US1922264A - Rodless pump - Google Patents

Description

Aug. 15, 1933. .1. M. sHlMER 1,922,264

RODLESS PUMP Filed Oct. l5, 1931 3 Sheets-Sheet l INVENTOR J. M. SHIMER RODLESS PUMP Aug. 15, 1933.

Filed Oct. l5, 1931 -5 Sheets-Sheet 2 44' Aug- 15, 1933- J. M. sHlMl-:R 1,922,264

RODLESS PUMP Filed Oct. l5, 1951 3 Sheets-Sheet 3 @L wm Patented Aug. 15, 1933 UNITED STATES PATENT oI-Frcs s claims. (el. 10s- 46) This inventiony relates to an improved method of operating a liquid lifting pump for elevating 4liquid from a source deep within a well; and further -to improved pumping apparatus for elevat- 5 ing liquid in a well, the-pumping apparatus being of the type which is actuated by a column of liquid. More particularly, apparatus embodying my invention may, in the form which I at present prefer, comprise a displacement pump in the well and a reciprocating pump at the surface, the two being connected by a column of actuating liquid.

Due to the extreme depth to which wells are being drilled for the production of oil. the sucker rod method is no longer satisfactory, and other methods of elevating oil 'from these wells are being sought. My improved method of pumping makes it possible to elevate oil with high eiliciency from these deep wells. The pumping is 0 carried on in accordance with my invention by means of a liquid lifting pump at a low level in the well and actuating means at the surface, the actuating means being connected to the pump by a column of actuating liquid.

In accordance with my invention, a liquid lifting pump is disposed deep within a well where a source of the desired liquid is to be found. This pump is connected to the surfaceby an actuating liquid line or column of actuating liquid; and in order to obtain high efiiciency in pumping, this column of liquid is balanced by a second column of liquid. The liquid is pumped from the source by the application of pressure to the actuating column of fluid into a lreservoir 5 chamber and is thereafter introduced into and and at the same time, a corresponding volume of liquid is discharged from .the actuating liquidy column at the'surface.

In accordance with my invention, the liquid is discharged from the system in timed relation with the cycle of the actuating means. The preferred method of actuating the liquid lifting pump disposed within the well is to reciprocate the column of actuating liquid. This, I prefer to do by" apparatus of the cylinder and piston type; and the discharge of liquid from the column of actuating iiuid at the surface may be controlled V-by a valve which is opened and closed in timed relation with the reciprocations of the piston.

In coordinating the variousparts of my imvproved pumping'system,` I have developed certain 'features `which render the operation of the 515 system more uniform and ellicient. The pumping system is primed and the inevitable losses of liquid through leakage, etc. are replaced automatically from a filler tank. The stroke of the displacement plunger is cushioned so that the momentum of the long and heavy column of liquid shall not cause damage to the displacement appa- V ratus. The arrangement of parts in my improved construction provides compact and inexpensive apparatus for elevating oil from these great depths.

In the accompanying drawings, in which -I have illustrated schematically one form which my invention may take: y C

Figure 1`is a central vertical section through apparatus of the displacement type constructed in accordance with the principles of myinvention, a reciprocating pump also shown in central vertical section being connected with the displacement apparatus;

Figure 2 is a similar sectional view showing the position of the parts of the apparatus on the discharge stroke;

Figure 3 is a detail view showing in central vertical section the displacement chamber and the discharge passages therefrom;

Figure 4 is a view illustrating the use of a twin cylinder reciprocating pump for actuating pumping apparatus of the type shown in Figs. 1, 2 and 3; and

Figure 5 is a plan view illustrating diagrammatically the connections whereby a central actuating means may be connected to a plurality of wells.

When a pump is disposed close enough to the surface of the ground so that the pump plunger,

piston or the like may be positively connected toI `a prime mover such as a steam engine, pumping may be carried on in the usual well known manner. When, however, the pump is disposed deep within a well, the positive connection entails high losses through friction, as for instance, with a long string of sucker rods. As has 'been above mentioned, wells are becoming increasingly deep; and my improved method of pumping takes advantage of a column of actuating liquid as a substitute for the positive connection between the pump. disposed within the well and the source of power at the surface.

