US1890720A

US1890720A - Pneumatic pumping apparatus

Info

Publication number: US1890720A
Application number: US586684A
Authority: US
Inventors: Roy L Chenault
Original assignee: GULF PRODUCTION Co
Current assignee: GULF PRODUCTION Co
Priority date: 1932-01-14
Filing date: 1932-01-14
Publication date: 1932-12-13
Anticipated expiration: 1949-12-13

Description

13, 1932. R, CHENAULT l 1,890,720

PNEUMATIC PUMPING APPARATUS Filed Jan. 14, 1952 2 Sheets-Sheet 1 Dec. 13, 1932. l R, L, CHENAULT 1,890,720

PNEUMATIC PUMPING APPARATUS Filed Jan. 14, 1932 2 Sheets-Sheet 2 oy L. enau ZZ;

abtoftmq Patented Dec. 13, 1932 UNITED STATES PATENT OFFICE ROY" L. CHENAULT, F PITTSBURGH, PENNSYLVANIAfASSIGNOR T0 .GULF PRODUCTION COMPANY, 0F PITTSBURGH, PENNSYLVANIA, A CORPORATION 0F TEXAS rnnna'rlc rUMPING APPARATUS Application led January 14, 1932. Serial No. 586,684.

ThisA invention relates to a pneumatic l pumping apparatus for raising liquids from deep wells in stages-'and discharging such liquids in a continuous succession o slugs 4under-a back pressure maintained on the flow line of the apparatus. More particularly, the invention is concerned withthe pumping of oil "from oil Wells by the use of A concentric stringsof tubing. which extend into the wll, one of which strings is recprocable to actuate a piston type valve for adother position, the liquid .being ejected from the pump in slugs, the velocity of which is retarded by maintaining the pump discharge under a back pressure; all as will be described more fully hereinafter, and as claimed. v

It is an object of this invention to vprovide a pumping apparatus for raising liquids from deep wells in stages by the admission of a pumping Huid to the apparatus successively at dierentlevels.

ratus to decrease the emulsiiication of pumped liquids and to eii'ect a saving of energy by maintaining a back pressure on the flow line which resultsl in a smaller increase in velocity of the pumped liquids as they approachl the top of the well and there-` by reduces their turbulence atthe outlet.

Other and further objects will be apparent from the following description and draw.- ings, in which Figure 1 is a View, partly in vertical section, showing the pump and apparatus with which it is associated in use;

Figure 2 is anenlarged detail view of the upper part of the pump mechanism with the Valve in one position for pumping;

Figure 3 is a similar enlarged detail'view of the upper part of the pump mechanism with the valve in the other position :for

pumping Another object is theprovision of appa-- Figure 4 is a horizontal sectional view, taken along the line 4 4 of Figure 2;

Figure 5 is a horizontal sectional view, taken along the line 5-5 of Figure 2;

Figure 6 is an enlarged detail view of the lower end of the pump, in vertical section, showing a modified form of foot valve in one position of pumping;

Figure 7 1s a vlew s'. 'lar to Figure 6, but

. showing the 'modified form of foot valve in the other position of pumping.

Referring` more particularly drawings: l

to the v' A casing 10 extends into the bore of a. well and encloses two concentric strings of tubing 11 and 12, the outer of which is composed of a displacement chamber 13 and a valve cylinder 14 in axial alignment and connected to the tubing 11 by a nipple 15. This string is run first mto the Well to a oint where the displacement chamber is su merged in the liquid which is to be pumped.

The inner string of tubing 12 is next lowered into the well within the string 11.` The tubing 12 comprises an eduction pipe 16 which is attached to a piston valve 17, the valve, in turn, being connected to the tubing 12. by a nipple 18 and threaded sleeve 19.

The foot valve assembly 20 may also be lowered Vinto position in the seat 21 which forms the-end of the displacement chamber,

by means of the rod 22 which is attached to the valve cage and which extends up into the eductor pipe 16 to be slidably received therein but prevented from removal bythe head 23 which cannot pass the projection 24 in the eductor pipe. This arrangement permits all\ working parts' to be remoyed for repairs or replacement by pulling the single inner string of tubing.

