US2933050A

US2933050A - Oil well pump

Info

Publication number: US2933050A
Application number: US661053A
Authority: US
Inventors: Leland S Crowl; Alvin M Markwell
Original assignee: Reynolds Oil Well Pumps Inc
Current assignee: Reynolds Oil Well Pumps Inc
Priority date: 1957-05-23
Filing date: 1957-05-23
Publication date: 1960-04-19
Anticipated expiration: 1977-04-19

Description

April 19, 1960 s. cRowL ET AL OIL WELL PUMP Filed May 23, 1957 'NIE x l1 FIG.I 2

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EL/WVU f5: @POM/L HLW/V M MHP/(Will BY MMO@ United OEL WELL PUMP Application May 23, 1957, Serial No. 651,053

Claims, (Cl. mm-179) This invention relates to improvements in reciprocating pumps, and more particularly, but not by way of limitation, to improvements in pumps used in the lower portion of an oil well to remove oil from the well.

As it is well known in the oil industry, the majority of the present day oil wells being produced by artiiicial lifting means utilize a sucker rod pump to lift the oil. Sucker rod pumps are reciprocating pumps which are operated by a surface power unit through use of a string of rods extending from the surface downwardly through the well to the piston of the pump. Many different types of sucker rod pumps have been devised, including pumps wherein all of the working parts of a pump are formed out of metal to minimize the possibility of damage to the pump when it is placed in operation following a substantial period of idleness. In many oil wells, the oil contains a substantial amount of sand which will gravitate, when the oil stands in the oil well tubing above the pump, onto the working parts of the pump and tend to stick the pistons and valves of the pump. When a sucker rod pump is started after a period of idleness, substantial force must be used to break the pistons and valves loose for their normal operation.

To the best of our knowledge, all-metal pumps heretofore devised were rather intricate and expensive to manufacture. Furthermore, previous all-metal sucker rod pumps were not easily adapted for use in wells of different depths. That is, a specic pump could not be used interchangeably in deep and shallow wells, unless the entire piston structure of the pump were duplicated when moving the pump from a shallow to a deep well. The piston and traveling valve assembly of prior all-metal pumps were constructed to operate individually; therefore, when a higher column of oil was to be lifted, the entire piston and traveling valve system had to be duplicated, with the various assemblies connected by extra rods to obtain the necessary pumping capacity. In addition, the previous all-metal sucker rod pumps are subject to excessive wear and have relatively short service lives.

The present invention contemplates a novel al1-metal reciprocating pump, wherein the piston and traveling valve assembly may be extended in an easy and convenient manner to provide a pump which may be readily adapted for use in wells of substantially any depth. The present piston and traveling valve assembly comprises a series of vertically spaced heads, with a sleeve disposed between each pair of the heads. During operation, each sleeve cooperates with the lower adjacent head on the up stroke to form a piston for lifting a column of oil above the pump. On the down stroke, each sleeve cooperates with the upper adjacent head to form a traveling valve for movement of the piston and traveling valve assembly downwardly through oil in the pump, while the oil is prevented from downward movement by the usual standing valve. Each head is constructed in the same manner, as is each sleeve, whereby the length of the piston and traveling valve assembly may be increased by the addition of a single head and sleeve to permit use rates Patent l threaded for connection with a of the pump at a lower pumping depth. The present invention also contemplates other improvements to provide a pump having a substantial service life.

An important object of this invention is to provide a sucker rod pump which may be easily and economically adapted for use in wells of diiierent depths.

Another object of this invention is to provide a sucker rod pump structure wherein the operating depth of the pump may be increased by the addition of a minimum number of working parts to the pump.

A further object of this invention is to provide a sucker rod pump structure which may be assembled, disassembled and adapted to a diierent depth well with the minimum possibility of error and which operations may be carried out with a minimum of training.

A still further object of this invention is to provide the maximum standardization in the various working parts of an al1-metal sucker rod pump to obtain an economical apparatus.

Another object of this invention is to provide an allmetal sucker rod pump which has a long service life.

Other objects and advantages of the invetnion will be evident from the following detailed description, when read in conjunction with the accompanying drawings which illustrate our invention.

In the drawings:

Figure l is a vertical sectional View through a pump constructed in acrdance with this invention.

Figure 2 is an enlarged cross sectional View illustrating the details of construction of the heads and sleeves.

Figure 3 is a sectional -view as taken along lines 3--3 of Fig. 2.

Figure 4 is a sectional View as taken along lines 4-4 of Fig. 2.

