US2805625A - Hydraulic pump and gas anchor associated therewith - Google Patents

Description

A. E. CROW sept. 1o, 1957 HYDRAULIC PUMP AND GAS ANCHOR ASSOCIATEDTHEREWITH Eiled May 7, 1956 3 Sheets-Sheet l INVENTOR.

A. E. CROW Sept. 1o, 1957 HYDRAULIC PUMP AND GAS ANCHOR ASSOCIATED THEREWITH 3 Sheets-Sheet 2 Filed May '7, 1956 /was [kann 1N VEN TOR. j

.g Y 1 (v A. E. CROW sept. 1o, 1957 HYDRAULIC PUMP AND GAS ANCHOR ASSOCIATED THEREWITH Filed May 7, 1956 3 Sheets-Shree?l 5 INVENTOR.

M C l rra/ewgg/ i am United States Patent @thee 2,805,625I Patented Sept. 10, 1957 HYDRAULIC PUMP AND GAS ANCHOR ASSOCIATED THEREWITH Amos E. Crow, Long Beach, Calif.

Application May 7, 1956, Serial No. 583,200

Claims. (Cl. 103-46) The present invention relates to the field of oil well equipment, and more particularly to a hydraulic pump and anchor adapted for use therewith.

A primary object of the present invention is to supply a hydraulic pump that is supported on the lower end portion of a tubing string, with the pump being actuated by iluid pumped down the tubing string, and the actu-l ating fluid and pumped fluid from the well being discharged upwardly through the annulus shaped space existing between the tubing and casing, or the annulus shaped space between two strings of tubing when such are used.

Another object of the invention is to provide a pump that requires but a single string of tubing for the actuation thereof.

A further object of the invention is to provide a huid-actuated pump that is of relatively simple mechanical structure, requires a minimum of rmaintenance attention, and is less expensive to operate than conventional present-day pumping equipment in that no sucker rod must be furnished or maintained in conjunction with the use of the invention.

A still further object of the invention is to provide a pump in which as many pump pistons and pump chambers may be incorporated as desired, depending on the volume of uid it is desired to discharge from a well by the use of the invention.

Another object of the invention is to provide a pump that can be made sufficiently small as to permit its use in a small first string of tubing that is inserted in a second string of tubing of larger internal diameter, and when the pump is so disposed it is capable of moving a large volume of fluid.

A further object of the invention is to provide a pump that can be used with two concentrically disposed strings of tubing, particularly where there is a large gas output, whereby if one tubing string breaks onlyv one fishing job is required rather than two as is necessary when the tubing strings are set side-by-side.

A further object of the invention is to provide'a pump in which all of the n working parts are mechanically actuated to assure positive and substantially trouble-free action by the invention. y

A further object of the invention is to provide a pump in which all of the working parts are disposed within the contines of the engine piston, thus permitting the use of a pumping unit of high volume production with a tubing string of relatively small crosssection.

These and other objects and advantages of the invention will become apparent from the following description of a preferred form of the invention when taken in conjunction with the accompanying drawings illustrating same in which:

Figure 1 is a vertical cross-sectional view of thepump and upper portion of the anchor; Y

Figure 2a is an enlarged vertical cross-sectional view of the upper portion of the pump;

Figure 2b is an enlarged vertical cross-sectional view of the lower portionr of the pump;

Figure 2c is an enlarged vertical cross-sectional view of a continuation of the lower portion of the pump of Figure 2b;

Figure 3 is an enlarged vertical cross-sectional view of the tubing packer shown at the bottom of Figure l;

Figure 4a is an enlarged vertical cross-sectional View of the engine piston and associated elements;

Figure 4b is a diagrammatic view of the engine piston as same starts to move downwardly;

Figure 4c is a diagrammatic view of the engine piston as same starts to move upwardly;

Figure 5a is a vertical cross-sectional view of the upper portion of the anchor;

Figure 5b is a vertical cross-sectional View of the lower portion of the anchor;

Figure 6 is a side elevational View of the anchor;

Figure 7 is a cross section of the top of the gas anchor, showing mechanical hold-down for standing valve used with a regular rod pump or tubing liner pump;

Figure 8 is a perspective view of two associated cornponents used in the pump engine; and,

Figure 9 is a vertical cross-sectional View of the lower portion of the pump when associated with a dual tubing set-up joint.

