elastomeric material within the annular space until the elastomeric material deforms in a radially inward direction to ultimately seal the wellbore. Metallic or other hardened segments are sometimes included in the annular packing element to help close off the wellbore and guide the elastomer. 
     Existing annular packing elements can have issues with rubber loss and decreased sealing performance when used over long periods of time. It is now recognized that an annular blowout preventer packing unit with improved sealing function and reduced elastomer loss over time is desired. 
     SUMMARY 
     In accordance with an embodiment of the present disclosure, an annular blowout preventer (BOP) packing element having a bore formed therethrough includes an elastomer, an array of hardened segments, and an energizer/extrusion ring. The hardened segments are arranged circumferentially about a longitudinal axis of the packing element and bonded to an upper surface of the elastomer. The energizer/extrusion ring is bonded to a lower portion of the elastomer opposite the upper surface of the elastomer. 
     In accordance with another embodiment of the present disclosure, a method includes locking and sealing a tubular within an annular blowout preventer (BOP) via a packing element of the annular BOP. The packing element includes an elastomer, an array of hardened segments, and an energizer/extrusion ring. The hardened segments are arranged circumferentially about a longitudinal axis of the packing element and bonded to an upper surface of the elastomer. The energizer/extrusion ring is bonded to a lower portion of the elastomer opposite the upper surface of the elastomer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic cross-sectional view of an annular blowout preventer, in accordance with an embodiment of the present disclosure; 
         FIG. 2  is a perspective view of an annular blowout preventer packing element, in accordance with an embodiment of the present disclosure; 
         FIG. 3  is a top view of the annular blowout preventer packing element of  FIG. 2 , in accordance with an embodiment of the present disclosure; 
         FIG. 4  is a cross-sectional view of the annular blowout preventer packing element taken along lines  4 - 4  of  FIG. 3 , in accordance with an embodiment of the present disclosure; 
         FIG. 5  is an expanded cross-sectional view of the annular blowout preventer packing element taken within the dashed lines of  FIG. 4 , in accordance with an embodiment of the present disclosure; 
         FIGS. 6A-6D  are top, left side, front, and right side views of a hardened segment of the annular blowout preventer packing element of  FIGS. 2-4 , in accordance with an embodiment of the present disclosure; 
         FIG. 7  is a perspective cutaway view of certain components of the annular blowout preventer packing element of  FIGS. 2-4  along with mold spacer parts used for shaping rubber during formation of the annular blowout preventer packing element, in accordance with an embodiment of the present disclosure; 
         FIG. 8  is a cross-sectional view of an energizer/extruder ring of the annular blowout preventer packing element of  FIGS. 2-4 , in accordance with an embodiment of the present disclosure; 
         FIG. 9A  is a top view of the energizer/extruder ring of  FIG. 8 , in accordance with an embodiment of the present disclosure; 
         FIG. 9B  is a perspective cutaway view of the energizer/extruder ring taken along lines  9 B- 9 B of  FIG. 9A , in accordance with an embodiment of the present disclosure; and 
         FIG. 9C  is a perspective cutaway view of the energizer/extruder ring taken within the dashed lines of  FIG. 9B , in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     Generally, embodiments of the disclosure are directed to an improved packing element that may be utilized in annular blowout preventers. Existing spherical packing elements function such that the elastomer (e.g., rubber) section is compressed and forced radially inward first and the metallic segments close around the tubular later. With this sequence of closing the packing element, there is a race between the elastomer and the metal segments as to which one is located first for sealing the wellbore. This leads to the possibility of parts of the rubber being extruded upward into a position between the tips of the metallic segments and the tubular, which can decrease the sealing function of the packing element. 
     The disclosed annular packing element overcomes the drawbacks associated with existing packing elements. Specifically, the disclosed packing element is arranged such that the timing of segment closure and rubber sealing is changed. The segment tips of the packing element close the extrusion gap first, and then the elastomer is squeezed in place for sealing. 
     The disclosed packing element may include an array of hardened metal segments, an elastomer, and an energizer/extrusion ring. The packing element may be a spherical annular packing element. The array of segments may be arranged radially about a longitudinal axis of the packing element and bonded to an upper surface of the elastomer. The energizer/extrusion ring may include an array of fingers projecting radially outward. The energizer/extrusion ring may be constructed from a hardened material and bonded to a lower surface of the elastomer opposite the upper surface of the elastomer. The energizer/extrusion ring may provide additional support to the packing element during actuation of the element into a closed configuration. Specific surfaces of the individual segments and the energizer/extrusion ring may be bonded directly to the elastomer in a manner that prevents the elastomer from extruding into the bore ahead of the segment tips closing. This may improve the sealing function of the packing element and prevent elastomer loss or degradation over long term use of the packing element. 
