US2314869A - Differential stage lift flow device - Google Patents

Description

March'SO, 1943. A. BOYNTN 2,314,869

DIFFERENTIAL STAGE LIFT FLOW DEVICE 26 Fig. 5.

24 ALEXANDER 50mm/v,

Mardi 30, 1943 A. BoYN'roN y 2,314,869

DIFFERENTIAL STAGE LIFT FLOW DEVICE Filed Dec. 8, 1959 2 Sheets-Sheet 2 ATTORNEYS.

Patented Mar. 30, 1943 UNITED STATES PATENT OFFICE.

nmFEaEN'rIAL STAGE HFT FLOW DEVICE VAlexander Boynton, San Antonio, Tex.

Application December s, 1939, serial No. 308,307

2 Claims. (Cl. 137-111) My invention relates to flowing devices using pressure fluid as a means for expelling liquids from wells, especially oil wells.

Broadly stated, the object is to cause a well to flow by means of Vpressure fluid of low values resulting in low gas-oil ratios.

An object is to motivate the valves by employing a secondary means adapted to develop and transmit more force than can be employed for that purpose without such means.

Another object is to provide mechanism for flowing wells through the tubing, such means lbeing readily adapted to flowing the well through the casing.

Another object is to provide a sensitive and positive acting valve for charging well liquid with i pressure fluid.

A further object is to provide automatic means for metering the pressure fluid into the well liquid in proportion to the energy required to expel it from the well.

Another object is to prevent the valves from opening by the force of temporary high pressure y areas in the flow tubing.

I attain the foregoing objects by employing a piston within a chamber interposed between the well liquid and the pressure fluid. 'I'his .piston is adapted to be motivated and to operate a valve by the difference in pressures existing interior and exterior of the tubing. This valve admits pressure fluid into the well liquid which is thereby expelled from the well, and at other times when lifting force is notl required, the valves exclude the admission of pressure iluid, as will be explained fully in the specification and clearly illustrated bythe accompanying drawings, in which- Fig.1 is an installation plan of the devices in a well to be flowed through the tubing.

Fig. 2 is a longitudinal section of the preferred embodiment of the invention.

Fig. 3 is a partial longitudinal section of a modied form of the invention.

Fig. 4 is a cross section on the line 4-4, Fig. 2.

Fig. 5 is an installation plan of the devices in a well to be owed/ through the casing.

Fig. 6 is a longitudinal section of a modification adapted to flow the well through the casing.

Fig. 'l is a partial longitudinal section of another modiflcation similar to that shown in Fig. 6, and also adapted to flow the well through the casing.

Fig. 8 is a cross section on the line 8 8, Fig. 6.

Similar characters refer to similar parts throughout the several views.

A section in Fig. 3 taken on the plane of line 55 4-4 Fig. 2 would be identical except that the member 40 in Fig. 3 is of slightly larger diameter than the member 24 in Fig. 2.

The .parts I8 to 22 will be known as the movable piston assembly.

The force resulting from the difference in pressures obtaining above and below the movable piston assembly will be referred to as the differential. This force and the force of the spring I3, acting in opposition to the force of the 4pressure iluid, control the movements ofthe movable assembly, which in turn imparts its movement to the valves 24a and 36a. This' assembly is slidable closely within the polished bore of the chamber 3c between and away from the slots 3c and 3g which slots are for the sole purpose of exposing the piston assembly to the dierential. The diameter of the bore 3c may be such as one to one and one-half inches. All pressure uid enters the tubing through the openings 35a, 32h, and 3f, as appears in Fig'. 2.

In Fig. 2, the nipple 3 and the shell 3a may be cast or otherwise made integral, the slot 3e and the opening 3f communicating between the inside of the tubing and the smooth bore 3c. Within the upper end 0f the bore 3c, the small annular shoulder 3d has the base plate I1 engaged upon it bythe force of plug I4 having threaded engagement within the upper end of shell 3a and containing the gland ring I'5 to compress the packing I6. The upper end of the cham-*ber 3c is thus hermetically closed.

