Abstract:
A handling and assembly system and method for use in deploying tubing in a subterranean environment. A framework is used to linearly engage sequential tubular members as a tubing string is formed and run into a subterranean environment. The system also facilitates the disassembly of the individual tubular components from the tubing string.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    The following is based on and claims priority to Provisional Application serial No. 60/408,279, filed Sep. 5, 2002 and to Provisional Application serial No. 60/385,272, filed Jun. 3, 2002. 
     
    
     
       BACKGROUND  
         [0002]    In a variety of subterranean environments, such as wellbore environments, tubing is deployed in sections that are sequentially connected. For example, sections of production tubing may be threaded together as tubing is continually run into a wellbore. Additionally, tubular members, such as sand screens and other wellbore completion components, are connected as such systems are moved downhole. Some existing tubular members comprise a joint area with a fixed shoulder that rests on plates of a screen table while the next sequential member is connected. However, new component designs, e.g. new sand screen designs, may be made without shoulders and without threaded engagement features. Accordingly, existing handling and assembly equipment may not be adequate for handling such components.  
         SUMMARY  
         [0003]    In general, the present invention provides handling and assembly equipment. Embodiments of the handling and assembly equipment provide for downhole applications using a variety of sand screen as well as other wellbore component configurations.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]    Certain exemplary embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like referenced numerals denote elements, and;  
         [0005]    [0005]FIG. 1 is a schematic illustration of a handling and assembling system, according to an embodiment of the present invention;  
         [0006]    [0006]FIG. 2 is an isometric view of an assembly press according to one embodiment of the invention;  
         [0007]    [0007]FIG. 3 is an isometric view of an embodiment of an upper or lower clamp illustrated in FIG. 1;  
         [0008]    [0008]FIG. 4 is an isometric view of a lifting wrap according to an embodiment of the present invention;  
         [0009]    [0009]FIG. 5 is an isometric view of an embodiment of a wrap key used with the lifting wrap illustrated in FIG. 4;  
         [0010]    [0010]FIG. 6 is generally an axial cross-sectional view illustrating the lifting wrap of FIG. 4 combined with a sand screen;  
         [0011]    [0011]FIG. 7 is a cross-sectional view of an embodiment of an upper sub assembly taken generally along its axis;  
         [0012]    [0012]FIG. 8 is a cross-sectional view similar to FIG. 7;  
         [0013]    [0013]FIG. 9 is another cross sectional view similar to FIG. 7;  
         [0014]    [0014]FIG. 10 is a front view of an embodiment of a screen having a hanging wrap profile;  
         [0015]    [0015]FIG. 11 is an isometric view of an embodiment of a shoulder key for use with a shoulder wrap;  
         [0016]    [0016]FIG. 12 is an isometric view of another embodiment of a shoulder wrap;  
         [0017]    [0017]FIG. 13A is a front view of the shoulder wrap and screen illustrated in FIG. 12 disposed on screen table plates;  
         [0018]    [0018]FIG. 13B is a front view similar to FIG. 13A but showing an alternate shoulder wrap;  
         [0019]    [0019]FIG. 14 is a front view of a tubular member having an embodiment of a slip gripping area; and  
         [0020]    [0020]FIG. 15 is a front view of the tubular member illustrated in FIG. 14 with slips applied to the slip gripping area. 
     
    
     DETAILED DESCRIPTION  
       [0021]    In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.  
         [0022]    The present invention generally relates to handling and assembly equipment and related methods. These equipment and methods are useful with, for example, tubulars fitted with bayonet-type connectors. However, the equipment and methods of the present invention are not limited to use with those specific type connectors and corresponding tubulars. The present invention may be used with other tubulars and other types of equipment. For example, the present invention may be useful with sand screens, well equipment having stab-in type connections, expandable tubing, expandable sand screens and other well equipment components and connections.  
         [0023]    Referring generally to FIG. 1, a system  20  is illustrated according to an embodiment of the present invention. The system  20  comprises an assembly tool  22  to facilitate the sequential assembly of tubular components that are deployed in, for example, a wellbore  24 . For example, a tubular component  26 , such as a sand screen, may be held by assembly tool  22  while another tubular member  28 , e.g. production tubing or sand screen section, is connected to sand screen  26 . Tubular members  26  and  28  are described to aid in the description of system  20 , however a variety of other types of downhole components can be utilized in the system.  
