Patent Document

FIELD OF THE INVENTION 
   The present invention relates in general to downhole submersible pump systems and more particularly to a non-electric drive mechanism for a submersible pump. 
   BACKGROUND 
   Submersible pumping systems have been employed in the pumping of oil and water from wells for many years. Typically, a submersible pumping system comprises an electric motor, a motor protector, and a centrifugal pump suspended co-linearly in a well casing by tubing or a cable. The electric motor rotates a power transmission shaft that concurrently operates the pump. The electric motor and motor protector are filled with oil to aid in heat dissipation, to maintain proper internal lubrication of the motor, and to separate the internal components of the motor from the surrounding wellbore fluids. The electric motor requires the provision of electricity to the motor positioned in the wellbore and surrounding fluids, and the motor protector needs to protect the electric motor by equalizing wellbore pressure and sealing against wellbore fluids entering the electric motor. 
   Therefore, it is a desire to provide a drive mechanism that addresses the drawbacks of the prior art electric motors utilized in submersible pump systems. It is a still further desire to provide a novel drive mechanism to replace the prior art electric motor and associated required equipment in a submersible pump system. 
   SUMMARY OF THE INVENTION 
   In view of the foregoing and other considerations, the present invention relates to submersible pump systems. More particularly the present invention relates to a non-electric drive mechanism for a submersible pump. 
   Accordingly, a non-electric drive mechanism connectable to a submersible pump for pumping a fluid from a wellbore to the surface is provided. In an embodiment of the present invention the drive mechanism includes a shaft rotatably disposed within a housing, the shaft operationally connectable to the submersible pump, at least one fan connected to the shaft and a supply manifold positioned to pass a pressurized fluid across the at least one fan in a manner to rotate the fan and the shaft. 
   The drive mechanism may include a gear box in functional connection with the shaft to reduce or amplify the rotational speed transmitted to the submersible pump. The drive mechanism may include a thrust bearing in functional connection with the shaft and a thrust runner in functional connection with the shaft. 
   In another embodiment of the present invention the drive mechanism includes a substantially cylindrical housing, a shaft rotatably disposed within the housing, the shaft operationally connectable to the submersible pump and at least one fan connected to the shaft. A supply manifold positioned to pass a pressurized fluid across the at least one fan in a manner to rotate the fan and the shaft wherein the supply manifold is connectable to a source of a pressurized fluid, and an exhaust manifold for removing the pressurized fluid from the housing. A thrust bearing in functional connection with the shaft and a thrust runner in functional connection with the shaft. 
   An embodiment of a non-electric drive mechanism submersible pump system for pumping a fluid from a wellbore to the surface includes a centrifugal submersible pump and a drive mechanism in operational connection with the centrifugal pump. The drive mechanism includes a substantially cylindrical housing, a shaft rotatably disposed within the housing wherein the shaft is operationally connectable to the submersible pump and at least one fan connected to the shaft. A supply manifold is positioned to pass a pressurized fluid across the at least one fan in a manner to rotate the fan and the shaft and an exhaust manifold for removing the pressurized fluid from the housing. The supply manifold is connectable to a source of a pressurized fluid. 
   The foregoing has outlined the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other features and aspects of the present invention will be best understood with reference to the following detailed description of a specific embodiment of the invention, when read in conjunction with the accompanying drawings, wherein: 
       FIG. 1  is a well schematic of a typical prior art submersible pump system; 
       FIG. 2  is a well schematic of an embodiment of the non-electric drive submersible pump system of the present invention; and 
       FIG. 3  is a partial, cross-sectional view of an embodiment of the drive mechanism of the present invention. 
   