Referring now to the drawings for the general arrangement of the invention, particularly Figures 1, 2a, 2b and 2c thereof, it will be seen to be in the form of a pump B and gas anchor C which are supported from the lower end portion of a string of tubing A in a bore hole D. Tubing A and pump B are disposed inside a string of casing E and are separated therefrom by an annulus shaped space F that extends upwardly from the pump to the ground surface.

Pump B includes an engine piston G, the detailed structure of which is best seen in Figures 4a, 4b and 4c. As it reciprocates, piston G discharges the actuating fluid (normally oil) into an escape chamber H from which it flows to the space F. Reciprocal movement of piston G results in like movement of piston I, the detailed structure of which is shown in Figure 4a. Piston I reciprocates in a pump chamber K and discharges fluid that has entered the bore hole D and owed to the chamber K therefrom on both the up and down stroke of the pump piston. After entering the bore hole D, fluid from the producing formation flows into the confines of the gas anchor C (Figures 5a and 5b) and moves upwardly therethrough to the pump chamber K.

Referring now to Figures l, 2a, 2b and 2c of the drawings for the speciiic structure of pump B, it will be seen to include an elongate tubular member i6 that is essentially the same diameter as tubing A and connected to the lower threaded end portion of the tubing by a collar 12. A circular tapered resilient packing cup 14 is provided that is mounted on an elongate packer nose 16 which terminates on its upper end portion in a suitably shaped member 18 adapted to be engaged by a wire line (not shown) to raise or lower the pump. Under normal conditions pump B is raised to the ground surface by reversing the flow of actuating liquid as will later be explained in detail. The pump is lowered into the well to the position shown in Figures l and 2a, by pumpying liquid downwardly therein in a manner to be described hereinafter. j

The packer nose 16 s formed with an enlarged portion 16a, the lower extremity of which portion has an external diameter sufficient to permit snug iit thereof within the contines of the collar 12. Portion 16a has'a circumferentially extending recess 1617 formed therein in which a resilient O-ring 20 is disposed and forms a fluid seal with the interior surface of collar 1,2. A longitudinally extending bore 22 is formed in nose 16, which bore in the upper portion of the packer nose develops .into a4 plurality of upwardly and outwardly extending fluid inlet ports 22a for` the actuating fluid. Bore 22 in the lower portion of the packer nose 16 develops into a tapered downwardly and outwardly extending counterbore 226; t v

The lower extremity of the packer nose `portion 16a has a segment 24 of smaller diameter extending downwardly therefrom, which segment is provided with threads 24a that engage the tapped-upper end of a rigid tubular member `26 situated within the upper confines of the pump body 10. Tubular member 26 (Figure 2a) supports ytwo substantially identical conical strainers 28 and 30 which are in spaced iverticalrelationship. Strainers 28 and `30 canbe aixed to the interior of tubular member 26 by welding, brazing, or the like.

l Internal threads 32 are formed on the lower end portion of tubular member 26, vwhich threads engage the threaded upper end of a plug 3`4. Plug y34 `is formed with a downwardly extending `section 36 smaller in diameter than the main body of the plug, and this section has threads formed thereon which engage the tapped upper end portion `38a.of a tube 38. A second plug 34 is provided that is identical in construction to plug 34 but is disposed in inverted relationship therewith and the section 36 thereof is threadedly connected to the tapped lower end portion38b of tube 38. Inasm-uch as plug 34 is identical to plug 34, the same identifying numerals will be employed relative thereto with a prime added. Plug 34 is provided with a centrally disposed, downwardly extending bore 40 `that on its lower end develops into an enlarged circular cavity 42.

