Abstract:
A barrier valve system includes one or more barrier valves, a connection sub having a first portion and a second portion connecting one or more control lines to each other, and a replacement portion of the connection sub connectable to the first portion subsequent to retrieval of the second portion. The replacement portion has a port from an outside diameter of the replacement portion to an inside diameter of the replacement portion and seals disposed to define an annular space between the replacement portion and the first portion encompassing only valve opening ports in the first portion.

Description:
BACKGROUND 
       [0001]    In downhole completion systems using Electric Submersible Pumps (ESPs), there is sometimes the need to retrieve the ESP to surface for repair or replacement. The ESP will be a part of an upper completion that will be retrieved as a unit when retrieval of the ESP is required. This will leave a lower completion in the borehole and hence require that a barrier be actuable to seal off the lower completion. Commonly, a valve is positioned near an uphole extent of the lower completion for this purpose. The valve is actuated usually hydraulically. When replacing the most recently installed completion it is necessary to use a wet connect arrangement to reconnect to the hydraulic control lines of the original barrier valve. While wet connect arrangements are well known and often used in the downhole environment, they are also potentially finicky and hence may not always be favored by operators. The art would therefore well receive alternate systems that increase the ease with which post retrieval valve actuation is achieved. 
       BRIEF DESCRIPTION 
       [0002]    Disclosed herein is a barrier valve system which includes one or more barrier valves, a connection sub having a first portion and a second portion connecting one or more control lines to each other, and a replacement portion of the connection sub connectable to the first portion subsequent to retrieval of the second portion. The replacement portion has a port from an outside diameter of the replacement portion to an inside diameter of the replacement portion and seals disposed to define an annular space between the replacement portion and the first portion encompassing only valve opening ports in the first portion. 
         [0003]    Also disclosed herein is a barrier valve system which includes one or more barrier valves and a connection sub having a first portion and a second portion connecting one or more control lines to each other. A replacement portion of the connection sub is connectable to the first portion subsequent to retrieval of the second portion, and the replacement portion is configured to convey applied tubing pressure to the one or more valves such that the one or more valves actuate to an open condition. 
         [0004]    Further disclosed is a method for retrieving and reconnecting an upper completion which includes closing one or more barrier valves in a lower completion proximate a downholemost end of the upper completion, retrieving the upper completion, reconnecting one of the original upper completion or a new upper completion to the lower completion by stabbing a replacement portion into a first portion of a connection sub connected to the lower completion, and applying tubing pressure through the replacement portion to the first portion of the connection sub and to the one or more barrier valves thereby opening the one or more barrier valves. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
           [0006]      FIG. 1  is a schematic view of a barrier system; and 
           [0007]      FIG. 2  is a schematic view of a reconnect system operable with the  FIG. 1  barrier system. 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
         [0009]    Referring to  FIG. 1 , an exemplary borehole completion  8  including a barrier valve system  10  is illustrated. The completion  8  includes a lower completion  12  having a packer  14 , and part of the barrier valve system  10  having one or more barrier valves  16  (illustrated as two but not limited to two) proximate an uphole extent of the lower completion  12 . The barrier valve system  10  itself comprises the one or more barrier valves  16 , control lines  18 ,  20 ,  22  and an annular connection sub  26 , all of which are discussed hereunder. The barrier valves  16  are in operable communication with the control lines  18 ,  20  and  22  (in this exemplary embodiment, more or fewer are contemplated). The control lines  18 ,  20  and  22  terminate at a first portion  24  of the annular connection sub  26  having ports  28 ,  30  and  32  extending radially of the portion  24  of the sub  26 . The portion  24  of the sub  26  is interactive with a second portion  34  of the connection sub  26  that is connected to an upper completion  36 . The second portion  34  also includes radial ports that are annularly in communication with the ports  28 ,  30  and  32 . The ports of portion  34  are labeled  38 ,  40  and  42  as three are shown but it is again noted that more or fewer are contemplated and that there are not necessarily the same number of ports on each portion of the connection sub  26 . Rather, depending upon where seals are located within the connection sub  26 , one or more control lines may be connected to one or more other control lines as desired. The connection sub is more fully described in U.S. Pat. No. 7,487,830, the entire disclosure of which is incorporated herein by reference. 
