US2775212A

US2775212A - Pumping equipment for wells

Info

Publication number: US2775212A
Application number: US293391A
Authority: US
Inventors: Lewis D Hilton
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-06-13
Filing date: 1952-06-13
Publication date: 1956-12-25
Anticipated expiration: 1973-12-25

Description

Dec. 25, 1956 L.. D. HILTON PUMPING EQUIPMENT EOE WELLS 2 Sheets-Sheet l Filed June l5, 1952 IN VEN TOR.

BY M @Wf- /4 TTOR/VEY Dec. 25, 1956 D. HILTON 2,775,212

l PUMPING EQUIPMENT FCR WELLS Filed June l5, `1952 2 Sheets-Sheet 2 Lem/A5` L7. H//zon INVENTOR.

/j TTOR/VE Y United States Patent PUMPING EQUIPMENT FOR WELLS Lewis D. Hilton, Houston, Tex.

Application June 13, 1952, Serial No. 293,391

6 Claims. (Cl. 103-225) This invention relates to pumping equipment for wells, and more particularly to a pump staging device adapted for application to a pump sucker rod.

The invention is particularly applicable to fluid lift pumps of the type used in the operation of oil wells, and

in which a working 'barrel is provided having a standing 4valve and a traveling valve associated therewithJ and a fsucker rod for reciprocating the traveling valve, the invention residing in the application of one or more stagers :at spaced intervals throughout the length of the sucker rod.

' In pumps of the type referred to the sucker rod is usually several thousand feet long, andis connected at its lower end to the pump traveling valve or plunger, which reciprocates within the working barrel or cylinder. This combination of sucker rod, `traveling valve,`working barrel and standing valve is subjected to the load imposed by a continuous column of fluid extending from the bottom of the well to the ground surface.

The `sucker rod and traveling valve are reciprocated during the pumping operation at a rate varying from about 8 to 2S strokes per minute depending upon the requirements of the well, with a stroke which varies from `V about 24 inches to about 94 inches or longer. Under these conditions the movement ofthe rod is `reversed at the rate of 16 to 56 or more times per minute, and the rod on the upstroke must bear a load, in addition to its own weight, which is equal to the weight of the entire column of fluid above the variable fluid level in the well traveling valve and the pounds weight of the uid which is lifted depends upon the diameter of the tubing, the height of the iluid column, the nature of the fluid and the friction between the Huid in the tubing.

The weight` imposed on the sucker rod during its upstroke causes the rod to stretch, so that the travelof the walking beam or other operating mechanism at the ground surface is usually substantially greater than the corresponding travel of thetraveling valve at the lower end I u of the upper end of the rod takes place substantially in advance of the beginning of such upward movement `of the traveling valve, which causes a sudden and violent jerking on the rod, at thebeginning of` each upward stroke.

Continued reciproeation of the rod, accompanied by the l reversal of movement at each end of its stroke, under the conditions` described, results in frequent breakage of .the rod involving great loss of timefand labor inmaking replacement, t

The eXCSsvf11Qadimpesed on the mechanism ofthe.

pump assembly, due to the fact that the pressure exerted by the fluid column is borne by the traveling valve, also results in rapid wear to the point finally of failure to lift the fluid to the required elevation, making it necessary that the mechanism be removed from the well to effect repairs. Such removal and repair constitutes a large item of expense in the operation of oil wells by the reciprocating pump method.

The present invention has for its chief object the provision of a pump stager, which may be readily applied to conventional sucker rods mechanism, and which functions to relieve the traveling valve of a large part of the pressure which would otherwise be imposed thereon during the operation of the pump.

Another object of the invention is the provision of a pump stager adapted to be applied to conventional sucker rod mechanism, and which functions to substantially reduce the stress resulting from the reversal of the motion ofthe rod at each end of its stroke.

A further object of the invention is to provide a pump stager of a construction to enable a number of such stagers to be readily applied at spaced intervals throughout the length of a sucker rod, and which functions to distribute the imposed pressure load along the rod to relieve the traveling valve of the undue stresses which would otherwise be borne by it.