Circumferentially extending, longitudinally spaced recesses are formed inbore 40 in which O-rings 44 are disposed that slidably engage a hollow tubular piston rod 46. `circular plate 48 is positioned inside the cavity 42 and is at all times urged downwardly by a helical spring 50 that is also situated in cavity 42. Displacement of `plate 48 from cavity 42 is prevented by a ring-shaped flange 52 that is aiiixed to the lower surface, of plug 34, by screws 54 or other suitable fastening means. A centrally disposed downwardly extending bore 48a is formed in lplate 48 `in which the piston rod 46 is` slidably disposed. A similar tubular pistonl rod 46 is slidably mounted in plug 34' in the same manner as above described.

The `lower end portion of piston rod 46 is tapped and threaded to a tubular member 56 which has two opposed fluid inlet ports` 56a and 56h formed therein. Tubular member 46 is threadedly connected to a tubularlmember 58, as may beseen in Figure 4a, and two opposing fluid outlet ports 58a and 58b are formed onthe upper end portion of member 58. The adjacentlend portions of members 56 and 58 `are rigidly connected by a solid collar 60 that prevents flow'of fluid between `a bore 56e in tubular member 56 and bore 58e in tubular member'58.

A cylindrical sleeve 62 is provided that has a centrally disposed, longitudinally extending bore 64 formed therein, in `which bore the adjacent end portions of tubular members 56 and 58 are `slidably disposed. Sleeve 62 is prevented. from rotating relative to tubes 56 and 58 by a splined construction (not shown) or other means, which sleeve has two oppositely` disposed, `longitudinally extending huid-carrying passages 66 and 68 formed therein. Two longitudinally spaced ports 66a and `66h are provided in passage 66 that extend inwardly therefrom. Passage 68 terminates in a port 68a, which by movement of sleeve 62, can be brought into registry with either port 56b or port 58b for reasons which will later be described in detail. Byvmovement of sleeve 62 port 66a can be brought into registry with port 56a only, and likewise port 66h can be brought into registry with port 58kt only by movement of sleeve 62. l

Sleeve 62 is vertically movable within the confines 'of a cylindrical piston shell 70 that is in slidable contact with the interior surface of tube 38. Shell 70 is provided with two longitudinally spaced, circumferentially extending recesses 72 in which sealer rings 74 are situated to maintain fluid sealing contact with the interior surface of tubular member 38. Two end plates 76 of identical construction are mounted on sleeve 70, which plates have two opposing bores 76a extending therethrough. Each of the end plates 7 6, as best seen in Figure 8, has two spaced ports 78 formed therein. Two circular plates 80 (Figure 8) are provided that have two spaced ports 82 formed therein which have two spaced rigid fingers 84 projecting outwardly therefrom. Plates 82 are oppositely disposed adjacent the ends of sleeve `62 within the con-` tines of the piston shell 70, with the fingers thereof extending through bores 476a as` shown in Figure 4a.y

In operation, lluidund'er pressure is discharged downwardly through the tubing'rstring A, tubular piston `rod 46 and bore 56c, and i'sdi'scharged therefrom when sleeve 62 is disposed as shown in Figure 4a, through port 56a into passage y66,` and then upwardly through ports 82 and -78 to Vbear against plate 48. As it is so admitted the iiuid causes the vengine piston G as a whole to move downwardly with concurrent movement of the piston rods 46 and 46. When piston G has moved downwardly to the extent that the downwardly depending ngers 84 contact the upper surface of plate 48', the sleeve 62 is then moved upwardly relative. to `the- tubular members 56 and 58 to place the port in registry withV port 58a and move port 66a out of registry with port 56a. Fluidthen disposed in the confined space 67 above the engine piston G and below plug 34, as shown in Figures 2a and 2b, can flow outwardly therefrom through ports 661) and 5841 intothe tubular piston rodI 46` from which the liuid llows through la 'p'ort 88 into the escape chamber H.