The spring I3 within the bore 3c is installed under some compression between the member I1 and the gland ring I8 compressing packing I9. The ring I8 is slidable 'Within the bore 3c and over the upper extension of the movable assembly base 20, these members being adapted to urge the packing I3 against the wall of bore 3c. The U cup 2 I, which may be of leather or any'other tough yieldable substance, is positioned between the member 20 and the plate 22 secured in the ,position shown by the threaded engagement between the lower extension o1' the member 20 and the coupling 23. 'I'he openings 22a are adapted to admit pressure fluid under the cup 2| to expand it into close contact with the surface of the bore 3c. Manifestly, metallic rings or a comblnation of such rings and fabric washers may be substituted for the U cup 2 I The valve rod 24, slidable centrally through the members 25, 21, 28, and 3|, has threaded engagement within the coupling 23. The check fvalve 24a nonmally lands with slight force from the spring I3 upon the seat in the upper end of the bore 32h. The valve 38a upon the upper end' of the member 38 is urged resiliently to its normal openlposition by the spring I3 by which it is positioned at proper'distance from its seat 32a to prevent the packing I8 from being moved upward as far as the slot 3e. The check valve 24a will land upon its seat within the member 35` beiore the cup 2| reaches the slot 3g. The valve member 38 and the gland .38 have threaded ensagement upon the lower end of the rod 24, the

packing 31 being engaged between them to prevent leakage between the valve member and the rod.

The valve housing member 35, having threaded engagement within the lower end of shell 3a, has its upper end engaged upon the gland ring 34 which urges the packing 33 upon the nether side of the valve seat member 32, which lands upon the slight internal annular shoulder 3d. The members 36 and 38 have ample clearance, s uch as M; inch, within the central opening 35a in the lower end of the member-35 for the purpose of admitting the proper volume of pressure uid into the device.

'I'he rod 2'4 between the valves 24a and 36a may be oppositely tapered so as to have its place of smallest diameter 24b approximately midway between the valves. 'Ihis taper provides that the greatest volume of pressure fluid passing through the opening 32h will pass through it when the valve 36a is approximately half way of its travel.

The untapered portions a of the rod 24 between the valves 24a and 36a may have a close sleeve valve t within the opening 32h, in order to prevent sudden opening of the valve when momentary. high pressures obtain at places in the ilow tubing during the owing operation. It will be understood that this construction may be employed also in Fig. 6.

If `the rod is tapered between the valves, the smallest diameter at 24h may be such as 1; inch, while the diameter of this rod proximate the valves may be such as T56 to 11s inch, the opening 32h having a diameter three to ilve thousandths of an inch greater than the greatest diameter of the rod. The opening 3f may be to inch diameter.

The packing assembly base 25, having openings 25a, may be pressed into the bore 3c, as appears in Fig. 2. The packing 30, the gland ring 29, and the assembly ring 3|, the latter having threaded engagement within the member 25, serve to prevent leakage between the member 25 and the shell 3a. The packing 28, engaged between the member 3| and the gland ring 21, is compressed by the spring 26, engaged under some compression between this ring and the upper end of the member 25 within which member the spring is otherwise i'ree.

The central opening 3Ia within the member 3| provides that the valve 24a may travel upward far enough to allow the valve 36a to seat, re-

gardless of the exact position of the member 25. The openings 25a allow that pressure iluid may ald the spring 26 in compressing the packing 28 which is provided to prevent leakage between the rod 24 and the member 3|. The parts 25 to 3|, both inclusive, are provided to form a hermetic barrier between the slot 3g and the opening 3f.

The force of the spring I3 should be such as to cause the valve 36a to seat at a differential somewhat greater than the force per square inch exerted by the weight of the well liquid upstanding between adjacent devices, in order to provide for even and continuous flow of the Well liquid.

Such ilow will result because the next upper valve will remain open until the next lower valve is uncovered by the receding well liquid.

It will be noted that the pressure iluid acting under the movable assembly is the only force tending to close the valve 36a upon its seat 32a;

while the force of the spring I3 and the pressure of the well liquid in the upstanding column acting above the movable assembly are the forces which resist the seating of this valve. The only one of these stated forces which varies is the pressure of the upstanding column, this variation being due to the lightening pressure at increasing distance from the base of that column.

