Abstract:
A submersible pumping system for use downhole, wherein the system includes tubing disposed in a wellbore having a wet connection formed for coupling with a pumping system disposable in the tubing. An electrical power cable connects to the wet connection through the tubing. The wet connection comprises receptacles configured to mate with electrically conducting pins, the receptacles and the pins are oriented substantially parallel with the tubing axis. The receptacles are formed to receive the pins therein and form an electrical connection for connecting electrical power from the cable to the pumping system.

Description:
BACKGROUND 
       [0001]    1. Field of Invention 
         [0002]    The present disclosure relates to downhole pumping systems submersible in well bore fluids. More specifically, the present disclosure concerns lowering a submersible pump through tubing and connecting it electrically to an electrical receptacle mounted in the tubing. 
         [0003]    2. Description of Prior Art 
         [0004]    Submersible pumping systems are often used in hydrocarbon producing wells for pumping fluids from within the wellbore to the surface. These fluids are generally liquids and include produced liquid hydrocarbon as well as water. One type of system used in this application employs an electrical submersible pump (ESP). ESPs are typically disposed at the end of a length of production tubing and have an electrically powered motor. Often electrical power may be supplied to the pump motor via a power cable. Normally, the power cable is strapped to the tubing or lowered along with the pump and the tubing. Typically, the pumping unit is disposed within the well bore just above where perforations are made into a hydrocarbon producing zone. ESP&#39;s typically require periodic retrieval for scheduled maintenance or repair. This usually entails removing the power cable, which is secured alongside the tubing. Pulling and reusing the power cable mechanically wears the cable and can sometimes damage the cable. 
       SUMMARY OF INVENTION 
       [0005]    The present disclosure includes a system for producing fluids from a hydrocarbon producing wellbore, the system comprises production tubing disposed within the wellbore, a pumping system having a pump with fluid inlets, and a pump motor mechanically coupled to the pump. The pumping system is deployable through the production tubing. A pedestal is affixed within the production tubing and configured to matingly couple with the pumping system. Also included is an electrical power supply line connected to a power source that terminates within the pedestal and a wet mate connector in electrical communication with the pump motor and the electrical power supply having receptacles and pins configured for insertion into the receptacles. Inserting the pins into the receptacles provides electrical communication between the pump motor and the electrical power supply. 
         [0006]    In one embodiment, a first portion of the wet mate connector is provided on the pump motor and a second portion of the wet mate connector is provided on the pedestal. The receptacles and pins are oriented substantially parallel to the production tubing. In one embodiment, the receptacles are coupled to the pump motor and hardwired into electrical communication with the pump motor and the pins are disposed on the pedestal and hardwired into electrical communication with the electrical power supply. Optionally the pins may be coupled to the pump motor and hardwired into electrical communication with the pump motor and the receptacles are disposed on the pedestal and hardwired into electrical communication with the electrical power supply. 
         [0007]    The present disclosure also includes an electrical submersible pumping system deployable in wellbore production tubing. The pumping system comprises a pump having a fluid inlet, a pump motor coupled to the pump, and a wet mate connection component with electrical receptacles provided therein in electrical communication with the pump motor. The connection component may be coupled to the pump motor with the electrical receptacles oriented substantially parallel to the production tubing. The electrical receptacles are formed to receive electrically conducting pins therein. The wet mate connection component may comprise a base portion affixed to the pump motor and an annular skirt coaxial with the pump motor which extends away from the pump motor thereby defining a recess bounded by the skirt and base. Optionally, the receptacles may be disposed on the base and extend into the recess. The wet mate connection component may be configured for mating connection with a corresponding wet mate connection component affixable to the production tubing. The corresponding wet mate connection is configured for insertion into the recess and the corresponding wet mate connection includes on its mating surface the electrically conducting pins. Mating connection between the wet mate connection component and the corresponding wet mate connection component provides electrical power to the pump motor. 
         [0008]    Also disclosed herein is an annular sub member disposed within wellbore production tubing comprising a pedestal provided in the sub member and affixed thereto, the pedestal having a portion configured to receive thereon a pumping system deployed within the production tubing, an electrical power cable in the pedestal, and a wet mate connection component on the pedestal having electrically conductive pins extending from the pedestal and substantially parallel to the sub member, the pins in electrical communication with the electrical power cable and configured to mate with corresponding receptacles provided on the pumping system. The sub may include connections on its respective terminal ends for connection to production tubing. A shoulder may be included formed on the pedestal outer surface configured for mating support with the pumping system. An orientation device on the pedestal may also be included with the sub member that azimuthally aligns the pins with the corresponding receptacles. 
     
    
     
       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 partial cross sectional view of an ESP disposed in production tubing with a wet mate connection. 
           [0011]      FIG. 2  is a side partial cross sectional view of an embodiment of a wet mate connection in a tubing sub. 
           [0012]      FIG. 3  is an upward looking view of an embodiment of a portion of a wet mate connection. 
           [0013]      FIG. 4  is a side view of an embodiment of an azimuthal orientation device. 
       
