US2262752A - Pneumatic piston pump, differential type - Google Patents

Description

' Nov. 18, 1941. A. BOYNTON 2,262,752

PNEUMATIC PISTON PUMP, DIFFERENTIAL T Filed Jan. 31, 19259 YPE 2 Sheets-Sheet 1 3H: F g 3 ALEXANDER eon/126 IiVENTOR,

ATTORNEYS.

NOV. 18, 1941. A, BQYNTON 2,262,752

I PNEUMATIC PISTON PUMP, DIFFERENTIAL TYPE Filed Jan. 31, 1959 2 Sheets-=Sheet 2 Fig. [0.

ALEXANDER BOYN TON,

ATTO R NEYS.

Patented Nov. 18, High vum'riso STATES PATENT, oF-FicE 2,262,752 rm-zma'rro rrsron rr m, nmacnmn Alexander BoyntomSan Antonio, Tex. Application January 31, 1939. Serial No. 253,880

9 Claims.

My invention relates to improvements in means for lilting liquids from wells by utilizing the expansive force of gaseous fluids to automatically expel slugs of liquids successively without allowing the pressure fluid to contact the producing formations of the well.

The invention relates to the subject matter my copendingapplications Serial Nos. 253,875, 253,876 and 253,877 flled of even date herewith.

By this means slugs of varying lengths may I be expelled by simply varying the value of the pressure fluid used to expel them. The slugs may thus be of such length asthe well will pro-' duce to accomplish any desired rate of production obtainable within the capacity of the well.

. To attain the foregoing, and other related 'ob-' Jects',-the invention utilizes a well casing within which is secured a tube for pressure fluid, internal of which a third tube is used as an eduction means. A hermetic seal is provided between the well casing and the pressure tube, proximate the ground surface, and another hermetic seal is provided between the pressure tube and the eduction tube, the second seal being somewhat above the flrst. A means is provided for conducting 25 the well formation gas, which accumulates in the annular space between the well casing and the pressure tubing, away from the well through an opening-in the casing head. A means is also provided for inducing air or gas into the pressure 0 tube proximateits upper end.

A seal is provided between the pressure tube and the eduction tube proximate their lower ends.

A valve to prevent well liquid from entering the pressure tube, when the eduction tube is not in place, is'alsc provided.

None of the foregoing parts or any combination of them are claimed as new, but'they are mentioned because their use is essential in combination with a valve to admit well liquid into the eduction tube when pressure fluid to flow the well is available within the pressure tube, and

, to cut oil the entrance of such liquid into the (liquid intake) valve closed also acts to hold the second (air or gas intake) valve open until the slug :is expelled. In the preferred form oi the invention, a third valve is utilized to hasten the Y action of the second valve in closing, and attached to said third valve is a fourth valve which acts as a check valve to prevent the escape of well .liquid into the pressure tubing at times when there may be no pressure fluid in the pressure tube.

x In the other form of the invention, all of the above referred to parts are employed except the third valve which is dispensed with, and a spring is used instead of a weight to' urge the movable assembly oi valves downward.

I attain the foregoing objects by mechanisms illustrated in the accompanying drawings, in which- Fig. 1 is a vertical sectionof' a well equipped with this invention.

Fig. 2 is mainly a vertical section of the device showing the liquid intake valve closed, and all other valves open, except the two check valves which are clcsed'.' i

Fig. 3 is mainly a vertical section of all except the lower portion of the device shown in-Fig. 2, showing the liquid intake valve open and all other valves closed, except the check valve which is open, all valves being shown in elevation.

Fig. 4 is a vertical section of a modifled form of the device shown in Figs. 2 and 3, the upper.

check valve being shown in elevation. I

Fig. 5 is mainly a vertical section of the device shown in Fig. 4, some partsging shown in eleon the line 6-1;,

- vation.

Fig. 6 is a horizontal secti Fig. 3.

