US2241656A - Means for flowing wells - Google Patents

Description

May 13, 1941. c, s. CRICKMER 2,241,656

MEANS FOR FLOWING WELLS Filed Dec. 21, 1936 5 Sheets-Sheet l y 1941- c. s. CRICKMER 2,241,656

MEANS FOR FLOWING WELLS Filed Dec. 21, 1936 Sheets-Sheet 2 y 1941- c. s. CRICKMER 2,241,656

MEANS FOR FLOWING WELLS Filed Dec. 21, 1936' 5 Sheets-Sheet s May 13, 1941.

C. S. CRICKMER MEANS FOR FLOWING WELLS Filed Dec. 21, 1936 5 Sheets-Sheet 5 Patented May 13, 1941 MEANS FOR FLOWING Charles S. Crlchner, Dallas, Ten, assignmto Merla Tool Tm:

Company, Dallas, Tex, a firm of Application December :1, ms. Serial No. 116,937

15 Claim.

This invention relates to new and useful improvements in means for flowing ,wells.

One object of the invention is to provide an improved means for lifting well liquids by means of an auxiliary lifting medium, such as gas or air.

An important object of the invention is to provide an improved means for flowing wells which is actuated by a differential in pressure between the well liquid within the well tubinB (Cl. its-cs2) from the well casing to the well tubing, said pissure into the liquid column in a well tubing to lift the column, the admittance of the fluid occurring when the liquid pressure has reached a predetermined point never equal to or in excess of the pressure of the lifting fluid.

Another object of the invention is to providean improved flow valve for controlling theadmittance of a lifting fluid from a well casing to a well tubing, said valve being constructed so that when in an open position, it exposes equal areas on both sides thereof, whereby it is baianced, and is moved to its closed position when the velocity of the lifting fluid flowing thereby reaches a predetermined point; and when the valve is in its closed position'unoqual areas are exposed on each'slde thereof. whereby the valve may be opened by a pressure less than the pressure holding said valve closed, which permits the valve to be opened by the well liquid pressure when said pressure is lower than the pressure of the lifting fluid.

Another object of the invention is to provide an improved system of flowing wells which consists in admitting a lifting fluid into the well tubing before the pressure of the well influent equals the pressure of the lifting fluid, and then cutting off the admission of the lifting fluid when the velocity of said fluid reaches a predetermined point, whereby the action is entirely automatic.

Still another object 'of the invention is to provide an improved system which consists in intermittently admitting a. liftingfluid into the well tubing to raise the well liquid thereim'the adton normally exposing equal areas to the lifting fluid when in an open position whereby the piston is balanced; the valve also including a second piston which has one end exposed to the pressure of the well liquid and its other end adapted to engage one end of the first piston when said first piston is in a closed position, the second piston having a larger cross-sectional area, whereby this increased area acted upon by the well pressure is transferred to one end of the first piston, so that unequal areas are exposed by the first piston to the lifting fluid and well liquid pressures whereby said piston is again moved to its open position by the differential therebetween.

Still another object of the invention is to provide an improved flow valve which is actuated by the differential in pressure of the well liquid within the tubing and the pressure of the lifting fluid in the well casing, and which is so arranged that the differential necessary to actuate the'valve may be positively'controlled.

A construction designed .to carry. out the invention will be hereinafter described, to ether with other features of the invention.

The invention will be more readily underst from a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and

wherein:

Figure 1 is a view, partly in section and partly in elevation of a well casing and tubing and having flow valves, constructed in accordance with the invention, connected in .the tubing string,

Figure 2 is a view, partly in elevation and partly in section of the valve, and showing the valve in its operative position,

Figures 3, 4 and 5 are enlarged, vertical sectional views of the va1ve, -showing the various operating positions of the same,

Figure 6 is an enlarged, horizontal, cross-sectional view, taken on the line 6-6 of Figure 2,

.Figure l is an enlarged, horizontal, cross-sectional view, taken on the line 1,--'I of Figure 2,

Figure 8 is an enlarged, horizontal, cross-sectional view, taken on the line ,8-8 of Figure 2, Figure 9 is a transverse, vertical, sectional view of a modified form of the invention,

Figures and 11 are similar views, showing the various operating positions of the valve,

Figure 12 is a view, similar to Figure 2, showing a slightly modified form of the valve, and

Figure 13 is a similar view with the valve in its packed oil from the tubing by a suitable packer l5, whereby gas introduced into the casing at the surface of the well cannot pass downwardly thereby. All of the above parts are of the usual construction and are, therefore, subject to variation.

In carrying, out the invention, a plurality of flow valves A are mounted at various stages in the tubing string l3. The valves control the flow of the gas, or other lifting fluid from the well casing into the tubing. Since the well liquid enters the tubing through the screen I 4 at the bottom of the hole below the packer, it is obvious that the gas introduced into the tubing will aid in lifting the liquid to the surface by aerating the fluid column. It is noted that the number of flow valves which are employed is subject to variation because the number of flow valves depends entirely upon the condition of the particular well. In some instances, a single valve located near the lower end of the tubing string may be found sufllcient to raise the liquid within the tubing. These instances would occur in wells having a comparatively low liquid level standing therein.

