US1553215A - Swab valve - Google Patents

Description

Sept. 8, l 925.

G. CHRISTENSON swAB VALVE Filed March 7.

Patented Sept.vv 8, 192.5.

UNITED STATES vPATENT oFFI-CE.

`G'EOIMJrIlll CHRISTENSON, 0F NORTH PLAINFIELD, NEW JERSEY,"ASSIGNOR TO JOHNS- MANVILLE, INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

swAB vALvE.

Application'led March 7,1924. Serial No. 697,574.

Specification.

This 'nvention relates to heavy-duty plungers, bailin devices orswabs, so called, particularly use l for driving fluids against great pressures or, specifically, for lifting a column of fluid from a deep well.

I I am aware of the use in oil well ractice, for example, of lifting plungers, ails or swabs comprising essentially aweighted tube of smaller diameter than the lining or casing of the well to be operated upon, equipped with packings of one kind or another adapt# ed to make a hydraulic piston contact be tween the periphery of the tube and the lining or .casing of the well, andy having therein a check valve permitting the weighted tube to be lowered by the adjunctive hoisting apparatus of the well into the fluid contents of the casing. When a well does not flow, the simplest way to recover the oil- .is to lower such a'swab or bail to a distance estimated to be suliiciently beneath the level of the oil standing in the well and then to haul up the swab, which brings the oil with it.V f

In the operation of such devices it is not only diicult'to maintain an oil-tight contact between the piston element ofthe swab andthe casing of the well, which is oftenarough tube, having burrs and sharp edges;

at its joints, with considerable variations in internal diameter, but it is also impossiblev to estimate from day to day the height of the column of oil inthe well. The hoisting .gear is rarely capable of lifting a whole column of oil, which may be 2000 or more feet long. When a swab or bail has been sent too deep into the oil, the enormous pressure developed on its piston element quite generally interlocks the piston element and the casing of the well, or results in the destruction of the piston element before the charge can be lifted; which, when the piston packings are rugged'enough, produces so much resistance to vlifting that the hoisting cable, drums or motor are incapable of the necessary eflort. Under these circumstances,it is now practice to drop the swab to the bot-y tom of the Well and break it up with an ex-. ploslve charge to permit recovery of the cable only.

' It will be understood that there is a certaln depth of immersion,- or height and weight cf the column of oil, which repre? lsents the mostv desirable quantity to lift out of a deep well by the swabbing or baillng operation. The nearer this quantity is to be thel practicable maximum capable of being lifted, the better will be the efficiency 'of the operation.

Objects of this invention are to provide devices for use with a hailing or swabbing plunger adapted to measure the height of the column of oil detained by the swab and lift-ed byv its hoisting cable; to provide a construction of plunger adapted to be used repeatedly with relatively infrequent renewals of renewable parts; to make the operation of hailing or' swabbing certain and eiicient, and to provide for the above and -other purposes a valve device adapted to operate under conditions of high pressure automatically .to entrap on .one side of a piston or plunger with which it is or may be combined a certainpq'uantity of fluid only, as measured b the hydrostatic pressure required to li a predetermined height.l

The invention will now be explained in connection with certain illustrated instances of devices containing it, as shown in the accompanying drawings, in which l F1g,'1 is an elevationof a plunger, swab or bail equipped with the new device;

Fig. 2 is a section of an automatic valve on the plane 2 2 of'Fig. 1 showing the main va ve open;

Fig. 3 is a corresponding section showing the valve closed, for example during the lifting of a charge by the device of Fig. 1;

Fig. 4 is a section on plane 4-4 of Fig. 3l showing the main valve closed and the auxiliary valve open, for example during operation ofthe device of Fig. -1 at hydrostatic pressures above a -predetermined limit; and l Fig. 5 is a section similar to Fig. 3 showing a modified form of auxiliary valve.

Referring now to Fig. 1 a suitable swab may comprise, as familiar to those skilled in the art, a suitable heavy metallic tubular stem 1 having a cable anchorage 2 for the wire cable 3, provided with a sufcient numa column of the said Huid of ber of openings 4 to permit a fluid surrounding the stem 1 freely to enter the interior of the tube, and a suflicient plurality of packing desired way; as shown, by a heavy metal annular socket or cup 7 suitably fastened to the stem 1. The bottom ofthe stem 1 is equipped with a valve casing 15 containing a check valve 16 adapted to open upwardly on mo. tion of the structure shown in Fig. ldownwardly in the direction of arrowl a against a gaseous or liquid resistance, and to close on motion upwardly against a similar resistance.

Preferably the casin 15 comprises a chamber formed as a cy indrical cavity 14, and is internally threaded at 17 to receive the reduced lower threaded end of an attachment collar 18 having a recess 19 providing an ample flow passage around an upward cylindrical extension 20 of the valve 16, which may have guide wings 47 for sliding contact in recess 19, and whlch is also provided with the usual crenellated upward extension or series of stop lugs 21 adapted, when the valve 16 is off its seat, to limit the upward motionl of the valve 16 by contact with the collar 18. The valve 16 may be provided with any appropriate closure face 26, and the vcasing 16 may be providedv with any 1appro riatel form of valve seat 27 roviding suitab e free spaces 28 when the va ve 16 is open.

