Abstract:
A self-propelled, remotely-controlled equipment deployment vehicle is configured to deliver equipment to a desired location within the horizontal portion of a deviated wellbore. The deployment vehicle includes a cargo frame, an electric motor and an active mobility assembly. The active mobility assembly is connected to the cargo frame and powered by the electric motor. The cargo frame can be configured to transport, offload and accurately position the selected cargo. Alternatively, the equipment deployment vehicle can be configured with a passive mobility assembly that allows the equipment deployment vehicle to be pushed or pulled along the horizontal section of the wellbore without power.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates generally to the field of downhole pumping systems, and more particularly to a deployment system for use in horizontal and deviated wellbores. 
       BACKGROUND 
       [0002]    Submersible pumping systems are often deployed into wells to recover petroleum fluids from subterranean reservoirs. Typically, a submersible pumping system includes a number of components, including an electric motor coupled to one or more pump assemblies. Production tubing is connected to the pump assemblies to deliver the wellbore fluids from the subterranean reservoir to a storage facility on the surface. 
         [0003]    With advancements in drilling technology, it is now possible to accurately drill wells with multiple horizontal deviations. Horizontal wells are particularly prevalent in unconventional shale plays, where vertical depths may range up to about 10,000 feet with lateral sections extending up to another 10,000 feet with multiple undulations. 
         [0004]    Current methods of inserting equipment and tools into lateral portions of a wellbore have had limited success. Coil tubing systems have been used but are limited by the extent to which these systems are capable of pushing equipment deep into the laterals. There is, therefore, a continued need for an improved deployment system that is capable of delivering equipment through the lateral sections of deviated wellbores. It is to these and other deficiencies in the prior art that the present invention is directed. 
       SUMMARY OF THE INVENTION 
       [0005]    In a first preferred embodiment, the present invention includes a self-propelled, remotely-controlled equipment deployment vehicle. The equipment deployment vehicle includes a cargo frame, an electric motor and an active mobility assembly. The active mobility assembly is connected to the cargo frame and powered by the electric motor. The cargo frame can be configured to transport, offload and accurately position the selected cargo. 
         [0006]    In a second preferred embodiment, the present invention includes a passive equipment deployment vehicle. The passive equipment deployment vehicle includes at least a cargo frame and a passive mobility assembly. The passive mobility assembly facilitates the movement of the cargo frame within the wellbore. The cargo frame can be configured to transport, offload and accurately position the selected cargo. 
         [0007]    In a third preferred embodiment, the present invention includes an equipment deployment system that includes a combination of at least one self-propelled, remotely controlled vehicle and at least one passive equipment deployment vehicle. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a side view of an equipment deployment vehicle constructed in accordance with a first preferred embodiment. 
           [0009]      FIG. 2  is a perspective view of the equipment deployment vehicle of  FIG. 1 . 
           [0010]      FIG. 3  is a side view of an equipment deployment vehicle constructed in accordance with a second preferred embodiment. 
           [0011]      FIG. 4  is a perspective view of the equipment deployment vehicle of  FIG. 3 . 
           [0012]      FIG. 5  is a side view of an equipment deployment vehicle constructed in accordance with a third preferred embodiment. 
           [0013]      FIG. 6  is a perspective view of the equipment deployment vehicle of  FIG. 5 . 
           [0014]      FIG. 7  is a side view of an equipment deployment vehicle constructed in accordance with a fourth preferred embodiment. 
           [0015]      FIG. 8  is a side view of an equipment deployment vehicle constructed in accordance with a fifth preferred embodiment. 
           [0016]      FIG. 9  is a depiction of a deviated wellbore and an equipment deployment vehicle constructed in accordance with a preferred embodiment. 
           [0017]      FIG. 10  is a depiction of a deviated wellbore and a pair or trained equipment deployment vehicles constructed in accordance with a preferred embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0018]    For the purposes of the disclosure herein, the terms “upstream” and “downstream” shall be used to refer to the relative positions of components or portions of components with respect to the general flow of fluids produced from the wellbore. “Upstream” refers to a position or component that is passed earlier than a “downstream” position or component as fluid is produced from the wellbore. The terms “upstream” and “downstream” are not necessarily dependent on the relative vertical orientation of a component or position. It will be appreciated that many of the components in the following description are substantially cylindrical and have a common longitudinal axis that extends through the center of the elongated cylinder and a radius extending from the longitudinal axis to an outer circumference. Objects and motion may be described in terms of radial positions. 