The foot valve assembly 20which is shown in Figure 1 and which includes a ball check valve may be replaced by a foot valve ofthe type shown in Figures 6 and 7 wherein a pipe 25 is connected to theeduct'or pipe 16 by a Esleeve 26 and is closed at itsend by a plug 27 which is tapered to permit installation and removal of the pipe 25 with the inner stringof tubing.

seat member 21 and is slotted at 28 so that when the inner tube string is lowered to the positionv shown in Figure 6 communication is established between the displacement chamber and the interior of the well, whereas when the string is raised to the position shown in Figure 7, while the displacement chamber is being emptied, communication between the displacement,chamber and well is cut olf. Y f

The piston valve cylinder. has inner and outer walls deinin separate

annular spaces

29 and 30 above an below the connecting web 31, and the spaces, respectively, communicate with

horizontal ports

32 and 33 which open into the interior of the cylinder. Exhaust ports 34 (Figures 2, 3 and 5) extend horizontally from the interior of the valve cylinder to the space between the outer tube string and the well casing. A radial series yof' such exhaust ports is provided as is shown in Fig'I ure 5.

The piston valve 17 is equipped with piston rin or other suitable packing for making a tlght seal between the various valve ports and the two ends of the valve, these rings or packings defining

annular spaces

35 and 36 for connecting the various valve ports. Ports 37 connect the annular groove or space 36 with the hollow interior of the piston.

A check valve 38 is provided and may be v located either in the eductor pipe 16, as shown, or in the piston'valve at any point be- .low the orts 32.

A stu g box 39 is provided at the top of the well which forms a tight seal between the two strings of tubing and allows the inner string to be raised and lowered suiiciently to operate the piston valve 17. Y

Y Any convenient lifting mechanism may be employed for raising and lowering the tube string 12. The preferred'mechanism, however, is shown in Figure 1 and it comprises a pneumatic power cylinder 40, controlled by an automatic timing valve 41 which admits compressed air or gas to the cylinder for raising the tubing 12, and, alternately exhausts the motive fluid from the cylinder to the atmosphere allowing the tubing to lower by gravity, The time interval for raising and lowering the tubing is controlled by regulation of the automatic valve. A mechanical or hydraulically operated lifting mechanism may be used in place of the pneumatic apparatus shown, if desired.y

In the illustrated system a compressor 42 receives gas or compressed air from a separating chamber '43 which is maintained unl der pressure, and forces such fluid through pipe44, past valve 45, into the space between tube strings 11 and 12 within the pump. A branch conduit 46 extends between the pipe 44 and the cylinder 40 and has'therein valves A flexible connection 51 is provided in the ,l

outlet tovpermit reciprocation of the inner tube string. Y

In assembling the pump the displacement chamber 13 is lowered on the outer string of tubing 1.1 until it is in the well liquid. It will fill with liquid to the level of liquid in the well. The inner string of tubing 12 is then lowered until the piston valve 17 is in its workin position in the valve cylinder 14. This position may be determined by noting the distance between the lower end of the eductor pipe 16 and the cage of the foot valve 20, when the piston valve is in its proper working position, before the device is installed in the well. The inner string is lowered until the lower end of the eductor pipe rests on ladmit compressed air or gas to the hoist the inner string of tubing is raised suiciently to lift the piston valve 17 to the position shown v in Figure 3.I Inthis position the -annular space between the two strings of tubin communicates with the displacement cham r 13 by means of the vertical passages'29, 30, the

horizontal ports

32, 33 in the cylinder wall, and the annularl space 35 around the piston valve.