Escape chamber H, as can best be seen in Figure 2b, is defined by a tube 90, the. upper end of which is threadedly connected tothe lower portion of plug -34 and a cylindrical valvel body 92-that is threadedly connected to the lower portion of the tube 90. Valve body 92 is preferably made in Athree parts; the first being in ,the` shape of a solid plug 92a having a threaded recess 921) formed thereinthat is engaged by the threaded upper portion of a secondY plug 94. A plate 96 is disposed within the conlines ofthe threaded recess 92h. Flug 92a is provided with a longitudinally `extending bore 98 that is in alignment with a bore 100 formed in plate 96, as well as a bore 102 formed in plug 94'. p A radially extending bore `104 is formed in plugl 94 and communicates with a bore 106 formed in tubular member 10.` A compressed helical spring 106 is situated in bore102`and at all times urges a ball 108 upwardly into sealing engagement with bore 100. Plug 94 has a bore 110 formed therein that is inralignment with a bore 112' provided inplate 96, which latter'bore is in alignment with a third b ore 114 formed in the upper plug. Bore 114 has` a compressed spring 116 therein that at all times urges `a ball 118 into seating engagement with bore 112. Bore 114 `.eommunicates with radially extending bore 120 formedirrthe .upper plug 94.

Bores 12411, 1,24b and 124e are formed in theupper plug 92a, pla'te 9 6 and lower plug 94 respectively. The tubular piston rod 146'v is slidably disposed within the confines of bores 12`4a, 124`b, and 124e and extends therebelow into the pump chamber K where it is connected to thepuni'p piston J. `Fluid discharged into thc escape chamberH'passes through discharge port S8 to flow downwardly through the bores 98 and 100 to `depress ball 108, and then through the bores 104, 106 and y107v into the annulus-shaped space F. The column of fluid in space `l: builds up in height until it discharges at the ground surface..

Thelpump piston I is formed with a cylindrical shell that preferably has several resilient sealer rings 132 mounted ou the exterior surface thereof which slidably engage the interior surface of a heavy-walled tube 134 that is threadedly connected at 138 to the lower portion of the plug 94. The endportions of tubular member 130 are tapped and threadedly connected to two end members or plates 136 and 138, as can best be'seen in Figure 2b. End member 136 has a centrally disposed tapped bore 140 formed therein to which the solid lower end portion of piston rod 46 is connected. End member 138 is provided with a tapped bore 141 that is connected to the upper threaded end of a tubular piston rod 142 extending downwardly therefrom. Disposed within the confines of theitube 130 and between the end members 136 and k138 is a body 144 that has a centrally disposed bore 146 extending upwardly therethrough to a radially extending passage 148 communicating with two upwardly extending boresv 150 and 152 and ltwo downwardly extending bores 154 and 156. Two balls 150e and 152e are urged into positions to obstruct the upper extremities of bores 150 and 152 respectively by springs 150b and 152i). Likewise two balls 1S4a and 1S6a are urged upwardly against the lowerrextremities of bores 154 and 156 respectively by springs 154b and 156b.

End member 136 has two uid discharge passages 160 and 162 formed therein through which iluid under pressure cart flow from bores 150 and 152 respectively when the` spring-loaded balls 150a and 152e are not in a seated position. The end member 138 is also provided with two duid passages 164 and 166 through which duid can ow downwardly from bores 154 and 156 when the balls 154e and 156e are not in seated positions.

The tapped lower end portion of tube 90 is engaged by the threaded upper end of a cylindrical sealer joint 170 in which a centrally disposed bore 172 is formed that slidably receives the piston rod 142. Piston rod 142 extends below'thejoint 170 and can support additional pump pistons J if desired. Sealer joint 170 is of slightly smaller diameter than theinterior of tubular member 10 whereby an annulusshaped space 174 is formed therebetween. A fluid passage 176 is formed in sealed joint 170 that perH mits fluid to fiow from the entrance 17061 thereof through the joint to discharge at the port 17027 into space 174.

