US1867115A - Fluid operated mechanism - Google Patents

Description

July ,12, 1932 R. H. THOMPSON FLUID OPERATED MECHANISM F'iled Nov. 24. 1930 Patented July 12, 1932 UNITED STATES vPivrENTfoI-I-ICE ROBERTVH. THOMPSON, OF LOS ANGELES, CALIFORNIA, ASSIGNOR T0 LEO IM'.. HARVEY,

I 0F LOS ANGELES, CALIFORNIA FLUID OPERATED IVfIECHANISM Application led November 24, 1930. Serial No. 497,796.

This invention relates to Huid operated mechanisms, and morefparticularly to a fluid operated mechanism utilizing a relatively non-compressible fluid for the purpose of driving a reciprocating motor piston to which a pump is attached, the motor and pump being located near the foot of a well,-or example, an oil or like well, for the 'purpose of aisilng the oil or similar fluid to the ground eve Heretofore many attempts have been made to provide a fluid operated pump particularly adapted for use in elevating oil from deep wells so as to enable the elimination of rods or mechanical connecting members commonly employed for the purpose of reciprocating such voil well pumps. v

A great many difiiculties are encountered in the use of such fluid operated pumps due to many factors, including the presence ofia gritty or sandy fluid accompanying gas which must be elevated from the well to enable recovery of the oil content thereof.

Complicated structures operating on the principle of double-acting pumps and provided with the necessary transfer ports have been'attempted but have been unsatisfactory due to the fact that they can not be maintained in operation under such conditions.

Many other forms of fluid actua-ted pumps have been suggested for use in such deep wells which are dependent upon their operation to derive power from the fluid being pumped as' it is alternately placed under pressure on the opposite sides of the piston of the driving motor. Such forms of structure have proven impracticable due to the high compressibility of the fluids being pumped which carry a high gas content enabling such fiuids to be compressed to a relatively high degree without causing the motorto be operated.

The principal object of my invention is to provide a. fluid operated mechanism which is of simple construction and which ,is operated by a pair of columns of fluid so proportioned that the piston of the driving motor for such fluid operated mechanism is first driven downwardly by a column of relatively noncompressible fluid such, for example, as water7 to which pressure may be applied without compressing the fluid, and which is then i driven upwardly by the static pressure of the column offluid being raised to the ground.

Another object of this invention is to prol vide a fluid operated mechanism including a driving motor having a piston provided with heads of differential area mounted to reciprocate within cylinders of a diHerent crosssection, and which piston is connected with 'i an oil well pump of any suitable or desirable construction, the smaller of .which piston heads is adapted to be driven downwardly by means of a non-compressible fiuid under pressure derivedv from the "surface of the well to drive the pump. plunger downwardly, and which piston is driven upwardly by the static pressure of the column of fluid being elevated from the well exerting its pressure upon the head of said piston of larger diam-` eter as the pressure is dissipated from the norlil-compressible fluid at the surface of the we Other objects and advantages of this in-f vention it is believed will' be apparent from the followin detailed description of a preferred emboi the accompanying drawing. l -In the drawing:

Figure 1 is a side elevation partly in section of a fluid operated pump embodying my invention.

Figure 2 is aQ fragmental sectional eleva v tion thereof.

Figure 3 is an enlarged fragmental section of the pressure relief valve embodied m my inventlon. V

Figure 4 is a sectional end elevation taken substantially on the line 4-4 of Figure 2.

Figure 5 is' an end.` sectional view taken substantially on the line 5-5 of Figure 2.

Figure 6 is a sectional side elevation of the modified form of fluid operated pump embodied in my invention.

In the preferred embodiment of my invention illustrated in Figures 1 to 5 of thedrawing, 1 indicates a casing which extends ment thereof as illustrated in downwardly from the surface of the well to the oil strata. l e

