Gas lift method

Abstract

A method is provided comprising the steps of: providing a production tubing to a production interval in a wellbore; providing a check valve in the production tubing at a lower end of the production tubing, the check valve effective to permit flow into the production tubing but not permit flow from the production tubing through the check valve; allowing liquids from the formation to flow into the production tubing; and after liquids from the formation have entered the production tubing, pressuring the production tubing with gas from below the level of the liquids from the formation and thereby forcing at least a portion of the liquids from the formation to the surface; and discontinuing pressuring the production tubing to allow liquids from the formation to again enter the production tubing.

What is claimed:  
     
         1 . A method comprising the steps of: 
 providing a production tubing to a production interval in a wellbore;    providing a check valve in the production tubing at a lower end of the production tubing, the check valve effective to permit flow into the production tubing but not permit flow from the production tubing through the check valve;    allowing liquids from the formation to flow into the production tubing; and after liquids from the formation have entered the production tubing;    injecting gas into the production tubing at a point below the level of the liquids from the formation and thereby forcing at least a portion of the liquids from the formation to the surface; and    discontinuing injection of the gas to allow liquids from the formation to again enter the production tubing.    
     
     
         2 . The method of    claim 1    further comprising the step of injecting gas through a gas tubing that extends from the surface inside of the production tubing.  
     
     
         3 . The method of    claim 2    wherein the gas tubing is a coiled tubing.  
     
     
         4 . The method of    claim 2    wherein the gas tubing extends to near the check valve in the production tubing.  
     
     
         5 . The method of    claim 4    wherein the check valve is attached to an end of the production tubing.  
     
     
         6 . The method of    claim 4    wherein the check valve is attached to the end of the coiled tubing.  
     
     
         7 . The method of    claim 5    wherein the check valve is seated into a nipple at or near the bottom of the production tubing.  
     
     
         8 . The method of    claim 6    wherein the check valve is seated into a nipple at or near the bottom of the coiled tubing.  
     
     
         9 . The method of    claim 1    further comprising the step of blocking the production tubing at the surface, and then reducing the pressure within the production line to allow liquids from the formation to enter the production tubing.  
     
     
         10 . An apparatus for production of liquid hydrocarbons from a wellbore to a gathering system at an accessible surface, the apparatus comprising: 
 a production tubing extending from the surface into the wellbore;    a check valve connected to an end of the production tubing inside of the wellbore, the check valve effective to permit flow from the wellbore outside of the production tubing into the production tubing but not allowing flow out of the production tubing into the wellbore;    a gas tubing extending from the surface to near the check valve, inside of the production tubing; and    a control system to intermittently inject gas into the production tubing from the gas tubing and thereby lift liquids from inside of the production tubing to the surface.    
     
     
         11 . The apparatus of    claim 10    further comprising a vent effective to reduce pressure within the production tubing when the gas is not being injected.