US2242551A

US2242551A - Pumping apparatus

Info

Publication number: US2242551A
Application number: US185295A
Authority: US
Inventors: Staerker Otto
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-01-17
Filing date: 1938-01-17
Publication date: 1941-05-20
Anticipated expiration: 1958-05-20

Description

f May 20, i941.

O. STAERKER vPUMPING APPARATUS Filed Jan. 17, 1938v 2 Sheets-Sheet l Gum/wea,

2 Sheets-Sheet? fnlwnlllllll O. STAERKER PUM'PING APPARATUS Filed Jan. 17, 1938 May 20., 1941.

Patented Ma'yzo, 1941 UNITED STATES PATENT OFFICE PUMPING APPARATUS Otto Staerker, Gladewater, Tex. l Application January 17, 1938, Serial No. 185,295

(Cl. S- 1) Claims.

This invention relates to new and useful improvements in pumping apparatus.

One object of the invention is to provide an improved pumping apparatus for efficiently liftingiiuids from-deep wells or shafts to the surface and being particularly adapted for use in the pumping of oil wells.

An important object of the invention is to provide an improved pumping apparatus having a pair of pump plungers, one of which is operated by the usual pump rods, while the second is actuated by the pressure of the fluid being pumped, whereby a greater or increased volume of fluid may be lifted without increasing the pumping stroke and without materially increasing the load on the pump rods.

Another object of the invention is to provide an improved pumping apparatus wherein an auxiliary pump plunger is located below the usual reciprocating plunger and has its lower end exposed to the bottom hole pressure, or pressure of the well fluid, whereby said auxiliary plunger is reciprocated by the differential in pressures above and below the same; the construction of the apparatus being such that the operation of the usual pump plunger results in setting up a sufficient pressure differential across the auxiliary plunger to permit movement thereof, whereby the usual pump plunger controls the operation of the auxiliary plunger so that both plungers operate at the same time to lift the well fluid.

A further object of the invention is to provide an apparatus of the character described wherein two fluid chambers, each of which communicates with the well tubing, are employed, with a pump plunger for each chamber for raising the fluid therefrom into the tubing; the lower plunger having means for permitting a flow therethrough into the chamber of the upper plunger upon the downstroke, whereby said upper chamber is supplied with fluid to be lifted; there also being means for by-passing fluid around the lower plunger to its fluid chamber when said lower plunger reaches the top of its stroke, whereby both chambers are supplied with fluid upon each stroke of the plungers so that upon the next successive stroke, said fluid may be lifted.

Still another object of the invention is to provide an auxiliary pump plunger in a pumping apparatus which is actuated bythe pressure differential above and below the same and having a bore for permitting ow therethrough, with a check valve for controlling said ow and normally actuated by the pressure differential thereacross; there being positive means for closing nected to and lowered with the well tubing, after which the plunger assembly may be lowered into the working barrels, whereby the plunger assembly may be removed or replaced within the working barrels without disturbing the working .barrels or the well tubing to which said barrels are connected.

A still further object of the invention is to construct the pump plungers in such manner that the pump rods may be connected thereto or disconnected therefrom from the well surface, vwhereby said rods may be run into the well separately from the well tubing and pump assembly.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and wherein:

Figure 1 is a View, partly in elevation and partly.. in section, of a pumping apparatus, constructed in accordance `with the invention, and mounted in a well casing,

Figure 2 is an enlarged, transverse, vertical, sectional view of the upper portion of the apparatus,

Figure 3 is a similar view of the lower portion of the apparatus,

Figure 4 is a partial, sectional view of the upper portion of the auxiliary plunger in its raised position,

Figure 5is-a horizontal, cross-sectional view, taken on theline 5 5 of Figure 2,

Figure 6 is a horizontal, cross`sectional view, taken on the line 6-*6 of Figure 3,

Figure 7 is a horizontal, taken on the line 1--1 of Figure 3,

Figure 8 is a transverse, vertical, sectional view of a modified form of the invention, and

Figure 9 is a transverse, vertical, sectional view of still another form of the invention.

This sole application is filed as a continuation-in-part of the abandoned joint application of Otto Staerker and Ben H. Ravenelli, Serial No. 139,872, led April 30, 1937; the invention set forth herein having been disclaimed by the latter.

In the drawings, the numeral i0 designates a cross-sectional view,

of the well.

well casing which has the usual casing head II at its upper end. The well tubing I2 extends axially through the casing and its upper end projects from the casing head. This projecting end of the tubing has the usual flow connections and controls mounted therein. In wells where pumping, or other auxiliary fluid lifting methods, are ernployed, the well fluid stands at a level in the casing and tubing and the elevation of such level is dependent upon the particular conditions In Figure 1, the standing liquid is designated at L, but it is manifest that the level will vary on each Well.