   DETAILED DESCRIPTION 
   Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views. 
     FIG. 1  is a well schematic of a typical prior art submersible pump system, generally denoted by the numeral  5 . A casing  12  is set in a wellbore formed into the earth  14  and a fluid producing formation  16 . Perforations  18  are formed through casing  12  to facilitate the flow of fluid from producing formation  16  into casing  12 . 
   The prior art submersible pump system  5  includes a centrifugal pump  20  and motor assembly  22 . Motor assembly  22  includes an electric motor  24  and a motor protector  26 . Motor protector  26  equalizes well pressure, prevents well fluid contamination of electric motor  24  and absorbs the thrust load transmitted from pump  20 . Electric power is provided to electric motor  24  by an electrical cable (not shown). 
   Centrifugal pump  20  and motor assembly  22  are coupled to one another co-linearly within casing  12  by tubing  28 . Pump  20  is positioned below wellbore fluid level  21  and conveys wellbore fluid  30  via tubing  28  to a storage facility  32  at the surface. 
     FIG. 2  is a well schematic of an embodiment of the non-electric drive submersible pump system of the present invention, generally denoted by the numeral  10 . Pump system  10  includes a centrifugal pump  20  and a non-electric drive mechanism  34 . Pump  20  and drive mechanism  34  are coupled to one another co-linearly within casing  12  by tubing  28 . 
   Drive mechanism  34  is powered by a pressurized fluid. Desirably the pressurized fluid is a gas such as, but not limited to, steam, air, nitrogen or natural gas. Pressurized gas is supplied to drive mechanism  34  from a surface facility  36  via a supply conduit  40 . The spent pressurized fluid may be returned to the surface via a return conduit  42  for venting, storage and/or recycling. Conduits  40  and  42  may be formed by any suitable conduit such as, but not limited to, a seamless, continuous tubing such as coiled tubing. 
   Surface facility  36  is described broadly to include any necessary and desired equipment to supply a fluid at the desired pressure, volume and quality and for treatment of the gas returned from drive mechanism  34 . For example, when the pressurized gas is steam, surface facility  36  may include a steam generator and associated water treatment plant. Further, in steam injection operations the steam for operating drive mechanism  34  may be slipped from a steam injection line. For receiving the returned steam, surface facility  36  may include storage tanks and/or vent lines. For compressed air, the system may include storage vessels, compressors, pumps, dehydration units and booster stations. Similar equipment and facilities may be incorporated for the use of other inert gasses or natural gas available at the well site. It should be recognized that the pressurized fluid returned from drive mechanism  34  may be recycled, recirculated through drive mechanism  34  or vented. 
   As can be seen through  FIGS. 1 and 2 , the non-electric drive mechanism  34  of the present invention eliminates electric motor  24 , the electrical supply cable, motor protector  26  and the associated drawbacks of the current and prior art electrical submersible pump systems. 
     FIG. 3  provides a partial, cross-sectional view of an embodiment of drive mechanism  34  of the present invention. Drive mechanism  34  includes a substantially cylindrical housing  44  and a fan shaft  46  connected to one or more fan sections  48 . Fan shaft  46  is operationally connected to the drive shaft of pump  20  ( FIG. 2 ). The top end  44   a  is adapted for connecting to pump  20 . Fan shaft  46  is mounted within housing  44  via bearings  50  to provide rotating operation and radial support of fan shaft  46 . 
   Fan sections  48  are connected along the keyed fan shaft  46  such that fan sections  48  can rotate fan shaft  46 . Drive mechanism  34  may include one or more fan sections  48 . As shown in the present example, drive mechanism  34  includes three fan sections  48   a ,  48   b ,  48   c . Fan sections  48  may each comprise a cylindrical blower fan configuration. 
   Pressurized fluid is provided to drive mechanism  34  via supply conduit  40  through one or more supply manifolds  64 . Supply manifold  64  may include an orifice  66  for passing the pressurized fluid, indicated by arrows  68 , across fans  48 . In the embodiment of  FIG. 3 , a supply manifold  64   a ,  64   b ,  64   c  is positioned proximate each fan section  48   a ,  48   b ,  48   c  respectively. 
   Flow of pressurized fluid  68  across fan sections  48  rotates fan sections  48  and fan shaft  46 . This rotation is transmitted to connected pump  20 . The speed of rotation of fan sections  48  and fan shaft  46  may be controlled by the volume and/or pressure of fluid  68 . Pressurized fluid  68  is removed from housing  44  via one or more exhaust manifolds  70  connected to return conduit  42 . Although exhaust manifold  70  is shown in  FIG. 3  positioned opposite supply manifolds  64  relative to housing  44  it should be recognized that exhaust manifold  70  may be located in various positions including adjacent supply manifolds  64 , incorporated as a section of supply manifold(s)  64 , and at the top and/or bottom end of drive mechanism  34 . 
   Drive mechanism  34  may further include a sealed gear box  52 . The rotation of fan sections  48   a ,  48   b ,  48   c  is transmitted to fan shaft  46  to gears  54  to reduce or amplify the rotational speed. The resultant rotational speed of gear train  56  is transmitted to drive shaft  58 . Drive shaft  58  may be the shaft of pump  20  ( FIG. 2 ) or coupled to the shaft of pump  20 . Gear box  52  is sealed to prevent contamination of the gear oil and avoid premature failure of gears  54  and the bearings. 
   Thrust bearings  62  for the pumps may be in connection with drive shaft  58 . A thrust runner  60  may also be coupled with drive shaft  58 . It should be recognized that in various embodiments thrust runner  60  and thrust bearings may be connected to fan shaft  46 , for example when gear box  52  is not incorporated. It should be further recognized that fan shaft  46  is effectively the drive shaft for pump  20  when all elements are coupled. 
   From the foregoing detailed description of specific embodiments of the invention, it should be apparent that a non-electric drive mechanism submersible pump system and more particularly a non-electric drive mechanism for a submersible pump that is novel has been disclosed. Although specific embodiments of the invention have been disclosed herein in some detail, this has been done solely for the purposes of describing various features and aspects of the invention, and is not intended to be limiting with respect to the scope of the invention. It is contemplated that various substitutions, alterations, and/or modifications, including but not limited to those implementation variations which may have been suggested herein, may be made to the disclosed embodiments without departing from the spirit and scope of the invention as defined by the appended claims which follow.

Technology Category: 2