Systems and methods of removing stagnant liquid from a hydrocarbon well

Abstract

The present invention is generally directed to systems and methods of removing liquids from hydrocarbon wells with liquid loading problems. More specifically, the present invention provides an intermittent gas lift system to remove stagnant liquid from hydrocarbon wells. The system includes a gas inlet port for gas to be injected into the well at a relatively low volume. The injected gas travels to a distal end of a lift tube inserted within a production tubing and then lifts or carries liquid up the lift tube to the surface.

What is claimed is: 
     
         1 . An intermittent gas lift system to remove stagnant liquid from a wellbore of a hydrocarbon well, comprising:
 a downhole check valve interconnected to a lower end of a production tubing positioned within the wellbore;   a lift tube positioned within the production tubing, wherein an annular space is formed between an exterior surface of the lift tube and an interior surface of the production tubing; and   a gas inlet port interconnected to the production tubing at a wellhead portion of the hydrocarbon well, wherein gas injected through the gas inlet port travels down the annular space to a distal end of the lift tube in a horizontal section of the wellbore and then pushes liquid up the lift tube.   
     
     
         2 . The gas lift system of  claim 1 , wherein the distal end of the lift tube is spaced from the lower end of the production tubing. 
     
     
         3 . The gas lift system of  claim 1 , wherein the downhole check valve prevents fluid from flowing out of the lower end of the production tubing. 
     
     
         4 . The gas lift system of  claim 3 , wherein when gas is injected through the gas inlet port into the annular space, pressure in the lower portion of the production tubing increases and the downhole check valve closes to prohibit fluid from a hydrocarbon reservoir proximate to the lower end of the production tubing from flowing into the production tubing. 
     
     
         5 . The gas lift system of  claim 3 , wherein when the injection of gas through the gas inlet port into the annular space stops, pressure in the lower portion of the production tubing decreases and the downhole check valve opens to permit fluid from a hydrocarbon reservoir proximate to the lower end of production tubing to flow into the production tubing. 
     
     
         6 . The gas lift system of  claim 1 , further comprising a solution inlet port at the wellhead portion of the hydrocarbon well to inject a pretreatment solution into at least one of the annular space and production tubing. 
     
     
         7 . The gas lift system of  claim 6 , wherein the solution inlet port is connected to at least one of the production tubing and the lift tube. 
     
     
         8 . The gas lift system of  claim 1 , further comprising a control system operable to automatically start the injection of gas into the gas inlet port when the control system determines that data from a sensor indicates the well is not producing hydrocarbons at a predetermined rate. 
     
     
         9 . The gas lift system of  claim 1 , wherein the distal end of the lift tube is within the horizontal section of the wellbore. 
     
     
         10 . The gas lift system of  claim 1 , further comprising a multiphase flowmeter interconnected to the lift tube proximate to the wellhead. 
     
     
         11 . The gas lift system of  claim 10 , wherein the multiphase flowmeter is positioned between the wellhead portion and a three-phase separator. 
     
     
         12 . The gas lift system of  claim 1 , further comprising a pressure sensor positioned within a horizontal section of the production tubing. 
     
     
         13 . A method of removing stagnant liquid from a wellbore of a hydrocarbon well, comprising:
 receiving first data from a sensor;   determining that the hydrocarbon well is not producing hydrocarbons at a predetermined rate;   injecting a gas into an annular space formed between an interior surface of a production tubing positioned within the wellbore and an exterior surface of a lift tube positioned within the production tubing;   receiving second data from the sensor indicating that liquid flowing in the lift tube at the surface includes some of the injected gas; and   stopping the injection of gas into the annular space.   
     
     
         14 . The method of  claim 13 , wherein the first data received by the sensor includes one or more of a pressure measured proximate to a bottom hole location and a pressure or a flow rate of hydrocarbons from the wellbore measured at or near the surface. 
     
     
         15 . The method of  claim 13 , further comprising injecting a pretreatment solution into the wellbore through at least one of the production tubing and the lift tube. 
     
     
         16 . The method of  claim 15 , wherein the pretreatment solution is injected into at least one of the annular space and directly into the lift tube. 
     
     
         17 . The method of  claim 13 , further comprising interconnecting a downhole check valve to a lower end of the production tubing. 
     
     
         18 . The method of  claim 13 , further comprising positioning the lift tube within the production tubing. 
     
     
         19 . The method of  claim 18 , wherein a distal end of the lift tube is spaced upstream from a lower end of the production tubing. 
     
     
         20 . A non-transitory computer readable medium comprising a set of instructions stored thereon which, when executed by a processor of a control unit, cause the processor to execute a method of removing stagnant liquid from a wellbore of a hydrocarbon well, comprising:
 an instruction to receive first data from a sensor;   an instruction to determine that the hydrocarbon well is not producing hydrocarbons at a predetermined rate;   an instruction to inject a gas into an annular space formed between an interior surface of a production tubing positioned within the wellbore and an exterior surface of a lift tube positioned within the production tubing;   an instruction to receive second data from the sensor indicating that liquid flowing in the lift tube at the surface includes some of the injected gas; and   an instruction to stop the injection of gas into the annular space.