US2326170A - Well pumping apparatus - Google Patents

Description

'Aug. 10, 1943. E. w. REARWIN WELL PUMPING APPARATUS Filed Nov. 30, 1940 5 Sheets-Sheet 2 ATTORNEYS Aug. 10, 1943. E. w. REARWIN WELL PUMPING APPARATUS Filed Nov. 50, 1940 3 Sheets-Sheet 3 k ATTORNEYS Mii Patented Aug. 10, 1943 WELL PUIVIPING APPARATUS Earle W. Rearwin, Bufialo, N. Y., assignor of onehalf to Fred Dobmeier, Buffalo, N. Y.

Application November 30, 1940, Serial No. 368,012

4 Claims.

This invention relates to well pumping apparatus in which the pumping mechanism and the power mechanism for actuating the same are 10- cat-ed in the well.

One of the objects of this invention is to provide a pump for use in connection with deep wells, which is of improved and simplified construction and of greatly increased efficiency in operation. A further object is to provide a mechanism of this kind which is so constructed as to prevent sediment, precipitated in the pumped liquid, from interfering with the operation of the mechanism. A further object of this invention is to provide a pumping mechanism of this kind with means for'collecting the sediment precipitated from the pumped liquid in such a manner that it does not collect on the valves and other parts of the pumping mechanism. A further object of this invention is to provide an improved mechanism of this kind with a sediment barrel which'can be readily removed from the mechanism and cleaned, when the same is removed from the well.

Other objects of this invention will appear from the following description and claims.

In the accompanying drawings:

Fig. 1 is an elevation, partly broken away, of

a pumping mechanism embodying this invention, and also showing one embodiment of my improved method of pumping oil wells, the pumping mechanism being shown in position in an oil well.

Fig. 2 is a sectional elevation thereof, on an enlarged scale, showing the upper portion of the pumping mechanism.

Fig. 3 is a, continuation of Fig. 2, showing in sectional elevation the lower portion of the pumping mechanism, the sectional views shown in Figs. 2 and 3 being taken approximately on line 23, Fig. 1.

Fig. 4 is a sectional elevation of the upper portion of my improved pumping mechanism, the section being taken on line 4--4, Fig. 2.

Fig. 5 is a sectional elevation of the lower portion of the pumping mechanism on line 55, Fig. 3.

Figs. 6 to 11 are sectional plan views, taken on lines 6-6, 1-4, 88, 9-9, l0l0 and ll--|l respectively of Fig. 4.

Figs. 12 and 13 are sectional plan views thereof, taken respectively on lines l2--i2 and l3l3 Fig. 5.

Fig. 14 is a fragmentary elevation thereof, partly in section, taken on line I4--l4, Fig. 5.

Fig. 15 is a perspective view showing the slide valve detached from the pumping mechanism.

Figs. 16 and 17 are diagrammatic views illustrating the operation of the valve shown in Fig. 15,.

Fig. 18 is a perspective central sectional view of a packing ring detached from the pumping mechanism.

A represents the ground into which a well has been drilled, and 20, represents a casing or lining for the upper part of the well, the lower end of which usually extends into solid rock. The casing prevents water from entering the well. In the case of oil wells which also yield gas, the upper end of the casing may be provided with a casing head of any suitable or desired form, that shown in the drawings including a collar 2| suitably secured to the upper end of the casing. Gas may be withdrawn from the well by means of one or more pipes 22 connected with openings in the collar 2|, and 23 represents a plate secured to the upper end of the collar to form a gas-tight joint therewith. This plate is provided with a hole or aperture through which a liquid discharge pipe 24 extends, and suitable packing 25 is preferably provided between the plate 23 and pipe 24. The pumped liquid from the well is discharged through the pipe 24, and the lower end of this pipe is suitably secured to the pumping mechanism.

Any suitable connection may be provided between the discharge pipe24 and the pumping mechanism, but preferably I provide a connecting member 21 between the lower end of the oil pipe 24 and a head 28 at the upper end of tire pumping mechanism. The connecting member shown is of'materially smaller diameter than the pumping mechanism and may be secured to the pumping mechanism, in any suitable manner, for example, by means of a screw-threaded connection with the head 28, as shown in Fig. 4. The upper end of the connecting member has an enlarged head or outwardly extending flange 29 provided with an abrupt shoulder or step at the lower end thereof, which forms a convenient means for connecting with a fishing or grappling tool, which may be used in the event that the pumping mechanism should become detached from the oil pipe and fall into the bottom of the well. Since the diameter of the pumping mechanism approaches rather closely to that of the well, it is very desirable to provide a connecting member of smaller diameter which will always be spaced from the wall of the well, where it may easily be engaged with a fishing tool, whereas it might be very diflicult otherwise to connect the fishing tool with the housing of the pump or the upper head or cap member 28 thereof. A shoulder or flange for engagement with a fishing tool may, however, be formed in any other part of the pumping mechanism.