Compressed air or gas is admitted to the space between the tube strings by opening the valve 45, and thenlowsdown around the piston valve to the displacement chamber where it exerts a downward force on the liquid trapped therein, seating the valve 20 and forcing the oil up through the eductor pipe 16 and past the check valve 38 toward the surface through the inner string of tubin After suilicient time has elapsed or the displacement chamber to be emptied of its charge of oil the inner string of tubing is lowered by shifting the timing valve to the exhaust position shown (in Figure 1, thusvrelieving pressure below the power piston in chamber 40, through the medium of which the inner tube string is reciprocated. The piston valve 17 is, thus, returned to its lower position as shown in Figures 1 and 2 and the pressure in the displacement chamber vis relieved by exhausting the gas to the well casing 10 through the vertical passage 30, the ports 33, the annular space 35 aroundthe piston valve, and the exhaust ports 34 (Figurels1 2 and 5) vleading through the cylinder Wa a 'i v When Athe piston valve is lowered, the annular space 36 between it and the cylinder wall is opposite the ports 32 so that compressed a1r or gas is admitted to the interior of the piston valve through the ports 37 and continues to lift the oil which has been raised previously to a level above the check valve 38, at the same time the displacement chamber' is being exhausted and refilled with a new char e of wellfluid.

A er suiiicient time has elapsed for the gas pressure to exhaust from the displacement chamber and a new charge of oil to flow in through the check valve 20, Figure 1, or the slot 28 in pipe 25 as shown in Figure 6, the piston .valve is again raised by raising the inner string of tubing whereby the check valve 20 is seated against return flow of liquid from thefdisplacement chamber, or, if the modified form of valve is used, the slotted pipe 25 will be raised to the position. shown in Figure 7 to cut oif communication between the well and the displacement chamber to prevent back flow of.y liquid. Another charge' of oil is then forced up the eductor ipe and into the inner tubing, and the cyc e is repeated. Thus, afnumber of separate slugs of oil, separated bycolumns of compressed air or gas, may be put into the inner string or flow line, andthe admission of a new charge does not interfere in any way with the progress of the slugs of oil and gas traveling up the How line to the'well outlet.

The ability to exhaust the'displacementA chamber and pick up a new charge of oil before preceding charges reach the surface isl an important feature of this apparatus, especially where uid levels are low and the well depth is greatfith low'fluid levels a short displacement chamber must be used, and the volume of fluid picked up per stroke is .necessarily small in wells of small diameter. If this relativelv small slug must be brought to the surface from a great depth before the displacement chamber can be ex-y hausted and refilled` with oil, therate of ypro duction is necessarily low and the gas or Aair consumption is high. v In the use of the present inventio'n, however, as many slugs as desired may be put into the flow line by regulating the frequency of operation of the piston valve, by adjusting the timing valve, or by varying the air or gas pressure to change the velocity of' flow up the discharge line. As the slugs of oil and gas reach the surface they flow through the discharge pipe 50 and flexible connection 51 to the separator from which the oil is withdrawn through an out.

let at a l low point while the gas is taken off Y from a high point in the separator and is led back to the compressor ,for re-cycling. p

` Gas exhausted from the displacement chamber to the space within thewell casing may be withdrawn by a vacuum gas gathering line mergence.

-in the case of the ordinary orlit may be conducted back to the compressor in et.

It is seen that this method of producin oil may be utilized in wells having low flui levels where'it is impossible to use the regular gas lift system because of insuiiicient sub- No back pressure is placed on the producin horizon when this apparatus is used as t e gas pressure is confined within the pumping unit and not the well casing as gas lift.

There are no ,pick-up losses such as occur in the regular gas lift as a result of gas slipping through the oil, especially in cases where the'submergence is low. With .this apparatus the flow of oil is accelerated by the pressure of air or4 gas acting downward on a fluid piston, and there is no' possibility of slippage during the time a charge of oil is being accelerated and started up the flow string. The arrangement of surface equipment shown in Figure 1 is especiall desirable as it permits a back pressure to. held on the flow lineand the gas separator. Operating with back pressure has advantages bo'th from the standpoint of energy. required, andthe size and cost of equipment. The 'size of the compressor and separator equipment necessary is reduced byoperating with back pressure, because when Working between the same pressure difference between inlet and exhaust, the compression ratio is less when exhausting to a pressure above atmospheric than when exhausting to atmosphere. This effect is better illustrated by the followingA separator, to operate the pum Then takin 1?# g atmospheric pressure as 14 /sq. in., the

compression ratio when exhausting to at-mosphere is gage pressure and supplying air or gas to the pumpk at 250:94?. gage pressure, the compression-ratio is `Thus 'it is seen that the compressor displacement necessary to supply the volume of gas or air at the required pressure is times as great when exhausting 'to atmospheric'A pressure as when exhausting to a gage pressure of 50# and supplying gas back to the compressor intake at this pressure.

