US2214343A - Well pump - Google Patents

Description

eP 10, E. c. OVERALL 2,214,343

WELL PUMP Filed May 27, 1938 INVENTOR. [IQ/V557 C OVER/41L M jwgw ATTORNEYS.

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Patented Sept. 10, 1940 PATENT OFFICE WELL 'PUMP Ernest 0. Overall, Gonzales, Tex.,

assignor of forty-five per cent to 0. S. Petty, San Antonio, Tex., and fifty-five per cent to J. H. Robertson, Hillsboro, Tex.

v Application May 27,1938, Se1;ia1 No. 210,450 4 Claims. 161. 193-5) This invention relates to pumps, particularly the pressure from the tube 2 to be cut off from for the pumping of. oil and water wells, and of a type described in applicants co-pending application, filed May 27, 1938, Serial Number 203,785. The principal object of the invention is to provide a pump of this nature whereby the usual sucker rods are eliminated. I

A further object of the invention. is the provision of apump whereby gas or air or a mixture 10 of both gas and air may be utilized for operating the pump in one direction of its stroke, thereby causing the fluid of the well to be elevated, and which power when released will continue to elevation of said fluid, thereby'attaining the-benefit on both the up-stroke and down-stroke of the pressure built up. l e v A still further object of the invention is the means employed for equalizing the well fluid pressure on both sides of the plunger piston, whereby the up-stroke of the pump is accomplished with a minimum of power. 4

Other minor, yet important objects of the invention ,will become apparent from a perusal of the followingdetailed description, taken in connection with the accompanying drawing, and in the drawing:

Figure 1 is an elevational view in vertical section of the pump embodying the invention, showing the pump mechanism on the extreme downward stroke; J Figure 2 is a view similar to that of Figure l, but illustrating the mechanism of the pump with the piston on the extreme upward stroke;

Figure 3 Ban enlarged cross-sectional view of l the pump, the view being had along the line 3-3 of Figure 1;

Figure 4 is a view similar to that of Figure 3, but showing a cross-section lower down and along the line 4-4 of Figure 2; and Figure 5 is an enlarged detail fragmentary view in vertical section of the check valve in the top of the pump mechanism. p In the preferred embodiment of the invention as illustrated in the drawing, the numeral 1 represents the casing of a well in-which the pump is to be operated. T

Mounted within the casing I is a tube-2, termed pressure tube, and which communicates; with a source of power outside the well, and having its 50 lower end extending down 'to a point near the fluid or'submerged in the fluid of the well.

- Threadedly or otherwise connected to the lower end of the tube 2 is a cylinder 3, termedpressure cylinder, the upper portion of this cylinder be- 55 ing reducd in diameter. Since for the most successful operation of the pump it is necessary for the cylinder 3 at provided intervals, a plug 4 is disposed in the top of the cylinder 3 for cutting off the normal communication between the tube 2 and the cylinder 3. Then for communication purposes between this tube and the cylinder there .is provided a passageway 5 leading to any desired point in the cylinder 3. 'A plurality of such passageways 5 may be utilized as shown in Figures 3 and 4, said passageways communicating with the cylinder 3 by means of an annularrecess 28 in this cylinder instead of having single ports for each passageway. A slidable valve 33 is provided for cutting ofi the pressureof the tube 2 from the cylinder 3, thus eliminating the necessity of a valve to be lifted against the pressure in the tube 2, such as a ball valve or the like,

since a slidable port type valve is easier to raise than a ball valve would be.

On the bottom of the cylinder 3 is threadedly or otherwise secured a second cylinder 6, commonly termed the working barrel of the pump. A perforated mud tube l is connected to the bottom of the cylinder 6* by a coupling or union 8, this tube and form of connection being commonly used in oil well equipment and which form no part of the invention.

In the bottom of the cylinder 6 is a conventional standing valve body IS with a central bore I6, said valve body having a seat'l'l for a ball valve 18, and. which permits the fluid from the well to pass up into the cylinder or pump barrel 6, but prevents its return into the well. A cage 19 maintains this valve in operable position.

