Abstract:
A self-actuated cyclical flow interruption valve on a deployment tool is positioned at a proximal end of a well completion assembly. Fluid is pumped though the self-actuated cyclical flow interruption valve and vented immediately distal of the valve, to return to surface of the well. A water hammer pulse is generated each time the self-actuated cyclical flow interruption valve closes, thereby generating an impact force that acts to push the completion equipment distally into the well. The continuous cyclic force of the impact facilitates placement of the completion equipment where desired in the well, including within a horizontal extension of the well. Fluid discharged through the self-actuated cyclical flow interruption valve circulates up to the surface through a vertical and inclined section of the well.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of U.S. Provisional Patent Application, Ser. No. 61/672,160 filed on Jul. 16, 2012 and U.S. Non-Provisional patent application Ser. No. 12/957,049 filed on Nov. 30, 2010, each incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to placement of wellbore completions. 
         [0004]    2. Description of the Related Art 
         [0005]    Downhole drilling operations have seen use of well casings for some time. After a well is drilled, casings are inserted into the borehole to provide structural integrity to the borehole. Casings are often made up of sections of steel pipe that connect end-to-end as they are inserted into the borehole. Many wells that are drilled require a casing, and typically as the depth of the well increases, the diameter of successive sections of the casing decreases. A final completion, which may incorporate a casing section, screens, liners, valves or other components, is often required in the producing formation. 
         [0006]    Often a borehole that begins as a vertical well will be extended in a horizontal direction, for example, to reach a petroleum reservoir that is disposed in a region laterally offset relative to the vertical portion of the well. In such wells, there is a need to ensure placement of completion equipment in the horizontal portion, and the horizontal extension can be relatively long. 
         [0007]    In addition, various types of downhole vibratory tools have been used for through-tubing well intervention operations, including cleaning and milling operations inside liners after they are placed. It would be desirable to provide a specialized tool that can assist in the placement of completion equipment such as liners, screens, valves, patches, plugs, packers, velocity strings, diverters, flow control devices, monitoring equipment, whipstocks or any other equipment in the horizontal portion of a borehole. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides a system and method to facilitate the placement of completion equipment or other similar equipment using a fluid actuated valve that helps push the equipment into the well. The exemplary embodiment of the system facilitates placement of completion equipment using a tool that includes a self-actuated cyclical flow interruption valve as the fluid actuated valve of the system. The self-actuated flow interruption valve can be placed on a deployment tool located at the top of the completion equipment. In the preferred embodiment the tool is releasably attached to the completion equipment. The valve and attached completion equipment are placed in position downhole, fluid is then pumped though the self-actuated flow interruption valve and vented to return to surface. The pulse that is generated when the self-actuated flow interruption valve closes creates an impact that acts to push the completion equipment distally into the well. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Various aspects and attendant advantages of one or more exemplary embodiments and modifications thereto will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
           [0010]      FIG. 1  is a schematic cross-sectional view of an exemplary system for extended reach completion placement including a self-actuated cyclical flow tool. 
           [0011]      FIG. 2A  is a schematic cross-sectional view of an exemplary system for extended reach completion placement including a self-actuated cyclical flow tool showing a pulse valve in the open state during completion placement. 
           [0012]      FIG. 2B  is a schematic cross-sectional view of an exemplary system for extended reach completion placement including a self-actuated cyclical flow tool showing a pulse valve in the closed state during completion placement. 
           [0013]      FIG. 3  is a schematic cross-sectional view of an exemplary system for extended reach completion placement including a self-actuated cyclical flow tool showing the completion after landing the liner hanger at the bottom of the casing. 
           [0014]      FIG. 4  is a schematic cross-sectional view of an exemplary system for extended reach completion placement including a self-actuated cyclical flow tool showing the retrieval of the deployment tools. 
           [0015]      FIG. 5  is an enlarged cross-sectional view of a shear pin release mechanism of an exemplary system for extended reach completion placement. 
           [0016]      FIG. 6  is an enlarged cross-sectional view of a reverse thread release mechanism of an alternate system for extended reach completion placement. 
           [0017]      FIG. 7  shows an example of a water hammer impulse force time history of a system for extended reach completion placement. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Exemplary embodiments are illustrated in referenced Figures of the drawings. It is intended that the embodiments and Figures disclosed herein are to be considered illustrative rather than restrictive. No limitation on the scope of the technology that follows is to be imputed to the examples shown in the drawings and discussed herein. 
         [0019]    The present invention provides a system and method to facilitate the placement of completion equipment or other similar equipment using a fluid-actuated valve that helps push the equipment into the well. The exemplary embodiment of the system facilitates placement of completion equipment using a tool that includes a self-actuated cyclical flow interruption valve as the fluid-actuated valve of the system. The self-actuated flow interruption valve can be placed on a deployment tool located at the top of the completion equipment. The completion equipment is fed into the well using deployment tubing. Fluid is then pumped though the self-actuated flow interruption valve and vented immediately below the valve to return to surface. The “water hammer pulse” that is generated when the self-actuated flow interruption valve closes creates an impact that acts to push the completion equipment distally into the well. Fluid discharged through the tool circulates up the vertical and inclined sections of the well, which is typically a larger diameter cased hole than the completion that is being placed. A portion of the flow, such as may be required for hole conditioning and lubrication, could be pumped into the liner during this procedure. The flow into the completion would be limited to prevent premature actuation of any pressure actuated completion equipment, such as packers and sleeve valves. 
