Gas lift system for oil production

Abstract

An improved gas lift system for use in oil production from a well bore ( 11 ) utilising a gas lift injection ( 10 ) system of the known type and further including a surface jet pump ( 16 ) downstream of the well head ( 13 ) for reducing the flowing well head pressure and capable of discharging produced fluid ( 14 ) at a pressure required by a downstream production system.

1 . An improved gas lift system for use in the production of fluid from a well bore including:
 an injector for supplying pressurized gas to the well bore;   a well head;   a tube extending from the well head into the well bore;   a plurality of openings or valves at different depths of the tube for permitting the ingress of injected gas to assist fluid flowing upwards through the tube by reducing the hydrostatic pressure;   further including a boosting unit downstream of the well head for reducing the flowing well head pressure and capable of discharging produced fluid at a pressure required by a downstream production system.   
     
     
         2 . The gas lift system of  claim 1  wherein the boosting unit is a surface jet pump. 
     
     
         3 . The gas lift system of  claim 2  wherein the surface jet pump utilizes a motive flow sourced from at least one of the following: high pressure gas, high pressure oil from at least one high pressure well, high pressure gas from at least one high pressure well, high pressure liquid phase oil already boosted for other reasons, and high pressure liquid phase water already boosted for other reasons. 
     
     
         4 . The gas lift system of  claim 1 , including a further boosting unit installed upstream of the injector to boost the pressure of the lift gas. 
     
     
         5 . The gas lift system of  claim 4  wherein the further boosting unit is a surface jet pump. 
     
     
         6 . An improved gas lift system for use in the production of fluid from a well bore including:
 an injector for supplying pressurized gas to the well bore;   a well head;   a tube extending from the well head into the well bore;   a plurality of openings or valves at different depths of the tube for permitting the ingress of injected gas to assist fluid flowing upwards through the tube by reducing the hydrostatic pressure;   further including a boosting unit upstream of the injector to boost the pressure of the lift gas.   
     
     
         7 . The gas lift system of  claim 6  wherein the boosting unit is a surface jet pump. 
     
     
         8 . The gas lift system of  claim 6  further including a second boosting unit downstream of the well head for reducing the flowing well head pressure and capable of discharging produced fluid at a pressure required by a downstream production system. 
     
     
         9 . The gas lift system of  claim 8  wherein the second boosting unit is a surface jet pump. 
     
     
         10 . The gas lift system of  claim 9  wherein the surface jet pump is configured to receive low pressure injection gas into a first inlet, the flow rate of gas at the first inlet being increased by a high pressure motive flow capable of being received into a second inlet downstream of a recycle loop from a gas lift compressor, wherein an outlet of the surface jet pump is configured to supply gas to the gas lift compressor. 
     
     
         11 . A method of fluid extraction from a well bore utilizing a gas lift system that includes:
 an injector for supplying pressurized gas to the well bore;   a well head;   a tube extending from the well head into the well bore;   a plurality of openings or valves at different depths of the tube for permitting the ingress of injected gas to assist fluids flowing upwards through the tube by reducing the hydrostatic pressure;   the method further including the provision of a surface jet pump downstream of the well head for reducing the flowing well head pressure and capable of discharging produced fluid at a pressure required by a downstream production system;   wherein the surface jet pump utilizes a motive flow sourced from one or more of the following: high pressure gas; high pressure oil and/or gas from one or more high pressure wells; high pressure liquid phase (oil or water) already boosted for other reasons.   
     
     
         12 . The method of  claim 11  including the provision of a further surface jet pump upstream of the injector to boost the pressure of the lift gas. 
     
     
         13 . A method of fluid extraction from a well bore utilizing a gas lift system that includes:
 an injector for supplying pressurized gas to the well bore;   a well head;   a tube extending from the well head into the well bore;   a plurality of openings or valves at different depths of the tube for permitting the ingress of injected gas to assist fluids flowing upwards through the tube by reducing the hydrostatic pressure;   the method further including the provision of a surface jet pump downstream of the well head for reducing the flowing well head pressure and capable of discharging produced fluid at a pressure required by a downstream production system;   wherein the surface jet pump is configured to receive lower pressure injection gas into a first inlet, the flow rate of gas at the first inlet being increased by a high pressure motive flow capable of being received into a second inlet downstream of a recycle loop from a gas lift compressor, wherein an outlet of the surface jet pump is configured to supply gas to the gas lift compressor.   
     
     
         14 . The method of  claim 13  including the provision of a second surface jet pump downstream of the well head for reducing the flowing well head pressure and capable of discharging produced fluid at a pressure required by a downstream production system;
 wherein the second surface jet pump utilizes a motive flow sourced from one or more of the following: high pressure gas; high pressure oil and/or gas from one or more high pressure wells; high pressure liquid phase (oil or water) already boosted for other reasons.