The connecting member is hollow and the uppart part thereof is provided with internal screw threads with which the lower threaded end of the oil pipe 24 connects. The liquid discharged from the pumping mechanism passes from the connecting member 21 to the discharge pipe 24.

My improved pumping mechanism and the power mechanism therefor are enclosed in a suitable cylindrical casing or housing, including upper and lower tubular members 30 and 3|. The upper end of the housing member 30 is threaded and engages with a correspondingly threaded, annular, flanged member 32, which in, turn is secured to the upper cap member 28 in any suitable or desired manner, for example, by means of screws 33. The lower end of the upper cylindrical housing member 30 is suitably secured to a lower head or casting 34, to which the upper end of the lower cylindrical housing member 3| is also secured, see Figs. 3 and 5. The lower end of the housing member 3| is secured to an apertured plug or bushing 35. An intake or suction pipe 36 is secured to the bushing 35 and extends into the lower portion of the well and may, if desired, rest on the bottom of the well. The intake pipe may be provided with intake apertures or openings 38 of any suitable kind, see Fig. 1, through which liquid from the well enters. Preferably, these intake openings are arranged at a distance above the bottom of the pipe 36 and above the bottom of the well, and in the case of oil wells, these openings should be below the bottom of the oil producing sand of the well.

The casting or head 34 forms the base or support for the lower end of a power cylinder 40 arranged within the cylindrical housing member 30, and this casting is also bored to receive a reciprocatory rod or shaft 4|, to the upper end of which the power piston is secured in any suitable manner. This piston may be of any suitable or desired construction, and as clearly shown in Fig.

4, comprises a pair of disks 42 and 43 which support suitable packing, such for example as cup leathers 44, one of which faces upwardly, and the other downwardly. The upper end of the piston rod 4|, which passes through the piston disks 42 and 43, may be of slightly reduced diameter, thus forming an annular shoulder on which the piston disks 42 and 43 are supported, and a nut 45 may cooperate with the threaded upper end of the piston rod to secure the parts of the piston on this rod. The upper end of the piston rod has a threaded aperture in which. the lower end of a valve rod 46 is secured. This valve rod extends upwardly through a valve housing 48, also arranged within the cylindrical housing member 30. The lower end of the piston rod 4| extends through an upright central aperture of the casting 34 and is suitably secured to a pumping piston arranged to reciprocate within a pumping cylinder 50, the upper end of which is secured to the casting 34. This pumping piston is arranged within the lower cylindrical housing member 3|.

The pumping piston may be of any suitable or desired construction. The piston shown by way of example in the drawing comprises a main body or piston which has a central bore or aperture 52 extending lengthwise therethrough. The lower end of the piston is of reduced diameter and is formed to receive packing 53 which forms a tight seal with the pumping piston and the cylinder 50. The lower extension of the piston 5| is threaded at its lower end to receive a nut 54, by means of which packing may be compressed and held in place. The nut 54 is preferably provided with a central, diametrically extending, reduced portion 55. Any suitable or desirable packing may, of course, be employed, that shown comprising a number of rings 56, preferably of synthetic or other oil-resistant rubber or other flexible material, and these rings are preferably of chevron or angle-shaped cross section,

so that the inner peripheral portions of these rings extend at an angle of about 45 degrees to the downward extension of the piston 5| and the outer portions of the rings also extend upwardly at an angle of about 45 degrees to the cylinder 50. The lower face of the enlarged portion of the piston 5|, about the extension or reduced portion 53 thereof, is of V-shape in cross section, so as to fit into the upper of the packing rings 56, and the packing nut 54 is preferably provided on its upper face with an annular V-shaped groove or recess in which the lower packing ring 56 may seat. Other forms of packing may, however, be employed, if desired.