A still further object of the invention is the provision of a pump stager of simple design, requiring no alteration or addition as to length or other dimension of the conventional sucker rod mechanism for application thereto, and which is easily applied without the use of any special tools or equipment.

The invention also embodies the provision of a pump stager comprising a sleeve-like body adapted to be positioned about a sucker rod, and having means thereon which may be bent inwardly to cooperate with an adjacent portion of the sucker rod to retain the stager in position thereon, the stager being also cooperable with a coupling member on the rod to close the stager during the upstroke of the rod.

The above and other objects and advantages of the invention will best be understood from the following detailed description, constituting a specication of the same, when taken in conjunction with the accompanying drawings, wherein- Figure l is a fragmentary, side elevational View, partly in cross-section, of a portion of a pump tubing in a well, showing the pump rod therein equipped with the invention;

Figure 2 is a cross-sectional view of the invention, taken along the line 2-2 of Figure 3;

Figure 3 is a central, vertical, cross-sectional view of the invention; l l

Figure 4 is a fragmentary, side elevational view, partly in cross-section on a somewhat enlarged scale, showing the invention in position on the pump rod, and illustrating the manner in which the invention operates during the upstroke of the rod;

Figure 5 is a fragmentary side elevational view, partly in cross-section, similar to Figure 4, showing the operation Vof the invention during the downstroke of the pump rod; and

Figure 6 is a fragmentary cross-sectional view of a modified form of the invention.

Referring now to the drawings in greater detail, the numeral 10 designates the pump barrel, within the lower end of which there is the upwardly opening and downwardly closing standing valve 12.

Positioned in the barrel, for reciprocation therein above the standing valve, there is a conventional upwardly opening anddownwardly closing traveling valveor plunger 14, which is connected to the lower end of thc pump rod, designated generally by the numeral 16, and which is also known as the sucker rod.

The conventional pump barrel is connected to the lower end of the well tubing 18, which is o f slightly greater inside diameter than the inside diameter of the barrel, and which extends to the ground surface.

The traveling valve 14 is reciprocable and is operated by the pump rod. This rod extends to the ground surface and is operated by a Walking beam, of conventional construction or other suitable operating equipment.

On the upstroke of the traveling valve this valve is closed and elevates the fluid labove it and at the same time draws in a charge of well uid 4through the standing valve 12. Upon upstroke of the traveling valve the standing Valve will open andthe fluid above it will pass up through the traveling valve to be elevated upon the next succeeding upstrokeV of the traveling valve.

During the operation of the pump the pump tubing is tilled'from the pump to the ground surface and upon each stroke of the traveling valve, when'operated by a pump rod of conventional construction, the entire colume Vof uid must be lifted thus imposing on the pump rod( not only its own weight but the' pounds weight of the colume of the duid being pumped as well; at the end of the upstroke and beginning of the downstroke the weight of the fluid is released and upon downstroke of the pump, relieved of its uid'load, the rod moves downwardly very rapidly, that is it substantially drops and is suddenly checked by the reversal of movementy of the walking beamv from downstroke to upstrokefthus imposingk great stress not only on the pump rod itself but also on the operating equipment. This'causes a stretching of the pump rod and also prevents the walking beam or other operating equipment from moving in unison with the traveling valve. In other words the true harmonics of the cycle is interfered with.

In order to overcome these objections the pump rod hasbeen equipped with lift valve assemblies, or stagers, spaced apart` therealong and whereby the load in the pump tubing will be distributed along the rod upon upstroke of the pump rod, said lift valve assemblies, or stagers, being of such construction that they will operate to overcome the undesirable out-of-harmonics movement of the pump rod and traveling valve in its operation.