A swaged nipple I3 is screwed onto the lower `and of the well tubing and a pipe section I4, which `zias a larger diameter than the tubing, has its -ipper portion connected to the nipple, whereby aid pipe section depends from' the tubing. A sleeve or elongate coupling member I5 is threaded onto the lower end of the section I4, while its lower end receives the upper endof a lower pipe section I6, which is of substantially .the same diameter as the upper pipe I4. The usual perforated sleeve or well screen I1 depends from the pipe I6, being secured thereto by a coupling collar I8. Thus, it will be seen that the assembly, which houses the pumping apparatus, includes the two pipe sections I4 and I6 which are connected by the coupling sleeve I5, said as sembly being mounted on the lower end o! the well tubing and being preferably submerged below the liquid level L in the well bore.

An upper working barrel A is mounted axially within the upper pipe section I4 and has its lower end threaded into a collar I9 which extends upwardly from a transverse partition 28 located within the coupling sleeve I5. The partition is preferably integral with the sleeve and extends laterally from one wall thereof. The partition terminates short of the opposite wall and is provided with an opening 2| located axially of the sleeve. The working barrel extends upwardly from the collar I9 and has its upper end extending through a guide spider 22 which holds the barrel in axial alinement with the pipe I4. 'I'he extreme upper end of the barrel terminates short of the Well tubing I2, whereby a ow from the pipe section I4 into the tubing is permitted.

A standing valve 23 is mounted in the lower endl of the working barrel A. and includes a seat 24, `ball 25 and cage 26. The cage and seat are carried by a supporting sleeve 21 which has its lower end screwed into a collar 28 and said collar is suitably secured within the opening 2| o1' the partition 20 with the coupling I5. Packing rings 29 surround the supporting sleeve and engage the bore of the working barrel to pack off between these parts and manifestly, a flow from below the partition 20 flowing through the opening 2I therein, must pass upwardly through the supporting sleeve 21 and unseat the ball 25 in order to enter the working barrel A.

A pump plunger 30 is slidable in the working barrel A above the standing valve 23, being secured to the lower end of the usual pump rods 3| which extend axially through the tubing. 'Ihe plunger is formed with an axial bore 32 and a valve seat 33 is mounted within .the upper end of the bore. A valve cage 34 is secured to the upper end of the plunger and a ball valve 35 is conned within said cage and constitutes the usual traveling valve. When the pump rods 3l are reciprocated, the plunger 30 is reciprocated within the working barrel to lift the fluid from below the standing valve upwardly into the tubing. The rods 3I may be operated by any suitable means (not shown).

As hereinbefore stated, the transverse partition 20 within the sleeve I5 has one edge terminating short of the sleeve and an arcuate de` pending wall 36 extends vertically from the partition. This wall is offset laterally at 31 (Figure 2) and then extended-downwardly to form an arcuate skirt 38. A collar 39 is formed at the lower end of the skirt and. with such arrangement, it will be obvious that the interior of the coupling sleeve I5 is divided into two substantially vertical passages or chambers A and B'.

The passage A has its lower end communicating with the interior of the lower pipe section I5 while its upper end communicates with the interior of the working barrel A, through the stand-.- ing valve 25. The passage or chamber B has its upper end communicating with the interior of the upper pipe section I4, such interior being the annular space between the pipe and the Working barrel A.

The lower end of the passage B communicates with a lower working barrel B which has its upper end threaded into the collar 39 andwhich extends axially through the pipe section I6. The

lower end of the barrel is held in axial alinement with the section I6 by a spider or guide member IB. A standing valve 40, which is similar in construction to the valve 23, is mounted within the upper end of the barrel B and this valve includes a seat 4I, ball 42 and cage 43, as well as a supporting sleeve 44 and packing cups 45. The valve 4I) acts as a check valve, being unseated by uid pressure from below and seated by fluid pressure from above. Of course, said valve will seat by gravity if the pressures thereacross are equalized. From the foregoing, it will be seen that uid from the lower pipe section I6 may flow upwardly through the passage A in the sleeve I5 and may then enter the working barrel A, from where it may be lifted into the tubing I2. Fluid from the lower working barrel B may iiow upwardly past the valve 40 into the passage B' and then into the pipe section I4, from where it may enter the tubing around the upper end of the upper working barrel A.

For lifting the iiuid within the lower working barrel B, a lower pump plunger 50 is mounted to reciprocate in said barrel. The plunger is tubular and is provided with packing cups 5I on its exterior. A valve seat 52 is located at the upper end of the plunger and is adapted to be engaged by a ball 53 which is conned within a. cage 54. The valve forms a traveling valve which moves with the plunger.