    
    
       [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 present invention will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments of the invention are shown. This invention may, however, be embodied 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 the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. For the convenience in referring to the accompanying figures, directional terms are used for reference and illustration only. For example, the directional terms such as “upper”, “lower”, “above”, “below”, and the like are being used to illustrate a relational location. It is to be understood that the invention 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 of the invention 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 invention is therefore to be limited only by the scope of the appended claims. 
         [0016]      FIG. 1  provides a side partial cross sectional view of an embodiment of an ESP pumping system  20  used for delivering produced subterranean fluid to the surface of the wellbore. The ESP pumping system  20  is inserted in production tubing  9  deployed in a wellbore  5 . The wellbore  5  is lined with casing  7  with the production tubing  9  affixed within the casing  7 . In the embodiment shown, the production tubing  9  includes a wet matable connection  34  for transmitting electrical power to the pumping system  20 . The wet matable connection  34  is included at the production tubing&#39;s  9  the lower end. The production tubing  9  terminates in the wellbore  5  adjacent perforations  13 . The perforations  13  are formed through the casing  7  and into a hydrocarbon producing formation  15  that circumscribes a portion of the wellbore  5 . Fluid flow, shown as arrows, enters the wellbore  5  from the formation  15  and through the perforations  13 . As shown in this example, the fluid enters the open end of the production tubing  9  and is drawn upwards to the ESP pumping system  20 . 
         [0017]    The ESP pumping system  20  comprises a pump motor  24 , a seal section or equalizer  26  on the upper end of the pump motor  24 , an optional gas separator  28 , and a pump  32 . Fluid inlets  30  are provided on the optional separator  28  through which produced fluid can be drawn into the pumping system  20 . After passing through the inlets  30  the fluid flows to the pump  32  where it is pressurized and discharged into a smaller diameter tubing  22  extending from the upper end of the pump  32 . If used, gas is separated by the gas separator  28  and discharged into the annulus surrounding the pumping system  20 . 
         [0018]    A power cable  38  is disposed in the wellbore and connected to the pump motor  24 . The power cable  38  extends down the wellbore  5  in the annular region between the casing  7  and the production tubing  9 . The power cable  38  passes through the housing  35  which lines the wet matable connection  34 . A pedestal  36  is shown affixed on the inner surface of the housing  35  that provides a wet mate connection for connecting to the pump motor  24  and electrical power supply while down hole. The pump system  20  includes a pump connector  40  on the portion of the pump motor  24  that couples onto the pedestal  36 . This portion of the pump motor  24  may be the bottom of the stator and rotor, or may be the bottom of an instrument module included at the lower end of the pump motor  24 . A corresponding pedestal connector  42  is provided on the portion of the pedestal  36  that mates with the pump motor  24 . 
         [0019]    The pumping system  20  is typically deployed after the production tubing ( 9 ,  10 ) (with its wet matable connection  34 ) is set within the casing  7 . Optional packers  11  are shown proximate to the lower terminal end of the production tubing  10  for setting the production tubing and directing produced fluid from the perforations  13  to the entrance of the tubing  10 . The power cable  38  is affixed to the web matable connection  34  prior to tubing deployment. 
         [0020]      FIG. 2  illustrates a partial cross sectional view of an embodiment of a wet matable connection  34 . The connection  34  comprises an outer housing  35  having threads  37  for coupling to the upper production tubing  9  and threads  39  for connecting to the lower production tubing  10 . The connection  34  also comprises a pedestal  36  having a base portion  33  mechanically affixed to the inner circumference of the housing  35 . The base portion  33  extends into the middle hollow portion of the housing  35  perpendicular to the axis A X  of the housing  35 . The pedestal  36  farther includes a pedestal connector  42  which attaches to the terminal end of the pedestal base  33 . The pedestal connector is generally cylindrical and elongated, and as shown, its elongated portion is oriented substantially parallel to the axis A X  of the housing  35 . 
         [0021]    The power cable  38  terminates in a cable connector  45  (commonly referred to as a pothead connector), the cable connector  45  inserts into a receptacle  69 . The receptacle  69  is received in a connector housing  70  which protrudes from the wet mateable connection  34  outer surface. A cable passage  44  is formed in the connector housing  70  and through the pedestal  36 ; a pedestal cable  46  extends through the passage  44  from the end of the connector  45 , through the pedestal base  33 , and into the pedestal connector section  42 . To accommodate the 3 phase power supply, the pedestal cable  46  splits into three different leads ( 48 ,  49 ,  50 ). The leads ( 48 ,  49 ,  50 ) travel in the same or separate passages and terminate proximate to the upper end of the pedestal connector  42 . Connection pins ( 51 ,  52 ,  53 ) are provided on the ends on each of the respective leads ( 48 ,  49 ,  50 ) that rise upward past the upper surface of the pedestal connector  42 . As shown, the pins ( 51 ,  52 ,  53 ) extend generally parallel with the axis A X  of the housing  35 . 
