US2642002A

US2642002A - Plunger lift device

Info

Publication number: US2642002A
Application number: US83850A
Authority: US
Inventors: Donald G Knox; Jr James W Lawrence
Original assignee: Nat Supply Co
Current assignee: National Supply Co
Priority date: 1949-03-28
Filing date: 1949-03-28
Publication date: 1953-06-16
Anticipated expiration: 1970-06-16

Description

Jl me 16,- 1953 Nox ETAL 2,642,002

, PLUNGER LIFT DEVICE Filed March 28, 1949 3 Sheets-Sheet 1 illlllllillllllmmm mmvroxs DOA/9L0 KNOX kn ves mweE//c'E,./e. v

June 16, 1953 I D. e. KNOX ETALI.

PLUNGER LIFT DEVICE s Sheets-Sheet 2 Filed March 28, 1949 June 16, 1953 2 ammo a. m/ax aqua-s :0. mums-wee .xe.

INVENT6RS.

provide a plunger body Patented June 16, 1953 PLUNGER LIFT DEVICE Donald G. Knox, Long Beach, and James W. Lawrence, Jr., Los Angeles, Calif., assignors to The'National Supply Company, Pittsburgh, Pa... a corporation of Pennsylvania Application March 28, 1949, Serial No. 83,850

This invention relates to plunger lift apparatus for raising fluid from a well by means of fluid pressure acting on a plunger which travels the full length of the eduction tubing. This invention is particularly directed to'improvements in the construction of the plunger.

One of the difliculties encountered in the operation of plunger lift devices has been the slip"- page and consequent loss of well fluid between the eduction tubing and the fluid operated plunger. It has been necessary to make the plunger considerably undersized in order that it may travel freely within the tubing, because the tubing is not machined on its inside surface. It is not practicable to employ piston ring type seals for minimizing slippage of well fluid between the plunger and the eduction tubing because such seal rings will not freely pass the joints connect ing the individual lengths of eduction tubing.

It is the principal object of this invention to provide a plunger employing a set of compensating shoes which perform the function of an expansion type piston ring and yet which is constructed to pass across recesses at each coupling jointwithout jamming and without detrimental effects.

A more detailed object of this invention is to having expansible ring segments acting to seal against the inside surface of the eduction tubing, which segments is regulated by radially movable members extending axially of the plunger body.

Other and more detailed objects and advantages will appear hereinafter. x

In the drawings: Figure l is a diagrammatic sectional view of a plunger lift installation and showing a plunger the radial position of;

' 8 Claims. (01. 103-52) embodying this invention positioned within an eduction tubing.

Figure 2 is a sectional elevation of the upper of Figure 2. I

Figure 4 is a transverse sectional view taken substantially on the lines 5-4 as shown in Figure 2.

Figure 5 is a perspective view partly broken away showing the assembly of the depression bars and ring segments, the plunger body being omit ted-for clarity of illustration.

- vFigure 6 is a perspective view of the plunger assembly.

Figure '7 is a sectional view taken substantially on the line 1-4 as shown in Figure 6.

Referring to the drawings, the swab plunger assembly generally designated it is positioned Within a sectional eduction tubing H which ex-- tends into a well bore 12. The bore may be provided with the usual casing i3. Gas under pressure admitted through'valve l4 passes downwardly in the annulus I5 between the casing and eduction tubing and acts to cause the well fluid to pass upwardly into the footpiece assembly is at the bottom of the well. The well fluid rises in the lower end of the eduction tubing H. The plunger assembly it drops by gravity through the interior of the eduction tubing until it strikes the bumper I! which is supported on the spring l8. A valve in the plunger assembly closes and gas pressure below the plunger assembly i0 then causes it to move upwardly through the eduction tubing, raising a load of well fluid above it. The well fluid is discharged through ports [9 in the flow nipple 22 and passes outwardly through a restriction valve 2!, The reduction in pressure beneath the plunger assembly Ill then allows its valve to open by gravity and the plunger descends by gravity to start a new cycle.

Since the eduction tubing ll may be several thousand feet in length it is composed of individual tubing sections 22 connected by coupling collars 23. The adjacent ends of tubing sections do not necessarily meet in abutting contact, but

and which avoid fouling or interference when the plunger assembly passes over a joint between adjacent tubing sections 22.