In order to actuate the pump in the well, I provide mechanism for pushing or, in other suitable fashion, applying pressure to the column of actuating liquid, so that the same moves downwardly to actuate the pumping apparatus. This column of actuating liquid may attain so great a length, that actuation of the pump cannot be carried on efliciently without a suitable arrangement for again liftingvthis column of actuating liquid. In accordance Awith my improved method drawn,` the counter-balancing column moves downwardly and pushes the actuating column upwardly. By thus alternately pushing the actuating column downwardly, and causing the same to again move upwardly due to the counterbalancing column, I am able to elevate liquid from a source deep within a well. I prefer to add the pumped liquid to the actuating column of liquid, each downward movement of the actuating column causing a new increment to be pumped from the source. As these increments are added to the column of actuating liquid, corresponding quantities are discharged from the actuating column at the surface.

Inasmuch as the column is intermittently subjected to pressure so as to force the same downwardly in the well, a discharge valve opening automatically in response to increases in pressure is not suitable; and, instead, I employ a discharge valve which is timed so as to synchronize with the cycle of the power means at the surface. Accordingly, this valve is closed while the column of actuating fluid is being pushed down the well, and opens for the discharge of liquid while this column is again rising in the well.

The process, as thus described, is not dependent upon particular apparatusfor carrying it out. The walls defining the actuating column and the counter-balancing column may be, in part, the surrounding walls of the well, or may be separate conduits. Moreover, the type of pump which is disposed in the well may assume various forms.

However, in accordance with anotheraspect of my invention, I have provided improved pumping apparatus for thus elevating liquid from a source deep within a well. When the well is drilled, the walls are usually lined with casing; and my improved apparatus is adapted to be used in connection with the casing thus placed in the well.

In Figure 1, the well has been lined with casing 5 extending from the derrick floor 6 to a point well below the level of the oil in the well. Within the casing 5 is disposed a string of tubing 7 having its upper end secured in slips 8.. The upper end of the casing 5 is sealed off by a casing head 9, having an outwardly beveled opening at its upper end. The slips 8 are disposed within the opening and carry at least a portion of the weight of the string of tubing 7.

At the bottom of Figure 1, there is shown a packer 10, carried by the string of tubing 7. This packer need not be at the very bottom of the well, but may be positioned at such a point in the casing 5 as to protect the producing sand. from back pressure. It is quite customary to support the packer on a perforated pipe or anchor pipe; but this anchor pipe has been omitted in the drawings, as the structure below the packer is not of importance in connection with the present invention.

Just above the packer 10 is disposed pumping apparatus. This apparatus operates to lift liquid, such as oil, from the source below the packer 10 in the well to the surface. As a preferred embodiment, I have shown displacement pumping apparatus. The pumping apparatus is connected to the string of tubing 7 by a nipple 11. To the nipple 11 is connected a length of' tubing 12, per- Iorated at 13. To the lower end of the length of tubing 12 is connected a cylindrical member 14 which, in the pumping apparatus, constitutes the displacement chamber. The upper end of the cylindrical member 14 provides a shoulder on which rests the head 16 of a servo-motor, which servo-motor includes a liner 17 within the tubing 12, this liner constituting the piston chamber of the servo-motor. In the embodiment shown, the head 16 and the liner 17 arc formed integrally. Perforations are formed in the liner 17 registering with the perforations 13; and free communication is thus afforded between the piston chamber and the annular space surrounding the length of tubing 12.

The `displacement chamber is placed in communication with the annular space surrounding the length of tubing 12 by check valve-controlled passageways for the discharge of fluid from the displacement chamber. In Figure l, these passageways are marked 18 and extend through the head 16 to the lower portion of the piston chamber. Because of this arrangement, only one set of perforations, namely, the perforations 13, is required for placing both the piston chamber and the displacement chamber in communication with the space surrounding the length of tubing 12. In the construction illustrated in the drawings, the passages 18 are controlled by a check valve in the form of a flexible dish-shaped valve 20. This valve is shown in open position in Figure 2.