Each valve A includes an upper cylinder l6 and a lower cylinder I! which are connected together by a. coupling sleeve l8. The lower end of the bore I6 of the cylinder i6 is internally screw threaded while the upper end of the bore ll of the lower cylinder I1 is similarly screw threaded to receive nipples I9 provided at the ends of the sleeve l8, whereby the cylinders and sleeve form an integral structure. It is noted that the bore l8 of the sleeve l8 has a smaller diameter than either of the bores of the cylinders. The provision of the connecting sleeve for the cylinders makes for easy assembling and dismantling of the device but if desired, these three members may be made in one piece.

The upper end of the cylinder i6 is provided with an upwardly extending nipple which is adapted to be screw threaded into a socket which is formed at the lower end of a sleeve member 2|. The bore 2| of this member has a smaller diameter than the diameter of the bore of the cylinder IS. The extreme upper end of the member 2| is formed with a screw threaded nipple 22 which is received within an opening 23 in the underside of a radially extending boss 24 formed on the tubing l3. The boss is preferably made integral with the tubing but may be welded, or otherwise secured thereto. The boss is formed with an angular passage or port 25 which leads from the upper end of the bore of the sleeve member 2| to the interior of the well tubing I3, whereby communication is established between the interior of the tubing and the member 2|.

From the above, it will be seen that the cylinders l6 and IT, as well as the sleeve I3 and member 2|, are suspended from the boss 24 and extend vertically in parallel relation to the exterior of the tubingstring l3. For supporting the lower end of the assembly, a similar boss 26 projects radially from the tubing and is disposed at a point below the lower end of the cylinder H. A supporting screw 21 is screw threaded through an opening 28 provided in the boss 26 and has its upper end engaging in an axial recess 28 which is provided in the underside of the cylinder II. By loosening the screw 21 so as to disengage the same from the recess 29 and then by unscrewing the nipple 23 at the upper end of the member 2 I, it will be obvious that the entire assembly may be readily removed from its position between the bosses 24 and 26. Similarly the assembly may be readily positioned on the well tubing.

The bore l8 of the sleeve I8 is slightly enlarged near its upper end to form a chamber 30 within said sleeve. The upper end of this chamber is closed except for an axial opening 3|, which opening has a diameter smaller than the diameter of the bore I8. Radial ports 32 extend through the wall of the sleeve l8 and communicate with the interior of the chamber 30. With this arrangement, it will be obvious that the gas or other lifting fluid within the well casing can flow through the ports 32 and into the chamber 30. From the chamber, such fluid may pass upwardly through the opening 3| and into the upper cylinder IS. A piston 33, preferably solidin cross section has its upper end slidable in the bore l3 of the sleeve l8, while the lower end of said piston projects downwardly within the lower cylinder H. The piston has a plurality of labyrinth grooves 34 in its outer surface and is also provided with an annular flange 35 at its lower end. A lug 36 is located axially at the bottom of the piston.

The piston is normally held in its lowered position by a coiled spring 31 which surrounds the lower end of the piston and is confined between the annular flange 35 and the lower end of the sleeve It. The bottom of the cylinder I! has a pair of vertical ports 38 extending therethrough whereby communication is established between the interior of the cylinder .II and the well casing. Therefore, the pressure of the lifting fluid within the well casing is exerted against the underside of the piston 33 at all times. The upper end of the piston 33 is reduced to form a head 39, which head is located within the chamber 30 when the piston is in its lowermost position. The head is formed'with an annular valve seat 40 near its upper end and a reduced conical pin 4| extends upwardly from said seat. With the piston in its lowermost position and the head 39 within the chamber 30, the conical pin 4| has its upper end just below the axial opening 3| in the top of the sleeve l8, whereby the lifting fluid within the well casing may flow through the ports 32, chamber 30 and through the opening 3|. It is pointed out that both the upper and lower ends of the piston 33 are exposed to the fluid pressure within the well casing and,'therefore, the pressures exerted against both the upper and lower ends of said piston are substantially equal, whereby the piston is in a balanced state. The coiled spring 31 which surrounds the lower end of the piston is, of course, exerting its pressure to hold the piston in its lowermost position and, therefore, it is the pressure of this spring which overcomes the balanced condition of the piston to normally hold said piston lowered.

The bore I6 of the upper cylinder i6 is slightly angular passage 25 in the boss 24 and thus flow reduced at its upper end whereby an annular internal 'shoulder Ila is formed at substantially mid-height of the cylinder I3. A tubular piston or velocity tube '42 is' mounted to reciprocate vertically within the reduced portion of the bore of said cylinder. The tube has a plurality of labyrinth grooves 43in its outer surface and is also provided with an enlarged valve or head 44 at its lower end. The valve 44 is arranged to seat on top of the sleeve I8 and is preferably conical so as to enter the opening- 3|. When the valve is engaging the top of the sleeve, it will be evident that the opening 3| is closed. The valve is normally held in a seated position with the piston or tube 42 in its lowermost position by a coiled spring 45 which surrounds the lower end of the tube and is confined between the enlarged valve head 44 and the internal annular shoulder |6a .within the cylinder I9.

When the piston or velocity tube 42 is raised by means of the pressure of the lifting fluid acting against its bottom, as will be explained, the fluid will, of course, pass through the openings 3| and into the interior of the cylinder l5. From the lower end of the bore of the cylinder, the lifting fluid will flow through inclined ports 46 which extend'through the valve head 44 and then into the bore 42 of the tube 42.