         [0024]    The upper tubular member  28  is brought into proximity with lower tubular member  26  to enable coupling of the tubular members via assembly tool  22 . Tubular member  28  may be moved towards assembly tool  22  and tubular member  26  by a lifting elevator  30 , such as the type utilized with a rig. Lifting elevator  30  may be connected to tubular member  28  through a damper unit  32  that aids in the connection of tubing members as well as the loading and unloading of the tubing string as sequential tubular members are added to the string.  
         [0025]    In FIG. 2, an embodiment of assembly tool  22  is illustrated. In this embodiment, assembly tool  22  comprises an assembly press  34  having a frame  36 , a securing system  37 , such as a spider  38 , an upper clamp  40 , a lower clamp  42  and a linear actuator  44 , such as a moving platform. Frame  36  comprises a linear guide  46  along which platform  44  moves in a linear, e.g. vertical, direction. Spider  38  is used to hang the tubular members, e.g. sand screen  26 , at the rig floor surface during assembly of subsequent tubular members.  
         [0026]    Although spider  38  is illustrated for hanging the string at the rig floor surface during assembly of tubular components, other devices, such as screen table plates, can be utilized as described in greater detail below. Examples of spiders that can be used in assembly tool  22  are commercially available spiders, such as the CAVINS ‘Advance’ spider available from Cavins Oil Well Tools of Long Beach, Calif., U.S.A. and illustrated at the Cavins website http://www.cavins.com/. The spider has hydraulically activated slips for holding tubular members at the rig floor. Such spiders come in a variety of sizes for various diameter pipes and other tubular members. It also should be noted that the handling of tubular members by spider  38  can be enhanced with the use of slip liners designed for “non-marking” applications, such as slip liners available from Cheyenne Services, Inc. of Houston, Tex. The slip liners provide smooth slip inserts able to hold the tubing string in the spider slips without substantial marking of the tubular members.  
         [0027]    During assembly of a tubular string, assembly tool  22  is used to hold the string, e.g. an expandable screen string, at the surface while assembling or disassembling connections. For assembly, the first tubular member  26  is lowered into the spider  38  and the slips are closed to hang the tubular member  26 , e.g. a sand screen section. The next tubular member  28  is then lowered into place over member  26 , as illustrated in FIG. 1, such that the ends of the tubular members are aligned. The moving platform  44  with upper clamp  40  is then moved towards tubular member  28  until upper clamp  40  may be closed on tubular member  28 . Platform  44  is then moved downwardly until a lower end  45  of tubular member  28  is snapped or otherwise joined to an upper end  47  of tubular member  26  (see FIG. 1). Following completion of the assembly, the upper clamp  40  is opened followed by release of spider  38  such that the tubing string may be run-in-hole until positioned for the next joint assembly. This process is continued until the screen string or other tubular string is completely assembled.  
         [0028]    For disassembly, the connection to be disconnected is moved into position below upper clamp  40  and securing system  37 , e.g. spider  38 , is set. Then, upper clamp  40  is clamped to the upper tubular member while lower clamp  42  is clamped to the lower tubular member. Actuating platform  44  moves upper clamp  40  upwardly along linear guide  46  to linearly disconnect the tubular members. The remaining tubing string is once again lifted to enable disconnection of the next joint, and this process is continued until the desired state of disassembly is achieved.  
         [0029]    In the embodiment illustrated, moving platform  44  is hydraulically actuated. However, platform  44  may be moved by a variety of other actuators, such as pneumatic actuators, ball screws and other mechanisms.  