         [0010]    It will be appreciated in  FIG. 1  that the connection sub  26  includes a number of seals (illustrated as four in  FIG. 1 )  44 ,  46 ,  48 ,  50  that separate various port connections from each other. This provides in the illustrated embodiment three control lines extending from the upper completion (likely to surface) to the lower completion. It is to be appreciated that the seals are mounted to the portion  34  so that they are removed from the connection sub  26  upon retrieval of the upper completion  36 . This is important to functionality of the system herein described as will be more apparent in the discussion below. As illustrated the three lines are for a common close line that will close all barrier valves of the lower completion upon pressure applied therein and two open lines that will selectively open each of the illustrated barrier valves. The installed system  10  will work appropriately in this configuration. 
         [0011]    Upon retrieval of an ESP  52  along with the upper completion  36 , the barrier valves  16  will need to be closed to prevent downhole fluids escaping the completion through an open upper extent of the lower completion  12 . This will be accomplished by pressuring the common control line  18  for closure of the valves  16 . The upper completion  36  may then be withdrawn from the borehole. Upon reintroducing a new upper completion  36  or the original one, the barrier valves  16  must be reopened to reestablish flow potential through the borehole completion system  10 . Wet connection as noted above can be problematic and hence the inventor hereof has devised a way to simplify reconnection using a much easier to connect configuration and applied tubing pressure for actuation of the valves  16 . 
         [0012]    More specifically, and referring to  FIG. 2 , a schematic illustration of the reconnect configuration is presented. Reference is made to first portion  24  of connection sub  26  for continuity from the previous discussion. This portion of the connection sub  26  does not change. Moreover, the reader is reminded that the seals were removed with the second portion  34  of the connection sub  26  when the upper completion was retrieved from the borehole leaving the first portion  24  a seal bore. The replacement portion  54  of the connection sub  26  presents seals  56  and  58  in a different position than the seals  44 ,  46 ,  48 ,  50  were in with the original portion  24  of connection sub  26 . Rather, seals  56  and  58  are positioned on either side of a port  60  through the replacement portion  54  to an inside diameter thereof such that tubing pressure is ported to a space between seals  56  and  58 . 
         [0013]    It was noted above that as an exemplary embodiment, the illustrated configuration has two open lines and a common close line. The ports for these lines are in portion  24  and are labeled  62 ,  64  and  66 . The replacement portion  54  does not use the common close line port  66  as can be seen in the drawing, as it is not within the annular space defined by the seals  56  and  58 . The ports  62  and  64  are however located between the seals  56  and  58  on replacement portion  54  when the replacement portion is landed in portion  24 . This allows the system to provide tubing pressure to the two “open” ports  62  and  64  and through those open the barrier valves  16  that had been closed prior to retrieving the ESP  52  and the upper completion  36 . These barrier valves  16  are to remain permanently open at this point. And the original (or previous) portion  24  is not again used to control the now permanently open valves  16 . 
         [0014]    As can be seen in  FIG. 2 , the replacement portion  54  is the downhole end of a new barrier valve system  110  having a packer  114 , one or more valves  116 , a first portion  124  and a portion  134  of a connection sub  126  and control lines equivalent to those described above. This system  110  is affixed to a downhole end of a new or re-run upper completion string  136  and new or repaired ESP  152 . The system provides for a very simple and tolerant wet connect that uses only tubing pressure to actuate previously closed valves  16  to the open position where they will remain pursuant to the addition of one or more new barrier valves  116  to replace the function of the previous ones should the need arise to retrieve the ESP  152  again. Potential pitfalls of conventional wet connect arrangements are avoided through the use of the applied tubing pressure based concept disclosed herein. 
         [0015]    While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.