Fig. 7 is a'horizontal section on the line 1-1,

Figs. 2 and 4. Y

Fig. 8 is a horizontal section on the line 8-8,

\ Figs. 2 and 3.

Fig. 9 is a horizo tal section on the line 9'9, v

Fig. 4.

Fig. 10 is a horizontal section on the line I fl-lll, Figs. 2, 4 and 5.

Identical characters refer to similar parts throughout th several views.

With reference to the invention as shown in Fig. 2, pressure fluid intake nipple 3! is the foundation member, so to speak, of the device.

Seal carrier nipple 25,'having check valve seat member 33 pressed or otherwise secured in its upper end, is threadedly engaged upon the lower end of check valve housing nipple 22, whichis 1 threadedly engaged upon the lower end of intake a housing: nipple 30., which;

' valve member 34 will moveto pass through them.

air or gas valve 36 to the The lower enlargement ;an easy working fit within the central bore in extension 310, is valve 36 to seat truly upon its seat 34h within r the central opening in threaded lower extension has slight clearance within the chamber 1 thus providing an upper guide to hold valve 36 in position to land centrally of its seat.

4 ing 3 head 33a.

nipple 3L Threadedly engaged. with the. upper end or pressure: fluid intake. nipple 3:! is; valve in turn is threaded upon. the lower' endof; valve sleeve nipple 23, the upper end of which is similarly engaged with. weight nipple; 2.1;, completing" the outside shell.

of the device.

Spacernipple 39 is. threadedly joined to the tubular extension 310 and to sleeve valve shell 40', the: latter having radial extensions 40a closely fitted nipple. 30' in order to provide tru alignment between members it and 23 so that I truly and not bind in its contact with said members.

Valve lifter piston 35, having legs 351:, that normally land upon the upper endoi extension Me, has its upper end threadedly joined to valve member 34. i

1' Weight 4|, having radial guide flns a, holds .the upper end central'and freely movable within nipple 28. A lower finned portion Mb holds the lower end of weight 4| central and freely movable within the central'bore through nipple 29. A further and more exact central alignment of flns Mb is provided by the pointed lower end of this flnned member resting within the cupped upper extension 34k of member.

1 It will be noted that upper shell valve 34a and lower guide shell 34b are separated by an opening 34d, which opening registers with the open-' ing 40' between members 29 and 40 when valve 34 engages upon its seat 400, and that ribs 340 join upper and lower portions 34a, 34b, and valve 34 together. The openings 34m between the fins (Fig. 7) are of sufllcient aggregate capacity to allow ample pressure fluid for expelling the slugs Within the valve lifter piston 35, there is a chamber 35d, proximate the lower end'of which is an internal circular shoulder 350 which supports the enlarged upper end 36b of fins 36b oin the enlarged portion 361: of tubular lower end 36c. 36b" of the fins, having which integrally 3 provided 'as a guide to cause 34a. The upper enlarged portion 36b of the flns 35d,

resistance to pressure fluid passing: upward between member 38 and nipple 33, and to provide lodgement space for foreign substances that might otherwise impair free movement of the member. I

Internal grooves 230 and 40b are to house a lubricant such as a mixture of graphite and cup grease, for the purpose of lubricating the valve 34a. It will be noted that once-these grobves are packed with a lubricant such as mentioned, the lubricant cannot readily escape on account of the closure produced by the valve, and will remain in place for a' considerable time. Lower extension 34b, while no part of the valve proper, serves to cover the grease filled grooves 40b. as appears in Fig. 3, when the valve is in its upper positio intaking well liquid through the open shell section 34d, then in registration with open- Within the tubular lower end 36c, a split bush:

38a, is pressed in or welded check valve 33 when valve 38 is free to seat upon seat Passage. 36d communicates between chamber of providing for fluid passage around the Radial openings 34) communicate with vertical passage 347' above valve seat 3471. in order to provide for the free passage of pressure fluid through the chambers 35d and 34p,.ample clearance for this purpose being allowed between 31, diaving a. central opening somewhat 1 smaller than the head i as shown at 36a to lift 1 3B rises. Check-valve 3le to close passage 3") as shown in Fig. 2, whenever the mdvable'assembly of valves is in the lower position. some clearance being then pro- 3 vided between head 38d and split bushing 31.