Between the upper end of the liner 17 and the nipple 11 is an abutment member 21, having an axial opening through the same surrounded on the lower side by a raised hub 22. A coiled spring 23 is lodged in the annular recess thus afforded. and provides a cushion for the upward stroke of the piston 24, which is reciprocable within the piston chamber. A plunger 25 extends through the head 16 into the displacement chamber and is actuated by the piston 24. In the embodiment shown, the plunger 25 is formed integrally with the piston 24. The downward stroke of the plunger 25 and piston 24 is cushioned by a coiled spring 27, lodged in a recess in a cap member 28 for the inlet valve 29 of the displacement pumping mechanism.

This valve 29 is disposed between the cylindrical member 14 and the packer l0. As illustrated, this valve is a check valve and comprises a casing 30, formed with a valve chamber which communicates with the displacement chamber by way of passages 31 through the cap member 28. The valve proper 32 is adapted to lift off its seat to permit upward flow of oil or other fluid through the packer 10, but seats again by force of gravity when upward flow stops so as to prevent return of the uid. In the embodiment shown, the seat 33 is formed as a separate member and is renewable. Upward movement of the valve proper 32 is limited by transverse pin 34.

It is apparent, therefore, that as the piston 24 reciprocates, the plunger 25 is moved intovand out of the displacement chamber. As the plunger 25 moves out of the displacement chamber, the valve 20 seats and the valve 32 lifts, oil being drawn up through the packer into the displacement chamber. As the plunger 25 descends. the valve 32 seats, and the fluid in the displacement chamber is forced upwardly by way of the passageways 18, the lower portion of the piston chamber, and out through the perforations 13 into the annular space surrounding the length of tubing 12. The travel of the piston 24 in both directions is cushioned, the upward stroke being cushioned by the spring 28 and the downward stroke by the spring 27.

This displacement pumping mechanism being positioned at a depth in the well too great for proper actuation by a sucker rod, a column of liquid is employed for reciprocating the piston 24 conduit 41 as the volume which enters the piston chamber below the piston 24 to lift the same through the proper stroke. Inasmuch as .the liquid which passes out at the top of the tubing 7 from the balancing column is to be received into the front end of the cylinder 43, it is desirable that the volume of liquid entering the front end of the reciprocating pump be equal to the volume of liquid dischargingfrom the piston chamber above the piston 24 during the upward stroke of the latter. The ldifference between the volume entering the piston chamber below the piston 24 to lift the same and the volume passing out of the piston chamber above the piston 24 is equal to the volume to be discharged from the pumping apparatus.

As a convenient way in which precisely such difference may be established on the two sides of the piston 57, I choose a piston rod of such diameter that the volume occupied by the piston rod bears the same relation to the cylinder 43 of the reciprocating pump that the plunger 25 bears to the liner 17 forming the piston chamber of the liquid lifting pump. If we designate the area of the front end of the piston 57 by the letter a and the cross-section of the piston rod by the letter b, and designate the effective area of the rear end of the piston rod 57 by the letter c, then a minus b is equal to c. If we designate the length of the reciprocating pumps stroke by the letter d, then aXd: (C-l-b) Xd.

If we designate the area of the top of the piston 24 by the letter e and the cross-section of the plunger 25 by the letter f, then the effective area of the lower side of the piston 24, which I Will designate by the letter g, is equal to e minus f. If the length of the stroke of the piston 24 and plunger 25 be designated by the letter h, then It will be apparent that as the cross-section of the plunger 25 is decreased, the effective area of the lower face of the piston 24 approaches more nearly the area of the top of the piston 24; and.

accordingly, the reciprocating pump is not called upon to exert so great pressure as is the case when the area of the cross-section ,of the plunger 25 is larger.y On the other hand, the volume of liquid pumped is directly proportional to the cross-section of the plunger 25, given the same length of stroke. Accordingly, when the well is so deep that a considerable difference between the area of the top of the piston 24 and the effective area of the bottom of the piston 24 will require that great pressure be developed by the reciprocating pump, the cross-section of plunger 25 may be made relatively small. It should be noted, on the other hand, that the length of the stroke of the plunger 25 may be large, and, in fact, many times the length of the stroke of the reciprocating pump. As a result, the cross-section of the plunger 25 may be quite small and the length of stroke correspondingly large, thus reducing the requisite pressure which must be developed by the reciprocating pump. As it is often convenient to deliver a relatively large volume of liquid under medium high pressure from the reciprocating pump, it

will be apparent that it is convenient to thus design the plunger 25 with a long stroke and a small cross-section.