The sealer joint 170, as can best be seen in Figures l, 2a and 2b, has a tubular member 180 depending downwardly therefrom that is of smaller diameter than the interior diameter of tubular member 10. Tubular member 180 preferably has one or more vertically disposed strainers 182 positioned within the confines thereof as shown in Figure 2c. The lower end of tube 180 terminates in a bottom plug 184 having a longitudinally extending bore 186 formed therein through which fluid can tiow upwardly into the pump. For reasons that will later become apparent, plug 184 is formed with a circular inwardly tapering face 188. Tubular member 10, as can best beseen in Figurespl and 3 extends below plug 18e, the lower end of which member is threaded and adapted to engagea tapped collar-185 from which a tubular outlet joint 187 depends. Outlet joint 187 has a number of ports 189 formed therein, and the lower end of this joint is threadedly connected toa tubular packer 191 that has a ring-shaped resilient member 193 forming a part thereof and effects a duid-tight seal with a portion of the interior surface of casing EL Tubular packer 191 is provided withnthreads 208 in the lowerportion thereof, which threads serve to support the gas anchor C shown in Figures u and Y5b at the desired position in the bore hole.

'In' operation, gas together Awith`liquid-carrying sand and other foreign solidsflow into the bore hole D and enterthe gas anchor C, the structure of which anchor will later be considered invdetaiL The sand and `solids carried into the'. gas anchor C tend to sink to the lower portion thereof, while the liquid and gas tlow upwardly inthe anchor.`` The upwardly flowing 4 liquid and `gas enter thepumppthrough the bore. 186 asy canbestbe seen in Figure 1, and continue such flow through the strainers 182 into the lower end of tubular piston rod 142. i

After entering tubular piston rod 142, the liquidand gas flow upwardly therein. The upstroke of pump piston J causes the portion of pump chamber K below the piston to be at a reduced pressure, and liquid and gas from the interior of piston I causes the spring-loaded balls 154a and 156a to assume unseated positions whereby the liquid and gas can ow through the bores 164 and 166 into the lower portion of the pump chamber. On the downstroke of pump piston I the balls 15401 and 156a assume seated positions, with the piston then exerting pressure on the liquid and gas in the lower portion of pump chamber K to force same through passage 176 into the space 174 as shown in Figure 2b.

On the downstroke of pump piston J the upper portion of chamber K is at a reduced pressure and liquid and gas flow therein through bores and 162 (Figure 2b). On the upstroke of piston I, balls 15001 and 152:1 are in the seated position, and as this movement occurs the piston places pressure on the liquid and gas in the upper portion of the pump chamber to cause same to be discharged into space 174 through a port 120 as shown in Figure 2b. The liquid and gas so discharged into space 174 pass through port 107 to space F as previously described. Actuation Vof engine piston G has been previously described in detail and need not be repeated herein.

After discharge into space 174, the liquid and gas ilow downwardly therein to the ports 189 shown in Figure 3, and through these ports to the annulus shaped space F leading to the ground surface. Should it be desired, dual tubular members 10 and 10 can be used in conjunction with the pump B as shown in Figure 8, and the liquid in this type of set-up flows to the ground surface through the annulus shaped space F formed between the two tubular members. Elimination of the resilient tubing packer 193 by means of a dual tubular member arrangement makes it possible for the gas anchor C to separate the liquid and gas, with the liquid rising to the ground surface in space F and the gas likewise ilowing to the ground surface through space F.

Gas anchor C is shown in Figures 5a and 5b and is particularly adapted for use with the above-described pump. Anchor C includes a first tubular member 202 provided with external threads 204 and 206 formed on the ends thereof. Threads 204- are adaptedV to be engaged by threads 208 formed on the lower end of tubing packer 191. Threads 206 are engaged by the upper tapped end of an elongate barrel 210 that has a number of spaced openings 212 formed in the upper portion thereof through which fluid and gas from the producing formation enter the contines of anchor C. An inwardly tapered seat 202a is formed on the upper end portion of member 202.

A second tubular member 214 is slidably disposed in member 202. A bore 216 extends longitudinally through member 214, which bore has threads 216.11 formed in the upper portion thereof. Threads 216a are engaged by the threaded lower end of a collar 218 that has a ring-shaped tapered seating member 220 mounted on the lower end thereof. A bore 222 extends through collar 218.

