Abstract:
A wellhead assembly having a production module that includes valves, modules, and passages and mounts onto a production tree. As the production module lands onto the production tree, flow passages in the production tree register with corresponding flow passages in the module. A production spool has an exit connected to a production flow jumper. The production spool can be supported by coupling to the production tree and has a stab that connects to a production flow passage when the production module is landed on the production tree. The production module can be removed from the production tree without disturbing the connection between the production spool and the production flow jumper.

Description:
BACKGROUND 
       [0001]    1. Field of Invention 
         [0002]    The invention relates generally to equipment for controlling the production of wellbore fluid. More specifically, the invention relates to a module removable from a production tree and having passages that register with passages in the production tree. 
         [0003]    2. Description of Prior Art 
         [0004]    Wellheads used in the production of hydrocarbons extracted from subterranean formations typically comprise a wellhead assembly attached at the upper end of a wellbore formed into a hydrocarbon producing formation. An annular wellhead housing typically makes up the outermost member where wellhead assemblies connect to a wellbore. A production tree usually connects to the upper end of a wellhead assembly for controlling flow in and out of the wellbore and allowing access into the wellbore. Support hangers are generally included within the wellhead housing for suspending production tubing and casing into the wellbore. The casing lines the wellbore, thereby isolating the wellbore from the surrounding formation. The tubing typically lies concentric within the casing and provides a conduit therein for producing the hydrocarbons entrained within the formation. 
         [0005]    Production trees typically include flow lines that connect with other lines outside of the wellhead assembly for porting fluid produced from the wellbore to a location for processing the fluid. Production trees also usually contain passages that also connect to a line is external to the production tree. Typically the passages are used for accessing annuli between concentric wellbore tubulars. The passages are also often used to provide a return path for fluid injected within a tubular (e.g. tubing or casing) that exits the bottom end of the tubular and flows up the wellbore in an annulus around the tubular. Generally, valves regulate flow through the lines and passages, which are included inline with the lines and passages. Thus removing the production tree for service or other reasons usually requires a separate step of disconnecting the lines and passages internal to the tree from the lines and passages external to the tree. 
       SUMMARY OF THE INVENTION 
       [0006]    Disclosed herein is an example of a wellhead assembly having a production module removably mountable on a production tree and a method of wellbore operations. An example embodiment of a wellhead assembly includes a tubular wellhead housing with a tubing hanger landed within, where the lower end of the tubing hanger is attachable to a tubing string. A production module is included having a mounting bore that extends through the production module; a flow passage projects from the mounting bore through the production module. A production tree is included that selectively inserts into the mounting bore, the production tree mounts on an upper end of the wellhead housing. The production tree includes an axial bore that registers with a bore axially through the tubing hanger. A port is included in the production tree that intersects the axial bore and also intersects an outer surface of the production tree. When the production tree inserts into the mounting bore and the production module lands on the production tree, the port registers with the flow passage. A production spool may optionally be included that couples to the production tree, and where the production spool registers with a production line in the production module when the production module is landed on the production tree. In an example, the port is above the upper end of the tubing hanger. Optionally, the port includes a production port for the flow of production fluid. In an example embodiment, the port has an auxiliary line in communication with an axial passage in the tubing hanger that communicates with an annular space between the tubing hanger and the wellhead housing. In an optional embodiment, the wellhead assembly further includes a selectively removable actuator disposed on the production module for actuating a valve disposed in the production module. 
         [0007]    Also included herein is a method of wellbore operations. In an example embodiment the method includes providing a production module that has an axial mounting bore and a passage that intersects the mounting bore. The production module is positioned on a production tree that mounts on a wellbore and that has a port intersecting an outer surface of the production tree. The method further includes inserting the production tree into the mounting bore to register the passage with the port thereby landing the production module on the production tree. Optionally, the method also includes coupling a production spool having a production stab with the production tree so that the production stab registers with a production flow line formed in the production module when the production module is landed on the production tree. In an alternative, the method further includes producing fluid from a wellbore in communication with the production tree and removing the production module from the production tree. In an example, closing a single valve in the production tree isolates the production module from communication with the wellbore. In an example embodiment, a production spool couples with a well flow jumper and the production spool includes a production stab; where the production spool is supported by being coupled with the production tree, and the production stab registers with a production flow line formed in the production module when the production module is landed on the production tree, so that when the production module is removed from the production tree, the production spool remains coupled with the well flow jumper. Optionally, the production tree mounts on a wellhead housing in which a tubing hanger is landed. An actuator may be coupled with the production tree that mechanically couples with a valve provided with the production module, the method can further include operating the valve with the actuator. Fluids may optionally be produced from the wellbore through the production module and actuators mounted on the production module can be removed. 