Mounted concentrically within the casing 1 is a water or relatively non-compressible Huid `tube'2 which-extends downwardly in the casof vs'rhichyis secured. an 4 oflarger diameter., v

the tubing 2 is a cylinder 3, hereinafter termed the down-pressure cylinder, to the lower end 11p-pressure cylinder f k"Secured to the lower end of the cylinder/4 i is a packing assembly 5 which is packed outwardly against the lnner periphery of the casing 1 to close the oil passage 6 formed within the casing 1 on the outside of the cylinders 3 and 4 and tubing 2 above the packing 5. Secured to the lower end ofthe cylinder 4 by any suitable means as indicated at 7 is a pump barrel 8 which extends through the packing 5 into the fluid to be elevated from within the well. The pump barrel 8 carries the customary standing valve 9 at its lower end and yis fitted with a reciprocating plunger 10. The plunger 10 is connected as indicated at 11 with a connecting rod 12, the

opposite end of which is secured to a pistonk 13. The piston 13 is provided at its opposed' ends with piston heads 14 and l5 of differential diameter, the upper vpiston head 14 mounted within the water cylinder 3 being less in cross-section area than the lower piston head 15 mounted within the oil cylinder 4.

The casing 1 is provided at its upper end with a casing head 16 through which the tube 2 extends through a packing gland 17 and which is provided with an oil discharge'pipe 18 through rwhich the oil elevated from the y well is discharged.

' The pipe 2 is filled with a non-com ressible iuid, such, for example, as water, rom the level of the piston head 14 to the priming tube 51. The oil passage 6 is filled with the wellfluid which it is desired to pump to the 'surface of the well. The area of the oil piston head 15 being greater than the area of the water piston head 14, the total pressures are regulated so that the piston 13 will at all times remain in elevated position in the cylinders 3 and 4 when there is no additional pressure exerted upon the water or non-compressible fluid in the'pipe 6.-

The static pressure of the oil within the oil passage 6 communicates with the under side of the oil pistonhead 15 through ports -19 formed through the oil cylinder 4 below the piston head 15. The ports 19 also provide passagesA for the delivery of oil or fluid being elevated from the well into the passage 6as the Huid is elevated from the pump cylinder 8 by means of the pump plunger 10. The pump plunger l() carries a working valve 20 and is a hollow plunger.

The lunger 10 rising in its barrel 8 causes oil or diiid from the well to be drawn in by the standing valve 9 as the pressure within the barrel 8 is reduced below the pressure of the oil or fluid in the oil strata. As the plunger 10 is raised the valve 20 seats. As

the plunger 10 is lowered, the standing valve 9 is seated andthe working valve 20 rises' \er and by the working valve 2O to a position above the working valve 20.,"

As the plunger'lO is again raised, the oil above the working valve 20 is raised upwardly and is caused to pass i'nto the cylinder 4 from which itis displaced on the next down stroke of piston 15, therebydisplacing a portionof the oil in the oil passage 6 up through the `oil passage 6 and-out of the discharge pipe 18 of the casing head 16.

The plunger 10 1s reciprocated to cause this pumping or raising'of the oil from the barrel 10 as follows:

, As the total pressure exerted against the oil head 15 of the piston 13 is greater than the total pressure of the water exerted against rthe piston head 14 of the piston 13 due to the difference' in area, the. piston 13 will at all times tend to assume an elevated position raising the plunger 10 in the barrel 8.

In order to drive the plunger 10 downwardly in the barrel 8, pressure is exerted on the water in thetube 2 and against the piston head 14 of the piston 13 in excess of the pressure exerted against the oil head 15 of the piston 13. This increase in pressure is caused by means of a piston 21 mounted within the upper section of the tube 2 and caused to move down therein by means of a. piston head 22 mounted within a surface power cylinder 23. Pressure is intermittently exerted on the upper surface of the piston 22 in the power cylinder I23 by any suitable or desirable means such, for example, as by means of pressure derived` from any suitable source of fluid under pressure through a conduit 24 in which a three-way valve 25 is mounted. The conduit 24 is coupled with the power cylinder 23 above the piston 22 so that when the control valve 25 is opened, the fluid under pressure from the conduit 24 exerts its pressure on the piston 22 in the powei` cylinder 23, causing the piston 22 to be forced downwardly, thereby exerting a pressure upon the Water or noncompressible Huid in the column 2. This pressure is immediately transmitted to the water piston head 14 causing the plunger 13 to be driven downwardly. In order to release the pressure from the water head 14 to allow the static pressure of the fluid in the column 6 to exert a pressure on the head 15 in excess of the pressure exerted on the head 14, the fluid pressure imposed upon the piston 22'is relieved through an exhaust conduit 26 connected to the three-way valve 25. As the pressure is thus released, the piston 131 rises, raisingvthe plunger 10 in the barre 8.

