Patent Publication Number: US-9422788-B2

Title: Straight-bore back pressure valve

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Non-Provisional patent application Ser. No. 12/920,826, entitled “Straight-Bore Back Pressure Valve”, filed on Sep. 2, 2010, which is herein incorporated by reference in its entirety, and which claims priority to and benefit of PCT Application No. PCT/US09/37731 entitled “Straight-Bore Back Pressure Valve”, filed on Mar. 19, 2009, which is herein incorporated by reference in its entirety, and which claims priority to and benefit of U.S. Provisional Patent Application No. 61/043,580, entitled “Straight-Bore Back Pressure Valve”, filed on Apr. 9, 2008, which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, 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 invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     As will be appreciated, oil and natural gas have a profound effect on modern economies and societies. In order to meet the demand for such natural resources, numerous companies invest significant amounts of time and money in searching for and extracting oil, natural gas, and other subterranean resources from the earth. Particularly, once a desired resource is discovered below the surface of the earth, drilling and production systems are employed to access and extract the resource. These systems can be located onshore or offshore depending on the location of a desired resource. Further, such systems generally include a wellhead assembly that is used to extract the resource. These wellhead assemblies include a wide variety of components and/or conduits, such as various control lines, casings, valves, and the like, that are conducive to drilling and/or extraction operations. In drilling and extraction operations, in addition to wellheads, various components and tools are employed to provide for drilling, completion, and the production of mineral resources. For instance, during drilling and extraction operations seals and valves are often employed to regulate pressures and/or fluid flow. 
     A wellhead system often includes a tubing hanger or casing hanger that is disposed within the wellhead assembly and configured to secure tubing and casing suspended in the well bore. In addition, the hanger generally regulates pressures and provides a path for hydraulic control fluid, chemical injections, or the like to be passed through the wellhead and into the well bore. In such a system, a back pressure valve is often disposed in the hanger bore and/or a similar bore of the wellhead. The back pressure valve plugs the bore to block pressures of the well bore from manifesting through the wellhead. 
     Typically, the back pressure valve is provided separately from the hanger, and is installed after the hanger has been landed in the wellhead assembly. In other words, the hanger is run down to the wellhead, followed by the installation of the back pressure valve. One resulting challenge includes installing the back pressure valve into the hanger bore in context of high pressures in the bore. Accordingly, installation of the back pressure valve may include the use of several tools and a sequence of procedures to set and lock the seal. Unfortunately, each of the sequential running procedures may consume a significant amount of time and money. Further, securing the back pressure valve generally includes complementary engagement features in the bore itself. The bore typically includes shoulders, grooves, notches, or similar features that are engaged by portions of the back pressure valve. Thus, the design of the bore is configured to accommodate a specific back pressure valve design. Typically, the back pressure valve and bore are designed specifically for use with one another, thereby, adding yet another level of complexity to the overall design of the wellhead. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying figures in which like characters represent like parts throughout the figures, wherein: 
         FIG. 1  is a block diagram that illustrates a mineral extraction system in accordance with an embodiment of the present technique; 
         FIG. 2  is a block diagram that illustrates a back pressure valve in accordance with an embodiment of the present technique; 
         FIG. 3  is an exploded cross-sectioned view of a back pressure valve system in accordance with an embodiment of the present technique; and 
         FIG. 4A-4E  are cross-sectioned views of the back pressure valve system in accordance with embodiments of the present technique. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     One or more specific embodiments of the present invention will be described below. These described embodiments are only exemplary of the present invention. Additionally, in an effort to provide a concise description of these exemplary embodiments, all features of an actual implementation may not be 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. 
     When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Moreover, the use of “top,” “bottom,” “above,” “below,” and variations of these terms is made for convenience, but does not require any particular orientation of the components. 
     Certain exemplary embodiments of the present technique include a system and method that each addresses one or more of the above-mentioned inadequacies of conventional sealing systems and methods. As explained in greater detail below, the disclosed embodiments include a back pressure valve that can be installed into a straight bore. More specifically, the back pressure valve is installed into a portion of a bore that does not include engagement features to secure the back pressure valve in the bore. Accordingly, the back pressure valve is secured against the generally smooth/flat walls of the bore, as opposed to grooves, shoulders, or similar features that are typically employed to secure a back pressure valve, or a similar valve, in a bore. As a result, the exemplary back pressure valve may be inserted into a large variety of tubing hangers with varying bore profiles. In certain embodiments, the back pressure valve includes a friction member that is expanded radially to secure the back pressure valve into the bore. In some embodiments, the friction member is moved longitudinally via hydraulic pressure exerted on an outer sleeve, and/or secured in a locked position via a locking ring that is rotated into position to block the outer sleeve in position when the hydraulic pressure is reduced. Before discussing embodiments of the system in detail, it may be beneficial to discuss a system that may employ such a back pressure valve. 
       FIG. 1  is a block diagram that illustrates a mineral extraction system  10  including a back pressure valve (BPV)  12  in accordance with embodiments of the present technique. The illustrated mineral extraction system  10  can be configured to extract various minerals and natural resources, including hydrocarbons (e.g., oil and/or natural gas), or configured to inject substances into the earth. In some embodiments, the mineral extraction system  10  is land-based (e.g., a surface system) or subsea (e.g., a subsea system). In the illustrated embodiment, the system  10  includes a wellhead  13  coupled to a mineral deposit  14  via a well  16 , wherein the well  16  includes a wellhead hub  18  and a well-bore  20 . 
     The wellhead hub  18  generally includes a large diameter hub that is disposed at the termination of the well bore  20 . The wellhead hub  18  provides for the connection of the wellhead  13  to the well  16 . In some embodiments, the wellhead  13  includes a connector that is coupled to a complementary connector of the wellhead hub  18 . For example, in one embodiment, the wellhead hub  18  includes a DWHC (Deep Water High Capacity) hub manufactured by Cameron, headquartered in Houston, Tex., and the wellhead  13  includes a complementary collet connector (e.g., a DWHC connector), also manufactured by Cameron. 