This effect is greater the higher the back pressure used, and the optimum conditions will be determined by the limitations of the equipment used. Besides the reduction in compressor'capacity, a further saving in compressor costs will result from the fact that a single-stage compressor can be used ,mosphere in many cases when pumping with back pres- A of a. given mass of gas a given amount decreases as the pressure increases; Referringl again to the example cited above, when compressing air from atmospheric to 200# gage pressure, the theoretical energy required per cubic foot of free 'air for isothermal compression is 5,676 foot pounds, while the en ergyrequired to compress 1 cubic foot of free air isothermally from a pressure of 5 0# K gage to 250# gage is only 2,982 foot pounds.

However, a greater mass of air is required in the system at the higher pressurein the ratio ofv the absolute pressures of the two ex amples, or

Then the net saving in energy required when operating between and 250# gage v pressure is 5,676*2,982 1.23=2,000 ft. lbs.

per unit volume the equivalent of that occu pied by'a cubic foot of free air when compressed to a pressure of 214.7# abs., or

m .0685 C11.' p'

at the working pressure in either case. ThisA represents a saving of about 35.5% in energy when operating against a back pressure of 50# gage. The saving when compressing adiabatically is about the same as for isothermal'compression, although the actual` energy required is greater both with backl pressure and when exhausting to atmosphere.

A further advantage of back pressure is thatresulting from the smaller increase in velocity as the fluid being vpumped approaches the top of the well, since the expansion ratio*is much less when pumping against any considerable back pressure. This acceleration of the well fluid as it approaehes the surface has been a source of considerable trouble in ordinary gas ,lift practice. The high velocities resulting from expansion of the gas as the pressure diminishes when it progresses up the How line, greatly increases the turbulence, and trouble from emulsions in wells which are producing both oil and water. The resistance to iiow also increases rapidly with the velocity. The

effect of back pressure in diminishing the acceleration toward ,the surface is readily seeny by referring again to the two examples cited. When the air or gas is exhausted to atmosphere the expansion ratio is 14.6. When exhaustingv to a back pressure of 50# gage the expansion ratio is 4.1 or less than l, that of the former case. This will result in a corres onding decrease in acceleration of the well uid as it approaches the surface, and a more uniform velocity of flow throughout the length of the flow line.

It should be pointed out that the advantages resulting from the utilization of back pressure with this device are obtained without putting any undesirable back pressure on the. producing formation. The pressure required to operatethe device is confined entirely within the two strings of tubing and the displacement chamber. If back pressure on the producing sand is desired for any reason, it may be held in the casing without interfering with the operation of the device.

In cases where extremely low fluid levels are encountered, making it impossible to collect the'V displacement chamber full of fluid by gravity, a packer may be set at any point below the exhaust ports 34 making a tight sealsbetween the displacement chamber, or Diston valve and well casing. If the casing is then connected to a vacuum gas gathering line, the displacement chamber may be eX- hausted to a pressure several pounds below atmospheric and oil may be made to rise in the displacement chamber to a point several feet above the Huid level in vthe well, re sulting in an increase in speed and eiiiciency of pumping.r