The upper end of the bore 42' of thepiston or tube 42 is normally closed by a metering pin 41 which is slidable verticallyin the bore 2| of the sleeve member 2 l. The pin is provided with an external annular seat 48 arranged to engage the upper end'of the piston 42 to close the bore thereof as clearly shown in Figure 1. That portion of the pin below the valve seat is tapered and when said seat is engaging the tube this tapered portion is located within the bore 42'. The portion of the pin' above the seat '48 is tubular, being open at its upper end. The interior of'this portion of the pin communicates with the bore |6' of the cylinder l6 by means of radial ports 49 provided in the wall of the metering pin 41.

Normally, with no pressure in the well casing N, the pin is in the position shown in Figure 2 with its seat 48 engaging the upper end of the piston 42. It is held so by its own weight. The bore 2| of the member 2| within which the metering pin'41 is slidable, is enlarged near its upper end to form a chamber 50 within the member 2|. Thatportion of the bore of the member 2| above this chamber is reduced as shown at 2 la whereby an annular shoulder 5| is provided within the member 2| directly below this reduced portion. When the metering pin 41 is unseated and moved upwardly within the bore 2|, as will be explained, its upper end will strike the annular shoulder 5| which acts as a stop to limit the upward movement of said pin.

From the above, it will be seen that the fluid which has entered the tubular piston or tube 42 when the valve head 44 has been unseated to admit fluid into the cylinder I5 and tube 42, the pressure of this fluid will overcome the weight of the metering pin to move the same upwardly against the shoulder 5|, whereby the bore 42' is open. The fluid may then flow into the upper end of the cylinder l6 and into the socket 20 at the lower end of the member 2|. When the metering pin 41 moves upwardly against the shoulder 5|, as shown in Figure 3, the fluid may enter the ports 49 in the metering pin, flow through the bore of saidpin and into the reduced portion 2|a of the bore of the member 2|. From the member 2| this fluid can then enter the the angular port 25, from where it enters the tubing l3. Therefore, a direct communication into the tubing I3 wherein theli'quid column is .standing. Thus, it will be seen that when the lower piston 33 is in its lowered position, and the tubular piston 42 as well as the metering pin 41 are in their raised positions, the lifting fluid such as gas or air in the well casing may flow through the ports '32, chamber 30, opening 3| and into the upper cylinder l0. From this cylinder the lifting fluid enters the tubular piston 42, then flows through the port 49 in the metering pin 41, then through thebore of 'said pin and finally to between the well casing and well' tubing is established.

In operation, it will 'be assumed that there is a liquid column standing within the well tubing l3 and that the auxiliary lifting medium, such as gas or air, has not been introduced into the well casing. The parts will be in the position shown in Figure 2 because obviously the pressure of the liquid within the tubing l3 will be exerted downwardly against the metering pin 41 and also against the projected area of the upper piston 42. The lower piston 33 will, of course, be in its lowered position because of the coiled spring 31 which is holding it so. Asv the lifting fluid is introduced into the well casing, it will, of course, completely fill the annularspace between the casing Ill and the well tubing l3. The fluid will enter the port 32 in the connecting sleeve l8 and will also enter the port or opening 38 in the bottom of the lower cylinder l1. Upon entering through the port 32 into-the chamber 39 it will be seen that the pressure of the fluid will be exerted against the upper area of the lower piston 33 and similarly by entering the ports 38 in the bottom of the cylinder l1, thefluid pressure will also be exerted against the lower end of the piston. Therefore, the lower piston 33 will be more or less balanced, which balance is overcome by the tension of the coiled spring 31 holding the piston in its lowermost position, with the conical pin 4| at the extreme upper end of said piston at a point below the opening 3|. The fluid pressure within the chamber 39 will, of course, be exerted against the projected area of the valve head 44 on the upper piston 42, which area is exposed within the opening 3 This fluid pressure acting against this area will be acting against the weight of the piston 42, the weight of the metering, pin 41, and the pressure of the coiled spring 35 plus the pressure of the liquid column which is, of course, acting on the projected area above the piston 42 and" the pin 41. Obviously, the area above the piston 42 and pin 41 which is subjected to the pressure of the liquid column within is acting. Therefore, it will take a greater pressure of the lifting fluid to raise the piston 42 than would be necessary if equal areas were exposed on each side of said piston.

Assuming for purposes of illustration, that the pressure of the liquid within the tubing is 50 pounds and the projected area upon which said liquid is acting is twiceas great as the area upon which the fluid pressure is acting, then it follows that the fluid pressure would have to double the amount of the liquid pressure before the piston 42 could be unseated to uncover the opening 3|. Therefore, by controlling the areas exposed on each side 01' the piston 42, it is possible to definitely control the exact'pressure differential which is necessary to actuate or raise said piston. when the fluid pressure within the casing has reached its predetermined point, it will raise the piston 42 so as to uncover the opening 3| and immediately the fluid, may then enter the lower end of the bore IQ of the upper cylinder l6. As the piston 42 begins to move upwardly, the coiled spring 45 is, of course, compressed. Upon entering the cylinder IS the fluid will immediately pass through the openings 43 and into the bore 42 of the piston 42. Since the only thing that is holding the metering pin 41 seated on the upper end of the piston 42 is the weight of said metering pin 41 and the liquid pressure in the tubing, the fluid pressure will immediately move said pin upwardly to its highest position which is in engagement with the annular shoulder 5| within the member 2|. The

fluid thenpasses through the openings or ports 49, through the pin 41 and then through the angular port 25 into the tubing I3. The fluid entering the tubing will aerate the liquid column therein and will raise the same to the surface of the well.