     Turning now to the drawings,  FIG. 1  is a schematic cross-sectional view of an annular BOP  10  which may employ the disclosed annular packing element  12 . The annular BOP  10  may generally include a housing  14 , a piston  16  disposed in an annular chamber  18  within the housing  14 , and the annular packing element  12 . The illustrated annular BOP  10  may be combined with a number of other BOP units arranged in a vertical stack. Such a stack of units is commonly referred to as a BOP stack, and may include one or more ram-type BOPs (not shown) as well as one or more annular BOPs (e.g.,  10 ). As such,  FIG. 1  is merely representative of a single annular BOP  10 , which may be combined with any number of other BOPs not shown. 
     The annular BOP  10  generally includes a vertical bore  20  extending therethrough, and a tubular  22  may be disposed within the vertical bore  20 . The tubular  22  may form part of a drillpipe, casing, riser, liner, production tubing, coiled tubing, or any other string of tubular that is being positioned within a wellbore below the BOP  10 . The BOP  10  is designed to lock the tubular  22  in place and seal the tubular  22  against large pressures from downhole in the event of a kick or other unanticipated event. 
     The housing  14  may generally enclose the other components of the annular BOP  10 . The housing  14  may be one continuous component or may include two or more outer housing components coupled together via appropriate fasteners such as bolts. An upper portion  24  of the housing  14  may have a curved or spherical shape for accommodating the annular packing element  12 . Inside the housing  14 , the annular packing element  12  is generally positioned above the piston  16 , and the piston  16  is at least partially seated within the annular chamber  18 . 
     One or more walls  26  located inside the housing  14  may define the annular chamber  18 . As shown, for example, the annular BOP  10  may include a cylindrical wall  26  coupled to and extending upward from a bottom surface of the housing  14  to form a radially internal wall of the annular chamber  18 . The rest of the annular chamber  18  may be defined by an external side wall of the housing  14  and the bottom surface of the housing  14 , as shown. However, other arrangements of walls, surfaces, and similar components may define the annular fluid chamber  18  in other embodiments. Seals  28  are generally located between the walls of the chamber  18  and the piston  16  disposed therein. 
     Actuating the annular BOP  10  to close off and seal the tubular  22  generally involves directing pressurized fluid into the chamber  18 . This pressurized fluid forces the piston  16  to move upward within the chamber  18 . An upper surface  30  of the piston  16  presses directly into the annular packing element  12  in response to this upward movement. This force from the piston  16  compresses the packing element  12  against the surfaces of the housing  14 , which direct the packing element  12  to collapse radially inward into locking/sealing engagement with the tubular  22  extending through the BOP  10 . 
     As illustrated, the packing element  12  may be a spherical annular packing element having a rounded or spherical upper surface shape. The packing element  12  of  FIG. 1  may include hardened segments bonded to an elastomer and an energizer/extrusion ring, and the arrangement of these components are such that the hardened packing element segments close against the tubular  22  prior to the elastomer portion sealing against the tubular  22 . As such, the disclosed packing element  12  may provide an enhanced timing of annular BOP element closure that prevents undesirable elastomer extrusion and degradation. 
       FIGS. 2-5  illustrate the presently disclosed annular packing element  12  and its constituent components in greater detail. As mentioned above, the annular packing element  12  generally includes a plurality of hardened segments  110 , an elastomer  112 , and an energizer/extrusion ring  114 . The hardened segments  110  are generally arranged in a circumferentially spaced array and are each coupled to an upper surface  116  ( FIG. 4 ) of the elastomer  112 . The hardened segments  110  generally form an upper bound of the overall packing element  12 . When the packing element  12  of  FIG. 2  is assembled into the BOP of  FIG. 1 , for example, these hardened segments  110  will be the portions of the packing element  12  that directly interface with the upper portion of the housing during actuation of the BOP. The hardened segments  110  have a generally rounded shape at their upper surfaces so as to form a spherical annular packing element  12 . The hardened segments  110  may be constructed from any sufficiently hard metallic material including, but not limited to, steel. The material of the segments  110  may be any material that meets the API 164 4th edition 5.3 pressure-containing parts requirements for 60 Ksi to 75 Ksi (see table 1 below) with a chemical composition in accordance with the steel composition limits for pressure-containing parts per table 2 below. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                   
                 Yield Strength 
                   