To the upper end of the pump piston 5| is secured a valve cage member 51, within which a suitable valve, such as a, ball valve 58, may be arranged. This cage member has the upper portion thereof of reduced diameter and spaced from the upper end of the pumping piston 50, and is also provided with a plurality of upwardly extending bars 59 which are spaced apart to form passages for the liquid, see Figs. 5 and 13. The upper end of this valve cage member forms a head 59a which is of further reduced diameter, and to which the lower end of the piston rod 4| may be suitably secured in any desired manner, for example, by means of a threaded engagement, as shown, the lower end of the piston rod being recessed or bored out, as shown at 60, and internally threaded to cooperatewith external threads on the head 59 of the cage member 51. 6| represents an annular seat member suitably secured in the upper end of the piston 5|, with which the valve 58 may cooperate.

Any suitable form of foot valve may be provided for the pump, and in the construction shown, this valve is located in the lower end of the pumping cylinder 50 and is of a construction similar to the piston valve which has been described. For example, the lower end of the pumping cylinder 50 may be secured to a suitable tubular cylinder head 65, which also form a connection between the lower end of the pump cylinder and the lower cap 35 0f the housing. This tubular member 65 is provided in the upper portion thereof with a seat member 66, upon which a valve 61 may seat, and 68 represents a cage for this valve, which is of somewhat similar construction to the valve cage 51 already described, being provided with a plurality of bars or rods 69 spaced apart to form passages for the liquid. The lower end of the tubular cylinder head or member 65 extends through a central hole or opening in the lower cap 35 and is formed to receive liquid, preferably through a plurality of small holes or openings 10, all of which connect with the central passage H of the member 65. Any other means for admitting liquid to be pumped to the pump cylinder may be employed, that shown being particularly designed for use in connection with the pumping of oil, since the relatively largenumber of small openings prevent the entry of wax or other solid or semi-solid materials into the pumping mechanism.

From the foregoing description, it will be clear that as the piston rod 4| is reciprocated by means of the power piston, the pumping piston 5i and the parts carried thereby will move up and down in the pumping cylinder'50. During the down stroke from the position shown in Figs. 3 and 5, the space in the pumping cylinder 58 below the piston 5| will be filled with liquid to be pumped, and the downward movement of the pumping piston consequently causes the liquid which is displaced by the pump piston to flow upwardly through the passage 52 of the piston, past the valve 58 and between the bars 58 of the cage into a chamber 13 in the casting 34. During this movement, the upper valve 58 is open, while the lower valve 61 is closed. Upon the upward movement of piston 5!, the valve 58 will remain on its seat while the foot valve 81 opens to admit liquid from the suction or intake pipe 36 through passage ll into the pumping cylinder 50. During this upward stroke of the pumping piston, the liquid in the cylinder 50 above the piston will be displaced upwardly into the chamber 13, so that the pump is double-acting and discharges liquid at each stroke.

When pumping mechanisms of this type are used in connection with oil wells, difficulty has been frequently encountered because of the sediment which precipitates out of the oil and settles on the valves or other parts of the pumping mechanism and eventually plugs them so that they cannot operate.

pumped intermittently, for example, for a few In many oil fields. the wells are hours or less each day, and when the pump is not in operation, the entire column of oil in the discharge pipe of the pump precipitates the sediment which, in many cases, cogs the pumping mechanism and the valves so that the pumps become inoperative and must be removed from the wells for cleaning.

In order to overcome this difliculty, I have provided a sediment chamber in which this precipitate can be collected without becoming deposited on any of the parts of the pumping mechanism. In th particular construction shown for this purpose, the space 15 between the lower cvlindrical housing member 3| and the pumping cylinder 50 constitutes the sediment chamber or barrel, and the liquid discharged into the chamber 13 in the casting 34 is discharged downwardly into the top of this sediment chamber 15 by means of one or more delivery passages 16 leading from the discharge chamber 13 of the pump to the sediment chamber. Two passages 16 are shown in the drawings, and these passages are inclined downwardly and outwardly toward one side of the sediment chamber, as clearly shown in Figs. 5 and 13.

Liquid may be discharged from the upper portion of the sediment chamber 15 by any suitable or desired means. For example, I have provided in the lower head or casting 34 a pair of upright passages H, the upper ends of which are connected by means of suitable couplings 18 to oil discharg pipes 19. While I have shown two oil discharge pipes, it will be obvious that, if desired, a single pipe may be provided, or more than two pipes may be employed. The passages 11 prefcrably terminate at their lower ends adjacent to a side of the sediment chamber remote from the side thereof in which the passages 16 terminate, so that liquid must pass substantiall horizontally in the top of the chamber 15 from the passages 16 to the passages 11.