     The wellhead  13  typically includes multiple components that control and regulate activities and conditions associated with the well  16 . In some embodiments, the wellhead  13  generally includes bodies, valves and seals that route produced minerals from the mineral deposit  14 , provides for regulating pressure in the well  16 , and provides for the injection of chemicals into the well bore  20  (down-hole). For example, in the illustrated embodiment, the wellhead  13  includes what is colloquially referred to as a christmas tree  22  (hereinafter, a tree), a tubing spool  24 , and a hanger  26  (e.g., a tubing hanger or a casing hanger). The system  10  may include other devices that are coupled to the wellhead  13 , and devices that are used to assemble and control various components of the wellhead  13 . For example, in the illustrated embodiment, the system  10  includes a tool  28  suspended from a drill string  30 . In certain embodiments, the tool  28  includes a running tool that is lowered (e.g., run) from an offshore vessel to the well  16  and/or the wellhead  13 . In other embodiments, such as surface systems, the tool  28  may include a device suspended over and/or lowered into the wellhead  13  via a crane or other supporting device. 
     The tree  22  generally includes a variety of flow paths (e.g., bores), valves, fittings, and controls for operating the well  16 . For instance, in some embodiments, the tree  22  includes a frame that is disposed about a tree body, a flow-loop, actuators, and valves. Further, the tree  22  generally provides fluid communication with the well  16 . For example, in the illustrated embodiment, the tree  22  includes a tree bore  32 . The tree bore  32  provides for completion and workover procedures, such as the insertion of tools (e.g., the hanger  26 ) into the well  16 , the injection of various chemicals into the well  16  (down-hole), and the like. Further, minerals extracted from the well  16  (e.g., oil and natural gas) are generally regulated and routed via the tree  22 . For instance, the tree  22  may be coupled to a jumper or a flowline that is tied back to other components, such as a manifold. Accordingly, in such an embodiment, produced minerals flow from the well  16  to the manifold via the wellhead  13  and/or the tree  22  before being routed to shipping or storage facilities. 
     The tubing spool  24  provides a base for the wellhead  24  and/or an intermediate connection between the wellhead hub  18  and the tree  22 . Typically, the tubing spool  24  (also referred to as a tubing head) is one of many components in a modular subsea or surface mineral extraction system  10  that are run from an offshore vessel and/or a surface installation system. As illustrated, the tubing spool  24  includes the tubing spool bore  34 . The tubing spool bore  34  connects (e.g., enables fluid communication between) the tree bore  32  and the well  16 . Thus, the tubing spool bore  34  provides access to the well bore  20  for various completion procedures, worker procedures, and the like. For example, components can be run down to the wellhead  13  and disposed in the tubing spool bore  34  to seal-off the well bore  20 , to inject chemicals down-hole, to suspend tools down-hole, and/or to retrieve tools from down-hole. 
     As will be appreciated, the well bore  20  may contain elevated pressures. For instance, in some systems, the well bore  20  may include pressures that exceed 10,000 pounds per square inch (PSI), that exceed 15,000 PSI, and/or that even exceed 20,000 PSI. Accordingly, mineral extraction systems  10  typically employ various mechanisms, such as seals, plugs and valves, to control and regulate the well  16 . In some instances, plugs and valves are employed to regulate the flow and pressures of fluids in various bores and channels throughout the mineral extraction system  10 . The illustrated hanger  26  (e.g., tubing hanger or casing hanger), for example, is typically disposed within the wellhead  13  to secure tubing and casing suspended in the well bore  20 , and to provide a path for hydraulic control fluid, chemical injections, and the like. The hanger  26  includes a hanger bore  38  that extends through the center of the hanger  26 , and that is in fluid communication with the tubing spool bore  34  and the well bore  20 . Unfortunately, if left unregulated, pressures in the bores  20  and  34  can manifest through the wellhead  13 . Accordingly, the back pressure valve (BPV)  12  is often seated and locked in the hanger bore  38  to regulate the pressure. Valves similar to the illustrated back pressure valve  12  can be used throughout the mineral extraction system  10  to regulate fluid and/or gas pressures and flow paths. 
     In the context of the hanger  26 , the back pressure valve  12  can be installed into the hanger  26 , or a similar location, before the hanger  26  is installed in the wellhead  13 , or may be installed into the hanger  26  after the hanger  26  has been installed in the wellhead  13  (e.g., landed in the tubing spool bore  34 ). In the latter case, the hanger  26  is typically run down and installed into the subsea wellhead  13  (or a similar surface wellhead), followed by the installation of the back pressure valve  12 . During installation of the back pressure valve  12 , pressure in the well bore  20  may exert a force (e.g., a backpressure) on the lower portion of the back pressure valve  12 . Unfortunately, the backpressure may increase the difficulty of installing the back pressure valve  12 . For example, the backpressure may resist the installation of the back pressure valve  12 . Although typical embodiments of the hanger bore  38  include shoulders, grooves, notches, or similar features that are engaged by portions of the back pressure valve  12 , in embodiments of the system  10 , the back pressure valve  12  is disposed in a portion of the hanger bore  38  that is a straight bore. Accordingly, the system and methods discussed in greater detail below provide a system and method including disposing the back pressure valve  12  in the straight hanger bore  38 , and/or a similar straight bore (e.g., a tubing or casing pipe bore). 
       FIG. 2  is a block diagram that illustrates an embodiment of the back pressure valve (BPV)  12  disposed in a bore  40  in accordance with embodiments of the present techniques. In the illustrated embodiment, the BPV  12  includes a body  42 , a friction member  44 , an outer sleeve  46 , a lock ring  48 , a plunger  50 , and a seal  52 . 
     The bore  40  includes a straight bore (e.g., a full-bore). A straight bore can be defined as a bore having an internal diameter including generally constant or uniform surfaces that do not include engagement/retention features such as shoulders, grooves, notches, or the like. For example, in some embodiments, the internal surface of the bore includes straight or flat walls that are generally parallel to a longitudinal axis of the bore. In some embodiments, the bore  40  includes a generally cylindrical bore formed from casing, tubing, or a bore internal to the system  10 , such as the hanger bore  38 . For example, in one embodiment, the bore  40  includes the hanger bore  38 , or a similar bore (e.g., a tubing or casing pipe bore), having a generally consistent internal diameter along its length. 