A tube 224 through which a bore 226 extends is slidably mounted in bore 216. The threaded upper end portion 224a of tube 224 engages a threaded bore 226a in the lowermost of three tubular sections 227, 229 and 231 that cooperatively dene a standing valve body 232 in which a check ball 234 is mounted. Valve body section 230 is formed with a circular tapered seat 230a on which the tapered face 188 of the pump plug 184 (Figure l) is adapted to rest.

Tube 224 is provided with an intermediately disposed sealing ring 236y that is slidably movable in bore 216 of the second tubular member 214. Threads 214a are formed on the lower exterior surface of member 214 and are connected to the upper threaded end of a pipe 238 that serves as the inner barrel of the anchor and has on the exterior surface of the sand trap 246 between the lower edge of ring 252 and a shoe 256, which shoe is threadedly or removably mounted in the lower portion of barrel 210. The purpose of the removable shoe 256 is to permit removal ottrap 246 from anchor C and the substitution of an elongate cylindrical screen vor chemical holder (not shown) in lieu thereof. Bow springs 250 are deformed inwardly in shell 210 and move ring 252 downwardly to compress ring 254 and expand it radially into fluid-*sealing `engagement with the interior surface of the shell. v

Tube 224 terminates in a ring-shaped stop 256 of such diameter as to permit its engagement with the lower edge of the second tubular member 214. A compressed helical spring 258 encircles tube 224 and is disposed above sealing ring 236 and the lower edge of collar 218. First tubular member 202 and second tubular member 214 have bores 202b and 214b` respectively leading transversely therethrough, as shown in Figure a, which bores communicate with one another.

The above-described gas anchor is so constructed that the tubing A, tubular member 10, first tubular member 202, and barrel 210 can remain in the bore hole D at all times. When it is desired to remove the inner barrel 238 from gas anchor C in order to clean the anchor, bail through the tubing without pulling same, or carry `out other maintenance work, the standing valve assembly 230 isengaged by a suitable tool` and drawn upwardly. Such upward movement causes a sealing ring 227a mounted on the lower end of section 227 to be unseated from an upper face 218a formed on collar 218. The fluid pressure on the inside of the tubing A and casing D is permitted to equalize as a result thereof, and the seating member 220 can be separated from its seat 202:1 without excess pull. Thebalance of the interior portion of gas anchor C may then be raised without creating a partial vacuum therein due to the porting actionof the bores 202b and 214b. It willbe apparent that when the re moved portions of gas anchor C `are `lowered into the b ore hole D that they willautomatically assume the positions` shown in Figures 5a and 5b.

A modification of the invention is shown in Figure 9 in which a dual tubing arrangement is utilized. In this form of the invention the first tubular member 10 and a second tubular member 310 serve to define an annulus-shaped space F therebetween thatextends to the ground surface in the same manner as annulus-shaped space F. Tubular member 310 is threadedly connected to a tubular dual set-up joint 312, which joint in turn is connected to hold down joint 200. `This form of the invention operates in the same manner as the pump shown in Figures 2a, 2b and 2c, with the exception that fluid is discharged upwardly through the space F'.

In both the "form of the invention shown in Figures 2a, 2b and 2c, as well as Figure 9, the strainers 182 can be used as receptacles to hold chemicals for use in treating of a well.

Although the form of the invention herein shown and described is fully capable ofaohieving the objects and providing the advantages 'hereinbefore mentioned, it is to be understood that it is merely illustrative of presently preferred embodiments` thereof and that I do not mean to be limited to the details of construction herein shown and .described other than as defined inthe appended claims.