In Figs. 2 and 3 only the pressure fluid is admitted under `the movable piston assembly via the slot 3g, and only the well liquid in the upstanding column can act to aid the spring Il in opposing this force, because the slot 3e is in contact with that column only.

In Fig. 2, the path of the pressure uid through the device is in through the opening 35a, through the annular space Within the opening 32h, and out into the upstanding column in the tubing through the lateral opening 3f.

The installation of the device for tubing ilow illustrated in Fig. 2 is show'n in Fig.v 1.

The devices 3 may be spaced at intervals of 150 to 300 feet in the tubing 2 by means of couplings 2a. 'I'he sloping ends 3b and 3b' serve to guide the devices through possible obstructions within the casing I. The casing head 4 is employed to form a hermetic seal between the casing and the tubing proximately above the ground surface 8. The flow line 2b, having an unshown valve, may extend to a production tank.

The line I2 will be employed to supply pressure uid within the annular space la if the well does not produce enough gas to flow it, or may be employed to convey surplus gas away. If there be no such surplus gas, and if the well produces enough gas, the pipe I2 may be replaced by a plug.

The anchor string 'l below the liquid intake nipple 6 having lateral openings 6a, to admit well fluid into the tubing, may extend to the bottom of the Well 9.

Preferably, the tubing should be enlarged near the upper end of the well as shown above swaged nipple 5 to allow for expansion of the gas in the method of flowing through the tubing. l

The formation I0 may produce into the annular space Ia through the gun perforations I I.

Before beginning the flowing operation, it will be understood that an unshown valve in the flow line 2b is closed, and that pressure iluid is in the annular space I a whether produced by the well or provided through\the line I2. 'Ihe value of this pressure fluid, for example, should be at least two or three times greater per square inch. and maybe much more, than the force per square inch required to compress the spring I3 far enough to close the valve 36a.

Now, to flow the well through the tubing, open the valve, not shown, in the ow line 2b. The valves normally open in all devices will remain open until the pressure in the tubing drops far enough to cause the excess pressure under the movable piston assembly to raise and seat the valve 36a.

By way of illustration, just before the unshown valve in the iiow line 2b is opened, it will be assumed that the well liquid in the annular space Ia and in the tubing is standing at the level A. Gas being more mobile than the well liquid. the

valve in the upper device above the level A will close quickly 'after the valvein the flow line is opened. Immediately thereafter, the well liquid becomes depressed in the annular space la to the level indicated at B, while the well liquid in the tubing rises to the level indicated at C. The upstanding column of well liquid in the tubing, of course, will balance against the force of the pressure fluid in the space la. This column will be referred to as the upstanding column, whether it be in the tubing or in the annular spacek la -due to changing the.- path of induction.

The valve in the device next above the level B will be open because, as was stated, the force required to seat the valve 36a is more than the weight of theliquid between any two devices. The second valve above the level B will be closing or closed. depending upon the differential, the force required to compress the spring I3, and upon the distance between the upper two devices.

As the flowing operation progresses, the depressed liquid level in the space I a will be lowered until the next lower device is uncovered. That device, like each lower one, will be uncovered in the open position of the valve 35a, because the differential thereiwill be slight, due to the balanced or almost balanced relation between the upstanding column in the tubing and the pressure fluid in the space la.

Manifestly, increasing the value of the pressure uid will increase the rate of well liquid flow through the tubing, and vice versa, because the greater the pressure. the more will be the expansion of the globules of pressure uid as they produce ow of the well liquid by expanding in their upward travel through the upstanding column in the eduction tube. I

When the depressed liquid level B recedes to the openings lia in the nipple 6, the upstanding liquid column in the tubing will be blown out of the tubing as a slug, at which time the well is pumped o This operation may be repeated at proper intervals or, if the production f the well is such that it will not pump off, the depressed liquid level B will come to rest at the place where the Well production and the rate of now are equal or in balance.

A check valve may be provided in the tubing proximately above` the nipple 6, and, if so provided, the check valves 2da will prevent the well liquid left in the tubing at conclusion of each owing operation from draining back through the devices.