         [0022]    The lower end of the pump motor  24  is provided with a pump connector  40  that comprises a connector base  57  and an annular skirt  41 . The connector base  57  is largely planar having an upper surface mating with the lower terminal end of the pump motor  24 . Extending from the outer periphery of the base  57 , the annular skirt  41  extends downward having a hollow space therein forming a recess  47 . The recess  47  insertingly receives the pedestal connector  42  therein. Electrical receptacles ( 54 ,  55 ,  56 ) are provided on the base  57  and have a generally annular configuration as shown. The receptacles ( 54 ,  55 ,  56 ) are formed to receive the pins ( 51 ,  52 ,  53 ) therein and are also generally aligned with the axis A X  of the housing  35 . Thus seating the pumping system  20  onto the pedestal  36  couples the pedestal connector  42  with the pump connector  40 . 
         [0023]    The receptacles ( 54 ,  55 ,  56 ) are in electrical communication with the pump motor  24 , therefore coupling the pedestal connector  42  to the pump connector  40  provides electrical communication between the pump motor  24  and the power cable  38 . Moreover, the connector  34  is designed for “wet mating” two electrical connectors in a wet environment. Thus electrical connection for the pump motor  24  may occur while fluid is present within the housing  35 . A plenum  61  exists between the pedestal connector  42  and the connector base  57 . The plenum  61  may include wellbore fluid while coupling the connectors ( 40 ,  42 ). After seating the motor  24  onto the pedestal  36  and mating the connectors ( 40 ,  42 ), the plenum  61  may be flushed to remove wellbore fluid from the plenum  61 . A dielectric fluid may be then injected into the plenum space  61 . The dielectric fluid could be injected from the surface via a small tube incorporated with the power cable  38 . 
         [0024]    A shoulder  43  is shown on the outer circumference of the pedestal connection  42  on which the annular skirt  41  may rest when the motor  24  seats onto the pedestal  36 . The shoulder  43  supports the annular skirt  41  thereon and prevents further downward movement of the motor  24 . This distributes weight onto the shoulder  43  and not the pins, which prevents mechanical damage to the respective pins and receptacles. Also on the outer surface of the pedestal connector  42  is an orientation guide  67  for use in aligning the respective pins and receptacles for proper electrical connection to the pump motor  24 . 
         [0025]      FIG. 3  provides an upward looking view of an embodiment of the lower portion of the pump connector  40  and into the recess  47 . Here the receptacles ( 51 ,  52 ,  53 ) extend downward from the lower planar surface of the base  57 , which is circumscribed by the annular skirt  41 . Optional alignment pins ( 58 ,  59 ,  60 ) also extend downward from the lower planar portion of the base  57  which may be used for alignment with corresponding bores (not shown) in the upper surface of the pedestal connector  42 . 
         [0026]      FIG. 4  is a side perspective view of a raised profile  62  that may be either on the outer circumference of the pedestal connector  42  or the inner surface of the annular skirt  41 . The raised profile  62  represents 360° of travel around one of these members. The profile  62  comprises a curved raised shoulder  64  extending outward from the respective surface. In one embodiment, the shoulder  64  is generally helical. With reference now to  FIG. 3 , the annular skirt  41  includes a guide pin  63  on its inner circumference for engaging the raised shoulder  64 . Landing the guide pin  63  at any location on the raised shoulder  64  with downward force will slide the guide pin towards the low point  65  thereby aligning the respective connectors ( 40 ,  42 ) such that the pins ( 51 ,  52 ,  53 ) are aligned with respective receptacles ( 54 ,  55 ,  56 ). It should be pointed out however that the location of the receptacles and the pins may be reversed so that the pins extend downward from the lower planar surface of the base  57  and the receptacles are disposed on the upper surface of the pedestal connector for engaging the pins. For the purposes of discussion herein, the term hardwired refers to a solid electrical conduit extending between different component parts of the apparatus described herein. 
         [0027]    With reference now to  FIG. 2 , the housing  35  radius bulges outward proximate to the pedestal  36  to assure free flow of well fluid past the pedestal  36 . The pedestal  36  could extend to the other side of the housing  35  and have flow-through passages defined by spokes, similar to a spider. Optional embodiments exist wherein the tubing radius is substantially consistent along the length of the connector  34  without an outward bulge. 
         [0028]    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. For example, rather than running the pump assembly into tubing and discharging the fluid through tubing, it could be run on a lift line cable or coiled tubing. A packer would be located around the pump above the intake and below the discharge. The discharge would be into the large diameter tubing above the packer. The packer could have a latch to support the weight of the ESP, allowing the lift line cable or coiled tubing retrieval.