mg 40 having communication with the .well liquid as will be explained. This lower extension the perfect alignment of the valve 34a, is wholly within the member 29. Except for this extension 341), the valve 34a might land and hang upon the upper end of member 40 when the valve seeks to return to its position shown in Fig. 2 if, through imperfect workman- I ship, the alignment between the central openings through members 29 and 40 should be untrue.

The construction shown in Figs. 2 and 3, as above described, will noW be shown installed in a well opposite the bracketed space A by means of a reducer 21 connecting the upper end of nipple 28 to the lower ,end of eduction tube 3, commonly called the flow tubing, Lead seal. 25b, in-. tegral with the member 25, engages upon landing seat swage H to produce a hermetic seal between the flow tubing 3 and the pressure tubing 2. In

this position extension 25c forces valve 24 from its seat a, upon which the valve engages whenevir the flow tubing. is not in place. The spring 23 within nipple I5, resting upon annular plate l'lin coupling I6, is of sufficient force to cause such engagement. Valve 24 serves to prevent Will liquid from entering the pressuife tubing at all times when the flow tubing is not in place. Swaged nipple l8, coupling l9, and perforated landing joint 20, closed at its lower end by cap 2l resting upon bottom of the well B, illustrate other proper parts and fittings such as should ordinarily be installed below the device.

In Fig. 1 .it will be noted that 4, closed on one side by pull plug 4a, cap 5, plate 6, seal ring 1', coupling 8, and weld 8d, are arranged to provide means for a hermetic seal between the well casing and pressure tubing 2 proximately above ground line G. It will also be observed that nipple 9, has an internal annular plate section 9a supporting coupling l0 upon packing H. Packing gland l2, and packing l3, likewise provide means forprodiicing a hermetic seal between pressure tubing 2 said/flow tubing 3. The swaged nipples 26 and 26;: "may be used to expand the annular space S in order to provide storage for ample pressure fluid within the well-that the slugs may be expelled without drawvalve shank 38b. and the opening through split bushing 31. a

I External grooves 35b are provided ar und valve lifter piston 35 for the purpose of increasing the ing heavily upon the pressure fluid supplied through pipe line 90.

None of the parts, nor their arrangement,- described in the two preceding paragraphs are new; .but the same are necessary to properly install and show the device illustratedin Figs. 2, a, 4

and 5, which I claim is new.

, the-upper end of well casing l,'casing head, composed .of base 2,202,752 j I i 3 It is understood that the upper end of flow line 3 leads to a tank. Surplus gas produced by I the well may be conducted away byline 4b. Air or gas for flowing the well may gsupplied from an external source through a pipe line So connected to extension 011; or ii the well produces enough gas to flow it, gas from the annular space S may be conducted into the annular space S by means of a tubular connection that can be easily made between 'nipple 4b and extension 9b. I Operation ofthe device shown in Figs. 2 and 3 as installed in Fig. 1' will now be explained.

It should be noted that the circular enlarged Valve 34 being seated as in Fig. 3, well liquid portion 36a'of valve 33 has impaired clearance around it which should vary directly with the size of the flow tubing. Around this enlarged portion 330, and through the slight clearance between valve lifter piston 35 and nipple 39, all the pressure fluid required to expel the slug must flow.

The well will be assumed to be standing with liquid in the annular space S atthe level L. Well liquid enters the wellv casing or liner through perforations P communicating with the producing formations. This liquid is kept out of the flow tubing 3, for the time being by valve 34a which closes opening 40' as appears in Fig. 2.

Compressed air or gas will now be admitted into the annular space S'within the pressure tubing through input line or nipple 90, it being borne in mind that tubular member 9c may receive its pressure fluid from an external source such as a compressor or a gas line; or 90 may be a nipple having connection with the nipple 4b through which gas from the well itself in the annular space 8 may be admitted into the annular space S.

