US2475739A - Valved piston reciprocating pump and valve - Google Patents

Description

Patented July 12, 1949 UNITED STATES PATENT OFFICE VALVE!) PISTON RECIPROCATIN G PUMP AND VALVE 4 Claims.

This invention relates to valves for passing liquids under high pressure heads; for example, in the lifting of liquids in a well from substantial depths. When the gas pressure in a well is insufficient to produce flow to the top of the well valves are required in the flow line and these valves must operate against high pressure heads; consequently, very high under valve pressures are required. The same is true of the valves in pumps when pumps are required.

The area of the valving member exposed through the valve seat is substantially less than the area exposed to the column of fluid in the well tubing; consequently, it is necessary to build up a pressure greatly in excess of the pressure of the fluid in the well tubing above the valve before the valve can open. Thus, if the pressure of well fluid above the valve should be 1000 pounds per square inch and the area of the valve exposed thereto is twenty-five per cent more than the area exposed through the valve seat, the oil below the valve must exert a pressure on the underside of the valve of more than 1250 pounds per square inch before the valve can open.

When pumps are required, this added pressure is not only destructive to the sucker rods and other working parts, but in oil wells handling extraneous fluids, the pressure exerted in the working barrel tends to produce emulsions which are sometimes diflicult to break down and require expensive chemical treatment. Another difficulty is that in wells declinin in production and particularly in stripper wells, the oil may come into the working barrel only a part of the way with the result that on the downstroke the weight of the rods and oil above the traveling valve practically drop until the piston reaches the oil level and then the rods are suddenly placed in compression due to contact with the liquid and pressure required to lift the valve. When the standing valve is defective or improperly seated, the traveling valve in attempting to build up a pressure suflicient to open the traveling valve, will force fluid therethrough and result in poor efliciency and increased emulsion of the well fluids.

It is a principal object of the present invention to overcome the above difficulties by providing an improved valve having cooperative differential sized valving members; that is, a relatively small sized valve subject to pressure of the column of fluid in the well tubing and a larger valve adapted to make contact therewith and having a, larger area exposed to the pressure of the fluid in the working barrel so that the valves operate at less differential in pressures.

In accomplishin these and other objects of the invention, I have provided improved valve structure, the preferred form of which is illustrated in the accompanying drawing wherein:

Fig. 1 is a vertical section through a pump equipped with an upper or traveling valve em-- bodying the features of the present invention.

Fig. 2 is an enlarged vertical section through the traveling valve on the line 2--2 of Fig. l and showing the differential sized valves thereof in seated position.

Fig. 3 is a, similar section showing the valves unseated as when the piston is moving on the downstroke.

Fig. 4 is a cross section on the line 4-4 of Fig. 2 particularly illustrating the smaller valve which sustain-s load of the column of fluid in the well tubing.

Fig. 5 is a similar cross section on the line 5-5 of Fig. 3 and particularly illustrating the larger valve which unseats against pressure built up in the working barrel on downward movement of the piston.

Referring more in detail to the drawing:

In illustrating and describing an adaptation of my invention, l designates the lower end of a string of well tubing that is connected with a workin barrel 2 having an inlet end 3 located at a position in the well to receive well liquid and effect filling of the working barrel on the upstroke of the piston 4. The piston 4 includes a working or traveling valve assembly 5 embodying the improvements of the present invention.

The piston 4 is actuated by a string of sucker rods '6 extending downwardly through the well tubing and which is reciprocated by a power unit located at the top of the well (not shown).

The pump also includes a standing valve assembly i that admits fluid into the working barrel on the upstroke of the piston and which seats to trap the fluid in the working barrel for transfer through a bore 8 of the piston to the well tubing above the traveling valve on the dovmstroke of the piston.

The pressure acting on the standing valve is that effected by the column of fluid extending from the traveling valve to the top of the well. In deep wells this pressure is of substantial amount and due to the fact that the area of the traveling valve member exposed thereto is considerably greater than the area exposed to the liquid trapped in the workin barrel, it is necessary for the pressure to build up in the working barrel in excess of the pressure in the well tubing to permit the standing valve to open. This pressure in the working barrel may be, for example, one-fourth greater than the pressure in the well tubing. Consequently, movement of the traveling valve against this excessive pressure results in difficulties particularly emulsification of the liquid. Furthermore, if the valve member of the standing valve does not have a perfect seat, the high WOIklllg barrel pressure produces greater leakage of fluid which results in inefficient operation and tends to increase emulsion should the well contain a mixture of liquids.

As above pointed out, I have overcome these difiiculties by providing an improved valve wherein the valving members are adapted to be opened by lower pressures in the working barrel.

The piston 4 as in the case of a standard pump includes a tubular body 9 having a plurality of sealing cups l mounted thereon and spaced apart by spacers ll. Fixed to or 'formed on the upper end of the tubular body above the uppermost cup is a standing valve :body H. having stepped bores l3, i i and I5 coaxial with the bore 8 extending through the body of the piston and through which \vell fluid is transferred as above described. The inner bore [3 is preferably of larger diameter than the bore 8 andpreferablycorresponds to the inner diameter of a valve seating ring 1'6 that is mounted in the next larger bore 14 and which engages the shoulder I! provided between the respective bores. The seating ring preferably has 'a peripheral seat 18 encircling the port l9 therein for a valving member such as a ball 20. The depth of the bore M. is such as to accommodate the ball valve 2E when the valve is in seated position as shown in Fig. 2.