After the metering pin 41 has been raised against the shoulder as described, the fluid rushing through the tubular piston 42 and also acting against the underside of the entire area of the valve head 44 will raise the piston 42 to its highest position under tension of the coiled spring 45. This highest position of the piston 42 is limited by a shoulder which is formed at the intersection of the bore 2| of the member 2| and the socket 20 at the lower end of said member. When the velocity tube or piston 42 strikes this shoulder 20 (Figure 3) its further upward movement is prevented. It is noted that when the piston has moved to this position it has not reengaged the annular seat 48 01' the metering pin 41 and the escape of fluid from the bore 42' of said piston may continue. There fore, once the metering pin 41 has moved to its uppermost position, it cannot against close the bore 42' of the upper piston until both members have begun their downward movement. It is noted that while the piston 42 is moving upwardly with relation to the metering pin which has previously been moved to its highest position, the tapered portion of the pin again enters the bore 42' whereby the flow of fluid from said bore is gradually metered as the piston 42 continues to rise.

While the metering pin 41 and the upper piston 42 have been moving to the position shown in Figure 3, as has been described, the lower piston 33 has remained inactive because the pressure on each side thereof is substantially equal. However, as soon as the piston 42 has moved to its highest position, and the liquid column in the tubing |3 has lightened, the velocity of th lifting fluid flowing through the openings 3| increases. This increase in velocity will, of course, lower the pressure within the chamber 30 accordingly and when this pressure reaches a predetermined point, the pressure below the piston 33 which'remains constant, overcomesthe tension of the spring 31 and raises the lower piston 33 to the position shown in Figure 4. In such position the conical pin 4| at the extreme upper end of the piston enters the opening 3| and the annular valve 40 engages the underside of the top of the sleeve l3 to close the opening 3| and thereby cut off the flow of fluid therethrough. After the lower piston has moved to this position (Figure 4), no more lifting fluid can enter the well tubing I3.

of the piston 42, the metering pin 41 drops so that its seat 48 engages the top of said piston as it did previously. The parts remain in this position until such time as the liquid column builds up in the tubing I3. As this liquid column builds up, the pressure within the tubing is, of course, built up and this pressure is exerted on the projected area of the metering pin 4'! tending to force the same downwardly. Due to the fact that the fluid pressure is within the chamber 30 surrounding the head 40 of the lower piston, the only area of said lower piston upon which the fluid is acting is the cross-sectional area of the opening 3|, which is much smaller than the projected area upon which the liquid pressure is acting. Therefore, the pressure of the liquid column within the well tubing need never equal or be in excess of the pressure of th fluid within the well casing in order to force the piston 33 downwardly against the fluid pressure. Just how much pressure the liquid must build up with relation to the pressure of the fluid within the well casing is dependent upon the particular areas exposed to each of these pressures. Whenever the pressure of the liquid column reaches this predetermined point, it will force the metering pin 43 and upper piston 42 downwardly as a unit, which will force the piston 33 downwardly so as to disengage the valve 40 from the opening 3|. This uncovers the opening 3| and immediately the fluid may again pass through the port 3| and into the cylinder I to again raise the metering pin 41 andupper piss ton 42 as has been explained. The cycle of operation is then repeated as above.

It is noted that after the original upward movement of the upper piston 42 upon the introduction of the lifting fluid into the casing ill, the valve head 44 at the lower end of said piston will probably not be again seated to close the opening 3| until the fluid pressure in the casing is entirely cut on. This is true because after having moved upwardly to the position shown in Figures 3 and 4, its immediate reengagement with the seat is prevented by the pin 4| which has moved into theopening 3| as shown in Figure 5. As soon as the pressure of the liquid in the tubing builds up sufllciently to force the lower piston downwardly, the port 3| is opened and more lifting fluid admitted, whereby the upper piston is again-returned to the positions shown in Figure 4. Therefore, under ordinary operating positions, the upper piston 42 fluctuates constantly within its cylinder. The main function of this upper piston is to transfer an increased projected area to the lower piston 34, when said piston is closing the inlet of lifting fluid, whereby a greater area is exposed to the pressure of the liquid in the tubing than is exposed to the pressprings 31 and II have been shown the pistons 34 and M respectively, these springs merely-insure the positive movement of the pistons to their lowered positions. .It has been found trolled by varying the areas which are exposed reduced as shown at 55b. An annular il'is provided .at the upper end or the portion 55b and the extreme upper endiic or thebore above said valve seat is iurther reduced to the same diameter as the diameter 01- the port 25" with which it communicates. The wall or the extending therecylinder 55 has radial ports 02 OI, whereby fluid through opposite the chamber under pressure within the well casing mayflow to the liquid pressure and to the fluid pressure.

This type of valve is particularly adaptable for use on a well which has a low liquid standing through these ports, into the chamber 5| and then upwardly through the angular ports and into the well tubing l3.