Pressure fluid so admitted enters intake ports 3la and passage 3Ib and liftscheck valve 38 from its seat 3le with a few ounces of pressure. The pressure fluid stream then divides, part going around head 38a, through chamber 360, 4

passage 36d, and out through openings between fins at upper end of passage 36d. The other part passes around tubular lower end 36c and unites with theflrst stream between fins 36b. Thence, the pressure fluid stream again divides, part passing between legs 35a and around piston 35. The other part passes around enlargment 36a, through chambers 35d and 34p, passage 341, and radial openings 34f, both streams again uniting in the chamber containing valve member 34. Thence the pressure fluid flows through the passages 34m between ribs 340 (Fig. 7), passes weight 4|, and enters the flow tubing 3.

At a predetermined velocity the pressure fluid, flowing through the path indicated in the preceding paragraph, due to resistance offered by the enlarged portion 36a will raise and seat valve 36, Preferably weighing 2-5 pounds, upon seat 34h. Seating of valve 36 forces all of the pressure fluid to pass between valve lifter piston 35 and nipple 39, at which time grooves 35b offer greatly increased resistance to such passage. The added resistance resulting from this closing of one of the pressure fluid paths quickly closes the other by causing valve 34 to engage upon valve seat 400, as shown in Fig. 3. Seating this valve wholly stops the escape of pressure fluid into the flow tubing. At the same time well liquid is admitted into the flow tubing by bringing openings 34d 75 and 40'- into registration as appears in Figs. 3 and5. p

The path of the well liquid from the annular space S into the flow tubing is via perforations 5 a, joint 20, nipple l0, opening through plate 11,

nipple l5, perforations a, extension 250, check valve 32 (free to be opened by pressure from below), cored passages 3ld '(Figs. 2, '4, 5. and l0) outermost annular passage within'nipple 30,

10 openings 40' and 34d, which last two mentioned openings are now in registration (see Figs. 3 and 5), openings 34m between ribs 340, and opening around weight 4| within nipples 28 and 29.

0 weight 4|, the forces seating and tending to unseat valve 34 become equal. Well liquid will continue to flow into theflow tubing until the unseating force (the weight of well liquid in flow tubing, plus weight 4|), is great enough to unseat 5 valve 34.

When valve 34 is unseated by the back pressure of well liquid in the flow tubing, aided by the force of weight 4| as stated, the entire movable in Fig. 3 to the position shown in Fig. 2, in which position the pressure fluid follows the path hereinbefore stated and expels the slug of well liquid from the flow tubing. 3

35 Attention should be called to the fact that the the movable assembly to return instantly to the position shown in Fig. 2 after valve 34 opens.

When theslug of well liquid begins to leave the flow tubing, the expansion'of the pressure fluid under the slug'becomes progressively more 5 rapid due to the constantly lightening load. The

velocity of pressure fluid entering through the movable assembly, therefore, rapidly increases and soon again causes valves 36 and 34 to seat, thereby cutting off the entrance of pressure fluid into the flow tubing and at the same time admitting well liquid into the flow tubing through the resulting registration of openings 34d and 40' as before described. This cycleautomatically repeats under the conditions stated.

To demonstrate, by example, the cycle as herein explained; the following is assumed:

I 1. The liquid level L in the space S is standing at 1000 feet above the device.

2. Each 100 feet of the liquid column exerts a pressure of 40 pounds per square inch at the level of the device.

3. Weight 41 weighs 50 pounds.

4. The area 34c of valve 34, exposed to back pressure in the flowtubing, equals one square inch.

5. The air or gas pressure in line 90 is 200 pounds per square inch.

6. Ten pounds per square inch is the force required to overcome valve friction.

The pressure fluid at 200 pounds per square inch, as assumed, is turned into the annular space S. Check valve 38 is almost instantly raised. Valve 36 closesquickly and valve 34 seats soon thereafter raising opening 34d to register with opening 40'. Well liquid rushes assembly quickly returns from the position shown i into the flow tubing thr 1 34d as explained.

when the flow tubing has filled 400 feet above valve 34.

enough to open valve 34 assembly to .the position Pressure fluid at 200 pounds per square inch is thereby discharged into the flow tubing under a liquid load of 160 pounds per square inch which will, of course, quickly expel the slug.