In order to automatically control the action of the piston 22, the three-way control valve 25 is provided with an actuating arm 27 which is coupled to triggers 28 and 29 mountface of the pistonengages the trigger 29 which is connected through a link 30 with the arm 27, causing the valve 25 to be rotated to a position to establish communication between the exhaust conduit 26 and the power c `linder 23, resulting in the fluid compressed a ove the piston 22 being relieved either into the atmosphere or a conduit under reduced pressure. `rlhe iston 22 is then moved upwardly by the static pressure of the fluid within the passage 6 exerting its pressure against the larger piston head 15 until the piston 22 engages the trigger 28. :The trigger 28 is connected through a pair of links 31 and 32 to a connecting rod 33 which is in turn connected with the arm 27. As the trigger 28 is pushed outwardly, the valve 1s rotated to a position to open the conduit 24 to the ,power cylinder 23 permitting the fluid under pressure from the conduit 24 to exert its pressure downwardly on the piston 22, thereby driving the piston 13, and hence the plunger 10, downwardly.

Formed above the piston head 15 when the piston head 15 is down, in the oil cylinder 4, is a chamber 34. As the piston head 15 is caused to move downwardly by the pressure s of the fluid exerted against the piston head 14, the chamber 34 increases in volume, resulting in the establishing within the chamber 34 of a rfegion of reduced pcressure.

As pumps of the class here under consideration are many times utilized for the raising of liquids containing sand and other foreign matter to the surface of the well, I prefer to provide a means whereby this sand or foreign matter may be carried out with a circulatin culation, provide means for circulating fluid from the surface of the well through the mechanism and back to the surface H"of the well.

To accomplish this I form the piston 13 hollow and mount at the upper end ofv the piston 13 a pressure control valve 35 which opens only lwhen the pressure withinthe cylinder 3 exceeds a cert-ain given pressure. The pressure valve 35 may be of any suit'- able or desirable construction and is herein illustrated as of the type including a disc head 36 provided Wit a valve stem 37 carried in aV bushing or lve cage 38 screwthreaded as indicated at 39 into the upper cylindrical extension 40 of the piston 13.

The valve stem 37 carries a stop 41 at its upper end and the valve cage 38 is provided with a bridge 42 spaced from the stop 31. Mounted around the valve stem 37 between the stop 41 and the bridge 42 is a spring. 43

fluid. In order to obtain the cir-- the tension of the spring 43. Formed at the lower end of the hollow piston 13 below the piston head 15 are a plurality of ports 44 through which the liquid passing the pressure valve 36 passes when the pressure in the cylinder 3 exceeds a predetermined' amount. The fiuidthus finding its way through the ports 44 passes through'the ports 19 to wash the ports 19 clean of y accumulated sand or foreign matter carried by the oil and is circulated up through the passage 6 to clean the passage 6 of sand or accumulated `foreign matter. The fluid is circulated from the surfacev of the well by coupling a circulating pump (not shown) to the priming nip-ple 51 to forcev a circulating fluid through tube 2, cylinder 3, piston 13, ports 44 and 19back through passage 6 to the surface of the well and out discharge pipe 18.

Each of the piston heads 14 and 15 is formed of a packing cup 45 which vis seated on a disc 46 mounted on a shoulder formed on the 'piston 13 and the packing cups 45 are'held in position by means of packing discs 47 forced against the packing cups by means of packing followers 48 which are threaded to 'the' respective fends of the piston 13: Packing cups 45 are each turned in a direction toward the source of pressure against I the respective ,packing heads 14 and 15, so that the pressure exerted on the heads 14 and 15 tends to expand thel packing cups -outwardly. 4

In order to stop the piston'` 13 on its downward stroke as an excess pressure is utilized in the cylinder 3 to open the valve 36, .a`

stop bridge 49 is mounted at thel lower end of the oil cylinder 4to engage the packing follower 48 ofl the vpiston head 15. The bridge 49 is provided at points spaced around its upper surface with raised stops 50 holding the packing follower 48 from seating tightly f way into the chamber'34 must be dispelled therefrom or there is a possibility that the device will become fluid-locked. In orderto insure the dispelling of the fluid from the chamber 34, I propose to operate the device as follows:

