Multiphase pump flow recirculation system

Abstract

In accordance with certain aspects of the invention, a pump system is provided. The pump system includes a pump casing having a process fluid inlet chamber connected to a process fluid inlet through the pump casing, and a process fluid outlet chamber connected to a process fluid outlet through the pump casing. The pump system also includes rotors disposed inside the process fluid inlet chamber and the process fluid outlet chamber. The rotors are configured to pump a process fluid from the process fluid inlet chamber to the process fluid outlet chamber. In addition, the pump casing comprises one or more fluid injection inlets axially located between the process fluid inlet and the process fluid outlet.

1 . A pump system, comprising:
 a pump casing having a process fluid inlet chamber connected to a process fluid inlet through the pump casing, and a process fluid outlet chamber connected to a process fluid outlet through the pump casing; and   rotors disposed inside the process fluid inlet chamber and the process fluid outlet chamber, wherein the rotors are configured to pump a process fluid from the process fluid inlet chamber to the process fluid outlet chamber;   wherein the pump casing comprises one or more fluid injection inlets axially located between the process fluid inlet and the process fluid outlet.   
     
     
         2 . The pump system of  claim 1 , wherein the pump casing comprises a plurality of process fluid inlet chambers connected to a plurality of process fluid inlets or a plurality of process fluid outlet chambers connected to a plurality of process fluid outlets, and a fluid injection inlet axially located between each combination of process fluid inlet chamber and process fluid outlet chamber. 
     
     
         3 . The pump system of  claim 2 , comprising a plurality of fluid injection inlets between each combination of process fluid inlet chamber and process fluid outlet chamber. 
     
     
         4 . The pump system of  claim 3 , comprising a controller configured to selectively adjust the flow rate of fluid through each fluid injection inlet. 
     
     
         5 . The pump system of  claim 4 , comprising sensors configured to communicate operating parameters of the pump system to the controller, wherein the controller selectively adjusts the flow rates of fluid through the fluid injection points based at least in part on the operating parameters. 
     
     
         6 . The pump system of  claim 5 , wherein each fluid injection inlet is associated with a respective flow control valve, and wherein the controller selectively adjusts the flow rates of fluid through the fluid injection points by actuating each respective flow control valve. 
     
     
         7 . The pump system of  claim 1 , wherein the process fluid or some component thereof is re-circulated through the one or more fluid injection inlets. 
     
     
         8 . The pump system of  claim 1 , wherein a fluid other than the process fluid is injected into the one or more fluid injection inlets. 
     
     
         9 . The pump system of  claim 1 , wherein the one or more fluid injection inlets are axially aligned between threading of one of the rotors. 
     
     
         10 . A method for operating a pump, comprising:
 pumping a first fluid along an axis of a pump from an inlet to an outlet; and   injecting a second fluid into the flow of the first fluid through a fluid injection inlet at an axial location between the inlet and the outlet.   
     
     
         11 . The method of  claim 10 , wherein the first fluid or some component thereof is re-circulated through the pump as the second fluid. 
     
     
         12 . The method of  claim 10 , wherein the axial location of the fluid injection inlet is selected based on operating conditions of the pump. 
     
     
         13 . The method of  claim 10 , comprising injecting a plurality of fluids into the flow of the first fluid through a plurality of fluid injection inlets at axial locations between the inlet and the outlet. 
     
     
         14 . The method of  claim 13 , comprising selectively adjusting the flow rates of the plurality of injected fluids. 
     
     
         15 . The method of  claim 14 , comprising monitoring operating parameters of the pump, and selectively adjusting the flow rates of the plurality of injected fluids based at least in part on the monitored operating parameters. 
     
     
         16 . A system, comprising:
 a twin screw pump configured to:
 pump a process fluid from a first axial location to a second axial location; and 
 inject an injected fluid into the flow of the process fluid at a third axial location between the first and second axial locations. 
   
     
     
         17 . The system of  claim 16 , wherein the process fluid or some component thereof is re-circulated through the twin screw pump as the injected fluid. 
     
     
         18 . The system of  claim 16 , wherein the third axial location is selected based on operating parameters of the twin screw pump. 
     
     
         19 . The system of  claim 16 , wherein the twin screw pump comprises two rotors configured to pump the process fluid from the first axial location to the second axial location, and wherein the third axial location corresponds to a groove between threads of one of the rotors. 
     
     
         20 . The system of  claim 16 , comprising a sub-sea oil and gas extraction system comprising the twin screw pump.