     Further, in one embodiment the bore  40  is straight along its entire length, whereas in other embodiment, the bore  40  is straight along some portion but not all of its length. For example, the bore  40  is straight at least in the portion of the bore  40  where the BPV  12  is seated, in one embodiment. In such an embodiment, other portions of the bore  40  may include engagement features that are configured for securing other valves and tools, for instance. 
     The surface of the bore  40  generally does not include any significant physical features or preparation, in some embodiments. For example, in one embodiment, the bore  40  includes a smooth unfinished surface. This includes the standard finish of the body that forms the bore  40 , such as, for example, the interior of the casing, the tubing, and the hanger bore  38 . However, in other embodiments, the internal surface of the bore  40  includes a modified surface. In other words, the internal surface of the bore  40  includes some form of preparation of the surface, but still does not include engagement/retention features, such as shoulders, grooves, notches, or the like. In one embodiment, the modified surface includes a scored surface, or otherwise coarse finish to encourage friction (e.g., increase the coefficient of friction) between the internal surface of the bore  40  and complementary features of the BPV  12 . In another embodiment, the modified surface includes polishing, smoothing, or otherwise preparing the surface for contact with the back pressure valve  12 . 
     In the illustrated embodiment, the bore  40  includes a longitudinal axis  54  running the length of the bore  40 . In operation, the BPV  12  is located along the longitudinal axis  54  and regulates pressures between an upper bore portion  56  and a lower bore portion  58 . The upper bore portion (e.g., a downstream and bore portion)  56  includes a portion of the bore  40  toward an upper end of the wellhead  13  and the lower bore portion (e.g., a downstream bore portion)  58  includes a portion of the bore  40  that is on an opposite end of the well-head  13 . For example, the lower bore portion  58  includes an end exposed and/or in the direction of the well-bore  20  and/or the mineral deposit  14 , in certain embodiments. 
     The body  42  of the BPV  12  includes an upper end  60  (e.g., downstream end), a lower end  62  (e.g., upstream end), a plunger bore  64 , and a recess  66 . The upper end  60  of the body  42  generally is exposed to and faces the upper bore portion  56  when installed. Similarly, the lower end  62  of the body generally is exposed to and faces the lower bore portion  58 . Accordingly, when installed, the lower end of the BPV  12  is exposed to the pressures associated with the lower bore portion  58 . These pressures typically include pressures from the well bore  20 , the mineral deposit  14 , fluids and gases injected down-hole and the like. The pressures generally act on the lower end  62  in the direction of the arrows  68  (e.g., toward the upper bore portion  56 ). 
     The plunger bore  64  includes a bore that extends through the length of the body  42  of the BPV  12 . The plunger bore  64  generally includes a path for the regulation of pressure between the upper bore portion  56  and the lower bore portion  58 . For example, when opened (e.g., not occluded) fluids and gases on either side of the BPV  12  can flow back and forth to maintain a balanced pressure between the upper bore portion  56  and the lower bore portion  58 . This may be particularly useful during installation and removal of the BPV  12  when the pressure is balanced to enable moving of the BPV  12  within the bore  40  and along the longitudinal axis  54  without additional loading to overcome the longitudinal forces, such as those acting on the lower end  62  of the BPV  12 . When closed (e.g., occluded) the BPV  12  generally occludes the bore to maintain a pressure differential between the upper bore portion  56  and the lower bore portion  58 . More specifically, in an embodiment in which the plunger  50  includes a unilateral check valve, the BPV  12  is typically configured to retain an elevated pressure in the lower bore portion  58 . 
     As mentioned briefly above, the plunger  50  is typically employed to regulate the flow of fluids and gases through the BPV  12 . More specifically, the plunger  50  includes an open position and a closed position in certain embodiments. For example, in one embodiment, the plunger  50  includes a sealing portion (e.g., a bell) that is configured to engage a complementary sealing surface or feature in the plunger bore  64 . In a closed position, the sealing portion of the plunger  50  engages the sealing surface/feature in the plunger bore  64  to occlude the plunger bore  64 . In an open position, the sealing portion of the plunger  50  is urged/located away from the sealing surface of the plunger bore  64 , thereby enabling fluid and gases to pass through the plunger bore  64 . Certain embodiments of the plunger  50  and the plunger bore  64  are discussed in more detail below with regard to  FIGS. 3 and 4A-4E . 
     The recess  66  generally includes one or more indentations in an external surface  70  of the body  42 . In one embodiment, the recess  66  includes a single groove about an external surface (e.g., circumference)  70  of the body  42 . In other embodiments, the recess  66  includes one or more separate recessed sections about the external surface  70  of the body  42 . In the illustrated embodiment, the recess  66  includes a groove that extends around the circumference of the body  42  and that includes an upper face  72 , a lower face  74  and an internal face  76 . The internal face  76  includes an angle (e.g., a taper) relative to the longitudinal axis  54 , in the illustrated embodiment. For example, the internal face  76  includes a smaller diameter proximate the upper face  72  and the upper end  60  of the body  42 , and includes a larger diameter proximate the lower face  74  and the lower end  62  of the body  24  (e.g., a conical section of the body  42 ). In other words, the internal face  76  includes a taper that increases in diameter from the upper face  72  to the lower face  74 . Thus, the internal face  76  is oriented at an angle  78  relative to the longitudinal axis  54 . As is discussed in greater detail below, the angle  78  may include any angle suitable for expanding the friction member  44 . For example, in one embodiment, the angle  78  is between about 5 degrees and 10 degrees. However, in other embodiments, the angle  78  may be greater than about 10 degrees or less than about 5 degrees. Further, a height  79  of the recess  66  is defined by the distance between the upper face  72  and the lower face  74 . 
     The friction member  44  generally includes one or more devices that are employed to secure the BPV  12  to the bore  40 . More specifically, in some embodiments, the friction member  44  includes one or more members (discussed in more detail below) that are expanded in a radial manner/direction to contact the walls of the bore  40 , thereby securing the BPV  12  to the bore  40 . In certain embodiments, an outer surface (e.g., friction surface) of the friction member  44  directly contacts a straight portion of the bore  40 , thereby securing the BPV  12  in the bore without the aid of any engagement/retention features, such as shoulders, grooves, notches, or the like. 