Fig. 3 illustrates a modified form of the invention wherein the valve housing sleeve 39, having threaded engagement within the lower end of the shell 3a, replaces the corresponding member 35 in Fig. 2.

The valve rod 40 ha-s an enlargement 40a at its upper end, having threaded engagement with the member of the movable piston assembly. Ihe lower end of this enlargement normally rests upon the upper end of the member to position the valve 4Ia at proper distance from its seat 46a properly to limit the travel of the movable piston assembly between the slots 3e and 3g. as is apparent in Fig. 3. The normal engagement of the enlargement 40a upon the upper end of the member 25 also positions the valve rod 40; so that the oppositely tapered portion, Ahaving its smallest diameter at 40h, is in proper position with relation to the opening 4Gb, through the member 46, to meter the pressure fluid, as was explained in connection with the similar construction indicated at 24h in The straight portion b immediately above the valve 4Ia is to prevent this valve from being opened by temporary high pressures which frequently obtain in the flow tubing during the flowing operation. The same construction may be employed in Fig. 7.

The valve member 4|, having the valve 4Ia adapted to engage upon the valve seat 46a, has threaded engagement over the lower end of the valve rod 40. 'I'he packing 43 is confined between the member 4l and the gland 42 by the threaded engagement of the latter part over the lower extremity of the rod 40.

It will be understood that the` members 4I and 42 have ample clearance, such as l/a inch, within the chamber 39a central of the member 39, and that the opening 45a may be such as 1/4 to 1/2 inch diameter.

Pressure uid enters the device, through the passage 45a, lifts the check valve 44, passes through the passage 4Gb, and enters the tubing through the opening 3f, the slots 3e and 3g being merely for the purpose of exposing the movable piston assembly to the differential, as has been explained.

, By the aid of an unshown check valve, which may be placed in the tubing anywhere between the nipple 6 and the lowest ow device, the check valve 44 will prevent well liquid left in the tubing at the conclusion of each owing operation from settling back into the well, as was explained for the valve 24a. in Fig. 2. The lower end plug 45, having threaded engagement within the lower end of the member 38, has a seat surrounding the central passage 45a adapted to engage the valve 44.

Fig. 6 illustrates another modified form of the invention, being an adaptation for casing flow of the device shown in Fig. 2.

The external slot 58 in the shell 3a and the internal slot 53 between the shell and the body nipple 3A, are for the purpose of allowing the differential to contact both sides oi themovable piston assembly, which assembly remains the same in all forms of the invention.

The valve housing member 54, which may be pressed into the shell 3a' against the packing 33 which secures the valve seat member 32A-against the annular shoulder 3d', has the packing 55 and the gland ring 56 engaged between it and the plug 5l which has threaded engagement within the lower end of the shell 3a', which thus is hermetically closed at its lower end. The

`valve member 36 and the gland 38 have ample clearance Within the chamber 54e, as stated for the preceding form.

The path of the pressure iluid employed to ow the well through the casing is out of the tubing through the opening 52, the recess 54a, the openings 54D, the chamber 54e, the annular opening 32h, and through the opening 5| into the annular space la'. The annular recess 54a and the openings 54b provide that the pressure ud will ind free passage from the opening 52 into the chamber 54e in all positions of the member 54.

Fig. '7 illustrates a modified form of the device shown in Fig. 3, the same being an adaptation to casing flow of the device shown in Fig. 3.

The spacer bushing 58 may be pressed into the shell 3a and securely landed upon the packing 33 by the plug 5I engaging upon the gland ring 68 with the packing 59 positioned between this ring and the member 58. In this manner the lower end of the shell bore 3c is hermetically closed. The valve seat member 46A is landed upon the slight internal shoulder 3d' by the force of the plug 6I acting on the spacer bushing 58 through the gland ring B0, the packing 59. and the packing 33, asis apparent in Fig. 7.

The annular recess 58a and the openings 58h, thechamber 58e, andthe central opening 48h, provide that the pressure fluid will always have free passage out of the tubing and into the annular space I a' through the openings 52 and 5I.

In Figs. 6 and 7 the pressure fluid acts under the movable assembly via the slots 53, and the pressure of the upstanding column in the annular space la.' acts through the slots 50 to aid the spring I3 in opposing this force.