The upper ends of the liquid discharge pipes"!!! may be connected to the main discharge p 24 in any suitable or desired manner. In the construction shown, the upper ends of the oil discharge pipes 19 terminate in a coupling membe 88 which may be suitably secured to the cap member or head 28 in any desired manner, Fig. 4. For example, the cap member may ha a threaded engagement with a short pipe or nipp 82 which extends through a central bore in the cap member or head 28. Both ends of the nipple 82 may be threaded and the upper end thereof has a threaded engagement with a nut or sleeve 83, the lower end of which bears on the cap member or head 28. By turning the nut 83, the coupling member 80 may be drawn into tightly fitting engagement with the cap member or head 28. Consequently, liquid discharged through the pipe 19 enters the coupling 80 and then passes upwardly through the nipple 82 into the connectmg member 21 from which it flows into the discharge pipe 24 to the surface of the well.

It Will be noted that there is an uninterrupted passage from the discharge pipe 24 to the sediment barrel or chamber 15 through which sediment may drop into the sediment barrel or receptacle 15. Since this sediment is necessarily heavier than the liquid being pumped, it will not enter into the upwardly inclined passage or passages 16 and will not become settled on the valve 58 or about the cage thereof. Even if the sediment barrel becomes completely filled with sediment, the operation of the pump will, nevertheless, force liquid through the sediment in the upper portion of the sediment chamber or barrel and will force liquid together with sediment upwardly into the discharge pipe 19, and this sediment may again become deposited in and completely fill the sediment chamber 15, when the pump is not operating; but even when the sediment chamber is completely filled, the sediment will still be unable to rise through the discharge passage 76 and, consequently, will not interfere with the operation of the valve 58 nor the pump.

The pumping apparatus may be provided with any suitable or desired means for alternately supplying motive fluid under pressure to and exhausting the same from one or both sides of the power piston. The valve which I have illustrated by way of example is substantially cylindrical in form and is slidably arranged in the valve housing 48 which is suitably secured to the upper end of the power cylinder 48 and forms a head for this cylinder, Figs. 2 and 4. This slide valve 81 may be arranged within a sleeve or liner 88, which may be held in place in the cylindrical interior of the valve housing 48 by any suitable means, such for example as a valve housing head or bushing 89 suitably secured in the lower end of the valve housing. The valve housing and liner are provided with ports or passages for connecting with passages leading to the power cylinder, to the exhaust or discharge, and to the supply of fluid under pressure. This motive fluid, in the particular construction illustrated, enters a passage 90 in the valve housing 48, this passage being connected by means of a tube or duct 9i within the housing member 30 and extending to an aperture or hole in the cap member or head 28. The upper end of this tube 9| connects with a fluid supply pipe 92 extending from the upper end of the cap member or head 28 upwardly through the well and through the casing head to any suitable source of supply of fluid under pressure.

The passage 90 which extends lengthwise of the valve housing 48 terminates in "a radially extending port 93 which registers with a hole in the sleeve or liner 88 and communicates with an elongated port 95 in the slide valve 31, see also Figs. and 15. When the slide valve ls in its upper position, the port 95 registers with the radial passage 93 in the valve housing and also with a radial passage 96, Fig. 9, in the valve upper portion of the power cylinder 40 to force the power piston downwardly.

When the slide valve is in its upper position, a port 98 in the valve, Fig. 11, registers with a passage 99 in the valve housing, which in turn connects with a tube or pipe I00, which leads into the upper portion of the casting, 34, the upper portion of which forms the lower head of the power cylinder 40. This pipe communicates with a passage IOI formed in the lower cylinder head and terminating at its upper end at the inner face of the lower cylinder head, see also Fig. 14, transmitting motive fluid to and from the lower portion of the power cylinder below the piston therein. 7

When the slide valve is in its -upper position, the port 98 thereof also communicates with a longitudinal passage I03 in the valve housing 48, see Figs. 2 and 11. An exhaust pipe I04 has the lower end thereof secured to the valve housing in communication with the passage I03. This pipe extends upwardly within the housing member 30 and the upper end of this-exhaust pipe extends through a hole or aperture extending through the cap member or head 28, suitable packing means being provided between the pipe I04 and the head 28. The upper end of this exhaust pipe may be coupled to an extension exhaust or discharge pipe I05. This extension exhaust pipe I05 may also extend upwardly through the well to the surface, but in the particular construction illustrated, I have shown the exhaust pipe I05 as terminating slightly above the cap member, so that the exhaust discharges into the well, and for reasons hereinafter to be explained, this exhaust pipe I05 includes a re verse turn so that it discharges the exhaust downwardly into the well. Consequently, when the slide valve is in the upper position, fluid under pressure will be supplied to the upper face of the power piston and the fluid in the lower portion of the power piston is discharged or exhausted. I 06 represents a check valve preferably arranged at the lower part of the exhaust pipe I04 to prevent liquid from the well from entering the valve housing 48 and the power mechanism. It will also be noted that the exhaust pipe extension I05 is arranged near the upward extension 21 of the pump housing, so that this extension 21 protects the exhaust pipe 105 against damage by falling objects.