     In the illustrated embodiment, the friction member  44  includes a friction face  80 , an internal face  82 , an upper face  84 , and a lower face  86 . The upper face  84  and lower face  86  are proximate the upper face  72  and lower face  74 , respectively, of the recess  66  in the body  42 . As depicted in the illustrated embodiment, a height  88  (e.g., the distance between the upper face  84  and the lower face  86 ) of the friction member  44  is less than the height  79  of the recess  66 . Accordingly, in one embodiment, the friction member  44  is capable of moving longitudinally (e.g., a long the longitudinal axis  54 ) relative to the recess  66  and the body  42  of the BPV  12 . 
     The internal face  82  generally includes a profile that is complementary to the profile of the internal face  72  of the body  42 . In the illustrated embodiment, for example, the internal face  82  of the friction member  44  includes a taper that is complementary to the taper (angle  78 ) of the internal face  76 . In other words, the internal face includes a profile (taper) that increases in diameter from the upper face  84  to the lower face  86 . Accordingly, in one embodiment, movement of the friction member  44  in a longitudinal direction (e.g., along the longitudinal axis  54 ) relative to the body  42  and the recess  66  causes the friction member to expand and/or contract radially. For example, in an embodiment where the friction member  44  is located proximate the upper face  72  of the recess  66  and urged toward the lower face  74  of the recess  66 , the friction member  44  expands radially in the direction of the arrows  90 . As is discussed below, the urging force to displace the friction member  44  can be provided downward on the friction member  44  (e.g., from the outer sleeve  46 ) or upward on the body  42  (e.g., the pressure acting on the lower end  62  of the body  42 ), in certain embodiments. In one embodiment, force may be applied in the opposite direction to urge the friction member  44  upward (e.g., toward the upper face  72  of the recess  66  and urge the friction member inward, in a direction opposite the arrows  90 . Further, it will be appreciated that although the illustrated embodiment includes urging the friction member downward (e.g., toward the lower face  74  and toward the lower bore portion  58 ) to expand the friction member radially, other embodiments include a similar configuration wherein urging the friction member  44  in an upward direction expands the friction member  44  radially. For example, the taper can be reversed in one embodiment such that the diameter is larger proximate the upper face  72  of the recess  66  and smaller proximate the lower face  74 . In any of the embodiments, expanding the friction member  44  causes the friction face  80  of the friction member  44  to contact the internal surface of the bore  40 . 
     The friction face  80  includes the face located on the outside of the friction member  44 . Generally, the friction face  80  contacts the walls of the bore  40  when the friction member  44  is expanded in a radial direction, represented by the arrows  90 . In certain embodiments, the friction face  80  includes one or more surface features conducive to securing the friction member  44 , and, thus, the BPV  12  to the bore  40 . Generally, the friction face  80  includes a surface that provides a coefficient of friction sufficient to secure the BPV  12  in the bore  40  in light of the pressures experienced across the BPV  12 . For example, in one embodiment, the friction face  80  includes a coarse finish. The coarse finish is provided by scoring, or sanding the friction face  80 , in one embodiment. In another embodiment, the coarse finish is provided by coating the friction face  80  with a composite material. For example, the friction face  80  includes a coating of a material having a hardness that is less than the hardness of the surface of the bore  40 , in one embodiment. 
     In other embodiments, the surface features include indentations and/or patterns of indentations in the friction face  80 . In one embodiment, the friction face  80  includes a plurality of grooves that provide localized areas of high surface contact forces when the friction member  44  is expanded radially against the surface of the bore  40 . These localized areas of force enable the friction member  44  to bite into the interior of the bore  40 . For example, in one embodiment, the indentations form rows and/or columns of teeth. 
     In some embodiments, the friction face  80  includes a generally flat and/or smooth surface. For example, in one embodiment, the friction face  80  includes an unfinished or polished surface. In such an embodiment, the increased contact area between the friction face  80  and the surface of the bore  40  provides the friction to secure the friction member  44  and the BPV  12  to the bore  40 . 
     The friction face  80 , in some embodiments, includes any combination of the surface features discussed above. For example, in one embodiment, the friction face  80  includes teeth like features in one region, a smooth finish in other regions, and a coating over at least a portion of the regions. In another embodiment, the friction face  80  includes a combination of recesses (e.g., teeth and grooves) and a coating, for example. 
     Further, the friction face  80  includes a profile that is conducive to generating a friction between the friction member  44  and the bore  40 . In one embodiment, the friction face  80  includes a profile that is similar to the profile of the bore  40 . For example, in the illustrated embodiment, the profile of the friction face  80  includes a surface that is in generally parallel to the surface of the bore  40 . In other words, the surface of the friction face  80  includes at least a portion that is parallel to the longitudinal axis  54  (e.g., cylindrical exterior). 
     The friction member  44  is formed from one or more devices that are capable of being expanded radially, as discussed above. In some embodiments, the friction member  44  includes one or more rings, one or more segments, one or more locking dogs, or a combination thereof. For example, in one embodiment, the friction member  44  includes a C-ring that is positioned in the recess  66 . In another embodiment, the C-ring includes one or more segments along its exterior that are configured to contact the surface of the bore  40 . In such embodiments, the recess  66  may include a groove that extends around circumference of the body  42 . In another embodiment, the friction member  44  includes one or more locking segments that are positioned in one or more recesses  66  about the circumferences. For example, in one embodiment, the segments are disposed about a single groove forming the recess  66 . In another embodiment, the recess  66  includes a plurality of separate indentations that are configured to accept one or more of the segments forming the friction member  44 . For example, the friction member  44  is formed form several segments that are not joined to one another in one embodiment. In another embodiment, the segments are coupled to one another by a common member. For example, in one embodiment, the friction ring  44  includes a plurality of segments coupled to a common ring. It will be appreciated that the friction member  44  may includes any mechanism or device configured to expand radially to provide a securing/friction force between the BPV  12  and an internal surface of the bore  40 . 