I claim: v

1. Pneumatic pumping apparatus for deep wells which comprises a displacement chamber adapted to extend into the liquid of a well, an eduction pipe extending into said displacement chamber, a source of pneumatic pressure, valve means positioned on said eduction pipe for alternately connecting said source of pneumatic pressure with the displacement chamber and then with the eduction pipe, whereby when the valve means is in one position the pressure o'f pneumatic fluid is directed into the displacement chamber to `force liquid therefrom into the eduction pipe and upon reversal of the said valve means the pressure of the pneumatic fluid is directed int-o the eduction pipe to lift the liquid1 in the eduction pipe to the surface of the We 2. Pneumatic pumping apparatus for deep Wells which comprises a displacement chamber having valved communication with the interior of a well below the surface of liquid therein, an eduction pipe extending into said displacement chamber, a source of pneumatic pressure, reciprocating valve means positioned on said eduction pipe for alternately admitting pneumatic fiuid under pressure first to the displacement chamber and then to the eduction pipe, a valve in said eduction pipe below the point of admission of pneumatic fluid to prevent return of liquid forced from the displacement chamber, whereby in one position of the reciprocating valve means the force of pneumatic fluid is directed into the displacement chamber to force liquid ltherefrom into the eduction pipe and past the said valve therein and in another position of the reciprocating valve the force of the pneumatic fluid is directed into the eduction pipe to lift the liquid in the eduction pipe to the outlet of the well in slugs, and means for simultaneously relieving the displacement chamber of pneumatic pressure to permit its refilling by liquid from the well preparatory to another cycle of operation.

In combination with a source of fluid under pressure, a pump comprising a displacement chamber immersed'in the liquid to be pumped, a valve for admitting well liquid into said chamber but preventing its returnl flow into't-he well, a valved eduction pipe ex-- tending to a low point in said displacement chamber, a reciprocating piston type valve positioned on said eduction pipe coaxial therewith, said valve serving to connect a source of fluid under pressure alternately with the displacement chamber and the eduction pipe above the valve therein. whereby said fluid under-pressure is first admitted to the displacement chamber to force liquid therefrom up into the eduction pipe and secondly uponreversal of said piston type valve said fluid under pressure is admitted to said eduction pipe to lift the liquid to the surface of the well in successive slugs said valve also simultaneously relieving the displacement chamber of pneumatic pressure, whereby the chamber is refilled by liquid from the well preparatory to another cycle of operation.

4. A deep well pump comprsing a tube string divided int-o upper and lower ported chambers, a dispacement chamber on the lower end of said tube string. an eduction pipe extending through said tube string and terminating in said displacement chamber, a piston type valve coaxial withysaid eduction pipe and reciprocable to alternately cover and uncover the ports in said upper and lower chambers, said eduction pipe, further, being the displacement chamber, thereby to force well liquid into the eduction pipe by downwa rd pressure upon the surface of such liquid and to substantially empty the displacement chamber, and whereby when the piston type valve is reversed, communication of fluid under pressure with the displacement chamber is cut off but is simultaneously established between the said upper chamber and the eduction pipe through the ports therein to further lift the liquid toward the surface of the well in successive slugs.

5. A deep well pump comprising concentric strings of tubing, the outer of which terminates at its lower end in a displacement chamber, a valved inlet in said displacement chamber, a pi ston cylinder open at both ends, supsaid cylinder, and an eduction pipe extending y into said displacement chamber, a plurality of enlargedpiston heads forming part of said piston type valve and closely received within said cylinder, ports extending through said piston type valve between certain of the piston heads, and a check valve in said inner tube string below said ports in the piston type valve` a source of fluid pressure communicating with the space between the outer and-inner tube strings, whereby upon reciprocation of the inner tube string compressed fluid will be admitted to the displacement chamber by passing through the ports on either side of the web element and around the piston type valve, thus exerting downward pressure on the liquid in the displacement chamber and forcing it up the inner tubestring past the check valve therein, from which point it is lifted by fluid pressure when the position of the piston type valve is reversed vto admit the pumping fluid through the ports in such valve, and means for simultaneously venting the displacement chamber to relieve it of pressure for refilling with well liquid preparatory' to another cycle of operation.

6. Pumping apparatus for wells comprisi and lower chambers, an inner string of tubing for discharging liquid from the well, a reciprocable valve carried by said inner string of tubing for -establishing and' interrupting communication between a source of pumping fluid and said strings of tubing, respectively, a fluid operated piston for reclprocating said valve and inner tube string, a compressor for forcing pumping fluid into the outer tube string and intermittently into the inner tube string upon actuation of the valve, a separating chamber, piping connecting the inner string of tubing with said chamber to conduct pumpirfglluid and well liquid from the inner string 'of' tubing thereinto, said separating chamber being maintained under superatmospheric pressure, andpiping leading from said separating chamber to said compressor, whereby the compressor and flow line of the apparatus will be maintained under back pressure.