The pressure exerted on the larger piston head 15 by the static head-of the fluid within the passage 6-due to the increased area of the head 15 over the head 14 must be sufficient to give to the piston assembly 13` during its upto carry .the piston assembly 13 the full length of the cylinder 4 until the piston head 15 stops against 'the lower end -of the smaller cylinder 3. The fluid in the chamber-34, which has found its way thereto by leakage, will be forced,v out of the chamber 34around the piston heads 14 or 15. This scavenging of the chamber 34/is caused by the relatively high pressure exerted yagainst this fluid in the vchamber 34 due to the inertia of the moving mass of the piston 13 and the column of fluid in the passage 6 as the piston head 15 `engages the fluid in the chamber 34. The packing cups are turned toward the respective columns of fluid in the casing 1 and pipe 2 and away from the chamber 34 and lwill open more easily from a high pressure barrel 8a.

piston 13a and hence the plun er 10a to its elevated position. As in the rst modificazoi tion of my invention, I prefer to employ wav ter or a similar non-compressible fluid inthe conduit 2a so that aspressure is exerted upon the water or non-compressible fluid, the pressure impulse is immediately transmitted to. the piston 13a and not taken up by the compressibility of the fluid in the column 2a.

Having fully described ymy invention, it is to be understood that I do not `wish to be limited to the details herein set forth, but` my invention is of the full scope ofv the lappended claims. f'

within the chamber 34, permitting the fluid J I claim:

within the chamber 34 to be squeezed out of the chamber 34 by the inertia of the movingv piston 13 and column of fluid in the passage before the piston 13 is brought to rest mechanically against the lower end of the cylinder 3.

In the modified form of my invention illustrated in -Figure 6, like part'sare numbered with the same numerals with the addition of an exponent a.

In this modification of my invention n0 differential area pistons are employed but the oil in the column 6a at the bottom of the well is maintained under a substantially constant pressure in excessof its static pressure by. any suitable or desirable means, this substanv tially constant pressure being in excess of the static pressure of the column of water in the tube 2a. The piston 13a isvconnected byv means of a rod 12a with the pump plunger 10a mounted in the barrel 8a in the same manner as in the modification heretofore dei scribed. The tube, 2a extends through the control head 16a and into a power cylinder 23a in which a piston 22a is mounted. Piston 22a is forced downwardly by means of pressure applied to its -upper surface through .any suitable or desirable means which may be similar -to thatdisclosed in the first modification of my invention heretofore described. The oil being pumped onto the passage 6a is maintained under a constant pressure in,

excess of its static head' by any suitable or desirable means such, for example, as by having the discharge pipe 18a dischargev the oil.

elevated from -the well through a pressure valve.

In the modification of my invention shown in Figure 6, vthe pressure of the oil in the column 6a exerted against the underside of the piston 13a tends to raise the plunger 10a to its`elevated positi 1i. As pressure is imposed upon the top of the piston 13a in exfcessfof .the pressure in the column 6a by the development of pressure above the piston 22a, the piston 13a is forced downwardly to exerted by the lattersaid column 4of flui on the upper side of said piston, and meansv under side of said piston, the static pressure of a column of fluid in the pipe being exerted against the upper side of said piston, means for intermittently increasing the pressure t exerted by the latter said column of fluid,l on the upper side of saidspistom'andmeansl carried by the piston for closing theI passage therethrough operable when the pressure ofl the fluid inthe pipe exceeds a given amountA to permit said fluid to pass through said piston and circulate through the cylinder. and out through said casing.

2. In a vdevice of the class `described the pir@ combination of a vertically extending casing, Y.

a pipe mounted concentrically within the casing, a fluid motor including a cylinder mounted within the casing and connected to said pipe, a hollow piston operatively mounted in said cylinder, means mounted in said fluid motor for limiting the downward travel of said piston, means for venting the cylinder below the piston into the casing, a pump mounted within the casing below said cylinder and including a pump plunger, means connecting the pump plunger with the iston, the static pressure of the column of fllflid 1n the casmg bemg exerted on the under side of said piston, the static pressure ofthe coll umn of liquid in the pipe being exerted agamst the upper side of said piston, means for intermittently increasing the pressur carried by the piston for closing the passage therethrough operable when the pressure' of the fluid in the i1pipe exceeds a given amount to permit said uid to pass through said pis- 5 ton and circulate throughv the cylinder and out through said easing.

Signed at Los Angeles, California, this 15th day of November, 1930. l

v ROBERT H. THOMPSON.

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