Abstract:
A remote operated tool string deployment apparatus (RODA) is provided for use with a remote operation coil connector (ROCC) in a well intervention system. The ROCC enables the remote connection of intervention tool strings or bottom hole assemblies (BHA) to the coiled tubing where manually changing them is not possible.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a remote operated tool string deployment apparatus (RODA) designed for use with a remote operated coil connector apparatus (ROCC) for deployment of coiled tubing within a well bore as part of a well intervention system.  
           [0002]    The ROCC with which the RODA is employed enables the remote connection of intervention tool strings or bottom hole assemblies (BHA) to the coiled tubing where manually changing them is not feasible. A ROCC, particularly adapted for this purpose and for use with the RODA of the instant application, is described in Norris et al., U.S. Patent Application “Remote Operated Coil Connector Apparatus”, filed May 2, 2002, Ser. No. ______. The disclosure of this patent application is fully incorporated by reference in the instant application.  
           [0003]    Where the overall length of the intervention tool string or BHA exceeds the capacity of the available lubricator section, it becomes necessary to make up the tool string in sections using the well as the lubricator. This requires a secondary RODA system for use with the ROCC system that enables the remote, sequential, staggered deployment of the intervention tool string or BHA into the well.  
           [0004]    Specifically, the RODA system permits the sequential remote mechanical, hydraulic and electrical disconnection and reconnection of the upper part of the ROCC to and from a plurality of deployed RODA working tool string sections. It locates and houses a deployed tool string section via the provision of a RODA tool holder situated and spaced immediately above the well head blowout preventer (BOP). The RODA provides for a deployment bar on the lower part of each deployed tool string section, spaced to suit the configuration of the well head BOP, thus enabling the coiled tubing sealing rams to close around it. There is further provided by the RODA an internal double-barrier to the well in each tool string section during the duration of the deployment operation.  
           [0005]    It is accordingly an object of the present invention to provide a RODA system having these features and functions for use with a ROCC system enabling the remote, sequential, staggered deployment of intervention tool strings or bottom hole assemblies into the well bore.  
         SUMMARY OF THE INVENTION  
         [0006]    In accordance with the invention, there is provided a remote operated tool string deployment apparatus having means for sequentially engaging and removing a plurality of tool strings from a remote container. It further provides means for sequentially moving the tool strings away from the container and into the well bore and means within the well bore for sequentially receiving these tool strings and retaining the tool strings. Means are provided for sequentially disconnecting the tool strings from the engaging means within the well bore and means for activating the tool strings within the well bore to perform a tool operating function.  
           [0007]    The apparatus may further include a coiled tubing as the means for sequentially engaging and removing a plurality of tool strings from a remote container.  
           [0008]    With the apparatus, the means for sequentially engaging and removing may further include a remote tool string connector.  
           [0009]    The means for sequentially receiving and retaining may include a plurality of tool holders.  
           [0010]    The tool holders may include a profile portion for engagement with a latching mechanism of the tool string connector.  
           [0011]    Each of the tool holders may further include a release mechanism for remotely releasing the coiled tubing from the tool string connector to separate the tool string connector from the tool string.  
           [0012]    The release mechanism may include means for radially, sequentially expanding and retracting a profile out of and into engagement with a corresponding abutting surface on the tool string connector.  
           [0013]    The release mechanism may further include hydraulic actuation means.  
           [0014]    The remote operated tool string deployment apparatus in accordance with the invention preferably includes a coiled tubing and a remote tool string connector for sequentially engaging and removing a plurality of tool strings from a remote container. Means are further provided for moving the tool strings away from this container and into a well bore. A plurality of tool holders are provided within the well bore for sequentially receiving the tool strings and retaining the tool strings. Means are provided for sequentially disconnecting the tool strings from the tool string connector within the well bore. Means are provided for activating the tool strings within the well bore to perform a tool operating function.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is an assembly view in vertical cross-section of one embodiment of a remote operated tool string deployment apparatus (RODA) for use with a remote operation coil connector (ROCC), as described in the aforementioned patent application;  
         [0016]    [0016]FIG. 1 a  is a view in vertical cross-section of the upper connector of the RODA shown in FIG. 1;  
         [0017]    [0017]FIG. 1 b  is a view similar to FIG. 1 a  of the bulkhead section of the assembly of FIG. 1;  
         [0018]    [0018]FIG. 1 c  is a view in partial cross-section of the deployment bar of the assembly shown in FIG. 1;  
         [0019]    [0019]FIG. 1 d  is a view similar to FIG. 1 a  of the lower connector of the assembly shown in FIG. 1; and  
         [0020]    [0020]FIG. 2 is a sectional view of a tool holder for use with the assembly of FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    With reference to the drawings, and for the present to FIG. 1 thereof, there is shown a RODA tool string section in accordance with a preferred embodiment of the invention. There is shown a RODA upper section designated as A and shown specifically in FIG. 1 a ; a TFCV bulkhead section designated as B and shown specifically in FIG. 1 b ; a deployment bar designated as C and shown specifically in FIG. 1 c ; and a RODA lower section designated as D and shown specifically in FIG. 1 d.    