7. A pneumatic pumping system in which no back pressure is placed on the producing horizon, consisting of two concentric strings of tubing,n a stuing box carried by the outer string of tubing to permit the inner string Vto be raised and lowered without leakage between the two said concentric strings, a piston -type valve attached to the inner movable string of tubing, a cylinder for said valve within the outer string of tubing, a displacement chamber attached to the outer, stationary string of tubing at its lower end and extending into the well hquid, a check valve in the bottom of the displacement chamber for admitting liquid from the well, an eduction' pipe extending into the displacement chamber to provide a continuous passage through the piston type valve h for delivering liquid from the displacement chamber to the inner string of tubing, a check valve in the eduction pipe, means for supplymg compressed gas to the annular space between the two strings of tubing, and means for admitting compressed gas to the displacement chamber from the annulus between the two strings of tubing, and means for exhaustlng compressed gas from the displacement chamberV by vertical motion of the inner string of tubing.

A .pneumatic pumping apparatus comprismg inner and outer concentric strings of tubing, a displacement chamber at the lower end of the outer string of tubing, a flow line of less diameter than the displacement chamber, reciprocating valve means carried by the flow line for admitting compressed gas intermittently to the displacement chamber to act downwardly on the surface of liquid therein and force it into the flow line, the valve means being reciprocable to interrupt the flow of pumping fluid to the displacement" chamber, whereby it may be relieved of pressure, an exhaust port from said outer string of `tubing, a well casing surrounding the concentric strings of tubing and a packing between the well casing and, outer string of tubin below the exhaust port therein to permit t e pressure in the casing to be reduced below atmospheric for increasing the volume of well liquid collected in the displacement chamber which extends above the normal Huid level of the well.

9. In combination with a source of fluid under pressure, a pump comprising a displacement chamber immersed in the liquid to be pumped, a stuing box vin the lower end.

of said displacement chamber, a hollow, ported rod extending through said stuiiing box and reciprocable to establish or interrupt communication between the interior of a well and the interior of said displacement chamber, an eduction pipe extending into said displacement chamber and attached to said hollow rod, a reciprocable piston type valve coaxial with said eduction pipe to establish communication between the source of fluid under pressure alternately with the displacement chamber when the hollow rod is in position to close the displacement chamber at its lower end, and with the eduction pipe at an intermediate point therein, a check valve in said eduction pipe below such intermediate point, whereby when fluid is admitted to the Vdisplacement chamber to force liquid r therefrom up into the eduction pipe, the liquid is prevented from owing back to the displacement chamber by said check v alve whereupon, when the position of sald plston type valve is reversed, the column of liquid is lifted to the surface of the well in successive slugs while, at the same time, the flow of pumping fluid to the displacement chamber aving been interrupted, such chamber 1s relieved of pneumatic pressure and, the hollow ported tube having been reciprocated simultaneously with the piston type valve, the displacement chamber is refilled with liquid preparatory to another cycle of operation.

10. Pneumatic pumping apparatus for deep wells comprising a well casmg, a pipe positioned in said well casing, a piston valve and an eduction pipe positioned in said first mentioned pipe, said piston valve dividing said first mentioned pipe into an upper chamber-for the reception of compressed air and a lower chamber adapted'to be submerged in the liquid in the well, the piston valve 'adapted to alternately admit compressed air into said lower chamber and then into said eduction pipe, said piston valve exhausting air from said lower chamber into the well casing during admission of air into the eduction pipe.