An elongate tubular piston 53 is mounted to reciprocate within the cylinder 55 and theunp end or this piston is reduced and screw threaded level and a resultant low pressure within the tubin'g. Heretoiore, it has been necessary inmost cases to build up a liquid column within the tubz o ing having a sufficient height to provide a pressure great enough to'overbalance the operating pressure of the lifting fluid; or springs have been employed to compensate for pressure. The former method is animpossibility'in the case or a well in which the standing level .of the liquid is comparatively low. The low liquid level, of course, reduces the'pressure and in wells of this kind a flow valve which depends on the pressure of the liquid being greater than the pressure of the lifting fluid for operation, cannot be used.

Spring compensated valves have proven impractical because although the spring aids in operation in one direction, it is detrimental when operating in a reverse direction with the valve herein shown, a liquid pressure of 50 pounds within the tubing could overbalance a pressure of 500 pounds within the well casing by merely changing the areas exposed to the liquid and to the fluid. The valve is automatic in operation and needs no adjustment after its assembly and mounting on the well tubing. It is specifically noted that the device is not to be limited to operating in a low pressure well, butcould be used in the usual manner in which a plurality of thevalves A would be mounted at various stages in the tubing string. In Figure 1 I have shown two valves mounted in the string but if desired one or any number could be employed depending upon the conditions of the particular well on which the device is used.

In Figures 9 to 11', a modified form or the in} vention is shown. In thisrorm a more simple structure is disclosed, wherein a single cylinder is employed. The cylinder has itsupper end externally screw threaded so as to engage with-- in the openings 23" provided in the underside of a radially projecting boss 24' formed on the tubin'g l3. The boss 24' is similar, to the upper boss 24 in-the first iorm and is provided with an angular port 25' which establishes communication between the interior of the tubing l3 and the upper end of the cylinder 55. The lower end of the cylinderbore 55 is internally screw threaded to receive a. closure cap 56. The cap is provided with an axial bore 51 extending entirely therethrough and an annular valve seat 58 is formed at the upper end of said bore. It is noted that the bore of the cap establishes communication between the interior of the well casing and the lower end of the cylinder 55. I

The bore 55' of the cylinder is reduced at 55a 4 so as to form an internal annular shoulder 55 within the cylinder. Above the reduced portion 55a the'bore is enlarged to form a, chamber 60 so as to receive the lower end of a head 5|. The

head has a diameter sfiibstantially the same as the diameter of the reduced portions 55a and 55b of the bore 01' said cylinder, whereby said head has a sliding fit therein. Since the head slides within the reduced portion 55a, it will be obvious that the lower end of the cylinder 63 is movable 7 within the lower end of the cylinder 55. The head 64 is formed with an integral, upwardly extending metering pin 65 which is hollowed out so as to provide a chamber 56 therein. A ball 81 is located within the chamber 66, being adapted forest on the upper end of the bore 63' of said piston.- Inclined ports 68 are provided in the shoulder formed between the head lil and tapered meter-' ing pin 65, whereby a communication is established between the chamber 60 in the upper end of the cylinder 55 and the ball chamber 55. Itis noted that the construction of the head SI and metering pin is such as to provide a cage for the ball 61. The extreme lower end oi. the piston 55 is provided with an annular flange 59 and acoiled spring 10 surrounds the piston and is confined between this flange and the internal shoulder 59 formed within the f cylinder. -Mani1'estly, the spring 10 constantlyexerts its pressure tohold the piston in its lowermost position resting on lugs 10' as shown in Figure 9. An annular valve seat H is formed within the bore 53'. of the piston 63 and this seat. is located nearer the lower end of said bore. An elongate stem 12 extends up wardly into the bore 53' and is adapted to have its upper end engaging the .seat II when the piston is in its lowermost position. The lower end of the stem. 12 is formed with an enlarged head.

15 which is slidable within the bore 51 of the cap member 55. This head normally has its lower end resting on a snap ring 14 which is inserted in agroove 15 provided within the lower endoi' the bore '51, whereby the stem cannot fall downwardly from said bore. The head is provided with vertical passages or groovw 16 in its peripheral portion, whereby the fluid below the cylinder and cap may pass upwardly through these grooves' and into the core .51 of saidcap, and then finally into the bore 55' of the cylinder 55. when the stem 12 is moved upwardly, as will be explained, the head I3 is arranged to engage the annular valve seat 58 provided at the upper end of the bore 51 of the cap 56 and when said head so engages the seat, the admittance oi! fluid from the well easing into the lower end of the cylinder 55 is prevented.

In operation, assuming the parts to be in the position shown in Figure 9 and before any fluid obvious that the liquid level in said well casing and in the tubing will be equalized because flow v 5 within the upper end or the cylinder. at the upper end 01 the chamber the-bore is valveseat of the liquid will occur through the angular port chamber 60 and radial port 62 in the upper end of the cylinder 55. When the lifting fluid is introduced into the upper end of the well casing, such fluid will force the liquid in the casing back through the angular port 25' and into the tubing l3. As the liquid flows into the tubing, the'gas or other lifting medium will, of course, follow the same to aerate the column and raise the liquid to the surface. With the parts in the position shown in Figure 9, the fluid pressure may act against the upper end of the piston by entering the chamber ill and may also act against the lower end of the piston by entering the bore 51 of the cap and then flowing into the bore 55' of the cylinder. This equalizes the pressure on each side of the piston i3 and permits the coil spring ll to overcome this balanced condition to hold said piston in its lowermost position. It is noted that at this time the stem 12 has its upper end engaging the valve seat 1| within the bore 63' of the piston and fluid may not flow upwardly through said bore. At the same time the fluid pressure within the chamber 6|! acts against the upper end of the ball 61 to hold the same seated because the fluid from the chamber may flow through the inclined ports 68 provided in the shoulder between the metering pin 65 and head 64.