The lower end of the plunger is connected, by a coupling collar 55, with a tubular mandrel 56 which extends from the lower open end of the working barrel B. The lower end of the mandrel is threaded into a swaged nipple 51 which is, in turn, carried by the upper end of a tubular piston 58. The piston is slidable within the pipe section I8 and has a plurality of packing rings 59 confined thereon and these rings engage the wall of the pipe IG to pack 01T between said pipe and the piston. A valve seat 60 is mounted at the lower end of the piston and is held in place by a valve cage 6I which is screwed onto the lower end of the piston. A ball 62 is confined within the cage and is adapted to engage the seat to close the bore 58' of the piston.

When the ball is unseated, it falls onto the concaved head S5 of an operating stern 56, which stem is slidably engaged within an axial opening "through the bore 58' of the extends into a metallic hanged cup V68. A :trans-A verse spider 59 is mounted between the ends of the pipe section |6` and well screen |1 and has an axial opening therein- The opening is surrounded by an upstanding coll-ar 10 and a coiled spring 1| is confined between the spider and the cup 68, exerting its pressure to urge the cup upwardly at all times. As shown in Figure 3, the spring is fully expanded and the piston 58 is raised with the stem 66 clear ofthe bottom of the cup. When the piston is lowered, the stem strikes the bottom of the cup and the head 65 is moved into engagement with the ball 52 to hold the same seated, as will be explained.

When the ball is unseated, fluid from below the piston may flow through the bore 58 and into the mandrel 56, from where it may now through the lower pump plunger 50 and into the working barrel B above sa-id plunger. From the working barrel the fluid may pass into the passage B' and then to the pipe section |4, as has been explained.

A portion of the fluid which ilows upwardly piston 58, when the ball 62 is unseated, passes outwardly through radial ports 63 which are located in the swaged nipple 51 (Figure 7). The nipple is below the mandrel 56 and the fluid owing through the ports 63 enters the pipe section I6 above the piston 58, This fluid iiows upwardly through the pipe |6 around the working barrel B and enters the passage A' within the coupling sleeve |5, from where it passes into the upper working barrel A and then is lifted into the tubing.

During the upper stroke of the piston 58, the valve 62 is closed as will be explained, and fluid from below the piston connot ow upwardly through the bore 58 thereof. When the piston reaches the top of its stroke, the fluid 4thereabove has been lifted and .to equalize the pressure above and below the piston 58, radial by-pa-ss openings or

ports

12 and 13 are provided in the wall of the pipe. The openings are spaced suiliciently far apart so that the packing rings 59 of the piston 58 are located therebetween when the .top of the piston stroke is reached. The upstroke of the piston is limited by the nipple 51 striking the lower end of the working barrel B, and this stop assures the piston halting in position with the packing rings between the

openings

12 and 13, as clearly shown in Figure 4.

When the packing rings 59 move between the

openings

12 and 13, the iluid from below the piston flows through the lower openings 12 andinto an'annular manifold 14 which is secured to the exterior of the pipe section I6. From .the manifold, the fluid ilows through the ports 13 and into the pipe I6 above the piston 58. As soon as the piston starts its downward movement the packing rings 58 cover -the ports 12 and further ilow therethrough is prevented. Upon the start of the downstroke of the piston, the ball 62 is unseated, as will be explained, and the uid from below the piston flows upwardly through the bore 58 thereof and then through the portsv 68 ln the swaged nipple 51, as well as upwardly into the mandrel 56.

In operation, assuming the plungers 30 and 50, as well as the ,piston 58 to bein their lowered positions, it will be obvious that the stem 66 has been engaged by the bottom of the cup '68 and the head 65 of said stem has been moved upwardly by the .tension of the spring 1|, whereby' the ball 82 is held in engagement with its seat time,

whereby the ball sn to close the bore of .the piston 5t. .mula is as well asin 4the working barrels A and B, this iluid having entered these parts upon the previous operation. As the pump rods 3| raise the upper plunger 30, the lluid `in the working barrely A above said a suction is created below the plunger, 25 of the standing valve 23 at the lower end of the upper working .barrel A is lifted from its seat. This permits the iluid to be drawn from the passage A' and from .the interior of the pipe section I6 above the piston 58. The weight of the iuid column within the well casing I0 or the bottom hole pressure of the well is acting upwardlyA against the lower end of Ithe piston 58 and this -well pressure is more or less constant. When the plunger' 30 is raised by the pump rods 3| to draw liquid from the pipe section I8 above the piston 58, the pressure of the fluid above said piston is reduced. This reduction in fluid pressureabove the piston 58 permits the bottom hole or well pressure to act upwardly against the piston to lift said piston same upwardly in the pipe section I6. As soon as the piston is moved suillciently to disengage the stem 66 from the cup 68, the head 65 falls away from the ball 62. However, since the pressure below the piston 58 is greater than the pressure thereabove, this greater pressure acts through the valvel cage 6| against the ball '62 to hold the same in its seated position upon upward movementof the piston.