         [0022]    The RODA upper connector, designated as A in FIG. 1 and shown specifically in FIG. 1 a , is compatible with the upper portion of a ROCC tool string, such as that described in the aforementioned patent application. Specifically, it forms the upper connection to a working tool string section, thus enabling the next deployed tool string section to locate and latch. Further, it provides an internal receptacle for the mechanical connection to the mating RODA connector. Further, it houses single or multiple electrical “wet” connections to match those of the mating RODA connector. A sealing area is provided for the mated connector to enable continuity of fluid passage through the assembly. Externally, the RODA upper connector provides a mechanical anchor to locate the RODA tool holder, the specific embodiment of which is shown in FIG. 2.  
         [0023]    Specifically, the RODA upper connector A includes a latch receptacle  1  to receive the mechanical latch connection of the upper ROCC. When the keys designated as  9  in FIG. 1 d  of the upper ROCC are latched into this receptacle  1 , a joint is formed which can only be released by extraneous means provided by the tool holder which will be later described.  
         [0024]    Internally, the latch receptacle  1  houses a bulkhead carrier  2  which in turn houses a pressure resistant multiple contact electrical “wet connect” stab connector  3  to mate with the connector in the upper ROCC designated in FIG. 1 d  as  12 . With the assembly so connected, a seal bore  1   a  is provided. This seal bore constitutes a chamber within the assembly that is pressure resistant to the well.  
         [0025]    Externally, a series of spring-loaded, downward-facing anchor keys  4  are positioned to provide a positive, downward load-bearing seat against a mating shoulder  1 , as shown in FIG. 2A, housed within the tool holder and capable of holding the hanging weight of the tool string. Similarly, a set of upward facing anchor keys  4   a  are positioned to provide a positive, upward load-bearing seat against a mating shoulder  2 , as shown in FIG. 2A, housed within the tool holder, thereby acting as a positive stop for the locating of the RODA tool string. The shoulder will enable an over-pull to be taken through the coiled tubing once the upper ROCC has latched.  
         [0026]    With respect to the TFCV bulkhead, designated as B in FIG. 1 and shown particularly in FIG. 1 b , an offset twin flapper check valve  5  is housed within a bulkhead joint  6 . To provide for electrical feedthrough when required, the bulkhead joint has an offset “wet matable” pressure resistant multi-contact electrical connector  7  to maintain electrical continuity through the assembly.  
         [0027]    With reference to FIG. 1 c , the deployment bar designated as  8  has a diameter corresponding to the size of the coiled tubing being used with the assembly. The length of the deployment bar is designed so that when the RODA tool string is located into the RODA tool holder, which will be described later with respect to FIG. 2, the deployment bar will be aligned with the BOP pipe rams designated as  8   a  in FIG. 1 c . Upon closing of these pipe rams  8   a , an external seal is formed around the tool string.  
         [0028]    With respect to FIG. 1 d , the RODA lower connector is shown for forming the lower connection of a working tool string section which locates and latches the next to be deployed tool string section. Specifically, it forms a mechanical latch connection for the mating RODA connector. In addition, it houses single or multiple electrical “wet” connectors to match with the mating RODA connector. It, likewise, provides a seal for the mating connector to enable continuity of fluid passage through the overall assembly of the RODA.  
         [0029]    This RODA lower connector includes a series of spring loaded latch keys  9  designed to locate and latch into the receptacle  1  in the RODA upper connector. Once the keys  9  of the connector are latched into the receptacle  1 , a joint is formed which can only be released by extraneous means provided by the tool holder, which will be later described.  
         [0030]    Internally, the body designated as  10  houses a bulkhead carrier  11  for a pressure resistant multiple electrical “wet” slab connector  12  which matches the connector  3  in the upper RODA shown in detail in FIG. 1 a . This body  10 , when in mated connection with the upper RODA, provides a sealed chamber that is pressure resistant to the well. The male fluid union  10   a  in the lower RODA will be engaged into the seal receptacle provided in the upper RODA shown in FIG. 1 a  to provide a continuous and pressure-containing chamber.  