As the liquid column within the tubing I3 is lightened the velocity of the fluid flowing through the angular ports 25' commences to increase and as the load continues to lighten the velocity of the lifting fluid increases in accordance therewith. When the velocity of the gas or the lifting fluid through the ports 25' reaches a predetermined point which brings about a lowering of the pressure in the chamber Bl, then the constant pressure of the fluid against the lower end of the piston 63 will begin moving said piston upwardly against tensionof the spring II. This upward movement of the piston will, of course, cause the metering pin 65 to enter the reduced upper end 55b of the bore of the cylinder and will also cause the shoulder between said pin and the head 64 to be moved toward the annular valve seat 8| at the upper end of the chamber 80, whereby the flow of fluid to the tubing I3 is decreased. At the same time, as the piston rises, the stem 12 remains seated against the seat ll, said stem following the piston. v

As the pressure above the piston, or the pressure in the tubing l3 continues to decrease, the fluid'pressure will flnally move the upper-end of the piston 63 into the reduced portion 55b of the bore and then to its uppermost position which engages the shoulder at the base of the metering pin with the valve seat 6!, whereby the flow of lifting fluid into the tubing is entirely out ofl. It is noted that as soon as the shoulder at the base of the pin enters this reduced portion, the fluid through the openings 82 is cut ofl. The stem 12 is of such length that as the piston enters the portion 55b and just before the piston engages the seat 6|, the head I! of said stem engages its seat 58 to shut off the lifting fluid from the interior of the cylinder. This seating of the head prevents further upward movement of the stem 12 and as the piston 63 moves into engagement with the seat, the upper end of the stem leaves its seat 1| within the bore of the cylinder, whereby the fluid trapped below the piston may flow upwardly through the bore 63 to unseat the ball 61. The fluid then flows past the ball and through the inclined ports i8 which are not covered by the seating of the piston on the seat II. Thus, the trapped fluid is bled into the tubing from below the piston.. As soon as this fluid is bled from the cylinder the spring II, together with the pressure of the well liquid in the tubing, forces the piston downwardly until the seat H within its bore engages the stem which is still held in its raised position'by the lifting fluid pressure acting against the bottom of the head II. At this time, the upper end of the head of the piston is still within the reduced portion 55b of the bore of the cylinder, whereby lifting fluid cannot flow through the ports Bl to the passage 25. The parts will remain in this position (Figure 10) until the pressure of the well liquid within the tubing acting against the top of the piston head overcomes the pressure of the lifting fluidin the casing acting against the underside of the head 13 of the stem 12.

It is noted that at this time the cross-sectional area on which the liquid pressure is exerted is greater than the cross-sectional area of the head of the stem 12, which latter area is acted upon by the lifting fluid pressure within the well casing. Therefore, the liquid pressure, since it acts upon a larger area, need not equal or exceed the pressure of the lifting fluid within the well casing in order to force the piston and stem downwardly to permit another injection of lifting fluid into the well tubing. After the liquid column builds up sufllciently to move the piston 63 downwardly, additional'lifting fluid is permitted to enter the tubing I I to aerate the column therein. As the column is raised and the pressure within the tubing is dropped, the oper-- ation of the device is repeated. Thus, it willbe seen that the valve shown in Figures 9 to 11 employs the .same principle as that of the flrst form although it is much simpler in construction. It is the variation in areas upon which the well liquidacts and upon which the lifting fluid acts that controls the actuation of the valve. By varying these areas, it is possible to accurately determine the differential necesary to operate the device.

In. Figures 12 and 13 a modified form of the valve shown in Figures 1 to 9 is disclosed. In this form, the metering pin 41 above the upper piston 42 is omitted and a ball is substituted therefor. A transverse pin 8| extends across the bore 2| of the member 2| to limit the upward movement of the valve. The ball operates exactly as the metering pin, being unseated by the lifting fluid pressure flowing through the upper piston 42 and being seated by liquid pressure from the tubing. The upwardly extending conical pin 4| on the upper, end of the lower piston a is eliminated and an elongate curved metering pin 82 substituted therefor. The upper end of this pin extends through the opening 3| in the top of the lower cylinder i1 and is secured axially in the underside of the upper piston 42, whereby both pistons move as a unit instead of independently.

The operation of this form same as that of the form Assuming the parts to be Figure 12, it will be obvious that the lifting fluid pressure will raise the upper piston 42 from its seat. As this occurs, the fluid enters the piston 42 and unseats the ball 80 to enter the tubing. As soon as the piston 4! begins its upward movement,, the lower piston 33 will also commence to move upwardly therewith because'of their connection through the metering pin l2. At the is substantially the shown in Figures 1 to 9.

in the position shown in.

same time,

' operation of the upward movement, of theppist'ons causes the pin 82 to move upwardly within the opening 3| to automatically meter the flow of lifting fluid into the tubing. when the upper piston strikes the shoulder ing fluid. The operation is then similar to the first form except that pistons instead of independently.

desire to secure by Letters move simultaneously What I claim and Patent, is: v

1. A well flowing apparatus including, a tubing having an influent liquid inlet and an inlet 'for admitting a lifting fluid, and a valve for controlling the admission of the lifting fluid and actuated by-the differential in pressure between the influent in the tubing and the lifting fluidin the casing, said valve exposing different crosssectlonal areas to the closed position, the cross-sectional area which is exposed to the liquid being greater than the cross-sectionalarea exposedto the fluid.