Mounted within the upper and larger bore I5 is a valve seating ring 21 having a'port 22 therein of smaller diameter than the port l9 whereby the port 22 may be closediby a valving member, for example, a ball 23 of smaller area than the ball 20. The seating ring ,2l is preferably concave on the respective sides of the port as indicated at 24 and 25 respective to facilitate positioning of the valve during movement thereof as later described. The ring 2| is retained against the shoulder '26 by a cage 21. The cage 2'! hasa threaded pin 28 connected with the string of sucker rods. posite end of the cage hasa threaded neck 29 to engage threadsfiflof the bore 15 asshownin Fig. 2 so that the end face 3| of the neck cooperates to clamp the valving ring 2! against its shoulder 28. The cage 21 forms achamber .32 about the upper valving member to permit free opening thereof and the chamber has outlet through ports 33 formed in the sidesof the cage so that the fluid is discharged into the well tubing.

The difference in size between the ports through the seats results in restriction in flow through the smaller port so that the ball of the larger'seat will not lift enough to close off the'smaller port under the flow of liquid. Also, in :designing the valves, suflicient clearance is providedbetween the larger ball and the underside of the seat for the smaller ball, which clearance is at )least substantially equal to the eflective 'flow capacity through the smaller seat.

The valves are so located that they are free to seat independently of each other but are sufficiently close so that unseating of the larger member efiects contact and unseating of the smaller member as now to be described in the operation of the pump.

The op- Assuming that a pump is equipped with a standing valve 1 as described and the piston 4 is reciprocated by a power unit at the top of the well, well fluid is caused to flow through the standing valve into the working barrel on the upstroke of thepiston,tl1e flow of oil following the piston to the top of its stroke. On the downstroke of the piston, the standing valve seats and pressure of the fluid in the working barrel acts upon the larger valve 26 through the port Is. As soon as the pressure has built up sufficiently to overcome the pressure in the bore 14, the valve 20 is unseated to contact and unseat the ball valve 23, the exposed area of the ball valve 23 above its seat being substantiallyless in exposed area than the ball valve 20,

opens against a pressure greater than the pressure built up in the working barrel; consequently, the valves open at lower pressure so that it is not necessary to build up the high pressure in the working barrel which is essential in operation of the traveling valve in any standard pumn'now on the market.

When the piston reaches the bottom of its stroke, the fluid in the working barrel has been transferred through the piston and valve ports l9 and 22 to the well tubing above the piston. Consequently, if the pump has been in operation sufiiciently to fill the well tubing, an equivalent of the transferred liquid will be displaced from the upper end of the well tubing on the upstroke.

While I have particularly described my invention applied in a sucker rod operated pump. it :is obvious that my improved valve may be usedon other forms of pumps, flow lines and the .likerequiring valves.

From the foregoing it is obvious that I have provided a valve which operates at lower pressures than that ordinarily required in the working barrel and the reduced pressure avoids emulsion and results in greater eiiiciency and cleaner-oil where salt water is present with the'oil.

It is also obvious that with a valve embodying the features of the present invention, the length of life service, and efficiency-of boththe standing and traveling valves will be increased by reducing the blow and pounding of the balls on their respective seats.

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

1. A traveling valve for a pump including a valve body and having stepped bores, seating members supported by shoulders formed between the stepped bores and having differential sized ports decreasing in capacity in the direction of flow through the traveling valve, and vdifferential sized valving members for said seats, said larger valving member being adapted to be unseated first by fluid pressure below the traveling valve and the smaller to be subsequently unseated by direct contact of the larger valving member therewith.

2. In combination with a pump including a. Working barrel, of a piston reciprocable in the working barrel, a traveling valve on the piston, and differential sized valving members carried by the traveling valve, the larger being subjected to the pressure in the working barrel below the piston and the smaller being subjected to pressure above the piston, said valving members being arranged for the larger to contact and unseat the smaller.

3. In a pump including a working barrel, a piston reciprocable in the working barrel, a traveling valve on :the piston including a valve body having stepped bores registering with a fiowpassageway through the piston, seat members supported 0n shoulders formed by the stepped bores and having differentially sized ports with the larger port directly registering with the flow passageway of the piston, a valving member for the larger seat to be unseated by flow of fluid through the flow passageway in said piston upon downward movement of the piston, and a smaller valving member seated on the other port and adapted to be unseated by unseating of the larger valving member.

4. In combination with a pump including a working barrel, of a piston reciprocable in the working barrel, a traveling valve on the piston, and difierential sized valving members carried by the traveling valve for contact with each other upon unseating of the larger valving member, the larger member being subjected to pressure in the working barrel below the piston and the 6 smaller being subjected to pressure above the piston.

GUSTAV FRANK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 796,392 Bailey Aug. 1, 1905 1,339,500 Criqui et a1 May 11, 1920 1,730,452 Davis Oct. 8, 1929 1,856,492 Marshall Apr. 26, 1932 15 2,344,786 Patterson et a1 Mar. 21, 1944 FOREIGN PATENTS Number Country Date 6,297 Great Britain Mar. 15, 1907

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