Plunger elevator - (from the English plunge - to dive, dive) - a device for lifting fluid from a well due to the energy of a gas under pressure , which is a type of periodic gas lift using a plunger and is used to remove fluid from a gas well [1] .
Content
Creation History
The device was invented by American engineers Fletcher ( 1924 ) and Hughes ( 1927 ), and has been used in the USSR since the 1930s [1] . At different times, many patents were registered for various modifications and improvements of these devices. Plunger lift installations can be continuous or intermittent. Designed for wells that are operated only on an elevator string or jointly on an elevator string and annular annulus. Units can be used in wells with one-dimensional and combined pipe columns, regardless of the depth of their descent. In continuous installations, the plunger is non-stop moving up and down the lift string, and in periodic installations it is delayed at the bottom or at the wellhead by gas flows or mechanical locks for a period of time set by the operator. Installations of continuous operation were developed at VNIIGAZ in 1963 . and were used in a number of gas fields [2] . In America, a plunger lift in gas wells was first used in 1958.
Device
Installation of a plunger elevator consists of surface mounted equipment, underground equipment and a plunger . The plunger is the main work item. Depending on the gas flow rate and fluid flow to the bottom, plungers are used:
- self-sealing;
- type “flying valve”;
- constant outer diameter;
- combined, designed for wells with a multi-sized string of tubing [2] .
Principle of Operation
With Flying Valve
Gas continuously flows into the elevator column, and liquid accumulates above the pipe stop. Plunger elements ( sleeve and ball ) fall in the upstream. The ball stops falling on a pipe stop located under the liquid level. The sleeve falling behind the ball reaches the pipe stopper and sits on the ball. From this moment, the plunger moves up. When lifting, the ball overlaps the lower hole of the sleeve. The liquid column above the plunger is displaced by the gas rising through the pipe. When the liquid level rises to the perforated nozzle at the mouth of the sleeve, the liquid is discharged through the discharge line into the separator . The upper shock absorbs the ball from the sleeve and falls in an upward flow of gas. The sleeve falls over the ball. The process is repeated. Flying valve type plungers can be used in another type of elevator. Multi-plunger elevator .
Self-sealing
The plunger body on the outer surface has additional pads that are pressed from the main body by springs and pressed against the pipe surface, significantly reducing the annular gap area and, accordingly, gas leakage relative to the plunger during its lifting. During the fall of the plunger, the pads may be in a compressed position.
Notes
- ↑ 1 2 Mountain Encyclopedia on the Academician
- ↑ 1 2 Shulyatikov V.I., Kobzev Yu.V. "Removing fluid from the bottom of gas wells using a plunger lift." Gas business, No. 4, 1966.
Links
OPERATION OF WELLS ON THE MEDVEZHIE GAS FIELD ON THE BASIS OF PLUNGER LIFT AT A FINAL STAGE OF THE FIELD DEVELOPMENT . International Gas Union (2006). - Report at the 23rd International Gas Congress. Date of treatment March 11, 2010. Archived on April 20, 2012.
See also
- Multi-plunger lift
- Plunger
- Natural gas