Plunger lift assembly

Abstract

A plunger lift assembly is provided comprising a flow diverter that effects separation of gaseous material from reservoir fluid. The gaseous material may be collected to provide a source of pressurized gaseous material to displace the plunger for producing liquid reservoir fluid.

What is claimed is: 
     
         1 . A reservoir fluid production assembly comprising:
 a reservoir fluid inlet for receiving reservoir fluid flow from a downhole wellbore space of the wellbore;   a downhole fluid conductor for conducting the received reservoir fluid flow;   a flow diverter fluidly coupled to the downhole fluid conductor such that the flow diverter receives reservoir fluid flow being conducted by the downhole fluid conductor, and including:
 a reservoir fluid discharge communicator for discharging the received reservoir fluid into an uphole wellbore space of the wellbore with effect that depletion of gaseous material, from the received reservoir fluid, is effected by separation of the gaseous material from the reservoir fluid within the wellbore fluid conductor, in response to at least buoyancy forces, such that a gaseous material-depleted reservoir fluid is obtained while displacement of the reservoir fluid from the subterranean formation is being effected such that the reservoir fluid is being received by the conductor inlet and conducted to the reservoir fluid discharge communicator via the reservoir fluid receiver; 
 a gas-depleted reservoir fluid receiver for receiving the obtained gas-depleted reservoir fluid and conducting the gas-depleted reservoir fluid to a gas-depleted reservoir fluid discharge communicator; 
   
       a sealed interface within the wellbore, between: (a) the uphole wellbore space of the wellbore, and (b) the downhole wellbore space of the wellbore, for preventing, or substantially preventing, bypassing of the gas-depleted reservoir fluid receiver by the gas-depleted reservoir fluid; 
       an uphole fluid conductor for conducting liquid reservoir fluid to the produced liquid reservoir fluid outlet, and including a liquid accumulator that is fluidly coupled to the gas-depleted reservoir fluid discharge communicator for accumulating of liquid reservoir fluid of the gas-depleted reservoir fluid that is discharged from the gas-depleted reservoir fluid discharge communicator; 
       a produced liquid reservoir fluid outlet; and 
       a plunger disposed within the uphole fluid conductor, uphole relative to the gas-depleted reservoir fluid discharge communicator of the flow diverter, and displaceable within the uphole fluid conductor between a downhole position and an uphole position; 
       wherein:
 the plunger and the produced gas-depleted reservoir fluid outlet are co-operatively configured such that, while uphole-disposed liquid reservoir fluid is disposed uphole of the plunger, displacement of the plunger, from the downhole position to the uphole position, by pressurized gaseous material is with effect that the uphole-disposed liquid reservoir fluid is displaced uphole by the plunger and discharged through the produced liquid reservoir fluid outlet; and 
 the plunger is configured for being conducted through liquid reservoir fluid that has accumulated within the liquid accumulator, while being displaced from the uphole position to the downhole position by gravitational force in the absence of gaseous material that is sufficiently pressurized to counterbalance the gravitational force, such that, after the plunger has passed through the accumulated liquid reservoir fluid, at least a fraction of the accumulated liquid reservoir fluid becomes disposed uphole relative to the plunger such that the uphole-disposed liquid reservoir fluid is obtained. 
 
     
     
         2 . The assembly as claimed in  claim 1 ;
 wherein:
 the downhole fluid conductor extends from the reservoir fluid inlet to the reservoir fluid receiver and defines a fluid passage; 
 the uphole fluid conductor extends from the gas-depleted reservoir fluid discharge communicator to the produced liquid reservoir fluid outlet and defines a fluid passage; and 
 the maximum cross-sectional flow area of the downhole fluid conductor is less than the minimum cross-sectional flow area of the uphole fluid conductor. 
   
     
     
         3 . The assembly as claimed in  claim 2 ;
 wherein the ratio of the maximum cross-sectional flow area of the downhole fluid conductor to the minimum cross-sectional flow area of the uphole fluid conductor is less than 0.85.   
     
     
         4 . The assembly as claimed in any one of  claims 1  to  3 ;
 wherein the gas-depleted reservoir fluid receiver is disposed downhole relative to the reservoir fluid discharge communicator. 
 
     
     
         5 . A reservoir fluid production system comprising:
 the assembly as claimed in any one of  claims 1  to  4 , wherein the assembly is disposed within a wellbore.   
     
     
         6 . The system as claimed in  claim 5 ;
 wherein:
 the wellbore includes a vertical portion and a horizontal portion; and 
 the plunger is disposed within the vertical portion. 
   
     
     
         7 . The system as claimed in  claim 5  or  6 ;
 wherein the horizontal portion has a length, measured along a longitudinal axis of the horizontal portion, of at least 100 metres. 
 
     
     
         8 . The system as claimed in any one of  claims 5  to  7 ;
 wherein:
 an intermediate fluid passage is disposed between the flow diverter and the wellbore; and 
 the minimum cross-sectional flow area of the uphole wellbore space is greater than the maximum cross-sectional flow area of the intermediate fluid passage. 
 
 
     
     
         9 . The system as claimed in  claim 8 ;
 wherein the ratio of the minimum cross-sectional flow area of the uphole wellbore space to the maximum cross-sectional flow area of the intermediate fluid passage is at least 1.2.