         [0030]    An embodiment of upper and lower clamps  40 ,  42  is illustrated in FIG. 3. In this embodiment, each clamp  40 ,  42  utilizes at least one hydraulic cylinder  48 , e.g. two hydraulic cylinders  48 , coupled to at least two C-shaped clamp faces  50  via linkage mechanisms  52 . Linkage mechanisms  52  are slideably or pivotably mounted within a clamp framework  54  to move C-shaped clamp faces towards and away from each other upon actuation via hydraulic cylinder  48 . The C-shaped clamps are designed to hold with enough force for the assembly and/or disassembly of the tubing string joints. The linear guide  46  maintains the upper clamp  40  and lower clamp  42  in general alignment.  
         [0031]    Referring generally to FIGS.  4 - 6 , a lifting mechanism  56  for moving tubular members, such as a tubular sand screen, is illustrated. Lifting mechanism  56  is designed to selectively couple a tubular member, e.g. tubular member  26  or  28 , to an appropriate deployment system, such as a lifting elevator  30  or the combined lifting elevator  30  and damper unit  32 . In the embodiment illustrated in FIGS.  4 - 6 , lifting mechanism  56  comprises a mandrel  58  and a lifting wrap  60  for selectively coupling mandrel  58  to a tubular member, such as tubular member  26 . In this embodiment, mandrel  58  may be connected to damper unit  32  either directly or by an appropriate connector or coupling. The mandrel  58  and lifting wrap  60  may be used to securely grab the end of a tubular member to lift the member in and out of wellbore  24 . As illustrated in FIGS. 4 and 5, an embodiment of lifting mechanism  56  comprises a plurality of lifting keys  62 . Each lifting key  62  comprises at least a pair of pivot features  64  that may have tabs  66  with openings  68  for receiving pivot pins  70 . Thus, each lifting key  62  may be pivoted with respect to the adjacent lifting keys to which it is pivotably attached via pivot pins  70 . Lifting wrap  60  is wrapped around a tubular member and connected by a final connector pin  72 , as illustrated in FIG. 4.  
         [0032]    In the embodiment illustrated, each lifting key  62  also comprises an engagement feature  74  able to engage both mandrel  58  and a selected tubing component, such as sand screen  26 . As illustrated in FIG. 5, engagement feature  74  may comprise a pair of extensions  76  configured to engage corresponding features  78  of mandrel  58  and tubular member  26 . In this embodiment, corresponding features  78  comprise a mandrel shoulder  80  extending radially upward from mandrel  58  and an opening or recess  82  formed in the sidewall of tubular member  26 .  
         [0033]    To connect lifting mechanism  56  to tubular member  26 , a lead end  84  of mandrel  58  is inserted into the interior of tubular member  26  until the upper extent of tubular member  26  is adjacent a lower end of mandrel shoulder  80 . The lifting wrap  60  is then wrapped around mandrel  58  and tubing member  26 , such that the lower extensions  76  of each lifting key  62  engage corresponding openings  82  formed in tubular member  26 . Simultaneously, each upper extension  76  of lifting key  62  is engaged with mandrel  58  above shoulder  80  to affectively secure mandrel  58  to the upper end of tubular member  26 . Upon insertion of the final connector pin  72 , the tubular member  26  may be lifted and moved via mandrel  58 . For example, tubular member  26  may be moved into position for connection to the next adjacent tubular member. Mandrel  58  may be released from tubular member  26  by releasing and unwrapping lifting wrap  60 . Similarly, mandrel  58  and lifting wrap  60  may be coupled to a tubular that is to be disconnected and lifted away from an adjacent tubular.  
         [0034]    Mandrel  58  may be connected to or formed as part of damper unit  32  which serves as an upper subassembly to accommodate movement of the tubular members during assembly. As illustrated in FIGS.  7 - 9 , an embodiment of damper unit  32  enables the movement of the upper screen  28  towards lower screen  26 . The damper unit contains a mechanism to absorb the movement of the upper tubular member during assembly and to dampen movement upon release from the tubing string.  
         [0035]    As illustrated in FIG. 7, damper unit  32  comprises an external housing  86  coupled to a pair of end caps  88 ,  90 . A shaft  92  is slideably mounted through end cap  88  and comprises a connector end  94  appropriately designed for connection with lifting elevator  30 . Opposite connector end  94 , shaft  92  is coupled to a piston  96 . Piston  96  has a generally hollow interior  98  and a distal flange  100 . A spring  102 , such as a coil spring, is disposed within external housing  86  between end cap  88  and distal flange  100  to bias piston  96  towards end cap  90 .  
