US2800859A - Subsurface pump - Google Patents

Description

July 30, 1957 R. L. CHENAULT 2,800,859

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his Attorney.

.United States PatentO.

v 4 SUBSURFACE PUMP Roy L. Chenault, Seneca, Pa., assignor to United States Steel Corporation, a corporation of New Jersey Application January 12, 1955, Serial No. 481,440

2 Claims. (Cl. 10S-46) e This invention lrelates to improved hydraulically oper- Vated free-type subsurface pumps.

Hydraulically operated pumps, which can be used in oil wells in lieu of the more vcommon sucker rod pumps,

area of the pump. Consequently the initial unseating requires abnormally high pressure, and equipment must be available for producing peak pressures considerably greater than needed for normal operations.

' An object of the present invention is to provide an improved free-type pump in which oil forced down to unseat the pump acts initially on the entire cross-sectional area, thereby facilitating unseating and reducing pressure requirements.

My earlier Patent No, 2,679,806', dated June 1, 1954, `shows a hydraulically operated vsubsurface pump combination whichembodiesa single-acting pump and yet Vaehieves a balanced load on both the upstroke and downstroke, although not illustrated as of the free-type. A further object of the present invention is to provide a free-type construction especially adapted for single-acting pumps, for example as shown in my earlier patent, although similar principles are applicable to double-acting pumps, more common in hydraulically operated installations.

A more specific object is to provide an improved freetype pump which includes means for transmitting the initial unseating pressure beneath the pump, thereby applying this pressure to the full cross-sectional area of the pump and reducing pressure requirements.

In accomplishing these and other objects of the invention, I have provided improved details of structure, preferred forms of which are shown in the accompanying drawing, in which:

Figure l is a vertical sectional View of a motor and pump combination constructed in accordance with my invention;

Figure 2 is a fragmentary vertical sectional view on a larger scale showing part of the combination in more detail;

Figure 3 is a fragmentary vertical sectional view showing a modification; and

Figure 4 is a fragmentary vertical sectional view showing another modification.

Figure 1 shows a free-type pump combination which includes a hydraulic motor 10 and a pump 12 joined to form a unit. The well contains parallel rst and second strings'of tubing 13 and 14. The rst tubing 13 includes a coupling 15, a nipple 16 extending downwardly from said coupling, a seating coupling 17 joined to the bottom of said nipple, a spacer 2,800,859 'Patented July 30, 1957 tube 18 extending downwardly from said seating coupling, a crossover coupling 19 joined 'to the bottom of said spacer tube, and an extension 20 extending downwardly from said crossover coupling. The lower end of the second tubing 14 is joined to the crossover coupling and communicates with the interior of the spacer tube 18 via a transverse passage 21. The motor and pump combination is housed within the first tubing. The upper end of the motor 10 has a head 22, the exterior of which carries a packing ring 23 that ts closely within the coupling 17 to furnish an upper seat.

An external shoulder member 24 is connected between the motor 10 and pump 12 and seats on a corresponding internal shoulder 25 in the crossover coupling 19 below the transverse passage 21 to furnish a lower seat. The outside of the pump 12 carries a packing ring 26 that fits closely within the crossover coupling 19 below the shoulder 25,

the tubing sections thereabove, and the packers t loosely therein. .When the pump is unseated and the strainer ascends above the nipple 16, the packers fit tightly within the tubing, except at the joints. Since there are two packers, one or the otherlis always away from a joint to provideaVV continuous fit. Preferably the strainer carries'a `fishing neck 30 for handling the unit when needed. The motor 10 per se can be of any standard or desired construction, although I prefer that shown in my earlier Patent No. 2,191,369, dated February 20, 1940. The

motor is powered by an oil stream forced down the tubing 13. The lower portion of the motor barrel contains outlet openings 31 through which a blend of exhaust power oil from the motor and oil pumped from the well discharge into the spacer tube 18 and thence flow through the transverse passage 21 and up tubing 14 to the surface. 1

As Figure 2 shows, the`pump 12 is single-acting. The motor and pump are proportioned to produce a balanced load on both strokes, as explained in my Patent No. 2,679,806. The pump includes a barrel 32 joined at its upper end to the shoulder member 24, a plunger 33 mounted for reciprocable movement in said barrel, and a plunger tube 34 joined to said plunger and to the reciprocating element of the motor 10. The lower end of the pump barrel carries a standing valve 35, and the plunger a traveling valve 36. In addition the lower end of the extension 20 carries a special standing valve 37. The upper end of the pump barrel 32 has a relief port 38, through which oil in the space above the plunger 33 escapes intothe tubing extension 20. The upper end of the plunger tube has a port 39 through which oil pumped from the well reaches the motor barrel where it blends with exhaust power oil.