Upward movement of the 'piston 58 by the well pressure causes an upward movement of the lower pump plunger 50, whereby the liquid above the pump plunger 50 within the working barrel B is raised. This upwardly moving iluid unseats the valve 42 and permits the fluid to flow through the passage B and into the interior of the upper pipe section |4. From the pipe section I4, the iluid travel-s past the upper end of the working barrel A and enters the ytubing |2. Of course, the uid lifted by the upper plunger 381s raised directly into the tubing |2.

With such arrangement, upon the upward movement of the plunger 30 by the pump rod, the lower pump plunger 50 is also actuated and therefore an increased amount of fluid is lifted due to the double plunger. The piston 58 continues its upward movement ple 51 at its upper end strikes the lower end of the lower working barrel B, at which time the upward movement of said piston and the plunger 50 attached thereto, is halted. In such position, the packing rings 59 on the exterior of the piston 58 have moved into a position between the by-

pass openings

12 and 13. This permits the well fluid below the piston to pass upwardly through the annular space between the piston and the wall of the pipe section I6, whereby such fluid may iiow through the openings 12 intothe manifold From the manifold the well`fluid passes through the openings 13 and into the pipe section I6 above the piston 58. The fluid in this portion of the pipe I6 may flow through the ports 63 in the swaged nipple so as to enter the bore 58' of the piston 58 above the' valve 62. Thus, it will each side of the piston to become equalized and plunger is lifted. At the same or move the f until the swaged nipas soon as such equalization occurs, the piston begins its downward movement due to the weight of the piston and the plunger 50 attached thereto. At the same time that the pressure across 1 the piston 58 is equalized the pressure on each side of. the ball valve 52 is also equalized, whereby said valve may fall by gravity, to its unseated position. y

` It is pointed out that at the time' that the lower piston 58 begins its downwardmovernent, the

upper pump plunger 30 has completed its upf stroke and is also beginning its downward 'movement through the medium of the pump rods 3|. This is true because the pressure above the piston 58 cannot equalize until the upper plunger 30 has vstopped drawing fluid from the pipe section i8 above the piston. As the piston 58 moves downstroke, unless the flow of the fluid is suflicient toovercome the back pressure of the column of fluid within the sleeve 82. A similar passage B2 which communicates with the lower working barrel Bl vand also with the interior of the upper section 88 is V also formed within the coupling 82. An upper pump plunger`83 is secured to the pump rods ll and is movable within the upper working barrel Al'. A lower pump plunger 84 is slidable within the lower working barrel `B| and is connected with the upper' pump plunger by a connecting ends of the sleeve are formed with relief openings above the valve 42. A `portion of the uid which is flowing through the bore 58 of the piston, upon the downstroke of said piston, passees through the ports 63 in the swaged nipple 51 and enters the interior of the pipe section I8 above said piston. During the downstroke fluid from the pipe IB will enter the passage A', from which it will be drawn upon the next succeeding operation. At the same time that the well fluid is bel ing introduced into the passages A and barrel B,

as explained,` the upper plunger is moving downwardly within its working barrel A and the fluid which has been drawn into said working barrel upon the upstroke of said plunger, moves upwardly through the plunger and unseats the traveling valve 35, whereby said fluid flows into the upper end of the working barrel A and then into the'tubing l2.

As soon as the piston 58 reaches the lower end of its strokey the stem B6 strikes the springpressed cup 68, whereby the head 65 is moved upwardly to raise the ball 62 into contact with its seat 60 to close the bore of the piston 58. The parts remain in this position until1 the upper plunger 30 is again moved upwardly by the pump rods 3|. Such upward movement of the plunger 30 reduces the pressure above the piston 58, as has been explained, thereby permitting the well fluid acting against the bottom of said piston to move the same upwardly to perform the next succeeding operation. With such arrangement, the upper pump plunger 30 is actuated in the usual manner by the pump rod, while the lower pump plunger 50 is actuated by means of the piston 58 which, in turn, is operated by the pressure of the well fluid. It will be evident that a greater amount of fluid may be lifted to the surface upon each operation of the plungers as both plungers are acting to lift fluid to the surface.