         [0036]    Within hollow interior  98 , a damper piston  104  is slideably positioned and coupled to end cap  90  by, for example, a shaft  106 . Damper piston  104  comprises a flow control system  108 . Additionally, damper unit  32  comprises an extension  110  that is coupled to end cap  90  and extends from end cap  90  to a connector end  112  designed to engage and lift the appropriate tubular members. For example, connector end  112  may be designed to latch to mandrel  58 .  
         [0037]    Referring specifically to FIGS. 8 and 9, operation of damper unit  32  can be further described. It should be noted that in FIGS. 8 and 9, the damper unit has been illustrated without spring  102 . In FIG. 8, damper unit  32  is shown in an unloaded state. As the string load is applied to damper unit  32  at connector end  112 , spring  102  is compressed, and the compression continues with the downforce of the overall tooling increasing until piston  96  abuts against end cap  88 , as illustrated best in FIG. 9. The additional string load is carried through the shouldering interface between end cap  88  and piston  96 . Furthermore, as piston  96  moves from the unloaded state, illustrated in FIG. 8, to the loaded state, illustrated in FIG. 9, damper piston  104  translates through the hollow interior  98  of piston  96 . During this translation, a hydraulic fluid  114  within hollow interior  98  passes through flow control system  108  of damper piston  104  to an opposite side of damper piston  104 , as illustrated in FIG. 9. Flow control system  108  is designed to permit relatively easy oil flow through damper piston  104  during loading of the tool and substantially more restricted flow upon unloading of damper unit  32 . For example, flow control system  108  may be designed such that as loading occurs, hydraulic oil moves valve plates to expose large holes for easy flow between chambers, i.e. from the right side of damper piston  104  (FIG. 8) to the left side of damper piston  104  (FIG. 9). When damper unit  32  is unloaded, however, the oil pushes the valve plates closed to cover the large holes. Small orifice holes formed either through the valve plates or other parts of damper piston  104  restrict the flow as damper unit  32  transitions from the loaded to the unloaded state. Thus, the energy is allowed to dissipate slowly and in a controlled manner during release of the damper unit or failure of a system component.  
         [0038]    System  20  is amenable to the relatively rapid assembly and disassembly of tubular members that have linear type connectors, such as connectors that stab into one another to form a connection. Although a wide variety of configurations, orientations, sizes and profiles can be used to form such linear connectors, an example is illustrated in FIG. 10. In this design, the tubular member  26  comprises a linear connector end  116 , such as a stab-in connector. Linear connector end  116  is designed to linearly engage a similar, corresponding connector end disposed on the next adjacent tubular member, e.g. tubular member  28 , to form a tubing string joint as the tubing members are linearly engaged. In this embodiment, tubular member  26  does not have a permanent shoulder, but instead has a plurality of fingers  118 . Each finger  118  includes a stab-in connector head  120  designed to linearly engage corresponding connector heads  120  on the next sequential tubular member. Additionally, linear connector end  116  comprises openings  82 , as described above with reference to FIG. 6. Openings  82  are sized to receive extensions  76  of lifting keys  62  when lifting wrap  60  is wrapped around tubular member  26  and mandrel  58 .  
         [0039]    Alternatively, a different embodiment of lifting wrap  60  can be used in conjunction with linear connector ends  116  of tubular members, such as tubular members  26  and  28 . In this embodiment, a plurality of shoulder keys  122  (see FIG. 11) are pivotably connected as illustrated in FIG. 12. For example, each shoulder key  122  may comprise a pair of opposed flanges  124  that are pivotably connected to one another via, for example, openings  126  and corresponding pivot pins. The plurality of pivotably connected shoulders keys  122  are combined to form a shoulder wrap  128  that securely engages the tubular member, e.g. sand screen  26 . In the example illustrated, each shoulder key  122  comprises an engagement feature  130  that enters a corresponding opening  131  when shoulder wrap  128  is wrapped around tubular member  26  and pinned together with a final retention pin, as described with respect to lifting wrap  60 .  