                 Elongation in 
                 Reduction of 
               
               
                   
                 0.2% Offset 
                 Tensile Strength 
                 50 mm 
                 Area 
               
               
                 Material 
                 min. 
                 min. 
                 min. 
                 min. 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Designation 
                 MPa 
                 (psi) 
                 MPa 
                 (psi) 
                 % 
                 % 
               
               
                   
               
               
                 36K 
                 248 
                 (36,000) 
                 483 
                 (70,000) 
                 21 
                 none 
               
               
                   
                   
                   
                   
                   
                   
                 specified 
               
               
                 45K 
                 310 
                 (45,000) 
                 483 
                 (70,000) 
                 19 
                 32 
               
               
                 60K 
                 414 
                 (60,000) 
                 586 
                 (85,000) 
                 18 
                 35 
               
               
                 75K 
                 517 
                 (75,000) 
                 655 
                 (95,000) 
                 18 
                 35 
               
               
                 Non-standard 
                 As specified 
                 As specified 
                 As specified 
                 As specified 
                 15 
                 20 
               
               
                 Materials 
               
               
                   
               
               
                 NOTE Information on strength of materials at elevated temperature is found in API 6A and API TR 6MET. 
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                   
                 Martensitic Stainless 
               
               
                   
                   
                 Steels Limit 
               
               
                 Alloying 
                 Carbon and Low-alloy Steels Limit 
                 % Mass Fraction 
               
               
                 Element 
                 % Mass Fraction (Maximum) 
                 (Maximum) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 Carbon 
                 0.45 
                 0.15 
               
               
                 Manganese 
                 1.80 
                 1.00 
               
               
                 Silicon 
                 1.00 
                 1.50 
               
               
                 Phosphorus 
                 0.025 
                 0.025 
               
               
                 Sulphur 
                 0.025 
                 0.025 
               
               
                 Nickel 
                 1.00 
                 4.50 
               
               
                 Chromium 
                 2.75 
                 11.0 to 14.0 
               
               
                 Molybdenum 
                 1.50 
                 1.00 
               
               
                 Vanadium 
                 0.30 
                 N/A 
               
               
                   
               
            
           
         
       
     