As has been above explained, the volume of fluid discharged from the rear end of the piston 57 should be substantially the same as the volume of liquid entering the perforations 13 to lift the piston 24. Should there be an excess of liquid between the rear end of the piston 57 and the bottom face of the piston 24, excessive pressure might be developed when the piston 24 has compressed the spring 23 against the abutment member 21. This excessive pressure will be relieved by the valve 41 as above described. In the same way, the downward stroke of the piston 24 is limited by engagement of the plunger 25 with the spring 27; and if excessive pressure should be developed within the tubing 7, this excessive pressure will be relieved by the relief valve 44. In actual practice, there will probably be some liquid lost through valves 20 and 32 during the reversal of the pump stroke, as valve 32 must seat completely before liquid can be elevated in the outer column between the casing 5 and the tubing 7. This loss may be taken care of by making the piston rod ofthe piston 57 slightly smaller in diameter than in theory would be required. Just how large this loss will be can be easily determined by experiment.

As has been brought out in the above description, the column of actuating fluid is forced down the well, and the counterbalancing column is mainly relied upon for bringing the column of actuating fluid back up the well. Accordingly, the piston of the power means carries its principal load on the stroke toward the crank shaft. In Fig. 4, I have shown an arrangement in which a crank shaft is formed with cranks 66 and 67 arranged 180 apart. Accordingly, when one piston 68 is being moved inwardly, the other piston 69 is being moved outwardly. This balances the power requirements on the crank shaft 65. 'Ihe piston 68 may actuate a liquid-lifting pump in the well 70, and the piston 69 may actuate a liquidlifting pump in the well 71. It is apparent that during the portion of the cycle of the crank shaft 65 during which the piston 68 is under heavy load, the piston 69 is under light load and vice versa.

Quite frequently, wells flow slowly, and it is' desirable to pump a given well for only a portion of the twenty-four hours. For this reason, it is customary in many oil fields to provide a central pumping power Which may be connected up to one, two or three of a plurality of wells at a time. When a given Well has been pumped for a sufficient number of hours, the connection is changed to the pump for pumping another well. My invention is adapted for this type of pumping; and in Fig. 5 I have shown an arrangement whereby a central power means may be connected to any one of a plurality of Wells for actuating a liquid-lifting pump in the same. In this figure, a reciprocating pump 73 is shown; and at .various places are located wells '74, 75, 76, 77, etc. A central Valve mechanism 79 is connected by a pair of conduits 8G and 8l to each of the wells. The two ends of the cylinder of the pump 73 are connected respectively to the valve mechanism 79 by pipes 82 and 83. In Fig. 5, a control element is shown diagrammatically at 84 whereby pipe 82 may be connected to any one of the pipes 80. At the same time, the pipe 83 will be connected to the corresponding pipe 81. It is apparent, therefore, that by suitable manipulation of the control element 84, the power means 73 may be connected for actuating any one of the wells.

In the course of the above description, certain advantages of my improved pumping mechanism have been pointed out. In addition, it should be noted that due to the necessity of forcing the column of actuating liquid downwardly in the well, it is important that a valve be employed which is properly timed. By actuating the rotary valve 51 from the crank shaft 56, I have provided timing means which causes the discharge of iiuid from the pumping apparatus at the proper time in the cycle of this apparatus. The apparatus -itself is of improved construction, the piston operating eiliciently to pump oil out of the well and having its stroke cushioned so as to save the apparatus from danger of jolts.

The use of the packer 10 has the great advantage of preventing pressure from acting on the sand so as to cause the oil to back up. The oil may flow freely into the displacement chamber during the upward stroke of the. piston 24; the check valve 32 seats during the downward stroke of the piston 24, and accordingly there is no possibility of' any back pressure being placed on the producing sand. The packer 10 prevents the pressure of the actuating uid from making its way down between the casing and the outside of the pumping apparatus.