Referring to the drawings in detail, and particularly Fig. l, reference character 6 generally designates a pump structure embodying the present invention and including an elongated tubular working barrel 8. The pump 6 may be of any suitable type, but is preferably of the type which is inserted in the lower portion of an oil well tubing and which may be removed separately from the tubing. The working barrel 3 is of substantial length and has a suitable guide structure (not shown) in its upper end to slidingly receive the lower end portion of a string of sucker rods extending from the :surface of the well. The lower end of the sucker rod string is suitably connected to the upper connecting rod lll of the pump 6 for operating the pump, as will be more fully hereinafter set forth.

The lower end of the working barrel S is internally tubular valve cage l2 having the usual spider lll: in the upper portion thereof to limit the upward movement of a ball type standing valve 16. Apertures i7 extend through the spider 14 in the usual manner. The lower end of the valve cage 12 is also internally threaded to receive the upper end of a suitably constructed anchor or shoe 1S. A seat 20 for the valve i6 may be secured between opposed shoulders in the cage l2 and the anchor i3.. The anchor 13 is utilized to seat the pump 6 in a complementary shaped shoe secured on the lower end of the well tubing in a conventional manner, whereby the pump a will be anchored in the lower end of the tubing by friction, yet the pump 6 may be pulled upwardly through the tubing when a substantial force is imposed on the sucker rod string.

The piston and traveling valve asesmbly, generally designated at 22, is reciprocally disposed in the wor g barrel S above the standing valve 16 to lift oil entering Y the working barrel through the anchor i8, valve seat 20 and valve cage 12. Generally speaking, the piston and,

traveling valve assembly comprises a series of vertically spaced heads 24 interconnected by the connectingrods le, and a sleeve 26 around each rod 10 between eachl pair. of heads 24. Aswill be observed, the length of each sleeve 26 is less than the distance between each pair of'heads 24, whereby the sleeves 26 will be moved in the working barrel 3 relative to the heads 24 when the direction of movement of the heads is reversed.

As shown in Figures 2, 3, and 4, each head 24 is cylindrical in configuration and of a diameter substantially conforming to the inner diameter of the working barrel il to provideaV sliding lit of each head 24 in the working barrel. A series of circumferentially spaced grooves 28 are4 cut longitudinally in the periphery of each head 24 to provide an upward flow of oil around each head on the down strokeY of the pump, yas will bemore fully hereinafter set forth.` Each groove 28 is of varying depth,v

with the depth of` the vgroove at the lower end of the respective head 24 being greater than the depth of the groovefat the upper end of the respective head. Therefore..V oilowing upwardly through the grooves 2S will be directed outwardly toward the inner. periphery of the working barrel S to provide a washing action against the barrel 8 at the upper end of each head 24 during downward movement of the heads.

A longitudinal bore 30 is provided through the central portion of each yhead 24, and the opposite end portions of each bore 3d are threaded to receive the threaded ends 32 of the respective rods 10 and'interconnect the heads 24. lt will also be observed that the end portions 32 of each connecting rod 10 are reduced in diameter to provide a circumferential shoulder 34 facing the respective end of the respective head 24. The threaded portions 32 of each rod it) are threaded into the respective heads 24 until the shoulders 34 seat against the ends of the heads, whereby the rods tend to retain the heads 24 in alignment. This alignment, in combination with the close fit of the heads 24 in the working barrel 8, minimizes Aany whipping action of the piston and traveling valveassembly during reciprocation of the pump which may be due to a whipping movement normally encountered with the sucker rods extending from the surface down through the well into connection with the upper head24. i Y

The outer portion 36 of the upper end of each head 24 is tapered downwardly and outwardly, and the outer portion 38 of the lower end of each head Z4 is tapered upwardly and outwardly. The upper and lower ends 4l), and 42, respectively, of each sleeve 26 are tapered in opposite directions, in such a manner that the upper end 4? of each sleeve 26 will seat on the lower end 38 of the respective upper adjacent head 24, in an upper position of the sleeve, and the lower end 42 of each sleeve 26 will seat on the lower adjacent head 24 in the lower position of the sleeve. It will alsobe observed that a small circumferential groove 44 is formed in the outerperiphery of each end of each headr24 to prevent interference with the outer end portion of the respective sleeve 26 and to provide a trap for sand, as will be more fully hereinafter set forth.