It will be readily understood that when the slide valve is in its lower position, the port 95 thereof will be out of registration with the passage 96 and in registration with the passage 99, so that motive fluid under pressure will be admitted to the pipe I00 leading to the lower portion of the power cylinder, and when in its lower position,

the slide valve also cuts oi the supply of fluid under pressure to the passages 96 and 91 leading to the upper end of the power cylinder. The

slide valve, however, is provided with an additional port I01, see also Fig. 8, which in the lower position of the slide valve establishes communication with the, passages 96 and 91 of the valve housing leadingto the upper part of the power cylinder, and with a lateral passage I0Ia leading to the longitudinal passage I03 in the valve housing, which connects with the exhaust pipe I04. Consequently, when in its lower position, the slide valve admits fluid under pressure to the lower part of the power cylinder and discharges fluid under pressure from the upper part of the power cylinder to the exhaust pipe I04. I08 represents the usual bleeder passages extending from the ports 98 and I0! to the adjacent ends of the slide valve.

In Figs. 16 and 17, I have shown diagrams matically the slide valve 81 and the valve housing, with the ports and passagesiall arranged in the same vertical plane, so that the operation of the valve maybe more easily understood. In Fig.

16, the valve is shown-in its upper position in which motive fluid from the passage 93 passes through port 95 to passage96 leading to the top of the power cylinder. At the same time, exhaust from the lower part of the power cylinder flows from the passage 99 through port 98 to the exhaust passage I03 of the valve housing. When the valve member 81 is in the lower position shown in Fig. 17, the valve port 95 connects the supply passage 93 for motive fluid with the passage 99 leading to the lower part of the power cylinder and the port I 01 connects the passage 96 leading to the upper part of the power cylinder with the exhaust passage I03.

A slide valve of any other'suitable construction for accomplishing these purposes may, of course, be provided, if desired.

Any suitable means may be employed for moving the slide valve alternately into its two operative positions, which are the upper and lower positions in the particular construction illustrated. In the preferred construction shown by way of example in the drawings, the slide valve is actuated by the movement of the power piston. The valve rod 46 extends loosely or slidably through a central aperture of the slide valve 81 and means are provided for applying yielding pressure to the slide valve alternately in opposite directions to move the same into its two positions. In the construction shown for this purpose, a pair of valve actuating members I09 are provided, which may be, for example, in the form of'flanged sleeves, which extend through apertures at opposite ends of the valve housing to engage the valve member 81 to move the same to opposite ends of its travel. In the construction shown, these sleeves I09 are arranged about the valve stem 46. The inner ends of these sleeves, consequently, engage the opposite ends of the slide valve 81 and these ends of these. sleeves may be provided with flanges or heads as shown. A spring III! is provided on the valve stem 46 above the upper sleeve I09, and the upper end of the valve stem is provided with a suitable part to engage the upper end of the spring'as the valve stem approaches the lower end of its travel. For example, the upper end of the valve stem may be threaded and provided with a nut II I adjustably mounted thereon and which may be secured inplace by a jamb or lock nut. The lower sleeve I09 is adapted to cooperate with a spring II3, the lower end of which may, for example, engage with the upper end of the piston rod 4|. As a result of this construction, it will be obvious that when the power piston approaches the upper end of its movement, the spring H3 will be compressed by the piston rod 4|, thus urging the lower sleeve I09 and the valve 81 into its upper position. Beiore the spring H3 is entirely compressed, the valve 81 will be in its upper position, thus reversing the pressure acting on the power piston, so that further movementof the same is stopped by the fluid under pressure and it is then moved in the reverse direction. When the power piston approaches the lower end of its downward travel, the nut III engages the spring H and compresses the same to move the valve 81 into its lower position through the medium of the upper sleeve I09, whereupon the reverse action of the fluid under pressure takes place, causing this fluid to stop the downward movement of the power piston and then reversing this movement. By means of this arrangement, there is no pounding of the power piston against the upper and lower cylinder heads.