     The outer sleeve  46  generally includes a device or mechanism that exerts a force on the friction member  44 . More specifically, in certain embodiments, the outer sleeve  46  exerts a longitudinal force (e.g., a force parallel to the longitudinal axis  54 ) on the friction member  44  that causes the friction member  44  to expand radially. For example, in the illustrated embodiment, urging the outer sleeve  46  in the direction of arrows  92  generates an axial load on at least a portion of the upper face  84  of the friction member  44 . The axial load urges the friction member  44  in the direction of the arrows  92 , thereby causing radial expansion of the friction member  44 , as discussed above. Although the outer sleeve  46  is located above the friction member  44  in the illustrated embodiment, all or at least a portion of the outer sleeve  46  may be located below the friction member  44  in other embodiments. For example, in an embodiment where an axial load is delivered to the lower face  86  of the friction member  44 , at least a portion of the outer sleeve may be located below the friction member  44 . For example, as discussed in greater detail below with regard to  FIGS. 3 and 4A-4E , a portion of the outer sleeve  46  is located below the friction member  44  to provide a force in the direction of arrows  94  to enable the friction member  44  to contract radially. In another embodiment, for example, the embodiment in which the taper is reversed, the axial force in the direction of the arrows  94  is employed to expand the friction member  44  radially. 
     The axial force provided by the outer sleeve is generated by hydraulic loading in some embodiments. For example, although not depicted in  FIG. 3 , as discussed in greater detail below with regard to  FIGS. 3 and 4A-4E , the BPV  12  includes a hydraulic port that terminates in a chamber proximate the outer sleeve  46  such that energizing the hydraulic port and chamber exerts a force on the outer sleeve  46  in the direction of the arrows  92 , thereby providing the axial loading on the friction member  44 . Other embodiments may include similar forms of loading. For example, in one embodiment, the outer sleeve  46  is threaded to the body  42 , such that rotation of the outer sleeve  46  generates the axial force in the direction of the arrows  92 . 
     The lock ring  48  secures the position of outer sleeve  46  and, thus, the position of the friction member  44 , in certain embodiments. In one embodiment, the lock ring  48  is positioned against the outer sleeve  46  to block the outer sleeve  46  from moving upward (e.g., in the opposite direction of the arrows  92 ). For example, in one embodiment, the lock ring  48  is threaded to the body  42  such that rotation of the lock ring  48  urges the locking ring downward (e.g., in the direction of the arrows  96 ), and toward the outer sleeve  46 . In another embodiment, the lock ring  48  is urged into movement via a hydraulic arrangement similar to that discussed above with regard to the outer sleeve  46 . Accordingly, the lock ring  48  is urged/moved along the longitudinal axis  54  until it abuts the outer sleeve  46 , thereby securing the outer sleeve  46  in a position. In one embodiment, the outer sleeve  46  is secured in a locked position (e.g., a position holding the friction member  44  in the radially expanded position), for instance. In one embodiment, hydraulic pressure is employed to urge the outer sleeve  46  into engagement with the friction member  44 . The lock ring  48  is rotated until it is proximate or abutting the outer sleeve  46 , and the hydraulic pressure is released. With the hydraulic pressure is released, the outer sleeve  46  is blocked from moving a significant longitudinal distance by the lock ring  48 . Thus, the friction member  44  is held in position (e.g., an expanded position) via the outer sleeve  46  and the lock ring  48 . 
     In some embodiments, the BPV  12  includes one or more additional seals that block/regulate the pressures between the lower bore portion  58  and the upper bore portion  56 . For instance, in the illustrated embodiment, the BPV  12  includes a seal  52  disposed between the body  42  and the internal surface of the bore  40 . In one embodiment, the seal  52  includes a mechanical (e.g., MEC) seal. In another embodiment, the seal  52  includes an elastomer seal or similar seal. 
     The seal  52 , in some embodiments, is compressed within a region between the body  42  and the surface of the bore  40 . For example, in the illustrated embodiment, the seal  52  is disposed between a tapered surface  98  of the body  42  and the internal surface of the bore  40 . More specifically, the tapered surface  98  includes a diameter that increases proximate the lower end  62  of the body  42 . Accordingly, urging the seal  52  toward the lower end  62  and into engagement with the tapered face  98  (e.g., urging the seal in the direction of arrows  100 ) compresses (e.g., seats) the seal  52  between the tapered face  98  and the internal surface of the bore  40 . In the seated position, the seal  52  provides a fluid seal that blocks fluids and gases from passing the BPV  12 . 
     In one embodiment, the seal  52  is seated by a member that is urged in the direction of the arrow  100  to compress and seat the seal  52 . For example, although not depicted in  FIG. 2 , as discussed in further detail with regard to  FIGS. 3 and 4A-4E , in one embodiment, the outer sleeve  46  includes an extension that protrudes below the friction member  44  and into contact with the seal  52 . Accordingly, the outer sleeve  46  is urged in the direction of the arrows  92  to seat the seal  52 , in one embodiment. Further, as is discussed below, in one embodiment, the outer sleeve  46  includes a window such that movement of the outer sleeve  46  in the direction of the arrow  92 , first, seats the seal  52 , and, second, urges the friction member  44  into radial expansion. 
     Further, as discussed in detail with regard to  FIGS. 3 and 4A-4E , the BPV  12  is disposed (e.g., run) into position within the bore and/or installed via one or more running tools. More specifically, in certain embodiment, a running tool couples to the upper end  60  of the BPV  12  to provide operation of the BPV  12  during installation and retrieval, among other operations. For example, as discussed below, a running tool urges the plunger  50  to an open position, runs the BPV  12  to the desired location, provides hydraulic pressure to engage the outer sleeve  46  to seat the seal  52  and radially expand the friction member  44  into contact with the bore  40 , rotates the lock ring  48  to abut the outer sleeve  46 , releases hydraulic pressure, urges the plunger  50  into a closed position, and disconnects itself from the BPV  12  before being extracted from the bore  40 . 
     Although the previously discussed embodiments include operation of the friction member  44  as relying on longitudinal forces provided via the outer sleeve  46 , the lock ring  48 , and the body, it is worth noting that pressure acting on the BPV  12  provides for urging the friction member  44  into an expanded position. For example, in one embodiment, the pressure in the lower bore portion  58  acts on the lower end  62  of the body  42  of the BPV  12 . Such a loading provides for urging the body  42  upward relative to the friction member  44 . The upward movement along the longitudinal axis  54  provides for increasing the radial force (e.g., in the direction of arrows  90 ) acting on the friction member  44 . Accordingly, as the pressure in the lower bore portion  58  increases, the radial expansion of the friction member  44  increases, thereby providing increased friction between the friction face  80  and the bore  40 . In other words, as the pressure in the lower portion increases  58 , the illustrated embodiment of the BPV  12  is secured even tighter into the bore  40 , helping to prevent the BPV  12  from becoming dislodged. 