.As shown in the drawings, the plunger assembly I0 includes a body 26 having an end'piece 21 secured at its upper end by means of threads 28 and a valve cage 29 secured at its lower end by means of threads 30. A pair of expandible sealing assemblies is provided on the body, and each of these assemblies includes a plurality of ring segments 3| which are received in a circumferential groove 32 provided on the body 26. This groove intersects a plurality of longitudinal slots 33 which extend axially of the body and receive axially extending deflector bars 34,. The ring segments 3| are notched adjacent their ends as shown at 35 and the bars 34 are each provided with a central relief 36 and side notches 31 which interfit with the notched ends of the ring segments 3|. This arrangement is clearly shown in Figure 5. The depths of the notches 35 and of the reliefs 36 are such that when the segments 3| and bars 34 are in fully extended position, as shown in Figure 4, a continuous circle is formed by the outer surfaces of the bars and segments.

Each of the ring segments 3| is provided with a radially extending recess 38 for reception of a compression spring 39. The inner ends of each of the compression springs 39 rest in the circumferential groove 32. The action of these springs is to urge the segments 3| to move radially outwardly. The bars 3 2 each overlie a joint between adjacent ring sections 3| and serve to limit outward movement of the segments under influence of the compression springs 33. Each of the bars 35 is provided with axially ex tending lips it at its opposed ends, and these lips 40 extend within counterbores ill provided at the ends of the valve cage 29 and end piece 21. The bars 3 are free to move radially within the longitudinal slots 33 and to tilt within the slots, but the extent of such movement is limited by engagement of the lips it within the counterbores 4|. It will be observed that each of the bars 34 is bowed on its outer surface so that the contour is straight for a portion of the bar length and then tapers off on both ends toward the plunger diameter so that when the bars are fully depressed into the slots 33, the maximum projection of the bars beyond the outside diameter of the end piece 2? and valve cage 29 is reduced to a minimum. When the bars are fully extended as shown in Figures 2 and 3,

their outer surfaces adjacent the extreme ends lie flush with the outside diameter of the end piece 2'! and valve cage 29.

The cage 29 is provided with a tapered seat and described in the copending application of 1* Donald G. Knox, Serial No. 767,401, filed August 8, 1947, may be mounted within the cage 29 and held in place against a shoulder 41 by means of bushing 45 and resilient washer 43. The function of this magnet is to assist in maintaining the valve '43 in open position as shown by the dotted lines in Figure 3. The valve is maintained in closed position by gas pressure within the eduction tubing below the plunger assembly II. A choke ring 43 which is of slightly smaller outside diameter than the end piece 27 and valve cage 29 may be mounted on the lower end 'of the bushing 45 and held in place by means of a suitable snap ring 50.

When two expansible sealing assemblies are used as shown in the drawings, it is desirable that the slots 33 in the upper assembly be positioned out of line with the slots in the other assembly. In the particular construction shown, using four depression bars 34 in each of the assemblies, it is preferable to position the slots 33 in one assembly at an angle of 45 with respect to the slots in the other assembly.

In operation the swab plunger I travels ver-,

'tically within the eduction tubing 11, and the 4, expansible sealing assemblies form a substantially fluid-tight fit within the interior of the I segments 3| radially inwardly to prevent inter- 'ference.

The springs 39 are sufliciently strong to maintain the ring segments and depression bars in sealing relationship with the eduction tubing, but permit contraction of the sealing assemblies in tight spots in the tubing without creating undue friction. The possibility of hanging up at joints between adjacent tubing sections is eliminated.

Actual field use has demonstrated that the slippage of well fluid between the plunger l0 and tubing H is materially reduced when the plunger incorporates the present invention.

Having fully described out invention, it is to be understood that we do not Wish to be limited to the details herein set forth, but our invention is of the full scope of the appended claims.

We claim:

1. A fluid operated swab plunger for travel in a sectional eduction tubing, comprising in combination: a body member, cooperating valve parts on the body member operable to prevent flow of fluid therethrough, a plurality of longitudinal deflector bars circumferentially spaced around the body member and mounted for radial movement relative to the body member, a segmental ring mountedfor radial movement on the body member and positioned between the ends of the deflector bars, resilient means on the body memher acting to move the ring segments and 1ongitudinal bars outwardly for sealing contact with the interior of the eduction tubing, the outer surface of each of the deflector bars bein curvedto cooperate with the ring segments to form substantially full circle contact with the interior of the eduction tubing.