In order to hold this cylindrical 'slide valve 81 in its two operative positions until moved out of these positions by the action of the springs H0 and H3 and also to keep this valve from turning about its axis, I have provided a valve retaining device which includes a yieldingly pressed key or spline member II8, which cooperates with a keyway or slot H9 cut in and extending lengthwise of the slide valve 81. This keyway H9 is provided with deeply cut portions adjacent to the opposite ends thereof and shallow portion in the middle thereof, so that when thevalve slides lengthwise of its housing, it exerts a cam action on the key or spline member I I8.

Any suitable means may be provided for yieldingly urging the spline member I I8 into the keyway or slot H9. For example as shown in Figs. 4 and 10, the key member Il8 has a head I20 which is slidable in a cylindrical bore formed in a cap I2I, which is secured to the valve housing, for example, by means of a screw-threaded engagement therewith. A spring I22 is arranged within the bore of the cap member IZI, and thus yieldingly presses the spline member H8 into the keyway or slot I I9. This construction serves the two-fold purpose of releasably and yieldingly holding the slide valve 81 in either of its operative positions and also, in conjunction with the springs H0 and H3 of making the slide valve move into its operative positions with an accelerated or snap action. It will be obvious from Fig. 4 that in moving the slide valve 81 into its lower position, more force is required to move the slide valve through the first half of its movement, since during this portion of its movement, the key or spline member H8 must ride on the cam-faced keyway or slot in such a manner as to compress the spring I22. However, after the valve has been moved downwardly to a suthcient extent so that the key member I I8 begins to move again into the deeper portion of the groove or keyway II9, then the key member and spring I22 cooperate with the spring III) to move the slide valve 81 rapidly into its lower position. A similar action, of course, takes place when the slide valve is moved into its upper position. The keyway or spline member H8 thus serves the several purposes of holding the slide valve against turning about its axis, holding the slide valve yieldingly to its extreme positions and providing a snap or acceler- The valve mechanism described is particularly desirable for use with well pumps in which the valve mechanism must be arranged at one end of the power mechanism, since by arranging the several parts of the valve and power mechanisms concentric about a common axis, there is no tendency of any parts of these mechanisms to seize or bind.

My improved power mechanism may be operated on any suitable fluid under pressure. If the exhaust or discharge pipe I05 is extended to the top of the well, the power mechanism shown may be operated by a gaseous medium, such for example as compressed air, or by a liquid under pressure. With air or liquid, the fluid pressure, must be suflicient to overcome the resistance of the discharge pipe, which in case of deep wells may be' an important item. It is also possible to use my improved mechanism in connection with a motive fluid similar to that which is being pumped. For example, in an-oil well, crude oil may be used as the motive fluid and may be discharged through a short discharge pipe I05 as shown, into the well, but if this is done, high pressures must be used, since the power cylinder must in that case be of materially smaller diameter than the pumping piston, since otherwise more crude oil will be discharged into the well than is pumped out of it.

When my improved pumping mechanism is used in connection with the pumping of oil wells, the various objectionable features of different motive fluids herein referred to may be overcome by means of my improved process of pumping oil wells, with which process, my pumping apparatus as herein described, is well adapted to cooperate. Nearly all oil wells yield natural or casing head gas and this gas is usually collected and used wherever possible. ess, this gas is used as the motive fluid, and consequently, is withdrawn from the upper part of the well and compressed. This casing head gas then passes through the power mechanism to actuate the pump and may then be discharged into the well near the bottom thereof without any detrimental effects upon the well or on the oil which is being pumped therefrom. In many oil wells, a pressure below that of the atmosphere is maintained within the well in order to increase the flow of oil into the well, and in cases of this kind, this suction helps to add to the power of the power mechanism. This process is illustrated more or less diagrammatically in Fig. 1, in which I25 represents a pipe for conducting casing head gas from the well to a compressor I26 of any suitable or desired construction. The compressed gas is discharged into a conduit I21 which may lead to a receiver of compressed gas (not shown) of any usual or suitable type, or which may be directed to the gas supply pipe 92. In the case of deep wells, a receiver may be eliminated, for the reason that the length of the pipe 92 may be so great that it contains a sufficient quantity of gas so that this pipe itself acts as a receiver for equalizing the pressure pulsations of gas delivered from the compressor. The excess of gas may be drawn oif through the pipe 22 as usual, since my improved process does not use up any of the natural gas. When my process is used in connection with a single well, all of the gas which is removed from the well through the pipe I25 is returned thereto. My process may, of course, be

used in connection with a group of wells, in which In accordance with my proc-,

case, only a single compressor may be employed, which supplies compressed gas to a plurality of wells and which may receive gas from only one or two wells, or from a gas receiver, in which gas from all of the wells of the group is collected.