         [0020]    In an exemplary embodiment of this tool, a self-piloted hydraulic valve, such as described in U.S. Pat. Nos. 6,237,701 and 7,139,219, U.S. patent application Ser. No. 12/957,049, and in other commonly assigned pending patent applications, can be included on a deployment tool that is disposed on top of the liner. U.S. patent application Ser. No. 12/957,049 is herein incorporated by reference. However, it is not intended that the tool be limited to use of the self-piloted hydraulic valve disclosed in these patents, since other types of self-actuated fluid valves can alternatively be used to create water hammer pulses or vibration. 
         [0021]    Referring to  FIG. 1 , the system for extended reach deployment  10  is shown during deployment from a drill rig  20 . The completion may incorporate equipment such as screens, perforated tubing, casing and multistage fracture completions containing multiple sliding valves and ball seats any of which may be deployed by such a system. The system is designed to overcome the challenges of inserting the completion into an extended-reach horizontal openhole and into deviated wells with a tortuous wellpath including toe-up or high dogleg severity where sliding friction can hamper full deployment of the completion. The completion must generally be deployed through casing  30  that extends from surface to some depth.  FIG. 1  shows a well that is cased  40  in the vertical section  50  with an openhole curve and horizontal section  60 , but more complex geometries, including multiple telescopic casing strings, are common and this figure is not meant to be limiting in regard to well geometry. 
         [0022]    The completion  70  is supported by a liner hanger  80  that is designed to latch into and seal with a casing profile  150  at the bottom of the casing  40 . In the preferred embodiment, the liner hanger  80  is coupled to a release mechanism  90  just below a self-actuated cyclic flow interruption valve or impulse valve  100 . Also in a preferred embodiment, this valve is of the pilot and poppet design disclosed in U.S. patent application Ser. No. 12/957,049. The valve is in turn supported on a deployment string  110  typically comprising joints of tubing that are deployed into the well by a drill rig  20  as shown or a workover rig or by a continuous string of coiled tubing. The deployment string  110  may include a section of heavy walled tubing to provide additional weight to push the completion though the curve and into the horizontal section of the well  50 . These rigs include a rotary table  120  as shown or a top drive that is capable of rotating the deployment string  110 . Fluid pumps  130  are provided and are connected to supply fluid to the deployment string  110  through a swivel  140 . A coiled tubing rig may also be employed although this equipment does not allow rotation of the deployment string. 
         [0023]      FIG. 1  shows the system  10  being lowered into a well with the completion  70  part way through the curved section of the openhole with no fluid flowing. Friction forces increase as the completion  70  enters the curve and horizontal section and the weight of the deployment string  110  may not be sufficient to push the completion  70  to bottom. At this point fluid can be pumped by pump  130  though swivel  140  and through the deployment string  110  as shown by arrows in  FIG. 2A . The fluid flows through the pulse valve  100  and is discharged into the well above the release mechanism  90  to return to surface. Although not shown, some flow may also be discharged into the completion for well conditioning. Surface valves and equipment for handling the return flow are well known and are not shown. 
         [0024]      FIG. 2A  shows the pulse valve  100  in the open position with all fluid being discharged.  FIG. 2B  shows the impulse valve  100  in the closed position. Closing the valve  100  stops the flow of fluid and results in a water hammer impulse force shown by the large open arrow acting downwards at the valve  100 . The water hammer impulse force is proportional to the mass flow rate of the fluid. An example of the cyclic impulse forces generated by the valve  100  as described in U.S. patent application Ser. No. 12/957,049, with a 2-78″ outer diameter, and while operating at 3 bbl per minute water flow rate, is shown in  FIG. 7 . The cyclic impulse forces act on the top of the completion  70  and drive it into the well. 
         [0025]      FIG. 3  shows the completion  70  after it has reached bottom. At this point the liner hanger  80  engages the casing profile  150  and latches in place to prevent reverse motion or rotation. The design of liner hangers  80  and casing profiles  150  are well known and not described in detail here. A variety of liner hangers  80  and casing profiles  150  may be deployed depending on the well requirements. Referring to  FIG. 3 , fluid pumping has stopped and the deployment string is now released using the release mechanism  90 . A shear pin type of release mechanism  90  is shown in  FIG. 5 . Once the liner hanger  80  is latched, overpull on the deployment string  110  will shear the pins  160  and allow retrieval of the deployment string  110 , pulse valve  100  and release mechanism  90  as shown in  FIG. 4 . The release mechanism  90  may also incorporate reverse, left hand, threads to engage the liner hanger  80  as shown in  FIG. 6 . For this embodiment, right-handed rotation of the deployment string  110  will disengage the release mechanism  90  from the liner hanger  80  and allow retrieval to surface. More complex latch and release mechanisms are also in common use for tool release of the completion and may be employed to release the deployment string  110 . The two options shown here are not meant to be limiting as other release mechanisms may be deployed with the extended reach deployment system  10 . 
         [0026]    Other exemplary embodiments (not shown) can use a plurality of fluid-actuated valves that are designed to interrupt the flow of fluid though tubing and to then impart an impact or cause a vibration due to the resulting water hammer effect. Multiple tools of this type can also be placed at different levels in the deployment string to increase the action of the tools. 
         [0027]    Although the concepts disclosed herein have been described in connection with one or more exemplary form of practicing them and modifications thereto, those of ordinary skill in the art will understand that many other modifications can be made thereto. Accordingly, it is not intended that the scope of these concepts in any way be limited by the above description.