     Turning now to  FIGS. 3 and 4A-4E , one embodiment of a BPV system  110  is depicted. More specifically, the illustrated embodiments include an installation sequence of a BPV system  110  including one embodiment of the BPV  12  and one embodiment of a back pressure valve (BPV) running tool  112 . The BPV  12  includes features similar to those discussed above with regard to the BPV  12  of  FIG. 2 . For example, as depicted, the BPV  12  includes one embodiment of the body  42 , the friction member  44 , the outer sleeve  46 , the lock ring  48 , the plunger  50 , and the seal  52 . 
     In the illustrated embodiment, the body  42  includes a lower body portion  120  and an upper body portion  122 . The lower body portion  120  includes the plunger bore  64 . The plunger bore  64  includes a plunger bore sealing face  124 . In the illustrated embodiment, the plunger bore sealing face  124  includes a taper between a lower plunger bore portion  126  and an upper plunger bore portion  128 . The taper  124  includes an angled face (e.g., conical shaped face) that extends between the lower plunger bore portion  126  and the upper plunger bore portion  128 . The taper  124  is shaped complementary to a plunger sealing face  130 . In the illustrated embodiment, the upper plunger bore portion  128  is narrower (e.g., has a smaller diameter) than the lower plunger bore portion  126 . 
     The lower body portion  120  also includes a holding ring  132  coupled to the lower end  62  of the lower body portion  120 . The holding ring  132  is coupled to the lower body portion  120  via mechanical fasteners (e.g., bolts)  134 . The holding ring  132  extends into the lower plunger bore portion  126  and includes a stem bore  135  that extends through the center of the holding ring  132  along the longitudinal axis  54 . As is discussed in further detail below, the holding ring  132  retains the plunger  50  in the plunger bore  64 . 
     The plunger  50  includes a stem  136 , a bell  138 , and a spring  140 . The stem  136  is coupled to and extends downward form the bell  138 . In the illustrated embodiment, the stem  136  is aligned along the longitudinal axis  54  and extends into the stem bore  135  of the holding ring  132 . Further, the spring  140  is disposed around the stem  136  and is retained between the bell  138  and the holding ring  132 . Accordingly, as the plunger  50  is urged toward the holding ring  132  (e.g., where the plunger  50  is urged to an open position), the spring  140  provides a biasing force urging the plunger  50  to a closed position (e.g., the sealing face  130  of the bell  138  into contact with the plunger bore sealing face  124 . 
     In the illustrated embodiment, the bell  138  includes a seal  142  (e.g., annular seal) and a bell stem  144 . The seal  142  generally includes a seal configured to seal against the plunger bore sealing face  124 . The bell stem  144  includes a protrusion extended from the bell  138  in the direction of the upper plunger bore portion  128 . In operation, the bell stem  144  enables a tool or similar device to engage the plunger via the upper plunger bore portion  128 . For example, as is discussed in further detail below, in one embodiment, the running tool  112  is threaded into a thread  146  of the upper plunger bore  128  and depresses the plunger  50  via the bell stem  144 , thereby urging the plunger  50  toward an open position. 
     The upper body portion  122  includes a cylindrical ring that is coupled to the lower body portion  120 . In the illustrated embodiment, the upper body portion  122  includes a cylindrical ring that is disposed about an external diameter of an upper end  148  of the lower body portion  120 . The upper body portion  122  is coupled to the lower body portion  120  via a mechanical fastener (e.g., a bolt)  150 . 
     Further, the upper body portion  122  includes a hollow center  152 . As is discussed in further detail below, the hollow center  152  is capable of receiving at least a portion of the BPV running tool  112 . An upper body hydraulic port  154  extends from an interior surface of the hollow center  152  and extends through the upper body portion  122  to a lower end  156  of the upper body portion  122 . The upper body hydraulic port  154  terminates into a cavity  158  formed between the upper body portion  122 , the lower body portion  120  and the outer sleeve  46 . The cavity  158  is sealed via three annular seals  160 ,  162  and  164  disposed between the upper body portion  122 , the lower body portion  120  and the outer sleeve  46 . 
     The friction member  44  includes, in the illustrated embodiment, segments disposed in the recess  66  of the lower body portion  120 . The friction member  44  is coupled to the body  42  via fasteners (e.g., bolts)  166 . The fasteners  166  are passed through through-holes  166 . The through-holes  166  includes slots that enable the friction member  44  to move relative to the fasteners  166  and the body  42 . More specifically, the friction member  44  is capable of being moved axially up and down in the recess to contract and expand, respectively, the friction member  44 . For example, in the illustrated embodiment, the friction member  44  is in the radially contracted (e.g., up) position, and may be slid/urged into the radially expanded (e.g., down) position, as discussed previously with regard to  FIG. 2 . 
     The outer sleeve  46  includes a cylindrical body  170  disposed around the exterior of the body  42 . In the illustrated embodiment, the outer sleeve  46  extends both above and below the friction member  44 . For example, the body  170  of the outer sleeve  46  includes windows  172  that span the region proximate the friction member  44 . More specifically, the windows  172  include cutouts through the body  170  that enable the outer sleeve  46  to slide in a longitudinal direction (e.g., parallel to the longitudinal axis  52 ) relative to the body  42  and/or the friction member  44 . For example, the windows  172  include an upper window face  174  and a lower window face  176  that are separated by a distance that is greater than the height  88  of the friction member  44 . Accordingly, in the illustrated embodiment, the outer sleeve  46  can be moved longitudinally downward for a distance before the upper face  174  of the body  170  contacts/engages the upper face  84  of the friction member  44 . As is discussed below, this longitudinal movement can be employed to urge the seal  52  into a seated position. Further, the outer sleeve  46  can continue to move in the longitudinal downward direction to engage the upper face  84  of the friction member  44  and to cause the friction member to move downward in the recess  66  and expand radially, as discussed above with regard to  FIG. 2 . 