In Figure 8, a modified form of the invention is shown, wherein an upper pipe section 80 and a lower pipe section 8l connected by a coupling .sleeve 82 is provided. An upper working barrel Al is located within the upper section 80 while a lowerA working barrel Bl is' mounted within the lower section 8l. A passage A2 which communicates with the upper working barrel AI and also with the interior of the lower section Il is formed '8511, whereby any fluid which may enter the sleeve 1s forced therefrom by the head and sliding of A the head within the sleeve will not be interfered with. The rod and sleeve form a connection between the

pump plungers

83 and 84 and this connectionv is such that the upper plunger has a longer stroke than the lower plunger. As is` clearly shown in Figure 8, initial upward movement of the upper plunger does not impart a movement to the lower plunger as the head 85a of the connecting rod 85 slides through the sleeve 85. When said head strikes the closed top of the sleeve, continued upward movement of the upper plunger imparts a similar upward movement to the lower plunger. From this point to the top of. the stroke the plungers move simultaneously. With the telescoping arrangement between the rod and sleeve, the Yupper plunger has a longer stroke than the lower plunger and the difference in such strokes is controlled by the length of the sleeves.

In order to'permit the well pressure to aid in operating the lower plunger 84, a piston 86 is preferably made integral with the lower end of said lower plunger. The valve cage 6l and ball 62 are mounted on the lower end of the piston 86 and are adapted to close the bore 84' of the lower plunger 84. The head 65, having the depending stexn 66, is mounted in the cage 6I and is adapted to engage a ring 8l which ls secured to a spring 88. The ring is substituted for the cup 88 in the first form and operates in the same manner. A spider 88 is mounted at the lower end of the pipe section 8l and has a ball check valve mounted therein. This valve is adapted to engage a seat 9| in the spider 89 and acts to prevent a downward ow from the pipe 8l, while permitting an upward flow thereby.

The operation of this form is somewhat similar to the rst form with the exception that the lower plunger is moved with the upper plunger after the connecting rod head a has engaged the top of the sleeve, being aided in its movement by the well pressure. Assuming the plungers to be in their lowered positions, it will be seen that the ball 62 is closed or seated, being held so by the head 65 which has its stem 86 engaged` by the ring. 81. move upwardly to raise the upper plunger Il, fluid is drawn from the pipe 8l into the passage A2. As soon as the connecting rod head 85a engages the sleeve 85', the lower plunger 84 is raised. Since the piston 88 is a part of the lower plunger 84, said piston-moves upwardly therewith and as it does so', the bal180 is lifted from its seat, whereby the well fluid may enter the pipe section-8l below the piston 88. This pressure acts against said piston to aid in lifting the same. The well fluid is also acting against As the pump rods When the

plungers

83 and 84 reach the upper end of their stroke, the weight of the fluid within the pipe section 8| above the ball 90 acts downwardly against said ball and causes the same to drop to its seated position. At the same time, the pressure of the liquid column within the pipe section above the piston 88acts downwardly through ports 82 in the plunger 84 and forces the ball 62 to its unseat'ed position. As the plungers are moved downwardly, the well fluid which has` entered the lower end of the pipe section 8| flows upwardly through the bore 84' and unseats the traveling valve of the lower plunger 84. From this point the uid flows into the passage B2 and upwardly into the upper section 80. A `portion of 4the i'luid flowing through the bore- 84' of the lower pump plunger 84 passes outwardly through the ports 92 and enters the interior of the pipe section 8| above the piston 86, from which point it flows into the passage A2. Upon the next succeeding operation of the

plungers

83 and 84, this ilud is lifted.

In many instances, it is desirable to run the well tubing, having the working barrels attached to its lower end, into the well prior to the running of the pump rods 3|. This is advantageous because it is difcult to run the tubing and rods simultaneously.. In order to run the tubing and working barrels, as shown in Figure 8 into the well, before the pump rods 3| are connected to the upper plunger 83, the working barrels and

pipe sections

80 and 8| are i'lrst assembled. with the

pump plungers

83 and 84 within their respective working barrels. The rods 3| are not connected with the upper plunger at this time.

the upper portion of the passage A2.

After the tubing and working barrel assembly has been run into the well, the rods 3| may then be lowered through the tubing. The lower end of the lowermost rod has the usual threaded socket 3|l` which is adapted to receive the upwardly extending pin 83A on the top of the upper plunger 83. This socket is'engaged with the pin and the rods 3| rotated, whereby the pin is screwed into said socket. The plunger 83 and the pin thereon is held against rotation by the engagement of one of the slots 83 with the lug 92' and obviously, the rods 3| may be readily connected to the upper plunger after the tubing and plunger assembly has been lowered into the well. nected from the plunger and removed at any time without disturbing the plunger and working barrel assembly. Thus, the rods 3| and tubing |2 may be run into the well individually.