2. A fluid operated swab plunger for travel in a sectional eduction tubing, comprising in combination: a tubular body member, a valve on the body member operable to prevent flow of fluid therethrough, a plurality of ring segments mounted for radial movement on the body member, resilient means on the body member acting to move the ring segments outwardly for sealing contact with the interior of the eduction tubing, a plurality of longitudinal deflector bars circumferentially spaced around the body member and mounted for radial movement relative to the body member, the outer surface of each of the deflector bars being shaped for contact with the interior of the eduction tubing, the deflector bars each overlying opposed ends of adjacent ring segments, and means on the body member for limiting outward movement of the bars.

3. A fluid operated swab plunger adapted for travel in a sectional education tubing, comprising in combination: a tubular body member provided with axially extending slots and a circumferential groove intersecting the slots, ring segments mounted for radial movement in the groove, resilient means on the body member acting to move the ring segments outwardly for contact with the interior of the eduction tubwith two sets of axially extending slots, the

slots in the first set being circumferentially staggered with respect to the second set, the body member having two circumferential grooves, one intersecting each set of slots, ring segments mounted for radial movement in each groove, resilient means on the body member acting to move the ring segments outwardly for contact with the interior of the eduction tubing, a plurality of axially extending deflector bars received in the body member slots and adapted to limit outward movement of the ring segments, the outer surface of each of the deflector bars bein shaped for contact with the interior of the eduction tubing, cooperating valve parts on the body member operable to prevent flow of fluid therethrough, and means on the body member for limiting outward movement of the bars.

5. A fluid operated swab plunger for travel in a sectional eduction tubing, comprising in combination: an elongated body member, cooperating valve parts on the body member operable to preventflow of fluid therethrough, a plurality of axially extending deflector bars circumferentially spaced on the body and each mounted for radial movement relative to the body, the outer surface of each of the deflector bars being transversely curved and being coni vexly bowed in an axial direction, circumferentially extending ring segment elements operatively associated with the bars intermediate the ends thereof and having outer'surfaces forming circumferential continuations of the adjacent portions of the outer surfaces of the bars, and cooperating therewith to form substantially full circle contact with the interior of the eduction tubing.

6. A fluid operated swab plunger for travel in a sectional eduction tubing, comprising in combination: an elongated body member, cooperating valve parts on the body member operable to prevent flow of fluid therethrough, a plurality of axially extending deflector bars circumferentially spaced on the body and each mounted for radial movement relative to the body, the outer surface of each of the deflector bars being transversely curved and being convexly bowed in an axial direction, circumferentially extending ring segment elements operatively associated with the bars intermediate the ends thereof and having outer surfaces forming circumferential continuations of the adjacent portions of the outer surfaces of the bars, and cooperating therewith to form substantially full circle contact with the interior of the eduction tubing, and resilient means on the body member acting to move the bars and ring se ments radially outwardly.

7. A fluid operated swab plunger for travel in a sectional eduction tubing, comprising in combination: a tubular body member provided with a plurality of axially extending circumferentially spaced slots, cooperating valve parts on the body member operable to prevent flow of fluid therethrough, a plurality ofaxially extending deflector bars each mounted for radial movement in one of said slots, the outer surface of each of the deflector bars being transversely curved and being convexly bowed in an axial direction, circumferentially extending ring se ment elements operatively associated with the bars intermediate the ends thereof and havin outer surfaces forming circumferential continuations of the adjacent portions of the outer surfaces of the bars, and cooperating therewith to form substantially full circle contact with the interior of theeduction tubing.

8. A fluid operated swab plunger in a sectional eduction tubing, comprising in combination: a tubular body member provided with a plurality of axially extending circumfer entially spaced slots and a circumferential groove intersectingthe slots, cooperating valve parts on the body member operable to prevent flow of fluid therethrough, a plurality of axially extending deflector bars each mounted for radial movement in one of said slots, the outer surface of each of the deflector bars being transversely curved and being convexly bowed in an axial direction, circumferentially extending ring segment elements operatively associated with the bars intermediate the ends thereof and received in said groove, the said elements having outer surfaces forming circumferential continuations of the adjacent portions of the outer surfaces of the bars, and cooperating therewith to form substantially full circle contact with the interior of the eduction tubing.

DONALD G. KNOX.

Bell Apr. 27, 1943 for travel