         [0008]    Also disclosed herein is an example embodiment of a wellhead assembly, that in an example embodiment includes a tubular wellhead housing, a tubing hanger landed in the wellhead housing with a lower end attachable to a tubing string, and a production module. The production module includes an axial mounting bore and a flow passage projecting from the mounting bore. A production tree is included that selectively inserts into the mounting bore; the production tree mounts on an upper end of the wellhead housing. An axial bore in the production tree registers with a tubing hanger bore, where the tubing hanger bore is axially formed through the tubing hanger. Also included is a production passage in the production tree extending between the axial bore and an outer surface of the production tree. A production line is provided in the production module with an entrance that selectively couples with the production passage when the production module is landed onto the production tree. A production stab selectively communicates with an exit of the production line fluid, so that when the production module is landed on the production tree, the production passage is in fluid communication with a production fluid jumper that is connectable to an exit of the production stab. An auxiliary passage may optionally be included in the production module. In an example embodiment, the auxiliary passage engages an auxiliary stab when the production module is landed on the production tree for communicating the auxiliary passage with a tubing annulus. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0009]    Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which: 
           [0010]      FIG. 1  is a side sectional view of a production module coupled onto a production tree in accordance with the present invention. 
           [0011]      FIG. 2  is a side perspective view of an example of engaging the production module and production tree of  FIG. 1 . 
           [0012]      FIG. 3  is a side perspective view of an alternate embodiment of the production module and production tree of  FIG. 1  in accordance with the present invention. 
           [0013]      FIG. 4  is a side perspective view of an example of recovering a production module from a subsea production tree in accordance with the present invention. 
       
    
    
       [0014]    While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION OF INVENTION 
       [0015]    The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout. 
         [0016]    It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation. Accordingly, the improvements herein described are therefore to be limited only by the scope of the appended claims. 
         [0017]    Shown in  FIG. 1  is a side sectional view of an example embodiment of a wellhead assembly  20  that includes a wellhead housing  22  with its lower end mounted on a surface  23  above a formation. In the example of  FIG. 1 , the surface  23  may be a sea floor. An annular casing hanger  24  is landed within the wellhead housing  22  and shown having a string of casing  26  connected on its lower end that depends downward into a wellbore.  FIG. 1  further illustrates a tubing hanger  28  shown landed on an inner surface of the wellhead housing  22  and above the upper end of the casing hanger  24 . A tubing string  30  attaches to a lower end of the tubing hanger  28  and projects downward concentrically within the casing hanger  24  and casing  26 . An annulus  32  is defined between the tubing  30 , wellhead housing  22 , casing hanger  24 , and casing  26 . 
         [0018]    Mounted on an upper end of the wellhead housing  22  is a production tree  34  that is attached to the wellhead housing  22  by a clamp  36 . Landed on the production tree  34  is a production module  38  that is shown having a bore  40  axially formed through the production module  38  and in which the upper end of the production tree  34  is inserted. Within the production module  38  is an auxiliary line  42  shown extending laterally outward from the bore  40  and intersected by another auxiliary line  44 . The production module  38  is positioned on the production tree  34  so that auxiliary line  42  registers with a vent line  46  shown formed axially through the production tree  34 . A valve  48  within the vent line  46  is provided that may be used for regulating or controlling flow through the vent line  46 . Similarly, within the auxiliary lines  42 ,  44  are valves  50 ,  52  for controlling flow through the auxiliary lines  42 ,  44 . An axial passage  54  extends through the tubing hanger  28 , thereby providing fluid communication from the tubing annulus  32  and into the vent  46 . Thus, communication to the tubing annulus  32  may be obtained via the auxiliary lines  42 ,  44  and selective control of the valves  48 ,  50 ,  52 . 
         [0019]    Also shown formed through the production nodule  38  and intersecting the bore  40  is a production line  56  that registers with a production port  58  when the production module  38  is landed on the production tree  34 . A valve  60  is shown disposed within the production port  58  for controlling flow or communication through the production port  58 . A bypass line  62  intersects the production line  56  within the production module  38 . Valves  64 ,  66  respectively provided in the production line  56  and bypass line  62  may be actuated for selectively diverting flow through the production line  56  or bypass line  62 . Also provided in the bypass line  62  is a choke  68  that restricts the cross-sectional area in the bypass line  62  for reducing pressure of the fluid flowing through the bypass line  62  into a pressure more manageable for production of fluid from the wellbore. 