Since the well fluid is to be elevated to the surface through the casing, a-pack-off 9 with a large 1 central bore is' disposed in said casing at any desired point and fits tightly against the walls of the casing to prevent passage of fluid between the 40 casing and the pack-oil. Said pack-01f has a support 34 on which the cylinder 3 seats. With the cylinder 3 seated the fluid from the well must pass up through the pump barrel 6 to the cylinder 3, the pack-off separating the fluid in the well from the fluid that is being elevated. v A plunger rod 25 reciprocates within the cyl-.' inders 3 and 6, and-connected to its lower end is 'a valved piston 20, which reciprocates in the cylinder 6. This valved piston 20 hasv a passage as shown and a seat 2| for a-ball valve 22, the ball valve 22 being held in operable position by the cage 23. This ball valve thus permits-fluid to pass upwardly, but preventsits returnto the Syvell or cylinder below said valve. inverted cup the piston 20 ensure a tight relation between the cylinder or pump barrel 6 and the piston in operation.v I

The plunger rod 25 has rigidly mounted thereon a plunger piston 26 with upwardly turned cups 21, these cups providing a fluid-tight relation between the piston and cylinder.

A coil spring 3|, or its equivalent, is operably associated with the plunger rod 25 for purposes hereinafter described. This spring is seated on a washer 32, apertured for the passage of the plunger rod, the washer being supported on an annular shoulder as shown. The upper end of the spring 3| is held in position by a perforated washer 30 and a nut 30a, the washer30 being spaced from the plug 4 when the plunger rodis in uppermost position.

Slidably mounted on the plunger rod 25 and within the cylinder 3 is a port type valve 33, with openings 35. This valve is for the purpose of cutting off and on pressure from the tube 2 to the cylinder 3, and for opening and closing pressure discharge port or ports 31 in the cylinder 3.

A port or ports ID are provided in the lower part of the cylinder 3 which communicate with fluid discharge passages II and permit elevation of fluid into the well casing. Disposed in the upper end of each of these passages is a check valve structure, consisting of a valve seat M, a ball valve I2 and a stop I 3, the latter maintaining the ball l2'within the recess 12a in operable position.

The operation of the pump is as follows: Figure 2 of the drawing shows the pressure piston 26 ready to begin its downward movement, called down stroke,for which gas, air or a mixture of both gas and air may be utilized--gas being preferable. By any suitable pressure pump, gas for instance, is forced down the pressure tube 2, thence through the passageway 5 and into the cylinder 3. The discharge port 31, as shown in Figure 2, is then closed. As additional gas is forced into the cylinder 3, a pressure is built up therein, thereby forcing the piston 26 downwardly. As the piston descends, the valved piston 20 likewise starts its descent. During this stage of the operation the ball valve I9 seats, while the ball valve l2 in the passage or passages II is raised from its seat and fluid thereby passes up- Wardly. The fluid in the pump b'arrel or cylinder 6 does not change it position on the downward stroke of the pump, other than to move above the valved piston 20. As the piston 26 nears its downward stroke, the stop 39 mounted on the plunger rod 25 strikes the port valve 33, and as this valve is moved downwardly, the discharge port 31 is opened, and the small annular recess 28 into which the passageway or passageways open, is closed. Simultaneously, the compressed gas in the,cylinder 3 is allowed to escape through the port 31 and into the column of fluid being elevated in the fluid elevation passage II and which passes upwardly into the casing of the well. Immediately upon the opening of the, port 31, the pressure is equalized on the upper and lower -sides of the piston 26, as some of the compressedgas goes up into the casing, while some of it may go down the passage II to some extent. As the pressure enualizes on both sides of the plunger piston 26, the back or static pressure of the column 'of fluid in the casing closes the check valve I2, thereby cutting off the back or static pressure of the fluid in the casing from all cylinders be-- low. As the pressure from the tube 2, and the static or back pressure of the column of fluid are in the cylinder 6 above the piston 20 to be lifted in the cylinder 6. As the piston 20 moves upwardly, it creates a suction, causing the fluid in the well to be pulled through the standing valve |5 up into the cylinder 6. In the event the cylinder 3 is of larger diameter and surface area than the cylinder 6, there will be some back flow of fluid in the passageway into the cylinder 3, following the piston 26 as it movesupwardly. As the coil spring 3| reaches its full normal expansion, whereby piston 26 is about to reach its extreme upstroke, the stop 38 strikes the valve 33, thereby moving this valve upwardly until the annular recess 28 is opened, and the pressure discharge port 31 is closed. Immediately upon the closing of the port 31 and the opening of the passageways 5'and the annular recess 28, pressure begins to build up again in the cylinder 3. The cycle of operation is then repeated. The annular recess 28 and the port 31 maybe so arranged as to require a separate valve for opening and closing each and several types of port valves may be used.