It will be noted in 'the preceding example that weight 4|, weighing 50 pounds, will be raised by 1 7 pounds per square inch of lifting force exerted upon valve lifter piston 35 if the cross sectional area of this member'is 7 square inches.

Such area is permissable within the limits of ordinary well equipment, and a differential of '7 to 10 pounds between the pressures above and below lif-ter 35 is readily obtainable by providing slight clearance between @015" to .025" clearance all around between these members has been found satisfactorily workable. Likewise .015" to..040" clearance between the members 35 and 36a has been found by experience to be workable for sizes approximately 1 to 3 times larger than the scale shown in Figs. 2,

the back pressure I on this valve will be 210 pounds per square inch (4 40+50), or exactly and return the movable shown in Fig. 2.

ugh openings 40' and members 35 and 39.

3, 4', and 5, it being understood that the propor- I tion between the size of device and flow tubingshown should preferably be approximately main tained.

It will be noted from the foregoing example that the length or weight of the slug can be varied by simply varying the value of the pressure fluid, and that directly 'with said pressure, and that the weight the weight of the slug varies on both sides of the movable assembly, and thus prevent freeing the valves by pressure so applied. It will furthermore be noted that the height of the liquid colunm in the annular space S does not'affect the operation ofthe device .because valve 34a does not open or close,.with,;.oragainst the liquid pressure.

A modified form of I Figs. 4 and 5. Theconstruction of thismod fl tion is so similar to the preferred form shown Figs. 2 and 3 that. the description of the modifi tion will be brief.

All parts bearing h in F tical in construction, are also id and purpose, as was explained for the preferred form. v

Valve lifter member 35A contains theliead 43a of check valve 43 movably engaged upon internal shoulder 350 in order that the check valve will be lifted from'its seat 3leabove passage 31b not employed in this construction. Some wells which produce clean oil do not require; such lubrication. Double valve member 34A, having.

' solid lower threaded extension 34Ag, employs of member 4| determines the difference between the weight of the slug and the pressure of the lifting force.

Weight 4| should preferably be of cast iron, brass, or other metal of great specific gravity'in order that it may be comparatively short, 2-4 feet being suitable-length.

It should be observed that while valves 34 and 3B are in the lower position, pressure fluid to expel the slug will flow freely around the expanded portion 36a and around piston 35, and that valve 36 should be of such weight and diameter as to not allow it to seat while the slug remains in the flow tubing. When the slug is expelled from the flow tubing, the decreased resistance in the flow tubing causes a rush of pressure fluid past the expanded portion 36a. The resulting resistance seats valve 36. This causes the entire pressure fluid flow to seek passage around valve lifter piston 35 which, due to the slight clearance around it, causes-it to act like a piston because, as the velocity increases. the lifting force multiplies approximately according to the square of the velocity.

Check valve 38, which in the lower position of the movable assembly, landing upon its seat 3le, serves to prevent the escape of well liquid into the pressure tubing space S if any liquid should leak past the valve 34a. while the Well is standing, as is apparent in Fig. 2. Provision is made to lift this valve with valve 36, as has been explained. This is done because if for any reason ' valves 34 and 34a should become stuck anywhere above their lower position, pressure may be applied in the flow tubing from the upper end thereof to force these valves downward and free them. Unless check valve 38 were lifted off its seat 3Ie above passage 3lb,it would cause the pressure applied into the fiow tubing to equalize 75 'able) by engagin nipple 28.

neither radial openings 34 valve seat 3471,, nor I vertical passages 347', as used in valve 34, Figs. 2 and 3, because valve 36 and its lower extension, shown in Figs. 2 and 3, are not here used.