     In the illustrated embodiment, the seal  52  includes a MEC seal  52  disposed at a lower end  180  of the outer sleeve  46 . As discussed previously, urging the outer sleeve  46  downward displaces the seal  52  downward along the longitudinal axis  54 . As the seal  52  is urged downward, it is compressed between the tapered face  98  of the body  42  and the bore  40  until it is proximate and/or disposed in a seated position. 
     An upper end  182  of the outer sleeve  46  includes shear pin holes  184  that support shear pins  186  disposed between the outer sleeve  46  and the lock ring  48 . Further, the upper end  182  includes a recess  188  that houses bearings  190  disposed between the outer sleeve  46  and the lock ring  48 . Similarly, the lock ring  48  includes complementary shear pin holes  192  configured to support the shear pins  186  and a complementary bearing groove  194  that supports and houses the bearings  190 . 
     The lock ring  48  includes a cylindrical ring that is disposed about the upper portion  122  of the body  42 . In the illustrated embodiment, the lock ring  48  includes threads  196  about the internal diameter that are complementary to external threads  198  about the external diameter of the upper body portion  122 . Accordingly, rotation of the lock ring  48  relative to the upper body portion  122  imparts a longitudinal movement of the lock ring  48  along the longitudinal axis  54 . For example, rotating the lock ring  48  may secure the outer sleeve  46  in a locked position as discussed previously with regard to  FIG. 2 . Further, in the illustrated embodiment, the lock ring  48  includes axial slots  199 . In operation, the slots  199  are engaged by complementary protrusions of the BPV running tool  112 . The slots  199  transfer rotational torque from the BPV running tool  112  to the lock ring  48 . Accordingly, rotation of the BPV running tool  112  imparts a rotation of the lock ring  48  via the slots  199 , in one embodiment. 
     Turning now to the BPV running tool  112 , as illustrated in  FIG. 3 , the BPV running tool  112  includes a lower tool portion  200  and an upper tool portion  202 . The lower tool portion  200  includes a stem  204 , a threaded portion  206 , a hydraulic port  208 , seals  210  and  212 , a check valve  214 , a groove  216 , and slots  218 . The upper body portion  202  includes a recess  220 , internal protrusions  222 , a port  224 , a check valve stem  226 , and external protrusions  228 . 
     The stem  204  includes a protrusion along the longitudinal axis  54  and extending downward. In operation, the stem  204  engages the bell stem  144 . In other words, as the BPV tool  112  is lowered into and/or engaged with the BPV  12 , the stem  204  engages the bell stem  144 , thereby urging the plunger  50  into the open position. 
     The threaded portion  206  includes an external thread that is complementary to the thread  146  of the upper plunger bore  128 . Accordingly, rotation of the lower portion  200  of the BPV running tool  112  relative to the body  42  generates longitudinal movement of the lower portion of the BPV running tool  112  relative to the body  42  and the BPV  12 . For example, prior to deploying the BPV  12  and the BPV running tool  112 , the BPV running tool  112  is coupled to the BPV  12  via the threaded portion  206  and the thread  146  of the upper plunger bore  128 . When threaded together, the longitudinal movement of the lower portion  200  of the BPV running tool  112  relative to the body  42  and the BPV  12  causes the stem  204  to urge the plunger  50  into an opened position. 
     The hydraulic port  208  includes a bore that extends from an upper end  230  of the lower portion  200  of the BPV running tool  112  and terminates in the external diameter of the lower body portion  200 . In the illustrated embodiment, the hydraulic port  208  includes an L-shape that enables the port  208  to align with the hydraulic port  154  in the upper body portion  122  of the body  42  of the BPV  12 . When the BPV  12  and the BPV running tool  112  are assembled, the two seals  210  and  212  flank the hydraulic ports  208  and  154  enabling pressurized fluid to pass between the ports  208  and  154 . For example, as is discussed in further detail below, hydraulic fluid is injected into the cavity  158  via the hydraulic ports  154  and  208  to urge the outer sleeve  46  into a locked position. 
     Further, the check valve  214  is disposed in the hydraulic port  208 . More specifically, the check valve  214  is disposed in the upper end  230  of the lower portion  200  of the BPV running tool  112 . The check valve  214  helps to block hydraulic fluid from reversing in direction once injected into the hydraulic port  208 . In other words, the check valve helps to maintain pressure within the hydraulic port  208 . In operation, the check valve is opened via the check valve stem  226  that protrudes from the upper portion  202  of the BPV running tool  112 . In the illustrated embodiment, the check valve stem  226  is disposed in the port  224  of the upper portion  202 , and includes a port  232  that extends through its length. Accordingly, the check valve stem  226  engages the check valve  214  (e.g., depresses or moves the check valve  214  along the longitudinal axis  54 , and enables hydraulic fluid to pass from the port  224  to the hydraulic port  208 , in the illustrated embodiment. 
     The groove  216  of the lower portion  200  includes an annular recess in the circumference that is engaged by the internal protrusions  222  of the upper portion  202 . The slots  218  include a plurality of depressions that extend upward from the groove  216  and are spaced around the circumference of the upper end  230  of the lower portion  200  of the BPV running tool  112 . The slots  218  are sized such that the internal protrusions  222  engage the slots  218  when the upper portion  202  and the lower portion  200  are moved longitudinally relative to one another. For example, as is discussed in further detail below, the protrusions  222  include stems that extend inward into the groove  216  enabling the upper portion to rotate about the lower portion  200  in the illustrated position. Upward axial movement of the upper portion  202  causes the internal protrusions  222  to engage the slots  218 , thereby enabling the rotational torque of the upper portion  202  to rotate the lower portion  200 . 
     The external protrusions  228  include pins or similar extensions that protrude from the external diameter of the upper portion  202 . As discussed previously, the external protrusions  228  are configured to engage the slots  199  of the locking ring  48 . Accordingly, rotation of the upper portion  202  translates into rotation of the locking ring  48 , in certain embodiments. 
     It is further noted that the upper portion  202  includes an attachment thread  234 . The attachment thread  234  includes an internal thread that is couplable to casing, tubing, or a similar device employed to run the BPV  12  and/or the BPV running tool  112  into the bore  40 . For example, casing is threaded into the attachment thread  234  to support the BPV running tool  112  and to provide for the delivery of hydraulic fluid in one embodiment. 