My improved pumping apparatus is compact, and the power from the reciprocating pump is used eiciently to pump fluid from-the depths of the well up to the surface. The eiciency of the apparatus is maintained by keeping the string of tubing lled with fluid from the filler tank 43.

While I have illustrated and described a preferred arrangement of apparatus for elevating liquid in a well and have shown a specic construction of such apparatus, it will be understood that the invention is not restricted to the particular construction or arrangement shown, but may be variously modified within the contemplation of the invention and under the scope of the following claims. L 1

I claim:

l. In well pumping apparatus, in combination, a liquid liftingpump of the displacement type disposed adjacent the bottom of a well, fluid columns to actuate said pump extending therefrom to the top of the well, a reciprocating pump disposed adjacent the top of the well andv operatively connected to said columns to apply'pressure alternately thereto to actuate said pump, means in said liquid lifting pump to displace well fluid into one of said columns, means to maintain the volume of the other column substantially constant, and rotary valve means adjacent the top of the well operatively connected in synchronism with the said reciprocating pump to permit the discharge from the said first column of a volume of fluid substantially equivalent to that displaced-therein by the said liquid lifting pump.

2. In well pumping apparatus, in combination, a liquid liftingpump disposed adjacent the bottom of a well, said pump comprising two aligned cylinders having a diameter adapting them to be disposed within a well casing, means toseal the outer periphery of the lower cylinder to the said Well casing, a valved opening in the bottom of said lower cylinder to permit a controlled flow of welldluid into said lower cylinder, a valved opening in the top of said lower cylinder into the bottom ofl the upper cylinder to permit a controlled ow of well fluid from the lower cylinder into the upper cylinder, a pumping piston disposed in the upper chamber, a plunger oper.- atively connected thereto and adapted to be reciprocated into and out of said lower cylinder upon reciprocating of said piston, a line of tubing concentrically disposed within the well casing closing the upper end of said upper cylinder, a plurality of openings adjacent the bottom of said upper cylinder opening into the interior of said well casing, iiuid columns contained in said casing and concentric tubing extending to the top of the well, means adjacent the top of the well to alternately apply pressure to said columns to reciprocate said piston up and down within the said upper cylinder, and valve means synchronized with said pressure applying means to permit the discharge from the casing uid column of a volume of fluid substantially equivalent to that displaced therein from the said lower cylinder.

3. In well pumping apparatus of the type described and claimed in claim 2, in which the means to apply pressure to the actuating uid columns comprises a reciprocating pump and the valve means comprises a rotary valve operatively connected in synchronism with said pump.

4. In well pumping apparatus of the type described and claimed in claim 2 including means l to maintain the volumes and pressures of thc two piston actuating fluid columns substantially constant. n

5. In well pumping apparatus of the type described and claimed in claim 2, in which the means to apply pressure to the actuating uid columns comprises a reciprocating pump and in which the areas of the two working faces of the liquid lifting pump piston and the areas of the two working faces of the reciprocating pump piston are proportioned with respect to the working loads thereon.

6. In deep well pumping apparatus, a liquid lifting pump adapted to be positioned at the bottom of a well and to be actuated by uid columns extending thereto. from the, top of the Well, said pump comprising a pair of aligned cylinders adapted to be enclosed by the Well casing, means to seal the bottom cylinder to the said well casing, a check valved opening in the bottom of the lower cylinder to permit a controlled flow of well uid into said cylinder, check valved openings in the top of said lower cylinder to permit controlled flow of uid from the lower cylinder into the upper cylinder, openings in the lower part of the upper cylinder to permit free ingress and egress of iluid from the casing into and out of said upper cylinder, -a string of tubing opening into the top of said upper cylinder and extending concentrically within the casing to the top of the well, a pumping piston disposed in the upper cylinder and a plunger member extending therefrom into the lower cylinder, said plunger being adapted upon a reciprocation of said piston downwardly and upwardly within said cylinder to be inserted into and to be with drawn from said lower cylinder, a column of fluid I in said casing about said string of tubing and a column of fluid in said tubing, means adjacent the top of the well to apply pressure alternately to said fluid columns to reciprocate said piston within the upper cylinder, and valve and pressure release means to control the amount of iluid in each column to maintain the said amount substantially constant.

JOHN M. SHIMER.

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