` 'The pump rod 16 is made up of sections of conventional construction, conforming to the standards of the American Petroleum Institute, each section being formed with an externally threaded pin at each end, the adjacent ends of successive sections being connected together by an internallythreaded'tubular coupling or box-member 215, The rod sections are also formed with enlargements 24- forming pin` shoulders adjacent the pinsland with squared wrench-engaging portions 20, adjacent each of the pin shoulders for the` convenient application `of a wrench'in connecting or disconnecting the rod sections. Each of the .Squared portionsZO terminates in a somewhatY rounded enlargement `22', called a bead, andwhose external diametermust be noA larger than the external diarneter of the pinv shoulder 24 according to A.` P. I.l standards. Each of the beads 22 has-an upset curve 23 mergingl into the squared portion 2i)` andV an up-start portionZS forming a smooth curve merging with the body of the rod.

The stager of the invention is applied to the labove described pump structure, as best seen in Figures 4 and 5 of the`drawings', the stager comprising a sleeve-like body 28, which may be ofone piece of suitable material, such as steel, or the like, or which may be formed with an upper portion 30, of a different material, such as plastic, rubber, ,Or the like, and a lower portion 32 which may be of a relatively harder material, such as steel, bronze, or material oflike properties. The upper and lower portions`30., and 32 of the stager may be secured to-A gether in any suitable manner,A such as byl a dovetailejd connection,,indicated-at 34..`

The stager 28 has an internal diameter slightly greater than the external diameter of the

enlargements

22 and 24, but substantially less than the external diameter of the coupling member 26, so that the stager may move freely on the rod over the enlargements, but will seat at its lower end upon the upper end of the coupling 26, during the upstroke of the rod.

Side openings or windows 36 are provided in the sleeve-like body 28, and the bodies are also formed with upwardly extending lugs 38 within the openings 36. When the upper portion 30 of the stager is formed of metal, or other suitable bendable material, the lugs 38 are cut out of the material, and extend straight upwardly from the bottom of the window opening before application of the stager to the pump rod. On the other hand, if the upper portion 3i) of the stager is formed of a somewhat resilient material, such as plastic, rubber or the like, the lugs 38 may then be formed by moulding in the inwardly curved condition, as best seen in Figures 4 and 5 of the drawings.

The sleeve-like body 28 constitutes in effect a valve cage which may be of any desired length, but is preferably of a length to extend upwardly beyond the enlargement 22, andthe lower end of the stager may, if desired, be provided with an internal beveled face 40 forming a valve seat, and the upper end of the coupling 26 may have a corresponding external beveled face 42 forming` a valve, upon which the face 40 may seat when the stager is in its lowermost position in contact with the coupling 26, to substantially close the tubing against downward flow of uid during upward movement of the rod.

The external diameter of the stager throughout its length is preferably somewhat smaller, than the internal diameter of the tubing 18, to provide an annular passageway about the body for the slight leakage of iluid past the body, which serves as a lubricant. By this arrangement the stager may move freely in the tubing with the rod 16, but will engage the tubing and prevent the rod from rubbing and in consequence wearing out the tubing during the operation of the pump. External downwardly and inwardly converging grooves, such as those indicated at 41, 41, may also be provided in the sleeve-like body, forming annular pockets for the retention of fluid therein from the annular passageway.

In applying the invention to the pump rod the lower end of one section of the rod is uncoupled at the location Where the stager is to be applied, and the stager is tted over the lower end of the rod, until the window openings 36 are opposite the squared portion 20, and the rod section is again attached to the coupling 26. When the upper portion 30 of the stager is formed of metal, the lugs-38 are bent inwardly by means of a hammer, or otheixtool, so that the upper ends of the lugs will engage the-*enlargement 22, upon upward movement of the stager ontherodwto limit the upward movement of the stager relative tethered. In the-event that the upper section 30of the stager is-formed of relative resilient material, sutsh` as plasticrubber, or the-like, then the lugs 3S` may bespread apart at their upper ends to enable theV stager to. be moved over t-he pin shoulder 24, after which the lugs willreturn to their inwardly curved positions, and Willengage the bead 22 to limit upward movement of the stager relative to thev rod.

It -will be noted that in the raised position of the stager, as Seenin-Figure 5 `of the drawings, the window openings 36 are opposite thefbead 22, and by varying the size ofithe opening, the cross-sectional area of the passageway about the bead 22may be adjusted to any desire-d size, so that the upward ow of uid through the stager on.the downstroke of the pump rod may regulate to any degree desired.