         [0020]    Still referring to  FIG. 1 , an annular production stab  70  is shown providing coupling between the tubing hanger  28  and lower end of the production tree  34  for providing seamless flow from within the wellbore and up to the production port  58 . The tubing  30 , tubing hanger  28 , production stab  70 , and inner bore of the production tree  34  are substantially coaxial and define a main production bore  71  through the wellhead assembly  20 . A production main valve  72  is shown set in the main production bore  71  in the portion within the production tree  34 . The production main valve  72  may be selectively opened or closed to regulate communication to the wellbore through the main production bore  71 . Proximate the upper end of the production tree  34  is a swab valve  74  also set within the main production bore  71  and that may be opened or closed to allow access to within the main bore  71  from the upper end of the production tree  34 . 
         [0021]    An optional sensor  76  is shown coupled on an outer surface of the production module  38  and in communication with the production tree  34 . A lateral passage  80  formed through the production module  38  provides a path for the line  78 . Similarly, an actuator  82  is shown mounted on the production module  38  and coupled to a control line  84  that is set within a passage  86 . The passage  86  enables path for the control line  84  to connect to actuators or devices within the production tree  34  and/or production module  38 . 
         [0022]    Referring now to  FIG. 2 , a side perspective view is shown of an example embodiment of landing the production module  38  of  FIG. 1  onto the production tree  34 . In this example, a bridle assembly  88  is coupled onto an upper end of the production module  38  and suspended by a line  90 . By lowering the production module  38  and aligning the bore  40  in the production module  38  with the upper end of the production tree  34 , the production tree  34  is inserted into the bore  40  as the production module  38  is lowered thereon. As the bore  40  extends through the production module  38 , access to the main production bore  71  in the production tree  34  is unimpeded by the production bore  38 . 
         [0023]    An alternate embodiment of the wellhead assembly  20 A is shown in a side perspective view in  FIG. 3  wherein the production module  38 A is set on the production tree  34 . In the example of  FIG. 3 , a production spool stab  92  is shown as part of a production spool  94 . The production spool  94  is supported by a coupling  95  attaching the production spool  94  to the production tree  34 . Valves  96 ,  98  are shown disposed within the production spool  98  for selectively controlling flow to lines  100 ,  102  that attach to the production spool  94 . The lines  100 ,  102  may provide a pathway for fluids produced from the wellbore to production facilities (not shown) that process or refine the produced fluids. In the example of  FIG. 3 , the production line  56 A has an exit shown intersecting a lower end of the production module  38 A. When the production module  38 A is landed on the production tree  34  the production spool stab  92  inserts into the exit of the production line  56 A. As such, fluid communication between the production spool  92  and main bore  71  is established via the production port  58  and production flow line  56 A through the production spool stab  92 . 
         [0024]    Also optionally provided in the example of  FIG. 3  is an optional choke actuator  104  shown mounted to the production tree via coupling  105 . Mechanical linkages  106 ,  108  extend from the choke actuator  104  to valves  64 ,  66  for regulating flow through the production flow line  56 A and/or bypass line  62  in the production module  38 A. Thus, by orienting the production module  38 A as it lands on the production tree  34 , communication can be established between the production flow line  56 A and production spool stab  92 , as well as automatic coupling of the choke actuator  104  and mechanical linkages  106 ,  108  for controlling flow through the production flow line  56 A. 
         [0025]    Referring now to  FIG. 4 , in an example of operation the production module  38  is shown being removed from the production tree  34 , such as for maintenance or other reasons. An advantage of the example shown is that the connectivity to the jumper flow lines  100 ,  102  may be maintained as the module  38  is removed from the production tree  34 . In this example, only the production main valve  72  is required to be closed in order to isolate flow from the wellbore for allowing removal of the production module  38 . Similar to the production spool  94  is an auxiliary spool  110  mounted to the production tree  34  and having an auxiliary stab  112  for automatic coupling with auxiliary line  42 A as the production module  38  is landed onto the production tree  34 . Further, in the example of  FIG. 4 , a work boat  114  is used for raising and lowering the line  94  removal and/or landing of the production module  38 . 
         [0026]    The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.