         [0040]    In this embodiment, shoulder keys  122  are combined into shoulder wrap  128  which creates a removable shoulder that may be selectively attached to each tubular member. The removable shoulder can be utilized with, for example, a hanging plate  132 , e.g. a screen table plate, as illustrated in FIG. 13A. The shoulder wrap  128  is coupled to the tubular member, e.g. tubular member  26 , and hung from a hanging plate  132 . Thus, in some embodiments and applications, spider  38  may be replaced or supplemented by hanging plate  132 . Additionally, the shoulder wrap  128  can be used independently with hanging plate  132  or other hanging devices.  
         [0041]    Another embodiment of a shoulder wrap  128  is illustrated in FIG. 13B. In this embodiment, shoulder wrap  128  is designed for engagement with a tubular member, e.g. tubular member  26 , via a profile  134 , such as a plurality of grooves and ridges, as illustrated by hidden lines in FIG. 13B. The profile  134  may comprise other features, such as notches, dimples and other types of profiles able to support increased axial loading. In the illustrated embodiment, profile  134  is directed inwardly for engagement with a corresponding profile  136 , e.g. grooves and ridges, formed in tubular  26 .  
         [0042]    Although the profile  134  may be formed in a variety of components, one example utilizes a pair of generally C-shaped collar members  138  pivotably connected via a pivot  140 , such as a pivot pin. Thus, collar members  138  may be pivoted between an opened position and a closed position in engagement with corresponding profile  136 . A fastener  142 , such as a threaded fastener, can be connected between collar members  138  to securely force collar members  138  to a closed position over corresponding grooves and ridges  136 . Thus, the weight of tubular member  26  along with any appropriate suspended tubing string can be supported by shoulder wrap  128  on, for example, hanging plate  132 . Furthermore, during assembly or disassembly of the tubular members, the shoulder wrap  128  may be selectively disengaged and reengaged with subsequent tubular members.  
         [0043]    The shoulder wrap illustrated in FIG. 13B also may comprise an abutment  141 , such as a pin, that extends into a corresponding feature of the tubular member or a coupling connected to the tubular member. Abutment  141  prevents relative rotation between collar members  138  and the tubular member. Furthermore, the shoulder wrap may comprise an interfering profile  143  positioned to engage a corresponding feature on hanging plate  132 . Profile  143  prevents rotation of the shoulder wrap relative to hanging plate  132  during assembly or disassembly of tubular components. The abutment  141  and profile  143  enable the coupling of a wide variety of tubulars including tubulars that are threaded together. For example, connector end  116  may be replaced with a threaded connector. In one embodiment, a lifting sub connected to lifting elevator  30  is coupled to a tubular via the shoulder wrap and a coupling. The lifting sub and the coupling are connected by a lift sub ring that attaches to the coupling with left handed threads. The left handed threads prevent unthreading/disconnection of the lift sub during connection of tubulars having threaded connector ends.  
         [0044]    In an alternate embodiment, openings  131  are replaced with another type of engagement feature, as illustrated in FIGS. 14 and 15. In this embodiment, a tubular member, such as sand screen  26 , comprises a plurality of thin slots that can be arranged in a variety of cell patterns along the tubular member. The thin slots  144  are transitioned to expanded slot regions  146  that form a slip grip area  148 . The increased slot width allows the screen  26  to be compressed when squeezed by, for example, a plurality of slips  150 , as illustrated in FIG. 15. Slips  150  may be of the type used with spider  38 . When slip grip area  148  is squeezed by slips  150 , the sand screen is radially compressed to a smaller diameter relative to the unsqueezed tubular portions. The smaller diameter creates a shoulder  152  that rests on an upper edge of slips  150  and provides mechanical holding power. Thus, this type of engagement feature allows each tubular member to be held by assembly tool  22  during coupling with the next sequential tubular member moved linearly into engagement with the hanging member.  
         [0045]    Although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art or readily appreciate that many modifications are possible without materially departing from the teachings of this invention. Accordingly, such modifications are intended to be included within the scope of this invention as defined in the claims.