Upon downward movement of the rod the stager will bezlifted as seen` in Figure 5,`to permit fluid beneath to pass upwardly through the stager, about the bead22of the rod. Aftenthe rod has reached the limit of its downward` movement and starts to move `upwardly the lower end of the stager engages the upper end of the coupling or box 26, thus closing the stager against downward movement of uid therethrough, and uid above the stager is then lifted by the stager during the upstroke of the sucker rod. Fluid above the stager is thus prevented from owing freely downwardly during upward movement of the pump rod, and because of the spacing of the stagers on the rod, the pressure load of the liquid column in the tubing will be distributed substantially uniformly along the rod.

In Figure 6 there is illustrated a somewhat modified form of the invention, wherein the sleeve-like body 28 is a similar construction to that previously described, except that instead of the lugs 38, portions 44 are provided extending longitudinally across the window openings 36', which portions are relatively narrow and may be provided with inwardly extending projections 38'.

Thismodiiied form` of the sleeve-like body is applied to the pump rod in a manner similar to that previously described, the portions 44 being suliiciently flexible to permit the projections 38' to be forced past the bead 22 or the pin shoulder 24, upon installation on the rod and then flex back into operating position, and the projections 38 being engageable with the bead 22 to limit upward movement of the stager on the downstroke of the pump rod.

The form of the invention illustrated in Figure 6 functions in the same manner as that previously described.

It will thus be seen that invention, as described above, provides a pump stager which is of simple design and rugged construction, capable of being easily applied to a sucker rod of standard construction, and which is efficient in operation to distribute the load of the liquid column substantially uniformly throughout the entire l length of the sucker rod, thus relieving the traveling valve of a large part of the load usually imposed thereon.

The invention has been described in connection with a specific embodiment of the same, but it will be understood that this is by way of illustration only, and that numerous changes 'can be made in the structure of the device, as well as the materials from which it is made, without departing from the spirit of the invention or the scope of the appended claims.

Having thus clearly shown and described the invention, what is claimed as new and desired to secure by Letters Patent is:

1. In well equipment the combination of a well tubing and a reciprocable sucker rod in the tubing to operate a pump beneath, said rod being formed in sections each having an externally threaded pin at its opposite ends terminating in an external enlargement providing a pinshoulder and also having an externally enlarged bead, internally threaded coupling of larger external diameter than said enlargement and bead connecting the adjacent ends of successive sections of the rod, and a tubular stager surrounding the rod and movable longitudinally in the tubing, said rod being movable longitudinally relative to the stager, said coupling being engageable with the lower end of the stager to close the stager upon upward movement of the rod and being movable downwardly out of engagement with said lower end to open the stager upon downward movement of the rod, and means on the stager positioned for engagement with said bead to limit downward movement of the rod relative to the stager, said stager having a lateral opening mediate its ends positioned to lie opposite said bead when the stager reaches the limit of its upward movement relative to the rod.

2. In well equipment the combination of a well tubing and a reciprocable sucker rod in the tubing to operate a pump beneath, said rod being formed in sections each having an externally threaded pin at its opposite ends terminating in an external enlargement providing a pinshoulder and also having an externally enlarged bead, an internally threaded coupling of larger external diameter than said enlargement and bead connecting the adjacent ends of successive sections of the rod, and a tubular stager surrounding the rod and movable longitudinally in the tubing, said stager having an internal diameter greater than said pin-shoulder and said bead and said rod being movable longitudinally in the stager, the lower end of said stager being engageable with said coupling upon upward movement of the rod to close the stager and being disengageable from the coupling upon downward movement of the rod to open the stager, said stager having a lateral opening and means on the stager projecting inwardly from the lower margin of the opening and in position for engagement with said bead to limit downward movement of the rod relative the stager.