     Turning now to  FIG. 4A-4C  a sequence of installing the BPV  12  is illustrated.  FIG. 4A  depicts the BPV  12  and the BPV running tool  112  assembled to one another and disposed in the straight bore  40 . In the illustrated embodiment, the check valve stem  226  has engaged the check valve  214 , the external protrusions  222  are located in the groove  216 , the hydraulic port  208  of the BPV running tool  112  is aligned with the hydraulic port  154  of the body  42  of the BPV  12 , the shear pins  186  are intact (e.g., un-sheared), the stem  204  of the BPV running tool  112  has engaged the bell stem  144  of the plunger  50  (e.g., urged/depressed the plunger  50  to the open position), the friction member  44  is disposed atop the recess  66  in the radially contracted position, a distance  240  exists between the upper face  84  of the friction member  44  and the upper window face  174 , and the seal  52  is engaged by the taper  98  of the body  42 . In other words, the BPV  12  is lowered into the bore  40  in a pre-landing position. 
       FIG. 4B  depicts the BPV system  10  after hydraulic loading of the BPV system  110 . In the illustrated embodiment, hydraulic fluid is injected into the cavity  158  via the hydraulic ports  208  and  154 . As hydraulic fluid is injected into the cavity  158 , the increase in pressure and volume causes a longitudinal downward force on the outer sleeve  42  in the direction of the arrows  92 . The resulting downward force and movement of the outer sleeve  46  shears the shear pins  186 , and urges the outer sleeve  46  downward in the direction of the arrows  92  into engagement with the friction member  44 . In other words, the downward movement of the outer sleeve  46  eliminates the distance between the upper face  84  of the friction member  44  and the upper window face  174  until the upper window face  174  engages the upper face  84  of the friction member  44 . The movement of the outer sleeve  42  creates a gap  160  between the lock ring  42  and the outer sleeve  46 . 
     In the illustrated embodiment, the outer sleeve  46  continues to urge the friction member  44  downward, creating a gap  242  between the body  42  and the friction member  44  and radially expanding the friction member in the direction of the arrows  90 . The radial expansion causes the friction face  80  of the friction member  44  to engage the internal diameter of the bore  40 . Further, the seal  52  is driven longitudinally beyond the taper  98  in the body  42  into a seated position. In other words, the seal is compressed between the body  42  of the BPV  12  and the bore  40 . With the cavity  158  pressurized and the outer sleeve  46  urged into the engage position, the BPV running tool  12  is moved up such that the check valve  214  is disengaged by the check valve stem  226 . Accordingly,  FIG. 4B  depicts the BPV system  110  wherein the BPV  12  has been hydraulically pressurized, and the BPV running tool  112  is hydraulically disengaged from the BPV valve  12 . 
       FIG. 4C  depicts the lock ring  48  rotated into a locked position. For example, with the BPV  12  hydraulically pressurized, and the BPV running tool  112  hydraulically disengaged from the BPV valve  12 , the upper portion  202  of the BPV running tool  112  is rotated. Rotation of the upper portion  202  of the BPV running tool  112  is provided via rotation of the casing, tubing, or other device coupled to the attachment threads  234 , in one embodiment. Accordingly, rotational torque generated by rotating the upper portion  202  of the BPV running tool  112  is transferred to the slots  199  of the locking ring  48  via the external protrusions  228 . The resulting rotation of the lock ring  48  about the threads  196  and  198  causes the locking ring  48  to move longitudinally downward in the direction of the arrows  96 . The rotation is continued until the lock ring  48  is proximate or engages the outer sleeve  46 . In other words, the gap  160  is reduced and/or eliminated. Accordingly, the illustrated embodiment includes the lock ring  48  moved into a locked position. In the locked position, the lock ring  48  abuts the outer sleeve  46 , thereby securing the outer sleeve  46  and the friction member  44  in the radially expanded position. 
       FIG. 4D  depicts the upper portion  202  of the BPV running tool  112  moved upward such that the internal protrusions  222  are disengaged from the groove  216  and have engaged the slots  218  located above the groove  216 . In other words, once the lock ring  48  is disposed in the locked position, the upper portion  202  of the BPV running tool  112  is retracted upward such that the external protrusions  220  disengage the slots  199  of the lock ring  48  and the internal protrusions  222  engage the slots  218  of the lower portion  200  of the BPV running tool  112 . With the internal protrusions  222  engaged in the slots  218 , the upper portion of the BPV running tool  112  is rotated, for example, via rotation of the casing, tubing, or other device coupled to the attachment threads  234 , causing rotation of the lower portion  200  of the BPV running tool  112  that disengages the threaded portion  206  of the lower portion of the BPV running tool  112  to disengage threads  146  in the body  42  of the BPV  12 . Accordingly, rotation of the BPV running tool  112  longitudinally disengages the BPV running tool  112  from the BPV  12 . In one embodiment, once the BPV running tool  112  is disengaged from the BPV  12 , the BPV running tool  112  is retrieved/extracted (e.g., retrieved to a vessel in a subsea system  10 ). 
       FIG. 4E  depicts an embodiment wherein the BPV  12  is installed in the straight bore  40  and the BPV running tool  112  is disengaged and retrieved from the bore  40 . More specifically, the friction member  44  is radially expanded into engagement with the internal surface of the bore  40 , the lock ring  48  is set in the locked position, the seal  52  is seated, and the BPV running tool  112  is retrieved from the bore  40 . 
     As discussed above with regard to  FIG. 2 , the embodiments discussed with regard to  FIGS. 3 and 4A-4E  may include any combination or variation of features. For example, the embodiments may include various configurations of the friction member  44  (e.g., a C-Ring, segments, and/or locking dogs). Further, the friction face  80  may include any variety or combination of surface finishes (e.g., scoring, grooves, teeth, etc.). In addition, the seal  52  may include a MEC seal and/or a LS seal. Further, although not depicted, retrieval of the tool may generally include the BPV running tool  112  being lowered to the BOV  12 , rotating the BPV running tool  112  to back-off the lock ring  48  and relieve the longitudinal force holding the outer sleeve  46  and the friction member  44  in place, and extraction of the BPV  12  and the BPV running tool  112  via the bore  40 . 
     While the invention 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 invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.