11. Pneumatic pumping apparatus for deep wells comprising a pipe positioned 1n said well, a piston valve and an eduction pipe positioned in said first mentioned pipe, said piston valve dividing said first mentioned I pipe into an upper cnamner for the reception of compressed a'ir and a lower chamber adapted to be submerged in the liquid in the well, the piston valve adapted to alternately admit compressed air into said lower chamber and then into said eduction pipe, said piston Valve exhausting air from said lower chamber into the well during admission of air into the eduction pipe.

12. Pneumatic pumping apparatus for deep wells comprising a pipe positioned in said well and a combined piston valve and eduction pipe positioned in said first ,mentioned pipe, s aidpiston valve dividing said first mentioned pipe into an upper chamber for the reception of compressed air and a lower chamber adapted` to be submerged in the liquid in the well, the valve means adapted to alternately admit compressed air into said lower chamber and then into said educ- 'tion pipe, said valve means exhausting air from said lower chamber into the well during admissionof air into the eduction pipe.

13. In apparatus for pneumatically pumping liquids from wells, a displacement chamber and an eduction pipe in communication therewith at its lower end, means for filling said chamber with liquid from the well to cover the lowerl end of said eduction pipe, means for admitting compressed air to the said chamber for discharging the liquid from the chamber into the eduction pipe, and means for supplying compressed air to the eduction pipeduring the fillin of the chamber withl oil from the well to ift the oil in said pipe and discharge it from the Well, the oil entering said eduction pipe during discharge thereof fromsaid displacement chamber, continuing to lift the 4oil in said eduction pipe to continuously discharge it from the well after admission of air to the eduction pipe has been discontinued.

14. In apparatus for pneumatically pumping liquids from wells, a well casing, a pipe extending into-said well casing and comprising a chamber having an upper part and a lower displacement part and an eduction pipe surrounded by said chamber and in communication therewith at its lower end, means Y for filling said chamber with liquid from 'the well to cover the lower end of said eduction pipe', hollow valve members in said rst mentioned pipe between the upper and the lower` parts thereof for admitting compressedfair to the said displacement part and for discharging the liquid therefrom into the eduction pipe, means for releasing the pressure in therewith at its lower end, means for lling said chamber with liquid from the well to cover the lowenend of'said eduction pipe, means for admitting compressed air to the said chamber for discharging the liquid from the chamber into the eduction pipe, means for releasing the pressure in the dis lacement chamber to permit entrance thereo of liquid from the well, and means for substantially ing liquids from wells, a well casing, a pipe Y extending into said well casing, a valve dividing said pipe into an upper part for the reception of compressed iuid and a lower chamber extending into the liquid in the well, and an eduction pipe positioned in said rst mentioned pipe and terminating in said lower chamber, operating means for said valve to'position it to admit compressed fluid into the lower chamber froml a source of compressed 'luid supply to force the liquid in said chamber upwardly in the eduction pipe and means for operating said valve to admit compressed iiuid into the eduction pipe at a point below the level of the liquid which has been forced into said pipe by the compressed air of the lower chamber, whereby the liquid in the eduction pipe may be lifted to the .top of the well, and means operable by said valve to release the pressure of the Huid in the lower chamber during the introduction of the compressed iuid to said eduction pipe.

. 17. Apparatus for pneumatically pump-` ing liquids from deep wells comprislng a dlsplacement chamberpositioned in the liquid at the bottom of the well, an eduction pipe communicating with said displacement chamber and extending to the top of the well, a valve positioned in the well adjacent the eduction pipe and displacement chamber said valve being connected to a source of Huid pressure and adapted to alternately connect rst, said displacement chamber and then Asaid eduction pipe withcvthe source of compressed luid and means including said eduction pipe for controlling the operation of said valve.

18. Apparatus for pneumatically pump-4 ing liquids from deep wells comprising a displacement chamber positioned in the liquid at the bottom of the well, an eduction pipe communicating with-said displacement chamber and extending to the top of the well, a valve positioned in the well, and means extending t the top of the well for controlling the operation of said valve, said valve being connected to a source of fluid ressure and adapted to alternately connect rst said displacement chamber and then saideduction pipe with the source of compressed uid for pumping the liquid out of the well.

In testimony whereof, I have hereunto affixed my signature.

ROY L. CHENAULT.