In accordance with the present invention, the t between the plunger tube 34 and the bore of the shoulder member 24 intentionally allows some leakage, although the t is sufficiently close not to impair pumping etliciency. To remove the pump from the well, an oil stream is forced down the well in the reverse direction, that is, down the tubing 14. In the absence of leakage which my arrangement atords, such oil would act initially upwardly against the head 22 and downwardly against the shoulder member 24. The former has a larger area than the latter to provide a net upward force on the pump, but the effective area is only the difference between these areas and is necessarily small. Once the pump is unseated, the upward pressure acts on the bottom of the pump andd the .effective area is muchV greater. `V With-my invention, the unseating pressure is transmitted through the outlet openings 31 into thel lower section f the motor barrel and thence throughlthe leakage space between plunger ytube4; .and the -bore ,inthe.shoulder-member :24 fanduhroughyithe. relief. port 38. v:Such pressure thus.,acts

immediately on the bottomoffthe pump; onthe fullcros'ssectional area thereof. Theparts.,areproportioned `so lthatfthepacking 2`6clears the..cr,ossover coupling..19 ,be- .fore the, packing ring'.Y 23. clears the seating,coupling,17. ,Hence the pressureverysoon. acts directly on. the bottom .of the*` pump. As. thepurnp ascends the tubing 13, pack- `'ers :28,and29 provide. a,c1ose fitA to give lthe-necessary piston .action `and 4the special, standingfvalve 37- is closed. 'The' pump is. installed in the well by,pumping it down vthe tubing 13unti1.it seats. asshown in Figure 1.

p Figures 3 .and 4 `showmodiications.which enable the `principles,off-the present invention to be. applied to pumps `which lackrelief ports corresponding with port 38 shown lirifFiguresfl vand2. InFigure 3l the.,crossover coupling `19a hasv a restricted vertical passageway -40.to provide communication between the space above the packing ring V,26a andthe spacek therebelow. In'Figure 4 lthe crossover ,coupling 19b has, a restrictedpassageway 41 which containsfa normally closedspring loaded valve 42. Pressure exerted to raise the pump opens this valve, which then lallows the passage-41m transmit the pressure to the botltom of the pump.

. Fromithe foregoing description it is seen that the pres- .Yent invention Yaffords a simple means for applying the unseating pressure initially to the'full cross-sectional area `otra free-type pump. Thus the peak power requirements Vare-materially reduced over arrangements where this pressurevactsron only a small differential area.

i While the invention is especially applicablel to pumps which have yreliefjports in their barrels, the modifications of Figures -3 vand 4 enable the same principles to be applied to free- Atype pumps generally.

While I have shown and described certainprefcrred .embodiments of myV invention, it-is apparent that other .modifications mayarise. Therefore, I do not -wish to be limited to the disclosure set forth but only by the scope of the appended claims.

I claim:

1. A subsurface pump installation comprisingparallel first and second strings of tubing, a crossover coupling to --which"said^`tubings are connected adjacent their lower ends and having a transverse passage providing communication between the tubings, a motor and pump combination housed in said first tubing and including a hydraulic motor powered by fluid forced down this tubing and a pump for delivering uid up said second tubing, said first tubing having upper and lower seats for said combination located on opposite sides of said transverse passage, said pump being single acting and having a relief port in its exteriorbelow said lower seat, said combination being removable from .the tubing by uid forced down bination housed in said rsttubing and including a hydraulicmotor. poweredI by-fiuid forced down this tubing ,rand Vapurnp for, delivering Huid up said second tubing, vsaid Yfirst-tubing.havingrupper and lower seats for said combination located on opposite sides 'of said transverse passage, .said pump being single acting andincluding-a rbarrel having a relief port in its upper end below said lower seat and a plunger and tubularplunger rod mounted for reciprocablermovement in saidbarrel, said com- Vbinationbeing removable from the tubing by fluid forced down said second-tubing, and meansv allowing leakage around said rod for transmitting uid forced down said -second tubing through saidk relief port beneath said lower seat to apply the pressure of this fluid against the full jcross-sectional area .ofthe combination initially for un- Aseating; it. ,v

References cited in the sie of this parent UNITED STATES PATENTS 971,612 Holliday Oct. 4, 1910 2,589,672 Coberly Mar. 18,1952 2,625,109 Coberly Jan. 13, 1953 2,663,261 Gage Dec. 22, 1953 K2,679,806 Chenault June 1, 1954

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