2. A well flowing apparatus including, a tubular body adapted to bemonnected with a well tubing and lowered therewith into a well casing, said body having a passage for establishing communication between the casing and tubing, and a valve within the passage for controlling the flow of lifting fluid from the well casing through the passage, said valve being actuated by the differential in pressure between the well liquid in the tubing and the lifting fluid in the casing, the valve exposing different cross-sectional areas to the liquid andfluid when in a closed position, the cross-sectional area which is exposed to the liquid being greater than the cross-sectional area exposed to the fluid.

3. A well flowing apparatus including, a tubular body adapted to be connected with a well tubing and lowered therewith into the well casing, said body having a passage for establishing communication between the casing and tubing, a movable piston for controlling the flow of a lifting fluid under pressure from the easing into the tubing and having a substantially constant crosssectional area, said piston exposing equal areas on each side thereof to the lifting fluid pressure when the valve is in an open position, whereby the piston is balanced in such position, means for moving the piston to its closed position when the velocity of the lifting fluid reaches a predetermined point, such movement of the piston exposing one side thereof to the well liquid pressure, and a movable member actuated by the well liquid pressure adapted to engage this side i of the piston when the same is in its closed position, said member having garger cross-sectional area than the piston whereby the side of the piston exposed to the well liquid is in effect increased in cross-sectional area.

4. A well flowing apparatus including, a tubular body adapted to be connected with a well tubing and lowered therewith into a well casing, said bodyhaving a passage for establishing communication between the casing and tubing, a

tubular piston within the body for controlling the admission of a lifting fluid from the well casing through the passage into the well tubing, said body having an opening having a smaller crosssectionalarea than the piston in itslower end whereby the lower end of the pistonis exposed to the lifting fluid pressure, means for closing the bore of the piston to trap the lifting fluid therebelow, means for moving the piston to its closed position when the velocity of the lifting fluid the seat lll'engages the opening II to cut oil. the flow of liftliquid and fluid when in a I lifting fluid trapped below entering the tubing reaches a predetermined point, means for closing the opening in the lower end of said body when the piston shuts oi! the admission of lifting fluid to the tubing, and means associated with the closing means for opening the bore of the-piston to permit the escape of body. I

5. A well flowing apparatus including, a tubdlar body adapted to be connected with a well tubing and lowered therewith into a well casing,

said body having a passage for establishing com-' munication between the casing and tubing, a movable piston for controlling the flow of shiting fluid under pressure from the casing into the tubing and having a substantially constant crosssectional area, said piston exposing substantially equal areas on each side thereof to the lifting fluid when in an open position, whereby the piston is balanced in such position, and a movable member actuated by the well liquid pressure connected to said piston and having a larger crosssectional area, whereby when the piston has moved to its closed position, the increased crosssectional area of the member is transferred to the piston through its connection therewith.

6. A well flowing apparatus including, a tubing having a well liquid inlet and an inlet for admitting an auxiliary lifting fluid, a valve for controlling the admission of the lifting fluid into the tubing, said valve exposing substantially equal cross-sectional areas on each side thereof to the pressure of 'the lifting fluid in the well casing when the valve is inan open position, the valve exposing one side to the well lifting pressure and its opposite side to the well liquid pressure when in a closed position, and a movable piston located in the line of flow of the lifting fluid and exposed to the liquid pressure-and having a. larger cross-sectional area than the valve, said piston being tubular to permit the lifting fluid to flow .therethrough and being arranged to engage one pressure reaches a predetermined proportion of the lifting fluid pressure.

'7. A well flowing apparatus including, a tubular body adapted to be connected with a well tubing and lowered therewith into the well casing, said body having a passage for establishing communication between the casing and tubing, a valve for controlling the flow of a litfing fluid under pressure from the easing into the tubing and having a substantially constant cross-sectional area, said valve exposing equal areas on each side thereof to the lifting fluid pressure when the valve is in an open positionwhereby the valve is balanced in such position, means for moving the valve when the velocity of the fluid entering the tubing reaches a predetermined point, and a mova-ble piston within the passage located in the line of the valve when in a closed position, whereby the increased area of the piston is transferred to the valve to open the valve when the liquid pressure reaches a. predetermined proportion of the lifting fluid pressure.

8. Awell flowing apparatus including, a tubular body adapted to'be connected with a well tubing andlowered therewith into the well casthe pis o .W fl

entering the tubing reaches a predetermined point, a movable piston within the passage located in the line of flow of the lifting fluid and exposed to the liquid pressure and having a larger cross-sectional area than the valve, said piston being tubular to permit the lifting fluid to flow therethrough and being arranged to engage one end of the valve when in a closed position,

whereby the increased area of the piston is transferred to the valve to open the valve when the liqiud pressure reaches a predetermined proportion of the lifting fluid pressure, and means adapted to enter one end of the bore of the piston for metering the flow of lifting fluid into the tubing.