     The energizer/extrusion ring  114  is located along a lower portion of the overall annular packing element  12 , as shown in  FIGS. 4 and 5 . The energizer/extrusion ring  114  has a relatively flat, annular shape. As shown, a small portion of the elastomer  112  may extend around a lower surface  118  of the energizer/extrusion ring  114  such that the ring  114  is disposed partially within the elastomer  112 . In other embodiments, the energizer/extrusion ring  114  may be coupled directly to a lower surface of the elastomer  112  such that the elastomer  112  does not extend around the lower surface  118  of the energizer/extrusion ring  114 . In any event, the energizer/extrusion ring  114  may provide a hardened bottom surface to the overall packing element  12  so as to support and direct the extrusion of the elastomer  112  as the piston ( 16  of  FIG. 1 ) presses upward against the packing element  12 . The energizer/extrusion ring  114  may be a single annular shaped piece, and the ring  114  may be constructed from any sufficiently hard metallic material including, but not limited to, steel. The material of the energizer/extruder ring  114  may be any material that meets the API 164 4th edition 5.3 pressure-containing parts requirements for 36 Ksi to 75 Ksi (see table 1 above) with a chemical composition in accordance with the steel composition limits for pressure-containing parts per table 2 above. 
     The elastomer  112  generally forms a bulk portion of the packing element  12 . The elastomer  112  is a single piece of material coupled between the lower surfaces of each of the hardened segments  110  and an upper surface of the energizer/extrusion ring  114 . As mentioned above, the elastomer  112  may in some instances be formed entirely around the energizer/extrusion ring  114 . The elastomer  112  has a cross-sectional shape that varies at different circumferential positions. The hardened segments  110  may be bonded directly to an upper surface of the elastomer  112  at certain circumferential positions, while the upper surface of the elastomer  112  may be exposed and uncovered at other circumferential positions. The elastomer  112  may be formed into the specific shape for the packing element  12  via a molding process, which will be described in detail below. The elastomer  112  may be made from rubber or any other desirable elastomeric material that is sufficiently compressible for use in the disclosed packing/sealing operation. 
     Having generally described the components that form the disclosed packing element  12 , a more detailed description of the relative shape, dimensions, and arrangement of these components will now be provided. 
     The packing element  12  includes an array of several segments  110  disposed circumferentially about a longitudinal axis  120  (see  FIG. 4 ) of the packing element  12 . As shown in  FIGS. 2 and 3 , for example, the packing element  12  may include eighteen total segments  110  arranged about the axis  120 . The segments  110  may be arranged equidistant from each other around the circumference of the packing element  12 , such that the segments  110  are separated from one another by an angle of approximately 20 degrees about the axis  120 . Other numbers of segments  110  may be utilized in other embodiments of the packing element  12 . Regardless of the number of segments  110  that are arranged within the packing element  12  in total, the segments  110  may be equidistantly arranged about the axis  120  (e.g., 12 segments each separated by 30 degrees, 20 segments each separated by 18 degrees, etc.). 
     Each of the segments  110  used in the packing element  12  may have a substantially identical shape. However, one or more of the segments  110  may be constructed with a tapped hole  122  formed therethrough. The tapped holes  122  on the upper side of the two segments  110  may be used for mounting lifting components (e.g., hooks or rings) that allow for lifting of the packing element in/out of the BOP. As shown in  FIG. 3 , the tapped holes  122  may be formed in two of the eighteen total segments  110 . These two segments  110  may be located on opposite sides of the packing element  12  from each other. As such, the array of eighteen segments  110  may include one tapped hole segment ( 110  with hole  122 ) followed circumferentially by eight regular segments  110  (without a hole), followed by the other tapped hole segment ( 110  with hole  122 ) and then the final eight regular segments  110 . 
       FIGS. 6A-6D  show detailed views of one of the plurality of segments  110  that have been described above. As illustrated, the segment  110  may be symmetrical with respect to a plane  124 . Upon assembly of the segment  110  into the packing element ( 12  of  FIG. 3 ), this plane  124  is defined by the longitudinal axis  120  of the packing element  12  and a radial line from the axis  120  to a center point of the segment  110 . 
     The segment  110  may include a body portion  126  and an outer flange portion  128 . The flange portion  128  curves in an upward direction from a base  130  to a tip  132 . The base  130  of the flange portion  128  is located at the furthest radial position from the longitudinal axis of the packing element once assembled, and the tip  132  of the flange portion  128  is located at the closest radial position to the axis. The base  130  of the flange portion  128  is wider in a circumferential direction (width  134 ) than the tip  132  of the flange portion  128  (width  136 ). Both sides of the flange portion  128  slope inwardly from the larger width  134  of the base  130  to the smaller width  136  of the tip  132 . The flange portion  128  of the segment  110  may have a substantially consistent thickness  138  throughout its entire curved shape. 
     The flange portion  128  may have a rounded shape that defines the overall spherical profile of the fully assembled packing element. When fully assembled into the packing element, the flange portions  128  of the plurality of segments  110  form the uppermost surfaces of the packing element that directly engage the spherical housing of the annular BOP. The segments  110  are designed to flex radially inward in response to this engagement with the housing so that the tips  132  of the segments  110  are brought into closing contact with the tubular in the BOP before the elastomer comes into sealing contact with the tubular. The tips  132  of the many segments  110 , once assembled into the packing element, partially define the bore through the packing element of the BOP. 