In this modified construction a spring 44 seats upon the finned support 42 and is held under some compression (30 to pounds being workits upper end upon the reducer 21. This spring serves the samepurpose as was explained for weight 4| in Figs. 2 and 3. The pointed lower end'of spring support 42 engages within the cupped upper xtension 34k. The upper end has a free working fit within In some wells which produce a considerable quantity of sand or other solids, a spring such as shown at 44 may be found more practicable than a weight.

It will be understood that the foregoing drawings and specification are illustrative and not intended to limit the construction-or uses of this invention which may be greatly varied within the intended scope and purpose'thereof.

I claim: I

1. In a device of the class described, an eduction tube, a tubular valve housing attached thereto, spaced annular walls in said housing-toprovide an annular passage longitudinally of the housing to conduct liquids from the lower end of the valve housing into the eduction tube, an

opening leading from said passage to the interior of the housing, a sleeve valve within the 'housing, said valve having an opening adapted .to be brought into mating relation with the first mentioned opening, means normally holding the sleeve valve in closed position, and pressure responsive means below the sleeve'valve, *or moving the valve to open position.

2. In a device of the class described, avalve assembly comprising a tubular housing having a central bore of reduced cross section at the upper end thereof, a valve seat at thelower end thisiinvention -valve assembly attached thereto and/including terior port adjacent the up a sleeve valve slidable within the reduced section, a piston loosely slidable in the bore below saidsleeve valve and having a surface adapted to make sealing engagement with the valve seat and close the bore when the valve sleeve is moved to open position, and means for admitting a pressure fluid below the piston .to flow about the piston and through the bore from below the ports and to control the position of the piston.

3. In a fluid lift device, an eduction tube a a housing, a central bore therein, passages in the walls of said housing to admit/liquid longitudinally thereof, said passages terminating in ports interiorlyof the housing adjacent the upper end thereof, a sleeve valve/within the houssaid eduction tube, an inlet member in said ing, means normally holding said valve inv closed position, pressure means for moving the valve to open position said pressure means including a second valve ember adapted to close the bore below the ports when the sleeve valve is open, and while liquid is admitted through the passages to the eduction tube, and means. for admitting a pressure fluid to the bore below said last mentioned means to control the position of said second valve member.

4. In'combination, a valve housing having a central bore therein, a passage in the wall of the housing d longitudinally from the lower. end thereof, id passage terminating in an in- I per end of the housing, a valve within the housing to move downwardly and close the port, means normally holding said valve in closed position, a valve lifter piston attached to said valve andfltting loosely within the bore to form a restricted passage in the bore below the valve, and means for admitting pressure fluid below said piston to lift the piston and valve and admit fluid through the 'flrst mentioned passage to said port.

5. In combination, a valve housing having a central bore reduced at its upper end, a passage in the wall of the housing from the lower end thereof and terminating in a port in the reduced portion of the bore, a sleeve valve adapted to move in the reduced portion to close said port, and lubricant containing grooves in the housing walls adjacent the port.

6. In combination, a valve housing having an axial bore, a by-pass passage from the lower end of ,the housing and terminating in a port opening into said bore adjacent the upper end there'- of, a sleeve valve, means normally holding the sleeve valve to cover said port, -a valve, lifter piston fltting loosely within said bore below the sleeve valve and connected thereto, and means for applying a gaseous fluid under pressure to the nether side of said piston to lift the piston and open the valve, said valve lifter piston having peripheral grooves whereby the lifting force of the gaseous fluid by passing the piston is increased.

. a 5" the piston, valve means within saidpiston and adapted to closesaid passage upon a predeter- -mln piston and associated valve is accelerated.

