Gas-charged unloading plunger

Patent metadata

Field	Value
Publication number	US-11261859-B2
Application number	US-202016890615-A
Country	US
Kind code	B2
Filing date	Jun 2, 2020
Priority date	Jun 2, 2020
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

An unloading plunger having a chamber for compressed gas and a method for unloading liquid from a wellbore via ascending of the unloading plunger including ascending via formation pressure the unloading plunger from the bottom portion of the wellbore to a rest position at a wellhead and releasing compressed gas from the chamber into the wellbore during the ascending to decrease hydrostatic pressure of liquid in the wellbore above the unloading plunger.

First claim

What is claimed is:

1. A method of operating a well comprising a wellhead and associated wellbore in a subterranean formation, the method comprising:
descending, via gravity, an unloading plunger from a rest position at the wellhead to a bottom portion of the wellbore, the unloading plunger comprising a chamber having compressed gas;
ascending, via formation pressure, the unloading plunger from the bottom portion of the wellbore to the rest position at the wellhead;
releasing the compressed gas from the chamber at an upper portion of the unloading plunger through a chamber discharge opening and a valve disposed at the chamber discharge opening into liquid in the wellbore above the unloading plunger during the ascending to decrease hydrostatic pressure of the liquid in the wellbore above the unloading plunger, wherein the unloading plunger comprises the valve that is a timer-operated valve comprising a timer;
maintaining the valve closed via the timer during the descending of the unloading plunger, and maintaining the valve open via the timer during the ascending of the unloading plunger, wherein the timer comprises a mechanical timer comprising an actuator to operate the valve, and wherein the mechanical timer does not receive electricity in operation; and
unloading the liquid from the wellbore via the ascending of the unloading plunger.

2. The method of claim 1 , wherein the wellbore is shut-in during the descending of the unloading plunger, and wherein the wellbore is not shut-in during the ascending of the unloading plunger.

3. The method of claim 2 , wherein placing the wellbore as shut-in comprises closing a production valve at the wellhead to stop flow of fluid from the wellbore through the production valve, and wherein the shut-in of the wellbore increases pressure in the wellbore.

4. The method of claim 1 , wherein the unloading of the liquid from the wellbore via the ascending of the unloading plunger comprises discharging the liquid through a production valve at the wellhead, and wherein the rest position comprises a wellhead lubricator pipe.

5. The method of claim 1 , comprising producing hydrocarbon from the subterranean formation through the wellbore and a production valve at the wellhead after unloading the liquid from the wellbore.

6. The method of claim 5 , wherein the wellbore comprises casing having perforations for introduction of the hydrocarbon into the wellbore from the subterranean formation, and wherein producing the hydrocarbon through the wellbore comprises flowing the hydrocarbon through production tubing in the wellbore.

7. The method of claim 1 , wherein descending the unloading plunger to the bottom portion of the wellbore comprises descending the unloading plunger through production tubing in the wellbore to a bottomhole bumper spring.

8. The method of claim 1 , wherein ascending the unloading plunger comprises ascending the unloading plunger through production tubing in the wellbore, and wherein the unloading plunger provides a seal in the production tubing between fluid above the unloading plunger and fluid below the unloading plunger.

9. The method of claim 1 , wherein releasing the compressed gas comprises discharging the compressed gas from the valve through a nozzle at the upper portion of the unloading plunger into the liquid above the unloading plunger, and wherein the chamber comprises an internal cavity of the unloading plunger.

10. The method of claim 9 , wherein the nozzle comprises multiple nozzles of the unloading plunger downstream of the valve, wherein a passage in the body of the unloading plunger couples the valve with the multiple nozzles, and wherein the compressed gas comprises a pressure in a range of 1000 pounds per square inch gauge (psig) to 5000 psig in the chamber before the releasing of the compressed gas from the chamber.

11. The method of claim 10 , wherein each nozzle of the multiple nozzles comprises a passage portion coupled to the passage in the body of the unloading plunger and an ejection opening at an exterior top surface of the body.

12. The method of claim 9 , wherein a passage in a body of the unloading plunger couples the valve to the nozzle, and wherein the nozzle comprises an ejection opening at a top exterior surface of the body of the unloading plunger.

13. The method of claim 1 , comprising inputting a first time setting to the timer that is length of time the timer maintains the valve closed in a cycle, and inputting a second time setting to the timer that is length of time the timer maintains the valve open in the cycle.

14. The method of claim 13 , wherein inputting the first time setting and the second time setting comprises removing a head of a body of the unloading plunger to access the timer, wherein the unloading plunger is available from the rest position at the wellhead.

15. The method of claim 1 , and wherein the compressed gas comprises nitrogen.

16. The method of claim 1 , wherein the timer directs operating position of the valve, wherein the valve comprises a plate that prevents release of the compressed gas through the chamber discharge opening when the valve is in a closed operating position.

17. The method of claim 1 , wherein the unloading plunger comprises a nozzle at an upper portion of the unloading plunger to receive the compressed gas from the timer-operated valve, and wherein releasing the compressed gas comprises discharging the compressed gas from the chamber through the chamber discharge opening, the timer-operated valve, and the nozzle into the liquid.

18. The method of claim 1 , comprising introducing the compressed gas into the chamber via an injection port of the unloading plunger disposed at a bottom portion of the unloading plunger, wherein the valve in a closed operating position prevents release of the compressed gas through the chamber discharge opening and the timer-operated valve, and wherein the valve in an open operating position releases the compressed gas through the chamber discharge opening and the timer-operated valve.

19. The method of claim 1 , comprising introducing the compressed gas into the chamber via an injection port of the unloading plunger as available at the rest position at the wellhead, and wherein the chamber comprises an internal chamber of the unloading plunger.

20. A method of operating a well comprising a wellhead operationally coupled to a wellbore in a subterranean formation, the method comprising:
introducing compressed gas into an internal chamber of an unloading plunger via an injection port of the unloading plunger disposed at a bottom portion of the unloading plunger;
closing a production valve at the wellhead to shut-in the wellbore and descending, via gravity, the unloading plunger from the wellhead through production tubing to a bottomhole of the wellbore, the unloading plunger comprising the internal chamber having the compressed gas;
opening the production valve and ascending, via formation pressure, the unloading plunger from the bottomhole through the production tubing to the wellhead;
decreasing hydrostatic pressure of liquid above the unloading plunger in the production tubing during the ascending by discharging, via a timer-operated valve of the unloading plunger, the compressed gas from the internal chamber through the timer-operated valve at an upper portion of the unloading plunger into the liquid above the unloading plunger;
maintaining a valve of the timer-operated valve in a closed operating position via a timer of the timer-operated valve during the descending of

Assignees

• Saudi Arabian Oil Co

Inventors

• Zahran Amr Mohamed

Classifications

• E21B43/123

  Gas lift valves · CPC title

• E21B43/121 Primary

  Lifting well fluids (monitoring of down-hole pump systems E21B47/008) · CPC title

• F04B53/14

  Pistons, piston-rods or piston-rod connections · CPC title

• F04B47/12 Primary

  having free plunger lifting the fluid to the surface · CPC title

• E21B34/02

  in well heads · CPC title