     The body portion  126  of the segment  110  may be entirely aligned with the symmetrical segment plane  124  and may extend along a lower surface  140  of the flange portion  128  from a center point of the tip  132  to a center point of the base  130 . The body portion  126  may have a substantially consistent width  142  for its entire surface area. Upon assembly of the segment  110  into the packing element, the body portion  126  generally extends into the elastomer, as opposed to the flange portion  128  which sits atop the elastomer. 
     In the assembled position, the body portion  126  may be shaped with a first edge  144  that extends in a radially outward and downward direction from the tip  132  of the flange portion  128 , and a second edge  146  that extends in a radially inward and upward direction from the base  130  of the flange portion  128 . As shown, the two edges  144  and  146  may meet at a point  148  corresponding generally to a midpoint of the spherical curve of the flange portion  128 . However, this point  148  may be repositioned in a different location by adjusting the angles of these edges  144  and  146  extending from the tip  132  and the base  130 , respectively. In other embodiments, the body portion  126  may feature a curved profile as opposed to the one formed of two relatively straight edges  144  and  146  in the figures. 
     Turning to  FIGS. 8 and 9A-9C , the shape and arrangement of the energizer/extrusion ring  114  will now be described in detail. The energizer/extrusion ring (hereinafter referred to as the “ring”)  114  of the packing element may be a single solid piece as shown. The ring  114  has a shallow cylindrical shape, meaning the ring  114  extends a further distance in an radially outward direction than it extends in a vertical thickness direction (parallel with axis  120 ). The ring  114  has a bore  210  formed therethrough, and this bore  210  partially defines the bore through the packing element of the BOP. The ring  114  may include a main body  212  immediately surrounding the bore  210  and a plurality of radially extending fingers  214  that extend outward from the main body  212 . Between the radially extending fingers  214 , a plurality of slots  216  are present. A width  218  of each finger  214  as taken along a circumference of the ring  114  may be larger than a width  220  of each slot  216  between adjacent fingers  214  as taken alone the circumference of the ring  114 . The main body  212  of the ring  114  at the location of the bore  210  is thicker in a vertical direction (thickness  222 ) than a thickness of the fingers  214  (thickness  224 ). The thickness of the main body  212  may gradually slope from this thickness  222  at the bore  210  to the thickness  224  of the fingers  214 , as shown. The thicker main body  212  may help to prevent the elastomer disposed directly above the main body  212  in the fully assembled packer element from extruding into the bore between the actuating piston of the BOP and the tubular. 
     The extended fingers  214  may provide increased stiffness to the lower portion of the packing element, as well as to distribute upward force from the actuating piston to the packing element in a controlled manner. The number of fingers  214  extending from the main body  212  of the ring  114  may coincide with the number of segments  110  disposed in the packing element. Upon assembly of the packing element, as shown in  FIG. 4  for example, the fingers  214  may be circumferentially aligned with respective segments  110  so that each finger  214  is located directly below a corresponding one of the segments  110 . This way, upon an upward actuation force acting on the packing element  12 , the ring  114  may direct the upward force in a concentrated manner directly to the plurality of segments  110 , thereby urging the segments  110  to close against the tubular prior to the elastomer  112  being compressed into sealing engagement with the tubular. 
     As shown in  FIG. 9A , the ring  114  may include two threaded holes  226  formed vertically through the main body  212  of the ring  114 . Upon assembly of the packing element, these threaded holes  226  may be disposed directly in alignment with the tapped holes formed through the two segments. The holes  226  may be utilized for removing the assembled packing element out of a mold used in construction of the elastomer. An upper surface  228  of the ring  114  is generally flat so as to provide an appropriate surface for bonding to the elastomer above. 
     Turning to  FIGS. 2-5 , a detailed description of the shape of the elastomer  112  will now be provided. The elastomer  112  is located between the ring  114  at the bottom and the plurality of segments  110  at the top. The elastomer may generally be molded into a desired shape and bonded to each of the segments  110  and the ring  114 . As illustrated, the elastomer  112  may have a bore  310  formed therethrough. This bore  310  may form part of the overall bore through the packing element  12 , along with the tips  132  of the segments  110  and the bore  210  of the ring  114 . 
     Along the bore  310 , the elastomer  112  may have a profile defined by a plurality of crests  312  and troughs  314 . The crests  312  may each be aligned with the body portion of one of the segments  110 , while the troughs  314  may each be located in a circumferential position between two adjacent segments  110 . The elastomer  112  may slope radially outward and downward from each of the crests  312  at angles defined by the two corresponding edges  144  and  146  of the segment  110 . 
