Plunger lift deliquefying system for increased recovery from oil and gas wells

Abstract

This invention provides a method to efficiently remove liquids—hydrocarbons or water—from a natural producing formation so as to reduce the resistance to gas inflow to the wellbore from the formation. The system will also serve as an efficient mechanism for producing hydrocarbon liquids by operating at a higher wellbore and near-wellbore formation pressure to maintain such liquids in a state of increased mobility due to the retained gas in solution. The system used is a downhole device containing a float-operated valve, said float being sensitive to fluid filling its interior such that it falls with liquid fill, opening a valve to the production tubing string liquids are allowed into the production tubing, while gas is produced up the tubing-casing annulus. A unique combination of artificial lift is incorporated in the tubing string, basically a plunger lift operated by one or more gas lift valves that open when a prescribed column of liquid is sensed above the valve. A venturi-type nozzle above the gas lift valve acts to disperse the gas bubbles to create a more efficient fluid slug to lift the plunger to surface.

What is claimed is:  
     
         1 . A method of increasing production and ultimate recovery of gaseous and liquid hydrocarbons from one or more downhole natural gas baring formations and through a production tubing string within a wellbore by complete removal of liquids from the wellbore and utilizing gas pressure drive of a natural gas baring formation, the method comprising: 
 the wellbore being perforated for liquid and gaseous hydrocarbon production in a gas baring formation;    providing a surface gas flow pressure regulator and a surface pressure gauge on the casing well head annulus exit port for respectively regulating gas flow production and measuring pressure white maintaining a predetermined flow pressure on the wellbore annulus;    positioning a downhole shrouded cover injector at the bottom of a production tubing string relative to the opened formation;    passing formation fluids through the downhole injector by pressure differential and through the production tubing string toward the surface while preventing formation gases from entering the production tubing string;    positioning a plunger lift within a production tubing string above the injector for lifting liquids to the surface;    positioning one or more fluid operated gas lift valves for lifting liquid to the surface by gas injection into the tubing string below the plunger lift;    plunger lifting liquid inflow efficiently by maintaining a gas fluid interface between plunger and liquid through the production tubing string to the surface of the well; and    maintaining direct fluid communication between the wellbore and the opened gas baring formation and liquids entering from the lower part of the formation, such that such gas pressure acts as a cap on the formation fluids in the opened formation to force the fluids out of the formation into the wellbore through the injector and toward the surface.    
     
     
         2 . The method as defined in  claim 1 , further comprising: 
 wherein the downhole injector is positioned relative to the lowest downhole opened gas baring formation in the wellbore so that all incoming liquid hydrocarbons and invading waters are efficiently and completely removed from the wellbore into the lower pressure production tubing string on to the surface thereby considerably increasing gaseous and liquid hydrocarbon recovery.    
     
     
         3 . The method as defined in  claim 1 , further comprising: 
 continually and comparatively measuring and monitoring the formation gas flow production, pressure and related recovery for the most effective optimum gas flow pressure at the wells surface gas flow meter and periodically making and observing fluid level and gas-oil ratio test, while continually and comparatively measuring and monitoring the production and recovery of formation liquids through a surface metering facility for a combined total maximum gaseous and liquid hydrocarbon production and ultimate recovery throughout the reservoir's formations total gaseous and liquid hydrocarbon recovery life for maximum hydrocarbon reserve value.    
     
     
         4 . The method as defined in  claim 1 , further comprising: 
 while recovering formation liquids at the surface production tubing string discharge, simultaneously flowing formation gas production and pressure at a regulated and controlled predetermined gas flow pressure at the surface gas flow pressure regulator with the surface gas pressure gauge to retain an optimum formation gas pressure in an annulus about the production tubing string, and thereby on and within all opened hydrocarbon formations, such that the gas pressure prevents solution gas within the liquid hydrocarbon in its formation and the wellbore from breaking out of solution, thereby maintaining its expulsive force, high mobility and low viscosity, and acts as a driving force to pass pressured higher pressure hydrostatic head liquids out of the formation and through the injector by pressure differential on up into the lower pressure production tubing string to recover formation liquids at the surface, wherein total in place liquid hydrocarbons are maintained highly fluid and recoverable, thereby increasing related liquid hydrocarbon reserve value.    
     
     
         5 . The method as defined in  claim 1 , further comprising: 
 maintaining a predetermined optimum formation gas flow pressure in the wellbore annulus such that gas pressure acts as a driving force on all liquid hydrocarbons and invading waters to pass them through the injector by pressure differential into the lower pressure production tubing string for formation fluid recovery at the surface, so that a liquid level is maintained in the wellbore at the injector liquid in take level for maximum free gas and pressurized fluid flow from all opened hydrocarbon formations for maximum gaseous and liquid hydrocarbon recovery, whereby total gaseous and liquid hydrocarbon reserve recoverability and related value is increased.    
     
     
         6 . The method as defined in  claim 1 , further comprising: 
 maintaining a wellbore gas pressure in the annulus above the downhole injector intake liquid level as a driving force to maintain a predetermined liquid level in the lower pressure production tubing string for maximum plunger lift or other artificial lift efficiency of incoming liquids on to the surface.    
     
     
         7 . The method as defined in  claim 1 , further comprising: 
 positioning a check valve within a production tubing string above the top of the injector for preventing fluids which pass by the check valve from returning to the injector; and    the injector housing having a nominal outer diameter, a fluid responsive float open at the top and closed at the bottom and moveable with respect to the injector housing as a function of fluid density surrounding the float, and a shut off valve member moveably responsive to the float for engagement with a shut off valve seat, the shut off valve member being spaced vertically below inside the injector housing from the check valve.    
     
     
         8 . The method as defined in  claim 1 , further comprising: 
 providing in high formation sand influx wells a sleeve-shaped filter screen across an inlet flow port at the top of the liquid injector for restricting at least 90% of solid particles 30 microns or greater from passing through the filter screen, accumulating and closing the injector outer housing at the bottom.    
     
     
         9 . The method as defined in  claim 4 , further comprising: 
 providing the surface gas flow pressure regulator for controlling gas flow from the wellbore annulus at the well head exit port throughout the complete production and total recovery of all in place liquid hydrocarbons until said production and recovery considerably declines, at such time converting over to maximum gas production by releasing the surface gas flow pressure to a lower predetermined optimum or open flow pressure at the surface gas flow regulator, to efficiently produce and recover natural gas white efficiently removing any incoming invading waters in the wellbore, whereby total in place liquid hydrocarbons have been recovered, leaving only the small quantities that stick to the formation rock pores as a thin film, and that are isolated in any formation structural traps, wherein total in place gas is free to flow to the surface for total in place natural gas production and recovery, thereby recovering total in place liquid and gaseous hydrocarbons maintained and converted by this recovery process to be ultimately recoverable.