In Fig. 5, either of the devices illustrated in Fig. 6 and Fig. 7 may be installed in the tubing 49 by means of the couplings 2a. The tubing, being the induction means for pressure uid in the operation of ilowing the well through the casing, preferably should be all of one size and somewhat smaller than that employed for tubing flow.

'I'he casing head 41 is adapted to form a hermetic seal between the tubing and the casing, the bull plug 41 being employed to close the unneeded opening in the casing head.

The flow line 48 may lead to a production tank.

The pressure iiuid is admitted into the tubingv through the extension line 49a which may be connected With the discharge from a compressor.

The devices may be spaced 150 to 300 feet apart in the tubing, as was stated for the tubing ilow method.

'I'he devices are assumed to be adjusted to close their valves at a differential somewhat greater than the weight of the well liquid between adjacent devices, and the value of the pressure fluid is assumed to be such as two orl three times the differential required to-close the valves and may be much greater, as desired.

Immediately before the flowing operation, a valve, not shown, in the line 49a is assumed to be closed to exclude pressure iluid from the tubing 49. The liquid level in both tubing and casing is assumed to be at D. Y ,Y

Now, to flow the well through the casing, open the unshown valve in the line 49a and admit pressure iiuid into the tubing. The liquid level in the tubing will be depressed from its normal level at D in the tubing to E and the top of the upstanding column in the annular space la' will rise to F.

The ilowing operation through the casing by means illustrated in Figs. 6 and 7, is so similar to that already described for tubing ilow as to be readily understood.

Manifestly, the valves in dierent devices may be' adjusted to close at progressively higher or lower differentials according to position in the well and also may vary otherwise according to different well conditions, as will be understood by those skilled in the art.

It is apparen 'that comparatively low gas-liquid ratios will result from these devices which meter the power to the load and which enable the employment of relatively low pressures.

In allforms of diirerential flowingdevices known to the art, the valve or valves which control the admission of pressure uid into the upstanding liquid column will remain open until closed by the diiferential, as these valves do; but means for metering the application of lifting medium according to the load by employing a floating piston of many times greater diameter than the valve it controls, is believed to be new and useful.

Since the diameter of the piston is many times the diameter of the valve it actuates. as shown, it is apparent that greater force will be employed to securely seat the valve than is employed to seat valves having the same seating area as that exposed to the pressure iluid which actuates them.

The scope and purpose of this invention, as illustrated and described, is-not intended to be limited to the drawings which will be understood as being diagrammatic only and set out by way of example to explain and clarify the stated' objects and appended claims.

The invention claimed is:

. 1. A device of the class described comprising a valve body having a passageway between the interior and the exterior thereof, a wall in said passageway forming upper and lower chambers therein, spaced openings in the upper chamber leading to interior and exterior of the valve body, a piston movable in the upper chamber intermediate said openings, means resiliently urging the piston toward the lower end of said chamber, a valve member attached to said piston and passing through aligned openings in the walls of the lower chamber, an outwardly facing valve seat in the wall of the lower chamber, valve seating surfaces on the valve member adapted to close the passage to the lower chamber when the piston moves to terminal position, there being an opening in the wall of the lower chamber to cooperate with said passage to provide a passage between the interior and exterior of the valve body.

2. A device of the class described comprising a valve body having a passageway between the interior and the exterior thereof, a wall in said passageway forming upper and lower chambers therein, spaced openings in the upper chamber leading to interior and exterior of the valve body. a piston movable in the upper chamber intermediate said openings, means resiliently urging the piston toward the lower end of said chamber, a valve member attached to said piston and passing through aligned openings in the walls of the lower chamber, oppositely facing valve seats in the wall of the lower chamber, and valve seating surfaces on the valve member adapted to engage said seats to close the passage to the lower chamber when the piston moves to terminal position, there being an opening in the wall of the lower chamber to cooperate with said passage to provide a passage between the interior and exterior of the valve body, said valve member being oppositely tapered between said seating surfaces to meter a pressure fluid to the lower chamber.

ALEXANDER BOYNION.

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