3. In well equipment the combination of a well tubing and a reciprocable sucker rod in the tubing to operate a pump beneath, said rod being formed in sections each having an externally threaded pin at its opposite ends terminating in an external enlargement providing a pinshoulder and also having an externally enlarged bead, an internally threaded coupling ot larger external diameter than said enlargement and bead connecting the adjacent ends of successive sections of the rod, and a tubular stager surrounding the rod and movable longitudinally in the tubing, said stager having an internal diameter greater than the pinshoulder and said bead and said rod being movable longitudinally in the stager, the lower end of said stager being engageable with the upper end of the coupling upon upward movement of Y the rod to close the stager and being disengageable from the coupling upon downward movement of the rod to open the stager, said stager having a lateral opening above its bottom end, and means on the stager extending inwardly of said opening in position for engagement with said bead when the opening reaches a point opposite said bead to limit downward movement of the rod relative to said stager.

4. In well equipment the combination of a well tubing and a reciprocable sucker rod in the tubing to operate a pump beneath, said rod being formed in sections each having an externally threaded pin at its opposite ends terminating in an external enlargement providing a pinshoulder and also having an externally enlarged bead, an internally threaded coupling of larger external diameter than said enlargement and bead connecting the adjacent ends of successive sections of the rod, and a tubular stager surrounding the rod and movable longitudinally in the tubing, said rod being movable longitudinally in the stager, said stager having a lower portion adapted to seat on said coupling to close the stager upon upward movement of the rod and to move out of engagement with the coupling to open the stager upon downward movement of the rod, said stager also having an upper portion of greater internal diameter than said bead, said upper portion having a lateral opening therethrough and resilient means on the upper portion and extending inwardly of said opening in position to engage said bead when the opening reaches a point opposite the bead to limit downward movement of the rod relative to the stager.

5. In well equipment the combination of a well tubing and a reciprocable sucker rod in the tubing to operate a pump beneath, said rod being formed in sections each having an externally threaded pin at its opposite ends terminating in an external enlargement providing a pinshoulder and also having an externally enlarged bead, an internally threaded coupling of larger external diameter than said enlargement and bea-d connecting the adjacent ends of successive sections of the rod, and a tubular stager surrounding the rod and movable longitudinally in the tubing, said stager having an internal diameter greater than the pin-shoulder and bead, said rod being movablelongitudinallyfin therstager, said stager being engageablefabits-lower end withV the couplingto closey the stagerL upon upward movement of the rod and being movable-outfof contact withA the coupling to open the stager uponV downward movement of the `rod, said stager having alv lateral opening therethrough, and bendable means'- in said opening adapted when bent to extend inwardly of=the stager to engage' said bead to limit down-` ward movement ofthe rod relative to said stager.

6. Inwell equipment the combination of a well tubing anda reciprocable sucker rod in the tubing to operate 'a'.pump, beneath; said rod being formed in sections each having an externally'threaded pin at its opposite ends terminating in-an external enlargement providing a pinshoulder aud also having externallyk enlarged bead, an internallyirthreaded coupling of larger external diameter than *said enlargement and bead connecting the adjacent ends of successive sectionsy of the rod, and a tubular stagen surrounding lthe rod and movable longitudinally in thetubing, said `stager having an internal diameter greater than the -pin-shoulderfandfsaid bead, and said rod'A being movable longitudinally in the= stager,` thel lower end.I of saidfstager' beingVV engageable` with the upper end' ofl-'thecoupling uponxupward movementlof the rod to close the-'stager andbeing disengageable fromthe coupling upon downward-movement ofwtherod to open the stager, said-stagerhaving a lateral opening above its bottom end, and; flexible means on the stager extending inwardly of'saidl opening and adapted tobe flexed out wardly by engagementwith said bead 'upon downward movementof the'stager on the'rodato permit said means to move downwardly past the bead,V` said means being engageablewiththe bead when said opening-reaches a point. opposite thel bead to limit upwardfmovement of the stager relative to the rod.

eier-ences Cited vin'the le of this patent UNITED STATES PATENTS 1,567g827 Zublin Dec. 29, 1925 1,646,134 Black Oct. 18, 1927 1,810,121 Black June 16, k19.31