It is to be understood that while the disclosure presents a practical working embodiment of the invention, it is not limited to the specific form shown, but may be modified, altered and changed, in keeping with the principle involved, andwhich may be said to fall fairly within the scope and meaning of the appended claims.

What is claimed is:

1. A pump of the class described in combination with a Well casing, comprising a collar connected to the lower end of the casing and constituting a pack-01f; a pressure cylinder in the well casing and seated on said pack-off, said pressure cylinder having one or more pressure inlet passageways and one or more valved fluid discharge passageways; a pressure tube connected to the upper end of said pressure cylinder and having mounted thereon; a spring mounted on the plunger rod for moving the plunger rod in one direction; a pump barrel connected to the lower end of said pressure cylinder and wherein said valved piston reciprocates; a standing valve in the pump barrel, a mud tube, means for connecting the mud tube to the pump barrel; and means carried on said plunger rod for actuating said sliding valve in the opening and closing of said pressure inlet and fluid discharge passageways, said fluid discharge passageways having ports opening into the bore of the pressure cylinder.

2. A pump of the class described such as deflned and as claimed in claim 1, and wherein said fluid discharge passageways'have. ports opening into said pressure cylinder for release of gas or air under pressure into the column of fluid being elevated in said fluid discharge passageways; said pressure inlet passageways in the pressure cylinder having means for conducting the air or gas from the pressure tube through a recess common to all the pressure inlet passageways and whereby said gas on escape after its compression passes from said recess into said discharge passageways through said ports; said fluid discharge passageways including elevation ports opening into the lower endot the pressure cylinder below the ports provided for gas or air release, said elevation ports being permanently open; 1

3. A pump of the class described in combination with a well casing. comprising a collar-connected to the lower end 01. the casing and constituting a pack-oil; a pressure cylinder in the well casing and seated on said pack-oft, a pump barrel connected to the lower end of the pressure cylinder, said pressure cylinder having one or more pressure inlet passageways and one or more valved fluid discharge passageways; a pressure tube connected to the upper end 01 said pressure cylinder, said tube being connected to a pumping .sure tube; said means embodying the assemblagev or, a plunger rod, 9. slidable valve mounted thereon, and stop elements for limiting the passage of the slidable valve across said ports; said plunger rod including a plunger piston and a valved piston mounted in spaced relation thereon, and a spring carried on the upper end of the plunger piston; said plunger piston reciprocable in said pressure cylinder and said valved piston slidable in said pump barrel, the operation of the pump by said pressure'moving the plunger rod downwardly and by which compression the plunger piston forces the well fluid upwardly into said fluid elevation ports into the discharge passageways and simultaneously through said slidable valve releases the gas or air pressure into the column of rising fluid; the pressure on said plunger piston being equalized on the downward stroke of the plunger rod, whereupon said spring expands and raises the plunger rod on its upward stroke.

4. A pump of the class described and asclaimed in claim 3 and wherein saidpressure cylinder is reduced in diameter at its upper end whereby an annular space is formed between ,the pressure cylinder and said well casing; the upper end of the pressure cylinder being closed by a removable plug.

ERNEST C; OVERALL.

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