I claim: 1. A fluid-actuated pump disposable in the lower end portion of a tubing string `in `a well bore, including: ank

elongate tubular member `adapt/cd to be placed within said tubing string; a first plug and a second plug spaced downwardly therefrom that with'said tubular member cooperatively defines a first elongate confined space; a valve A.body spaced downwardly from lsaid Ysecond `plug that cooperates with said tubular member to define a second lconfined space; a sealer joint spaced downwardly from said valve body that with. said tubular member cooperatively defines a third confined space; an engine piston slidably movable in said first confined space; a

pump piston slidably movable in said third confined space; a first tubular piston rod extending upwardly from said engine piston and slidably mounted in said first plug; a second tubular piston rod extending downwardly from said engine piston throughsaid valve body that is in slidable engagement therewith to said pump piston, with the lower portion ofsaid second rod being closed; a third tubular piston rod extending downwardly from said pump piston through said sealer joint in which it it is slidably mounted; an apertured Ibottom plug mounted on the lower end of said tubular member that permits fluid entering said bore hole below said pump tor flow upwardly in said third tubular rod; first valve means mounted on said engine piston that direct said actuating fluid discharged down said tubing string into said first confined space to reciprocate said engine piston up and down, with spent actuating fiuid after so moving said engine piston being discharged into said second confined space through a port formed in said second tubular rod; second valve means in said valve` body that discharge said spent actuating fluid to the exterior of said tubing string; third valve means insaid valve body that permits fluid in said third confined space above said pumppiston to escape therefrom when pressure is placed on said fluid by the upward movement of said pump piston; and fourth and fifth valve means `in said pump piston that permits fluid entering said third tubular rod to enter said third confined space, which fourth valvemeans closes on the upstrolce of said pump piston to exert pressure on said fluid situated thereabove in said third confined space, and said fifth valve means closes onthe downstroke of said pump piston to cause fluid in said third confined space below said pump piston `to be discharged therefrom through fluid passage means leading from said confined space to the exterior of said tubing string.

2. A pump as defined in claim 1 in which the upper end of said tubular member is closediby an apertured member through which actuating fluid can flow from said tubing string to said first tubular piston rod, and in which sealing means are `provided that effect a seal between said apertured member and the interior surface of said tubing string.

3. A pump as defined in claim 2 in which the shape of `said apertured member is such that it can be engaged by a line or cableto move said pump upwardly through said tubing string to the ground surface.

4. A pump as Vdefined in claim 2 in which first and second solids removing means are provided, said first removing means being disposed in said tubular member be tween said apertured member and the upper end of said first tubular piston rod, with said second removing means being positioned in said tubular member betweenthe lower ends of said sealer joint and the lower end of said tubular member. s

5. A pump as defined in claim 2 in which a portion of said engine piston is hollow andmeans are provided therein to block fluid communication between` saidiirst and second tubular piston rods, with saidiirst piston rod havingfirstand second ports formed therein through which actuating fluid from said tubing string is `admitted 4to move said engine piston upwardly and downwardly,

and said second tubular piston rod has third Vand fourth ports formed therein through which spent actuating uid passes; a sleeve slidably mounted on said first and second tubular piston rods, which sleeve in a first position closes said rst and third ports and when in a second position closes said second and fourth ports; and means for moving said sleeve as said piston approaches said first and second plugs.

6. A pump as defined in claim 5 in which said sleeve moving means are two ring-shaped plates slidably mounted on said rst and second tubular piston rods that are adapted to slide said sleeve, which plates are provided with a plurality of projecting iingers that engage one of Isaid plugs as said engine piston approaches same, with each of said plates causing said sleeve to assume the opposite position after engagement of said fingers of that sleeve with one of said plugs.

7. A pump as defined in claim 5in which said iirst and second valve means are spring-loaded balls disposed in Huid conducting passages formed in said engine piston.

8. A pump as defined in `claim 5 in which said third valve means is a spring-loaded ball mounted in a iuid conducting passage formed in said valve body.

9. A pump as defined in claim 5 in which said fourth and fifth valve means are spring-loaded balls mounted in uid conducting passages formed in said'pump piston.

l0. A pump as 4delined in claim 5 in which said bottom plug projects below said tubular member and has a circular inwardly tapering face formed on the bottom portion thereof.

No references cited.

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