9. A well flowing having a well liquid inlet and an inlet for admitting an auxiliary lifting fluid, a valve for' controlling the admission of the lifting fluid into the tubing, said valve exposing substantially equal cross-sectional areas on each side thereof to the pressure of the lifting fluid in the well casing when the valve is in an open position, the valve exposing one side to the well lifting pressure and its opposite side to the well liquid pressure when in a closed position, a movable piston located in the line of flow of the lifting fluid and exposed to the liquid pressure and having a larger cross-sectional area than the valve, said piston being tubular to permit the lifting fluid to flow therethrough and being arranged to engage one end of the valve when in a closed position, whereby the increased area of the piston is transferred to the valve to Open the valve when the liquid pressure reaches a predetermined proportion of the lifting fluid pressure, resilient means for urging the valve to its open position, and yieldable means for urging the piston toward said valve.

10. A well flowing apparatus including, a tubular body adapted to be connected with a well tubing and lowered therewith into the well casing and having a passage for establishing communication between the casing and tubing, a double valve seat within the passage, a movable valve for controlling the flow of lifting fluid through said passage located below the double seat and adapted to engage the seat to cut oil! the flow, said valve being of a substantially constant cross-sectional area and exposing equal areas on each side thereof to the lifting fluid pressure when in an unseated or open position whereby the valve is balanced in such position, means for moving the valve from its open position when the velocity of the fluid entering the tubing reaches a predetermined point, and a movable piston located above the double valve seat and exposed to the liquid pressure and having a larger cross-sectional area than the valve, said'piston being tubular to permit the lifting fluid to flow therethrough and being arranged to engage one end of the valve when in a closed position, whereby the increased area of the piston is transferred to the valve to open the valve when the liquid pressure reaches a apparatus including, a tubing predetermined proportion of the lifting fluid pressure. i 11. A well flowing apparatus including, a tubular body adapted to be connected with a well tubing and lowered therewith into a well casing, said body having a passage for establishing communication between the casingand tubing, a tubular piston within the body for controlling the admission-of a lifting fluid from the well casing through the passage into the well tubing, said body having an opening having a smaller cross-sectional area than the piston in its lower end whereby the lower end of the piston is exposed to the lifting fluid pressure, means for closing the bore of the piston to trap the lifting fluid therebelow, means for moving the piston to its closed position when the velocity of the lifting fluid entering the tubing reaches a predetermined point, means for metering the flow of the. lifting fluid into the tubing as the piston moves, means for closingv the opening in the lower end of said body when the piston shuts off the admission of lifting fluid to the tubing, and means associated with the closing means for opening the bore of the piston to permit the,

escape of lifting fluid trapped below the piston within the 12. A well flowing apparatus including, a tubular body adapted to be connected with a well tubing and lowered therewith into the well casing, said body having a passage for establishing communication between the casing and tubing, a valve for controlling the flow of a lifting fluid under pressure from the easing into the tubing and having a substantially constant crosssectional area, said valve exposing equal areas on each side thereof to the lifting fluid pressure when the valve is in an open position whereby the valve is balanced in such position, means for moving the valve when the velocity of the fluid entering the tubing reaches a predetermined point, means for engaging one end of the valve when the same is in a closed position and having a larger cross-sectional area than the valve whereby this increased area is transferred to the valve, said last named means being exposed to the well liquid pressure, whereby the valve is opened when the liquid pressure reaches a predetermined proportion of the lifting fluid pressure, and means within the passage for metering the volume of lifting fluid flowing through the passage.

13. A well flowing apparatus including, a tubing having a well liquid inlet and an inlet for admitting an auxiliary lifting fluid, a valve for controlling the admission of the lifting fluid into the tubing, said valve exposing substantially equal cross-sectional areas on each side thereof to the pressure of the lifting fluid in the well casing when the valve is in an open position, the valve exposing one side to the well lifting pressure and its opposite side to the well liquid pressure when in'a closed position, means for transferring an increased cross-sectional area to the side of the valve exposed to well liquid whereby the valve is opened by the differential in lifting fluid and well liquid pressures, and means for metering the flow of lifting fluid entering the tubing.

14. A well flowing apparatus including, a tubing having an influent liquid inlet, means for introducinga lifting fluid into the tubing for lifting the influent flowing up the tubing, means for controlling the admission of the lifting fluid and actuated by the differential in pressure between the well influent in the tubing and the lifting fluid in the well casing, said means exposing different cross-sectional area to the liquid and fluid, the cross-sectional area which is exposed to the liquid being greater than the cross sectional area exposed to fluid, whereby when the pressure of the liquid reaches a predetermined proportion of the pressure of the lifting fluid, said means is actuated, and means for metering the flow of lifting fluid entering the tubing.

15. A well flowing apparatus including, a tubing havin an influent liquid inlet and an inlet for admitting a lifting fluid, a valve for controlling the admission of the lifting fluid and actuated by the difierential in pressure between the influent in the tubing and the lifting fluid in the casing, said valve exposing different crosssectional areas to the liquid and fluid when in a closed position, the cross-sectional area which is exposed to the liquid being greater than the cross-sectional area exposed to the fluid, and movable metering means associated with the valve for metering the flow of lifting fluid entering the tubing.

CHARLES S. CRICKMER.

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