Since the pump plungers having the traveling valvesitherein may become worn or for other reasons may necessitate removal from their working barrels, it is desirable that said plungers be removable without disturbing the working barrels and tubing. In Figure 9, a modified form of the invention. wherein the plungers are readily Similarly, the rods may be d'Lscon:`-

removable and replaceable within their respective working barrels, is shown..

lateral portion of the partition is formed with-v a threaded opening |05 which ls adapted to re' ceive a packing element |06, as will be explained.; An upperv working barrel A4 extends upwardlyv from the coupling |02 while a lower working barrel B4 has its upper end secured in said coupling, whereby said lower workingbarrel extends axially through the pipesection |0I. It is pointed out that the diameter of @the lower working barrel is less than the diameter of the upper barrel and both barrels are axially alined with the opening |05 in the lateral portion of the partition |04. l The pipe sections |00 and IOI, 'together with the couplings |02 and workingv barrels A4 and B4 are assembled and loweredl with the tubing I2. At the surface anA upper plunger |01 and a lower plunger |08 are connected together by a connecting rod |09. The packing' element |061- surrounds the rod between the plungers and this element includes a body portion |06 havingits external surface threaded. A cap |^|0 on the packing element confines the packing material around the rod |09 and this cap is formed with a transverse groove in its top, said groove being in cross-section. The depending socket |01' which is provided on the lower end of the plunger |01 and which receives the connecting rod |09, is also angular in cross-section and is adapted to engage the groove as shown in` Figure 9. y

After the tubing and working barrel assembly has been lowered into the well, the double plun-A ger assembly is connected to the pump rods 3| and is lowered through the tubing |2. The low-l er plunger |08 passes downwardly through thev upper -barrel A4, through the opening |05 in the partition |04 and into the lower working barrel B4. The packing element |06 engages the open ilar to the plungers 83 and84 of Figure 8 to lift the well fluid to the surface except 'the valve 82 and piston 86 are omitted.

When it is desired to remove the plungers |0`|v and |08 and the packing element |06, the pump rods 3| and plungers are raised until an angular socket |09' on the lower end of the rod |09 engages within an angular recess ||2 formed'in the lower end of the body |08 of the packing element |06. Rotation of the rods 3| and plungers will ycause the packing element to be unscrewed from the opening |05, after which the plungers may be withdrawn from the working barrels and well tubing.

What I claim and desire to secure'by Letters Patent is:

l. A pumping apparatus including, a well tubing, a conductor adapted to be connected in the 6 well tubing string and having a pair of duid passages therein, anv upper working barrel having communication with one of the passages, a pump plunger operable from the surface of the Well movable within said barrel for lifting the fluid from the passage communicating therewith, a lower working barrel communicating with the second passage, a lower pump plunger reciprocable within the lower working barrel for lifting the fluid in the second passage, and a slidable piston connected with the lower plunger for operating the same and having its upper end exposed to the fluid pressure in the first passage which communicates with the upper barrel and having its lower end exposed to the pressure of the well fluid in the well bore, whereby the piston and lower plunger are operated by the pressure differential across the piston.

2. A pumping apparatus including, a well tubing, a conductor adapted to be connected in the well tubing string and having a pair of fluid passages therein, an upper working barrel having communication with one of the passages, a pump plunger operable from the surface. of the well movable within said barrel for lifting the fluid from the passage communicating therewith, a lower working barrel communicating with the second passage, a lower pump plunger reciprocable within the lower working barrel for lifting the fluid in the second passage, a slidable piston connected with the lower plunger for operating the same and having its upper end exposed to the fluid pressure in the first passage which communicates with the upper barrel, and having its lower end exposed-to the pressure of the well fluid in the well bore, whereby the piston and lower plunger are operated by the'pressure differential across the piston, said lower plunger having a bore therethrough which communicates with the fluid passages, and means controlling the flow through said bore and arranged to per mit a flow through the bore on the downstroke of the plunger and for closing said bore upon the upstroke thereof 3. A pumping apparatus including, a well tubing, a conductor adapted to be connected in the well tubing string and having a pair of fluid passages' therein, an upper working barrel having communication with one of the passages, a pump plunger operable from the surface of the well movable within said barrel for lifting the fluid from the passage communicating therewith, a lower working barrel communicating with the second passage, a lower pump plunger reciprocable within the lower working barrel for lifting the fluid in the second passage, a slidable piston connected with the lower plunger for operating the same and having its upper end exposed to the fluid pressure in the first passage which communicates with the upper barrel and having its lower end exposed to the pressure of the well fluid in the well bore, whereby the piston and lower plunger are operated by the pressure difmovable within said barrel for lifting the fluid from the passage communicating therewith, a lower working barrel communicating with the second passage, a lower pump plunger reciprocable within the lower working barrel for lifting the fluid in the second passage, means for connecting the plungers together so thatthey move simultaneously, and a piston connected with the lower plunger and exposed to the pressure of the well fluid in the bore, whereby said well fluid pressure aids in lifting the plungers on the upstroke.