My process as herein described has a number of advantages. In the first place, by using casing head gas as the motive fluid, there is no need for a return or discharge pipe leading to the surface. This not only simplifies and reduces the cost of the installation and removal of the pumping apparatus in or from a well, but also materially increases the efficiency of the pumping device, since the casing head gas discharged into the bottom of the well may flow back to the top thereof with a very" low resistance be- .cause of the relatively large size of the well and the casing 2|. My process does not interfere in any way with the delivery of easing head gas from the well, and furthermore, since this gas originates in the well and exists there at all times, it is in no way injurious to the well or to the oil. If, on the other hand, air were discharged into the interior of the well, it would not only mix with the gas so as to render this gas practically useless as well as to form an explosive mixture, but furthermore, the oxygen of the air reacts with the oil sand in the well in such a manner as to gradually decrease the quantity of oil flowing into the well. Air 'alsoreacts to some extent with the oil itself and deteriorates the same. Consequently, when air. is used as the motive fluid, it must be conducted out of the well by means of a discharge orexhaust pipe extending from the power mechanism near the bottom of the well, to the surface. The frictional resistance to the flow of air in such a long pipe is an important item which decreases the efficiency of any pumping mechanism using air.

My process has very decided advantages over the use of crude oil as a motive fluid, since, in the first place, as has already been stated, a relativelysmall power piston would be necessary, which in turn would necessitate much higher pressures of the motive fluid. Furthermore, in order tomake it possible to use crude oil as a motive fluid, it is necessary to remove gas therefrom and, in most cases, it is also necessary to remove other ingredients, such for xample as wax, from the crude oil. This may at times alter the crude oil sufliciently to decrease the value thereof. However, a further objection may result from the use of crude oil as a motive fluid, namely, that the agitation or churning of the crude oil necessary to impart the necessary pressure thereto and to pass the same through the pumping mechanism may result in a homogenizing action on the crude oil which may materially change its characteristics and diminish its value. On the other hand, the casing head gas used in accordance with my process does not become altered or diminished in value by the compressing of the same and by discharging the same into the well.

When used in connection with natural or casing head gas, the discharge pipe. I05 of my pumping mechanism is preferably of bent or curved form, so as to discharge the exhaust gas downwardly, as clearly shown in Fig. 2. This is done so that if the pumping mechanism is submerged in the oil or liquid which is to be pumped, there will be no tendency of the liquid to flow downwardly into the pipe If necessary, the exhaust pipe I may be bent into coil shape with one or more turns to insure against the entrance of the liquid from the well into the pipe I04 and possibly into the slide valve 81. The check valve I06, however, eifectively prevents liquid from passing to the slide valve.

Packing formed of a plurality of rings of V- shaped cross section, such as the-rings 56 shown in Figs. 3, 5, and 18, which may be made of rubber or other flexible material capable of withstanding oil and which may be reinforced with fabric, if desired, has been found to be very desirable for use in connection with surfaces which are lubricated with oil, such for example as crude oil with which my apparatus may advantageously be used. These rings as used in connection with the pumping piston in conjunction with the annular rigid grooves and projections which coopperate with the end rings serve to spread the inner and outer edge portions of the rings into contact with the inner and outer surfaces with which they cooperate. Each ring by itself forms a seal equivalent to that of ,a cup leather, and since these rings may be nested one within the other, it is obvious that a, plurality of such seals may be provided in a relatively small space. Furthermore, a plurality of these rings may be nested one within the other and no metallic or rigid rings are required between adjacent flexible packing rings, which further reduces the cost of the packing and decreases the space required. Consequently, the use of these packing rings with parts exposed to crude oil results in a very efficient seal or packing which has a much longer life than cup leathers or the like heretofore used. However, if the power piston is to be used in connection with air or gas, cup leathers 44, such as have heretofore been commonly used, are preferred, since packing rings, such as the rings 56, would require a large quantity of oil or lubricant, if used on the power piston.