         [0019]    In accordance with a preferred embodiment of the present invention,  FIGS. 1 and 2  present side and perspective views, respectively, of an equipment deployment vehicle  100  constructed in accordance with a first preferred embodiment. The equipment deployment vehicle  100  is generally configured and designed to deliver, deploy or position tools and other equipment within a deviated wellbore. The use of the equipment deployment vehicle  100  presents a significant advance over prior art efforts to position equipment within deviated wellbores. 
         [0020]    The equipment deployment vehicle  100  preferably includes a cargo frame  102 , an electric motor  104  and a mobility assembly  106 . In the first preferred embodiment depicted in  FIG. 1 , the equipment deployment vehicle  100  is shown with cargo  108  present within the cargo frame  102 . The cargo frame  102  is preferably sized and configured to securely support the cargo  108 . The cargo  108  may include any tool, equipment or other cargo that is intended to be deployed or positioned downhole, such as, for example, electric submersible pumping units, tubing, tubing connectors, tubing adaptors, sensor packages, gas separators, perforating tools, and injection pumps. The weight of the cargo  108  holds the mobility assembly  106  to the surface of the wellbore. The relatively small diameter of the wellbore encourages an arc of tight contact between the wellbore and the articulated surfaces of the mobility assembly  106 . 
         [0021]    In the perspective depiction in  FIG. 2 , the tool  108  is shown connected to tubing  110 . All of the components of the equipment deployment vehicle  100  are constructed from steel, high-temperature polymers or other materials that are capable of withstanding the elevated temperatures, significant pressures and corrosive fluids found in the wellbore. The mobility assembly  106  can be configured to move and change the direction of movement of the equipment deployment vehicle  100 . 
         [0022]    In the first preferred embodiment, the equipment deployment vehicle  100  is configured as a self-propelled, remote-controlled vehicle that includes an “active” mobility assembly  106 . The active mobility assembly  106  includes a pair of endless tracks  112  that are controllably driven by the electric motor  104 . The tracks  112  preferably include an aggressively treaded exterior surface for efficiently moving the equipment deployment vehicle  100  along the deviated wellbore. 
         [0023]    In a variation of the first preferred embodiment, the active mobility assembly  106  is replaced with a passive mobility assembly in which the tracks  112  are not driven by the electric motor  104 . The use of the passive mobility assembly may be desirable in situations in which the equipment deployment vehicle  100  is connected to and moved by a second equipment deployment vehicle  100 . 
         [0024]    Turning to  FIGS. 3 and 4 , shown therein are side and perspective views, respectively, of the equipment deployment vehicle  100  constructed in accordance with a second preferred embodiment. In the second preferred embodiment, the mobility assembly  106  includes a series of wheels  114  connected to articulating legs  116 . The mobility assembly  106  further includes a series of independent motors  118  positioned near one or more of the wheels  114 . In the highly preferred embodiment depicted in  FIG. 4 , the independent motors  118  and wheels  114  are pivotally connected to the articulating legs  116 . The independent motors  118  are configured to drive the wheels  114  without the need for an intermediate transmission. The articulating legs  116  are configured to extend, contract and pivot to provide a suspension system that permits the movement of the equipment deployment vehicle  100  over large obstacles. 
         [0025]    Turning to  FIGS. 5 and 6 , shown therein are side and perspective views, respectively, of a third preferred embodiment of the equipment deployment vehicle  100 . In the third preferred embodiment, the mobility assembly  106  of the equipment deployment vehicle  100  is configured as a cylindrical sleeve  120  that surrounds the cargo frame  102 . The sleeve  120  includes a plurality of ball bearings  122  that extend through the sleeve  120 . In a particularly preferred variation of the third preferred embodiment, the ball bearings  122  and sleeve  120  constitute a passive mobility assembly  106  that allows the cargo  108  to be pulled or pushed along the wellbore. The ball bearings  122  provide a low-friction mechanism for supporting and moving the cargo  108 . Additionally, the cylindrical sleeve  120  and ball bearings  122  can be configured such that the equipment deployment vehicle  100  functions as a mobile centralizer to position the cargo  108  within the center of the wellbore. 
