Fluid displacement system using gerotor pump

Abstract

A fluid displacement system for a fluid producing subterranean well includes a well extending from a surface to a subterranean fluid bearing formation, the formation being in fluid communication with the well; and a gerotor pump in the well for pumping fluid from the formation to the surface.

1 . A fluid displacement system for a fluid producing subterranean well, comprising:
 a well extending from a surface to a subterranean fluid bearing formation, the formation being in fluid communication with the well; and   a gerotor pump in the well for pumping fluid from the formation to the surface.   
     
     
         2 . The apparatus of  claim 1 , wherein the gerotor pump is driven by an electric submersible motor. 
     
     
         3 . The apparatus of  claim 2 , wherein at least one of the gerotor pump and the electric submersible motor is located in the well at a depth from the surface of at least 3,000 feet. 
     
     
         4 . The apparatus of  claim 1 , wherein the gerotor pump comprises at least one set of inner and outer rotors rotatably engaged within a journal bearing. 
     
     
         5 . The apparatus of  claim 1 , wherein the journal bearing defines an eccentric inner surface rotatably housing the outer rotor, and wherein the inner rotor engages the outer rotor such that the inner rotor is concentric with an outer cylindrical surface of the journal bearing. 
     
     
         6 . The apparatus of  claim 4 , wherein the rotors are mounted in the journal bearing between disks having inlet and outlet ports for fluid to be compressed and discharged by the rotors, respectively. 
     
     
         7 . The apparatus of  claim 1 , wherein the gerotor pump comprises a plurality of gerotor pumps each having at least one set of inner and outer rotors. 
     
     
         8 . The apparatus of  claim 7 , wherein the plurality of gerotor pumps are communicated with each other in series. 
     
     
         9 . The apparatus of  claim 8 , wherein the gerotor pumps are communicated in series through an intermediate cylinder having a port aligned with an outlet of a first gerotor pump and an inlet of a second gerotor pump. 
     
     
         10 . The apparatus of  claim 6 , wherein the plurality of gerotor pumps are communicated in parallel. 
     
     
         11 . The apparatus of  claim 10 , wherein the plurality of gerotor pumps are communicated in parallel through a middle casing. 
     
     
         12 . The apparatus of  claim 11 , wherein the middle casing comprises a cylindrical member having a first opening at one end for receiving a first gerotor pump, a second opening at the other end for receiving a second gerotor pump, a central wall separating the first opening from the second opening, an inlet in the central wall aligned within an outlet of the first gerotor pump, the inlet leading through a passage to a radial outlet by passing the second gerotor pump, and a radial inlet defined in a wall surrounding the first opening which leads through a passage that bypasses the first gerotor pump and has an outlet aligned with an inlet of the second gerotor pump. 
     
     
         13 . The apparatus of  claim 12 , wherein each of the first and second gerotor pumps comprises a pumping stage each having a plurality of gerotor assemblies communicated in series. 
     
     
         14 . The apparatus of  claim 12 , further comprising an inlet bearing carrier and an outlet bearing carrier, wherein the inlet bearing carrier is mounted to the middle casing at the one end and has a first inlet aligned with the inlet of the first gerotor pump and a second inlet aligned with the radial inlet of the middle casing, and wherein the outlet bearing carrier is mounted to the middle casing at the other end and has a first outlet aligned with the radial outlet of the middle casing and a second outlet aligned with the outlet of the second gerotor pump. 
     
     
         15 . The apparatus of  claim 14 , wherein the gerotor pumps are mounted on a shaft, and wherein the inlet bearing carrier and the outlet bearing carrier support bearings in which the shaft is rotatably mounted. 
     
     
         16 . A method for pumping a fluid from a well, comprising the steps of:
 positioning a well from a surface to a subterranean formation;   placing a gerotor pump in the well; and   operating the gerotor pump to drive fluids from the subterranean well to the surface.   
     
     
         17 . The method of  claim 12 , wherein the gerotor pump is driven by an electric submersible motor. 
     
     
         18 . The method of  claim 13 , wherein at least one of the gerotor pump and the electric submersible motor is located in the well at a depth from the surface of at least 3,000 feet.