/ '8. In a fluid lift device for wells, an eduction tube having an extension upon the lower end thereof, inlet ports in said extension adapted to admit well fluid to said eduction tube, a check valve within and proximate the lower end of eduction tube proximately above said check valve, said member having a transverse inlet opening for pressure fluid and an axial passage communicating with and extending upward from said inlet opening, a valve seat around the upper end of said passage andanv-axial opening vextend ing upward from said seat, a sleeve surrounding the upper end oi said inlet member, a tubular valve housing upon the upper end of said sleeve and having within it a downwardly facing valve seat, longitudinal openings for well fluid in said inlet member, said openings lay-passing said transverse opening for pressure fluid, an annular valve seat within the lower end of said valve housing, there being an annular space between said eduction tube and said valve housing, another tubular valvehousing within said eduction tube in spaced relation to said flrst valve housing, such relation forming a radial opening communicating between the interior of said valve housings and said by-pass openings for well fluid through said annular space, a loosely flttingpiston within said sleeve, said piston having legs normally engaging the upper end of said inlet member and an axial opening having restrictions proximate the upper and lower ends thereof, a valve seat formed within and at the extreme end of said upper restriction and an axial opening communicating with cross bores proximately above said seat, a poppet valve formed upon a reduced portion 01' said piston proximate the upper. end thereof and asleeve valve upward extension of said poppet valve, said sleeve valve I being slidable within said tubular valve housings 7. In combination, a housing having a central I bore and a by-pass passage in the walls thereof,

and adapted to close said radial opening when said piston is engaged upon said inlet member and to open said radial opening when said poppet valve is engaged u ing seat in said first valve housing, means normally urging said sleeve valve downwardly, 1ongitudinal openings through said-sleeve valve for pressure fluid passing upward around said piston when said poppet valve is open and for well fluid from said radial opening when Said sleeve valve is open, a pressure fluid secondary control valve within said piston for closing said axial opening thereof and diverting the pressure fluid around'said piston to hasten the closing of said poppet valve, a depending shell on said secondary control valve and a check valve having a head within said shell and adapted to, engage.

said first mentioned valve seat when no pressure fluid is supplied to the tran 9. In a differential fluid an eduction tubehaving extension upon the lower end thereof, inlet ports in said extension adapted to admit well fluid to saideduction tube, a check valve within and proximate the lower end of said eduction tube, an inlet member in said eduction tube proximately above said check valve, said member having a transverse opening for pressure fluid communicating with and extending upward from said inlet opening, a valve sverse inlet opening. lift device for wells,

velocity of pressure fluid therethrough, so t the pressure fluid is restricted to flow about the piston whereby the movementof the pon the downwardly facseat aroun'd'the upper end of said passage and I an axial openingv extending upward from said seat, a sleeve surrounding the upper end of said 3 inlet member a tubular valve housing upon the .upper end of said sleeve and having within it a downwardly facing valve seat, longitudinal openings jorwell fluid in said inlet member, said openings, by-passing said transverse opening for pressure fluid, an annular valve seat within the. lower end of saidvalve housing, there being an,

annular space between said eduction tube and said sleeve and valve housing, another tubular valve housing within said eduction tube in spaced sleeve valve being slidable within said tubular valve housings and adapted to close said radial opening between them when said piston is engaged upon said inlet member, an annular member secured in said eduction tube, a spring sup:- port having clearance around it within said eduction tube and being engaged with the'upper end relation to said first valve housing, such relation forming a radial opening communicating between the interior of said valve housings and of said sleeve valve, a spring between said annular member and said sleeve valve, said spring being adapted to provide the operating differential between the well fluid in said eduction tube and the pressure fluid in said first annular space, longitudinal openings through said sleeve valve for pressure fluid passingupward around said piston when said poppet valve is open and for well fluid from said radial'opening when said sleeve valve is open, a check valve having a head. loosely secured within said piston, said check valve normally closing saidaxial passage to pre vent well fluid from escaping through the open-' I ing in the inlet member tube into the annular,

space.

1 I ALEXANDER BOYNTON.

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