An opening through the stem 1 or past the packings 5, according to this invention, lis arranged to be closed upon the occurrence of a predetermined downward pressure, or any lesser pressure, on the device as a whole. The opening referred to and the means for its obstruction or closure may be in any suitable part of the swab, but are referably provided as adjunctive parts o the casing 15, and in relation to thecheck valve 16.

Valve 16, for example, may be provided with a depending extension 22, having exterior guide wings 48, preferably cylindrically chambered within, having lateralopenings at 23 of liberal size, and interiorly threaded at 24 to receive an ad'ustable threaded plug 30 having a squared ead 31 and an upwardly projecting positioning lug 32 for the lower end of a strong spiral spring 33. Plug 30 is locked in adjusted position by a locking cap-nut 34 or otherwise.

The upward extension 20 of the valve 16is cylindrically bored at 36 and recessed at 37 to receive a cylindrical plunger 38 of adifferential auxiliary valve 39 adapted under stress of spring 33 to close upon a seat 40 closing an opening 41'in the valve 16, which opening 41 communicates through ports 42 with the passages around the valve 16. The clearance space 37 communicates with the space under the valve 16 through a central bore 43 in the differential valve 38, 39, which valve is further provided with a seatlng lug 45 for the upper end of the spring 33. The bore 43 operates as a vent to enable the differential valve to operate under the influence of ressures on its parts 16 and 38 without hin rance by Huid in the chamber 37.

It will be obvious that the spring 33 holds the valve 39 upon its seat 40'in the valve 16 against pressures acting-downwardly on the area represented by the differencesin size between the valvel 39 and the plunger 38. The valve 39 is slightly the larger, as shown. The spring 33 therefore opposes downwardly acting pressures tending to open the valve 39 and effective in relation to the area comprising the difference between the area of 38 and the area of 39 only. For example, if the difference in area is 0.001 sq. in., the valve 39 willclose at pressures of 3000 pounds to the square inch or less when the spring 33 exerts a force of 3 pounds, and at other pressures proportional to vthe stress of spring 33 as it may be' adjusted.

The diiferential valve 38, 39 may be varied structed as a cylindrical piston interfitting' a cylindrical seat 40,'with when 'closed wit advantage in theaccuracy with which the structure 38, 39 opens and closes at a particular pressure in anyadjustment of spring 33. l

In operation, the whole device of Fig. 1, appropriately weighted if not already sufviciently heavy, is allowed to sink in the well to any predetermined depth in excess of the proper depth below the up r level o f he oil or water to be swabbe out. This is permitted by ythe opening, unopposed, of valve 16, as shown in Fig. 2, during motion in direction a. The upper level of the column of uid is generally unknown, and is never capable of bein determined with any accuracy7 y devices likely to be on hand v at an oil we l If the swab is now hauled up, moving in the -direction of arrow b, Fi 3, motion will result in closing valve 16, ig.

' 3,- whereupon the h drostatic pressure result.-

ing from. the dept of the column of liquid the differential auxiliary valve 39 will open Fig. 4, and remain open during upward travel of the swab at a^-rate permitted by the resistance of the tluid passages through stem l, ports 42, and theannular space around valve 39, without any greater strain on the .cable 3 and cups 5 than the predetermined weight of the column of liquid intended to be lifted `out of the well. When the swab is suciently withdrawn, decreasing weight and pressure of the column of liquid then above the swab permits the valve 39 or 39al ,automatically to be seated by spring 33, Fig.

practice this is not essential, the spring 33 being set up in response to experience to permit aconvenient maximum effort only of the hoisting apparatus to be exerted.

It is obvious that the automatic valve described may be used with any desired typeA of tubular stem and any kind or kinds of packing cup, swab or plunger desired, with great advantage, and that when so used, the

lifting stroke of the swab will deliver a maximum measured quantity of liquid only.

I claim: 1. Valve mechanism for use in deep-well swabs comprising a casing adapted for attachment to such swabs, said casing having an opening therethrough, a checkvalve.

auxiliary. valve in said extension co-operating with said opening in said check-valve, and adjustable means for maintaining said auxiliary valve in open position upon the occurrence of lpressures tending to close said check-valve and exceeding a predetermined pressure.

2. Valve mechanism comprising a. casing and a check-valve for closing an opening in said casing; an auxiliary valve carried by the movable element lof said check-valve and' adapted to open and close a'passage through the checkfvalve ,when the check-valve `is seated, said auxiliary Valve having therein oppositely effectivepressure-actuated parts onevo which is of greater eect than the otherfin combination with a spring opposy ing the combined effect of said pressureaetuated parts. y

3. Valve mechanism comprising a casing and a check-valve for closing an opening in said casing; an "auxiliary valve carried by the movable element of said check-valve and adapted to open and close a passage through the check-valve when Ithe check-valve is seated, said auxiliary Valve having therein oppositely effective pressure-actuated parts oneof which is of greater effect than the other, in combination with a spring and means for adjusting said spring mounted on` said check-valve for opposing the combined effect of said pressure-actuated parts. l Signed by me at New York, N. Y., this 28th day of December 1923.

GEORGE CHR'ISTENSON.

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