5. A pumping apparatus including, a well tubing, a conductor adapted to be connected in the well tubing and having a pair of fluid passages therein, an upper working barrel having communication with one of the passages, a lower working barrel communicating with the second passage, a plunger adapted to reciprocate in each working barrel, a telescoping connection between the plungers whereby one plunger has a longer stroke than the other, and means for reciprocating the piungers from the surface of the well to raise the well fluid.

ferential across the piston, said piston having a bore communicating with the fluid passages,

a valve at the lower end of the piston actuated by the pressure differential thereacross, and means for positively closing said valve when the piston is at the end of its downstroke.

4. A pumping apparatus including, a well tubing. a conductor adapted to be connected in the well tubing string and having a pair of fluid passages therein, an upper; working barrel having communication with one of the passages. a pump plunger operable from the surface of the well 6. A pumping apparatus including, a well tubing, a conductor adapted to be connected in the well tubing and having a pair of fluid passages therein, an upper working barrel having communication with one of the passages, a lower working barrel communicating with the second passage, a plunger adapted to reciprocate in each working barrel, a telescoping connection between the plungers whereby one plunger has a longer stroke than the other, and pump rods adapted to be lowered through the tubing and arranged tobe connected'to the upper plunger for operating said plungers.

'7. A pumping apparatus including, a well tubing, a fluid conductor adapted to be'connected in the tubing string and having a well fluid inlet and also having a, pair of communicating fluid passages therein, each passage communicating with the well fluid inlet, an upper cylinder communicating with one of the passages, an upper pump plunger movable within the cylinder and operable from the well surface for lifting the fluid from the passage communicating therewith, a lower cylinder communicating with the second passage, and a lower pump plunger movable within the lower cylinder for lifting the fluid in the second passage, the lower plunger having its upper end exposed to the fluid pressure within the passages and its lower end exposed to the well fluid pressure, whereby said plunger is operable by the differential in pressures above and below the plunger.

8. A pumping apparatus including, a well tubing, a fluid conductor adapted to be connected in the well tubing string and having a well fluid inlet and also having a pair of fluid passages therein, each passage communicating with the well fluid inlet, an upper cylinder communicating with one of the passages, an upper pump plunger movable within the cylinder and operable from the well surface for lifting the fluid from the passage communicating therewith, a lower cylinder communicating with the second passage, a lower pump plunger movable within the lower cylinder for lifting the fluid in the second passage, the lower plunger having its u-pper end exposed to the fluid pressure within the passages and its lower end exposed '-to the well fluid pressure so as to be operable by the differential in pressures thereabove and therebelow, and .means for reducing the pressure above the lower plunger when the upper plunger begins its upward movement, whereby the well pressure below said lower plunger acts to raise the lower plunger simultaneously with the upper plunger.

9. A pumping apparatus including, a well tubing, a fluid conductor adapted to be connected in the well tubing string and having a well fluid inlet and also having a pair of fluid passages therein, each passage communicating with `the Well fluid inlet, an upper cylinder communicating with one of the passages, an upper pump plunger movable within the cylinder and operable from the well surface for lifting the fluid from the passage communicating therewith, a lower cylinder communicating with the second passage, a lower pump plunger movable within the lower cylinder for lifting the fluid in the second passage, the lower plunger having its upper end` exposed to the fluid pressure within the passages and-its lower end exposed to the well fluid pressure so as to be operable by the differential in pressures thereabove and therebelow, means for reducing the pressure above the lower plunger when the upper plunger begins its upward movement, whereby the well pressure below said lower plunger acts to raise the lower plunger simultaneously with the upper plunger, and means for equalizing the pressures above and below the lower plunger when the upstroke is completed, whereby the weight of said plunger will return the same to its lower position.

10. Apumping apparatus including, a well tubing, a fluid conductor adapted to be connected in the tubing string and having a well fluid inlet and also having a pair of communicating fluid passages therein, each passage communicating with the well fluid inlet, an upper cylinder communicating with one of the passages, an upper pump plunger movable within the cylinder and operable from the well surface for lifting the fluid from the passage communicating therewith, a lower cylinder communicating with the second passage, a lower pump plunger movable within the lower cylinder for lifting the fluid in the second passage, the lower plunger having its upper end exposed to the fluid premure within the passages and its lower end exposed to the well fluid pressure, whereby said plunger is operable by the differential in pressure on opposite sides thereof,

the lower plunger having a bore therethrough which communicates with the fluid passages, and means controlling the flow through the bore and arranged to permit a flow through said bore on the downstroke of the plunger and for closing the bore upon the upstroke thereof.

ll. A pumping `apparatus including, a well tubing, a fluid conductor adapted to be connected in the tubing string and having a well uid passages, and means actuated by the differential in pressures thereabove and therebelow for controlling the flow through the bore.

