Oil well assembly for oil production and fluid injection

Abstract

An oil well assembly and a method thereof for injecting fluid into an oil reservoir to promote production of oil from the oil reservoir is provided. The oil well assembly comprises a pump for pumping oil from the oil reservoir to the surface and for transporting treatment fluid from the surface to a valve for controlling flow of treatment fluid to the oil reservoir. The pump may be lubricated using the treatment fluid even when the valve has closed the flow of treatment fluid.

1 . An oil well assembly comprising:
 a production tubing for transporting oil from an oil reservoir to a surface;   an injection string at least partially disposed within the production tubing for injecting treatment fluid from the surface to the oil reservoir;   a pump disposed within the production tubing and in fluid communication with the injection string and comprising an outlet end and an inlet end, for pumping oil within the production tubing from the oil reservoir to the surface in a direction from the inlet end to the outlet end, and for transporting treatment fluid from the surface to the injection string in a direction from the outlet end to the inlet end;   a wellhead assembly located at the surface and coupled to the production tubing for receiving oil from the production tubing, and coupled to the outlet end of the pump for providing treatment fluid to the injection string via the pump, the wellhead assembly comprising a lift apparatus to raise or lower the pump within the production tubing;   a tension regulated valve disposed within the production tubing and coupled both to the injection string and to the inlet end of the pump, wherein raising or lowering the pump opens or closes the tension regulated valve for controlling an amount of treatment fluid passed from the pump to the injection string; and   a port located on the pump, at the inlet end, and in fluid communication with the wellhead assembly for providing treatment fluid to the pump.   
     
     
         2 . The oil well assembly of  claim 1 , wherein the lift apparatus controls the tension regulated valve to reduce a flow of treatment fluid passed from the pump to the injection string without reducing a flow of treatment fluid to the port. 
     
     
         3 . The oil well assembly of  claim 1 , wherein the lift apparatus controls the tension regulated valve to shut off a flow of treatment fluid passed from the pump to the injection string without reducing a flow of treatment fluid to the port. 
     
     
         4 . The oil well assembly of  claim 1 , wherein the pump comprises a hollow rotor disposed within a housing, and the port is located on the hollow rotor at the inlet end of the pump, and the hollow rotor comprises an interior passage for passing treatment fluid from the wellhead assembly to the injection string and the port. 
     
     
         5 . The oil well assembly of  claim 23 , wherein provided from the port is pumped with the oil within the production tubing from the inlet end to the outlet end for lubricating the pump. 
     
     
         6 . The oil well assembly of  claim 5 , wherein the valve is disposed between the injection string and the inlet end of the pump for fluidly coupling the injection string and the pump to control the passage of treatment fluid to the injection string without restricting the passage of treatment fluid to the port. 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . The oil well assembly of  claim 4 , wherein the pump is one of: a progressive cavity pump, a screw pump, a positive displacement pump, a kinetic-energy pump, or a centrifugal pump. 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . The oil well assembly of  claim 1 , wherein the injection string comprises a tail string located at a bottom end of the production tubing, the tail string comprising a horizontal section for injecting treatment fluid at horizontally spaced apart regions of the oil reservoir. 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . A process comprising:
 a) providing the oil well assembly of  claim 1 ;   b) passing treatment fluid through the pump in a direction from the outlet end to the inlet end;   c) pumping treatment fluid with crude oil through the pump in a direction from the inlet end to the outlet end; and   d) controlling, via the valve, an amount of treatment fluid passed from the pump to the injection string.   
     
     
         21 . The process of  claim 20 , wherein the treatment fluid comprises a corrosion inhibitor, a demulsifier, a scale inhibitor, a wax inhibitor, a paraffin inhibitor, or a pump lubricant. 
     
     
         22 . The process of  claim 20 , wherein the treatment fluid comprises water or steam. 
     
     
         23 . The oil well assembly of  claim 4 , further comprising a hollow sucker rod string disposed between the wellhead and the pump for mechanically coupling the wellhead to the pump in order to drive the pump from a drive mechanism of the wellhead assembly and for fluidly coupling the wellhead to the interior passage to transport treatment fluid from the wellhead assembly to the injection string and the port. 
     
     
         24 . The process of  claim 20 , further comprising providing the treatment fluid passed through the pump to the port. 
     
     
         25 . The process of  claim 24 , further comprising providing the treatment fluid passed through the pump to the injection string. 
     
     
         26 . The process of  claim 24 , further comprising pumping the crude oil with the treatment fluid passed to the port. 
     
     
         27 . The process of  claim 25 , further comprising pumping the crude oil with the treatment fluid passed to both the port and the injection string. 
     
     
         28 . The process of  claim 20 , further comprising controlling, via the valve, the amount of treatment fluid passed from the pump to the injection string without restricting the passage of treatment fluid to the port.