         [0031]    With reference to FIG. 2, there is shown a RODA tool holder for use with the remote operated tool string deployment apparatus in accordance with the instant invention. The tool holder of FIG. 2 differs from that shown and described in the aforementioned patent application in that it is a permanent fixture incorporated immediately above or close to the BOP of the well head. It provides a secondary locator and housing for the deployed tool string sections.  
         [0032]    The tool holder includes a catcher sleeve compatible with the anchor keys of the RODA tool string. An upper and lower profile is provided to mechanically release the anchor keys. A remote operated profile is incorporated that may be energized in order to release the lower connector latch keys of the RODA tool string.  
         [0033]    Specifically, within the body  13  of the tool holder, there is provided a spring-loaded catcher sleeve  14 . A preloaded spring  15  set to a selected force is likewise provided. At each end of the internal diameter of the catcher sleeve  14 , square, load-bearing shoulders  20  are formed into which the anchor keys  4  and  4   a  of the upper RODA connector will locate. If these keys are pulled or pushed beyond a selected force, they will contact an upper or lower profile  16  in the body of the RODA tool holder and at this point be compressed and released from the catcher sleeve  14 .  
         [0034]    Also housed within the body of the RODA tool holder is a normally retracted or “floating” series of lugs  17  that act as a release profile when energized. This release profile may be energized hydraulically through an external hydraulic control line port  18 . As the hydraulic pressure is applied through the port  18 , a spring-loaded piston sleeve  19  moves down and over the profile, thereby locking it into the internal bore  13   a  of the tool holder to form a reduced-neck internal diameter portion. This will serve to release the lower connector latch keys designated as  9  in FIG. 1 d  of the RODA tool string. When the lugs  17  forming the release profile have served their purpose, the hydraulic pressure supply is reduced and the spring-loaded piston sleeve  19  will thus move back to its original position. This allows the release profile lug  17  to retract so that the tool string may pass through the internal bore  13   a  of the tool holder without obstruction.  
         [0035]    Description of Operation  
         [0036]    The ROCC connector provides the first connection to the RODA tool string. When its connection is completed, the RODA tool string can be moved to the RODA tool holder. Once the RODA tool string is so located, which an upward overpull of the coiled tubing will confirm, the pipe rams of the BOP are operated to close around the deployment section  8  of the RODA tool string. The RODA tool string is now constrained by this operation.  
         [0037]    To release the ROCC from the RODA tool string, the tool holder, remote operated release profile  17  is energized. This is achieved hydraulically via control line  18 . The energized release profile  17  provides a reduced neck portion, as shown in FIG. 2B. If the RODA tool string is pulled beyond a preset force, the latch keys  9  of the ROCC will contact this reduced neck portion. As this pulling is continued, the ROCC latch keys  9  will be compressed, thereby releasing the ROCC from the upper connector of the RODA tool string which will remain in situ. The ROCC is then free to return to its start position in order to pick up the next required RODA tool string for the deployment cycle to be continued. In order to introduce the deployed RODA tool string into the well, the BOP pipe rams must be opened. The RODA tool string is then pushed down against the catcher sleeve  14  via the anchor keys  4  and  4   a  beyond a preselected force so that they will contact the lower profile  16  in the body of the RODA tool holder to compress and be released from the catcher sleeve  14 . The tool string is now free to enter the well bore.  
         [0038]    When this operation is completed and the RODA tool string is removed from the well bore, each deployed section must be dismantled to be stored for subsequent use. To achieve this, the last deployed tool string section must be pulled through the RODA tool holder catcher sleeve  14 , as shown in FIG. 2. An overpull load will result as this occurs.  
         [0039]    Once the next RODA tool string has been located into the RODA tool holder, the BOP pipe rams are closed. Again, the RODA tool holder remote operated release profile must be energized. The RODA lower tool string connection can then be released by over-pulling as previously described, leaving the upper RODA tool string connection of the next section and remainder of the tool string BHA in situ.  
         [0040]    The ROCC connector, providing the connection to the released RODA tool string section, can now move upward to locate it into the ROCC tool holder from where it was originally located and now will be released. The ROCC tool holder, now housed in a released RODA tool string section, can then be stored and replaced with another empty tool holder ready for the next RODA tool string section.