12. A pumping apparatus including, a Well tubing, a fluid conductor adapted to be connected in the well tubing string and having a well iluid inlet and also having a pair of fluid passages inlet and also having a pair of communicating fluid passages therein, each passage communicating with the well fluid inlet, an upper cylinder communicating with one of the passages, an upper pump plunger movable within the cylinder and operable from the well surface for lifting'r the uid from the passage communicating therewith, a lower cylinder communicating with the second passage, a lower pump plunger movable therein, each passage communicating with the well fluid inlet, an upper cylinder communicating with one of the passages, an upper pump plunger movable within the cylinder and operable from the well surface for lifting the fluid from the passage communicating therewith, a lower linder communicating with the second passage, the lower ylinder for lifting the fluid in the second pass e, the lower plunger having its upper end expo d to the fluid pressure withinthe passages and ts lower end exposed to the well fluid pressure so as to be operable by the differential in pressures thereabove `and, therebelow, said lower plunger having a bore therethrough which communicates with the fluid passages, a valve actuated by the pressure differential thereacross for controlling the flow through the bore, and means for reducing the pressure above the lower plunger and valve when the upper plunger begins its upward movement, whereby the well pressure below the 'lower plunger may act against the valve to close the same and also whereby said pressure` mayact against the lower end of the plunger to lift the same.

13. A pumping apparatus including, a well tubing, a fluid conductor adapted to be connected in the well tubing string and having a well fluid inlet and also having a pair of fluid passages therein, each passage communicating with the well fluid inlet, an upper cylinder communicating with one of the passagesyan upper pump plunger movable within the cylinder and operable from the well surface for lifting the fluid from the passage communicating therewith, a lower cylinder communicating with the second passage, a lower pump plunger movable within the lower cylinder for lifting the fluid in the second passage, the lower plunger having its upper end exposed to the fluid pressure within the passages and its lower end exposed to the wellfluid pressure so as ,to be operable by the differential in pressures thereabove and therebelow, said lower plunger having a bore therethrough which communicates with the fluid passages, a valve actuated by the pressure differential thereacross for controlling the flow through the bore", means for reducing the pressure above the lower plunger and valve when the upper plunger begins its upward movement, whereby the well pressure below the lower plunger may act against the valve to close the same and also whereby said pressure may act against the lower end of the plunger to lift the same, and means for equalizing the pressures across the Valve and lower plunger when the upstroke is completed, whereby the valve may fall to an open position and said plunger may move downwardly by gravity, the opening of said valve permitting fluid to flow through the bore of the plunger upon the downstrolre 'of said plunger.

14. A pumping apparatus including, a well tubing. a fluid conductor adapted to be connected in the well tubing string and having a well fluid inlet and also having a pair of iluld passages therein, each passage communicating with the well fluid inlet, an upper cylinder communicating with one of the passages, an upper pump plunger lower pump plunger movable within movable within the cylinder and operable from the well surface for lifting the fluid from the passage communicating therewith, a lower cylinder communicating with the second passage, a lower pump plunger movable within the lower cylinder for lifting in the second passage, the lower plunger having its upper end exposed to the fluid pressure within the passages and its lower end exposed to the well uid pressure so as to be operable by the differential in pressures thereabove and therebelow, said lower plunger having a bore therethrough which communicates with the fluid passages, a valve actuated bythe pressure differential thereacross for controlling the flow through the bore, means for reducing the pressure above the lower plunger and valve when the upper plunger beginsiits upward movement, whereby the well pressure below thelower plunger may act against the valve to close the same and also whereby said pressure may act l against the lower end of the plunger to lift the same, means for equalizing the pressures'across the valve and lower plunger when the upstroke is completed, whereby the valve may fall to an open position and said plunger may move downwardly by gravity, the opening of said valve permltting fluid to flow through the bore of the plunger uponlthe downstroke of said plunger,

and means for closing the valve whenth'e down-l stroke of the lower plunger is completed.

15. A pumping apparatus including, awell tubing, a conductoradapted to be connected in the well tubing string and having a pair of fluid'passages therein, an upper Working barrel having communication with one of the passages, .a pump plunger operable from the surface of the well movable within said barrel for lifting the fluid` municates with the upper barrel and having its lower end exposed to the pressure of the well fluid in the well bore, whereby the piston and lower plunger are operated by the pressure difier-` ential across the piston,.said piston having a bore communicating with the uid passages, and a valve at the lower end of the piston actuated by the pressure differentialfthereacross for closingl the bore of said piston on the upstroke thereof and arranged to permit a flow through said bore on the downstroke.

OTTO STAERKER.