I have also shown packing rings I30 of the same form as the rings 53 in connection with a packing between the piston rod 4| and the upper portion of the casting or cylinder head 34, to prevent the liquid which is being pumped from entering the power cylinder. These packing rings I30 are arranged in two groups, the rings of the lower group being arranged so that the V-shaped cross section is inverted or faces downwardly to prevent the pumped liquid from entering into the power cylinder, and the upper roup of rings faces .the opposite direction or upwardly to prevent gas or other motive fluid from the power cylinder 40 from passing downwardly into the pumped liquid. In this construction, I have shown a metal ring I3I having an upwardly extending annular portion of inverted V-shape, which fits into the annular concave portion of the lowest ring. Between the two groups of packing rings, I provide another metal or rigid ring I32 having annular V-shaped recesses in the upper and lower faces thereof, in which the ad- Jacent packing rings I30 of the two groups may seat. A packing nut I33 which engages the upper ring of the upper group and has its lower face provided with an annular V-shaped projecting part which enters within the upper ring. Consequently, by tightening this packing nut I33, all of the rings are compressed so that their inner and outer edges are urged into contact with the piston rod BI and the wall of the casting 34 respectively. Other packing or sealing means may, of course, be employed in place of those described.

The wellpumping mechanism described, in addition to the advantages already referred to, is very efilcient and positive in its operation.

The valve'mechanism described enableslth'e reciprocatory parts of the pumping mechanism to be stopped at the opposite ends of their strokes by cushions of the motive fluid, thus avoiding jars or vibrations, which would tend todecrease the life of the mechanism. By means'of the sediment receptacle described, the finely divided oilsand or. other sediment is' kept out of the operating parts of the pump, which makes it possibleto keep this pump in operation in a well for much longer periods of time than has heretofore been possible in'connection with other pumps. The

the top of said sediment chamber, said'head also having a passage therethrough through which liquid may pass upwardly out of said sediment chamber. a

3, In an oil well pump, the combination of a pump cylinder, a piston therein, a housing member arranged about said cylinder and forming therewith a sediment chamber, a cap closing the pump piston packing describedfis not only more efiicient in preventing the passage of pumped liquid, but also is lower in first cost and of much longer" life than packing heretofore employed. All of these featuresadd verygreatly toithe lower end of said housing member, means'extendin hrough said cap for admitting liquid to the lower end of said cylinder, a head for said cylinder which also closes the upper end of said sediment'chamber and having a passage therein for conducting liquid from the upper end of said cylinder and extending downwardly into the up- -per portion'of'sald sediment chamber, said head length' oftheperiodof time during which the pump may operate ina wellbefore'itis necessary to pull the same .out' for cleaning; adjustment'orrepairs. i

Some of the subject matter not herein claimed 1-. The combinationof an oil well pump having afreciprocatory piston'and adapted to deliver oil at each stroke of the piston, a stationary downwardly directed delivery duct through which -oil"is 'discharged from said pump, a sediment forms thebasisof my copending divisional a-pplic'atlon, Serial ,No. 439,014; filed May V29, 1943. v I claim as my invention:

having another passage through which liquid may 'pass'upwardly from the upper portion of said sediment chamber, and a discharge duct connected with said other passage for conducting liquid from said sediment chamber out of the ,well, whereby sediment precipitated in said duct will collect in said sediment chamber and is prevented from passing upwardly into said downwardly directed passage leading to the upper end of said cylinder.

4. In an .oil well pump, the combination of a pumping cylinder, a housing member arranged about said cylinder and forming therewith a sedichamber having one side of thevupperportion thereof communicating with said delivery duct,

and a discharge passage leading upwardly from the opposite side'of theupper end of said chambeIQtD form a-path forthe flow of oil which I extends downwardly in said delivery duct, sub- 'stantially horizontally in the upper portion of said sedimentchamber, and then upwardly in said discharge passage.

2. In a well pump, the combination of a pumping cylinder, a housing'member arranged about said cylinder and forming therewith a sediment chamber, means for closing the lower endof said housing, means for admittingliquid' to be pumped ment chamber, a cap forthe lower end of said housing member and provided with an opening for admitting oil to the pump through said cap intoithe lower end of said cylinder, 9. piston in said cylinder formed to discharge oil during each stroke thereof, a head closing the upper end of said cylinder and said housing member and having a passage therein for discharging oil from the upper end of said cylinder into the top of said sediment chamber, said head also having a sec- 0nd passage-therein'through which, oil-may be discharged upwardly out of said sediment chamber, said passages in said head being spaced from each other to cause oil to flow from one passage to another through the upper portion of said sediment chamber, whereby when said pump is in operation, a. substantially continuous stream of oil passes through the upper portion of said I sediment chamber.

EARLE w. REARWIN.

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