     The elastomer  112  may similarly slope radially outward and downward from each of the troughs  314 . However, the angles and lengths of sloping edges  316  and  318  of the elastomer  112  from the trough  314  to an outer surface of the packing element  12  may be different from the sloping edges from the crest  312  to the outer surface. Specifically, the angles of the sloping edges  316  and  318  of the elastomer  112  may each be larger (as measured from the vertical axis  120 ) than the corresponding sloping surfaces of the elastomer  112  defined by edges  144  and  146 . At a radially outer surface of the packing element  12 , a height  320  of the elastomer  112  at a circumferential position corresponding to the crest  312  is smaller than a corresponding height  322  of the elastomer  112  at a circumferential position corresponding to the trough  314 . However, other shapes of the elastomer may be possible in other embodiments. 
     As shown in  FIG. 5 , a radially internal portion of the elastomer  112  located immediately above the embedded ring  114  may be removed. That is, the bore  310  of the elastomer  112  may have a relatively larger diameter immediately above the ring  114  than it has along the rest of the bore  310 . The edges of the annular space  324  formed along the bore  310  of the elastomer  112  may be rounded, as shown. This space  324  within the elastomer  112  may help to prevent the elastomer  112  from extruding into a bore location between the ring  114  and the tubular during actuation of the packing element. 
       FIG. 4  shows that, upon assembly of the packing element  12 , the segment  110  does not form part of a lower surface  412  of the packing element  12  that interfaces with the actuation piston of the BOP. A total vertical height  410  of the segment  110  (from tip  132  to base  130 ) is shorter than a total vertical height  411  of the elastomer  112  and segment  110  combined (from tip  132  to lower surface  412 ). The segments  110  do not reach all the way downward into contact with the ring  114  or to a position near where the piston interfaces with the ring  114  and/or elastomer  112 . This reduction of height in the segments  110  may prevent undesirable mechanical lockup of the segments  110  with the piston below, as is possible with existing packing elements. 
     It should be noted that, as illustrated, the edges  144  and tips  132  of the segments  110  are located relatively close to the diameter of the overall bore formed through the packing element  12 . For example, the point  148  at which the edges  144  and  146  of the body portion of the segment  110  meet is located a radial distance  414  from the bore of the packing element  12 , and this distance  414  is equal to approximately one third of a radial distance  416  from the point  148  to a radially outer edge of the packing element  12 . The tip  132  of the segment  110 , as shown, actually defines an upper part of the bore through the packing element  12 . Because the edges  144  and tips  132  of the segments  110  are located closer to the drift diameter of the packing element  12 , the tips  132  are in better position to be quickly closed into engagement with a tubular disposed therethrough before the elastomer  112  below the tips  132  reach the tubular. Instead, the tips  132  will be brought into contact with the tubular first, and the elastomer  112  will then be compressed into sealing engagement with the tubular at locations bounded by the tips  132  at the upper end and by the ring  114  at the lower end of the packing element  12 . 
       FIG. 7  illustrates an arrangement of the ring  114 , segments  110 , and certain components used during the construction process of the disclosed packing element  12 . Specifically,  FIG. 7  shows the ring  114  and segments  110  arranged along with spacers  510  that are used during the mold process to shape the elastomer (not shown). Before positioning the components as shown, the process of building the packing element  12  may begin with applying bonding material to surfaces of the segments  110  and ring  114  that will interface directly with the elastomer  112 . The surfaces that will receive the bonding material may include the lower surface  140  of the flange portion  128  of each segments  110  ( FIG. 6C ), as well as the entire body portion  126  of each segment  110  ( FIGS. 6B-6D ), and the flat upper surface  228  of the ring  114  ( FIG. 9A ). 
     After the bonding is applied, the segments  110 , ring  114 , and spacers  510  are arranged in a mold cavity in the arrangement depicted in  FIG. 7 . The spacers  510  may sit one between each of the adjacent segments  110 . These spacers  510  will define the shape of the elastomer at circumferential positions between the segments  110  (corresponding to the elastomer troughs). The spacers  510  may be integrally formed with the mold cavity or they may be separate parts that are independently positioned within the mold cavity. The segments  110  will be disposed in the mold cavity in positions between the spacers  510 . The ring  114  will then be positioned in the mold cavity. The ring  114  will be clocked such that holes  226  through the ring  114  align with the corresponding tapped holes through two of the segments  110 . At this point, the mold cavity may be filled with elastomer to complete the formation of the packing element  12 . 
     The presence of the energizer/extrusion ring  114  and having the surfaces of the segments  110  and ring  114  bonded to the elastomer  112  provides extrusion resistance of the elastomer into the bore of the BOP. That is, upper and lower portions of the elastomer do not extrude into positions that are radially between the closed tips  132  and the sealed tubular or radially between the ring  114  (and below piston) and the tubular. This improves the sealing function of the packing element  12  as compared to existing annular packing elements, because more elastomer is available to seal the space between the closed segments tips  132  at the top and the ring  114  at the bottom of the packing element  12 . In addition, this lack of undesired elastomer extrusion prevents loss of elastomer from the packing element  12  from long-term use. 
     While the disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the following appended claims.