As previously indicated, each sleeve 26 is of a length less' than the distance between the respective upper and lower heads 24- to provide a relative movement of the sleeves with respect to the heads. The outer Vdiameter of each sleeve 26 substantially conforms to the inner diameter of the working barrel 3 to provide atight sliding lit of the sleeves inthe barrel such that the sleeves will not slide in the barrel under their own weight. The inner diameterofeach sleeve 26 is substantially greater than the diameters of the connecting rods 10 to provide enlarged annular-shaped passageways 46 through the sleeves. The wall thickness of each sleeve 26 is less than the depth of the grooves 28 at the lower 'gaseoso ends of theheads 24, but greater than the depth of the grooves 23 at the upper ends of the headv 24. Thus,

when a sleeve 26 is seated on the upper end of a head 24, the sleeve Z6 closes olf the upper ends of the respec-` tive grooves 28 to prevent a liow of oil through the respective head 24. However, when the upper end of a sleeve 26 is heated against the lower end of a head 24, the respective grooves Ztrare not closed off, and oil may flow through the respective grooves 2S.

Y Operation With the pump 6 installed in the lower end of a string lof' well tubing, and the upper connecting rod 10 conas illustrated in Fig. l, each sleeve 26will be seated on v the lower adjacent head 24,' whereby Yeach sleeve 26 and head 24 forms a pistonfto force oil upwardly through*y the working barrel 3 and the tubing string extending' Each sleeve 26 will electively above the working barrel. close o the upper ends of the grooves 28 of the head 24 in contact with the sleeve, whereby the downward ilow of oil through each head 24 is prevented. Also during this up stroke, a suction is provided in the lower end of the working barrel 8 to provide an upward ow of oil through the anchor 18, valve seat 2t) and cage l2' into the lower end of the working ybarrelrS below the'lowerfhead 24. The standing valve 16 will be opened by the reduced pressure in the lower end of the working barrel d. V

.Upon areversal of movement, for the down stroke of the pump', each sleeve 26 will tend to remain stationary inV ther Working barrel 8, due to the friction fit of the sleevesl in the working barrel. Therefore, during the initial portion of the down stroke, ,the heads 24 will move downward relative tothe sleeves 26 to unseat the sleeves 26 from the heads 24 and open the various grooves 2S. Thus, the heads 24 are moved downwardly through oil standing in the working barrel 8, with the oil ilowing relatively upward through the grooves 2S around each head 24. It will be understood that the standing valve 16 will seat o'nto the seat 20 when the down stroke of the pump 6 is begun, due to the increased pressure in the lower end portion ofthe working barrel relative to the pressure of the uid standing in the well and in the anchor V19,.` v

'Continued downward movement of the heads 24 pro- Y vides a seating of each sleeve 26 on the lowerV end 38 ofaround each headr24. This downward movement provides, in effect, a displacement of oil from the lower portion` to the upper portion of the working barrel 8 above the piston and traveling valve assembly 22. At the completion of the down stro'ke, the direction of movement of the heads V24 is reversed; whereas the sleeves26 will again tend to remain stationary in the working barrel 3.V

During the initial portion of the up stroke, oil will llow downwardly through the grooves 23 around each head 24 and no pumping action will take place. However, after the heads24 have been moved upwardly a relatively short VdistanceLthe heads will contact the sleeves 26 and the sleeves, will be seated on the upper ends of the heads to again provide a pumping action in the man ner previously described.

Itis tobe especially notedthat the upward and outward ow ofoil through the grooves 28 aro'und each head 24;' during the down stroke of the pump provides an clicctive washing action. The oil is directed upwardly and outwardly .into` contact with the inner periphery .of the` working barrel 8 above each head 24 during the down stroke. This movement of the oil provides substantial turbulence to minimize the fgettling of sand and the like from the oil onto the inner periphery of the working barrel 8 where it would tend to interfere with the efficient operation of the sleeves 2d. However, when a substantial amount of sand is being pumped, a small portion of the sand will invariably deposit on the inner periphery of the working barrel at the opposite ends of each sleeve 26 during operation of the pump. The tapered ends of the sleeves 26 provides sharp edges for the the outer periphery at the end of each sleeve to edectively scrape deposited sand from the inner periphery of the working barrel 8. A portion of this sand will be moved ahead of the respective sleeve 26, and when a sleeve is seated on the end of a head 24, the scraped sand will be moved into the respective ends of the grooves 28 and into the small circumferential groove 44. The scraped sand will therefore not interfere with the seating of the sleeves 26. In addition to providing a receptacle fo'r sand, each groove 44 prevents the extreme outer edge portion of each sleeve 26 from coming into contact with the ends of the heads 24, where the ends of the sleeves 26 might be damaged.