         [0026]    Turning to  FIG. 7 , shown therein is a side view of a fourth preferred embodiment in which the mobility assembly  106  includes four aggressively treaded wheels  124  connected to the electric motor  104 . The treaded wheels  124  can be selectively controlled to drive and maneuver the equipment deployment vehicle  100  within the wellbore. 
         [0027]    Turning to  FIG. 8 , shown therein is a side view of a fifth preferred embodiment in which the mobility assembly  106  includes a rotary auger  126  that pulls the equipment deployment vehicle  100  along the wellbore. The rotary auger  126  includes one or more continuous spiraled flights  128 . The continuous spiraled flights  128  provide a slow, incremental movement. In a particularly preferred embodiment, the rotary auger  126  is constructed from a low durometer polymer. The use of the rotary auger  126  is particularly useful in non-cased wells in which the wellbore is an “open-hole” that includes exposed rock. 
         [0028]    Referring now to  FIG. 9 , shown therein is a depiction of the equipment deployment vehicle  100  positioned within a wellbore  200 . The wellbore  200  includes a vertical section  200   a  and a horizontal section  200   b.  The equipment deployment vehicle  100  has been deployed from the surface through the vertical section  200   a  and has driven under its own power through the horizontal section  200   b.  The equipment deployment vehicle  100  is connected to surface-based control systems  202  with an umbilical  204 . It will be understood that the umbilical  204  carries power, telemetry and signal data between the equipment deployment vehicle  100  and the surface-based control systems  202 . The umbilical  204  can also be used to retrieve the equipment deployment vehicle  100  through the wellbore  200 . Although the umbilical is well-suited to carry information from the equipment deployment vehicle  100 , it will be appreciated that the equipment deployment vehicle  100  may also include wireless transmitters and receivers that are configured to communicate wirelessly with the surface-based control systems  202 , satellites or wireless radio networks. 
         [0029]    Turning to  FIG. 10 , depicted therein are three equipment deployment vehicles  100   a,    100   b  and  100   c  deployed within the horizontal section  200   b  of the wellbore  200 . In addition to the three equipment deployment vehicles  100 , an electric submersible pumping system  206  is also disposed within the vertical section  200   a  of the wellbore  200 . The electric submersible pumping system  206  generally includes a motor  208 , a pump  210  and a seal section  212  disposed between the motor  208  and the pump  210 . When energized with electric power from the surface, the motor  208  drives the pump  210 , which pushes wellbore fluids to the surface through production tubing  214 . Power and communication signals are provided to the electric submersible pumping system  206  from the surface-based control systems  202  through a power cable  216 . 
         [0030]    The three equipment deployment vehicles  100   a,    100   b  and  100   c  are connected to each other and to the electric submersible pumping system  206  by high-pressure flexible conduits  218 . The three equipment deployment vehicles  100   a,    100   b  and  100   c  are connected to the surface-based controls  202  through the electric submersible pumping system  206 . The umbilical  204  may be attached to the outside of the flexible conduits  218  or housed on the inside of the flexible conduits  218 . 
         [0031]    As a non-limiting example of the types of cargo  108  carried by the equipment deployment vehicles  100 , the equipment deployment vehicle  100   a  and equipment deployment vehicle  100   c  are each provided with a sensor module  220  that measure wellbore conditions (e.g., temperature, pressure and fluid composition) and output electric signals representative of these measurements. The equipment deployment vehicle  100   b  includes a conduit connector  222  that connects the flexible tubing  110  extending between the equipment deployment vehicle  100   a  and equipment deployment vehicle  100   c.    
         [0032]    It will be further noted that equipment deployment vehicle  100   a  and equipment deployment vehicle  100   100   c  are provided with active mobility assemblies  106  in the form of powered endless tracks  112 . The intermediate equipment deployment vehicle  100   b  is configured with a passive mobility assembly  106  that includes the cylindrical sleeve  120  with free-spinning ball bearings  122 . In this way, the equipment deployment vehicles  100   a,    100   c  pull and push, respectively, the intermediate equipment deployment vehicle  100   b.    
         [0033]    It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and functions of various embodiments of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. It will be appreciated by those skilled in the art that the teachings of the present invention can be applied to other systems without departing from the scope and spirit of the present invention.