We have found that a sleeve 26 eight to ten inches in length is required to lift about a o'ne thousand foot column of oil. Therefore, a three thousand foot well would require the use of three of the sleeves 26 and four of the heads 24 as illustrated in Fig. 1. With this combination, the three thousand foot column of oil in the well tubing would be raised by the piston and traveling valve assembly,'without appreciable leakage of oil downwardly around the sleeve 25 and between the sleeves 26 and the upper ends of the heads 24 during the up stroke of the pump. One of the major advantages of the present invention is the minimum additions required to be made to a pump structure when it is desired to use the pump in a deeper well. For example, when converting the pump 6 illustrated in Fig. 1 for use in a ve thousand foot well, it is simply necessary to add two sleeves 26, two heads 24 and two connecting rods 10 to the upper or lower end of the existing piston and traveling valve assembly 22. Assumingthe additional sleeves and heads are added to the upper end of the assembly 22, the rst sleeve 26 added will cooperate with the existing uppermost head 24 to prevent the necessity of adding an additional head for cooperating with the lower end of the lowermost sleeve addedto the assembly. Thus, the minimum number of elements need be added to an existing pump structure to convert the pump for use in a deeper well. This feature is particularly advantageous, not only from a cost standpoint, but also when it is realized that it is a practical impossibility for a supplier to retain a sucient stock of sucker rod pumps when special pump constructions are required for wells o'f different depths. With the present invention, a supplier need retain on hand a minimum number of working parts for a pump assembly, and a pump for any desired well depth can be obtained easily and economically by interconnecting the required number of sleeves and heads and inserting them in a working barrel of the required length.

From the foregoing it will be apparent that the present invention provides a novel pump construction which may be readily adapted to wells of different depths. When a pump is to be used in a deeper well, it is simply necessary to add working parts to the pump construction to obtain the necessary pumping capacity. Also, the uniform construction of the heads and sleeves facilitates the assembly and disassembly of the pump with the minimum chance of error in getting a part reversed, and such operations may be carried out with a minimum of training. It will be further apparent that the present pump construction has a long service life and may be economically manufactured.

Changes may be made in the combination and arrangement of parts or elements set forth in the specication and shown in the drawings, it being understood that changes may be made in the precise embodiment shown without departing from the spirit and scope of the invention as defined in the following claims.

We claim:

1. A pump for use in an oil well, comprising a tubular barrel; a standing valve in the lower end of the barrel to prevent a downward dow of oil from the barrel; a plurality of vertically spaced cylindrically shaped heads of uniform construction in the barrel; rods interconnecting the heads and maintaining the heads in equally spaced, and axially aligned relation; each of said heads being of a diameter to provide a sliding tit thereof in the barrel and having at least one longitudinal groove in the outer periphery extending from end-to-end thereof, with the depth of said groove being less at the upper end of the head than at the lower end of the head, and a sleeve in the barrel around the connecting rod between each pair of heads having an inner diameter substantially greater than the diameter of the respective rod and an outer diameter of a size to provide a sliding t of the sleeve in the barrel, the length of each sleeve being less than the distance between the adjacent heads, and the wall thickness of each sleeve being less than the depth of said groove at the lower end of each head and greater than the depth of said groove at the upper end of each head.

2. A pump as defined in claim l characterized further in that each head has a plurality of longitudinal, circumferentially spaced grooves in the outer periphery extending from end-to-end thereof, with each groove being of a depth at its upper end less than the thickness of said sleeve and a depth at its lower end greater than the thickness of said sleeves.

3. A pump as defined in claim 1 characterized further in that each head has a circumferential groove in each end thereof around the periphery thereof, each circumferential groove having a width less than the thickness of said sleeves.

4. A pump as defined in claim 3 characterized further in that the outer portion of the upper end of each head is tapered downwardly and outwardly, the outer portion of the lower end of each head is tapered upwardly and outwardly, and the ends of each sleeve are tapered to mate with the adjacent tapered ends of adjacent heads.

5. A pump as dened in claim 1 characterized further in that each of said rods is reduced in diameter and threaded at each end thereof, each of said heads has a longitudinal bore through the central portion thereof threaded at its opposite ends to receive the threaded portions of the respective rods, said threads being of a length such that each rod is threaded into the adjacent heads until the circumferential shoulders formed by the variations in diameter of the rod engage the respective end faces of the heads receiving the rod.

References Cited in the file of this patent UNITED STATES PATENTS 1,254,024 Bryan Ian. 22, 1918 1,545,722 Zublin July 14, 1925 2,261,469 Harter Nov. 4, 1941 2,475,705 Hunter July 12, 1949 2,615,401 Mock Oct. 28, 1952 2,674,955 Hilton Apr. 13, 1954 2,791,970 Hunter May 14, 1957