US2295598A - Well flowing device - Google Patents

Description

Sept. l5, 1942.l L. D. MQWREY f WELL FLOWING DEVICE Filed Feb. 21, 1940 7%, lo M Leste r' D. M

Patente-cl Sept. 15, 1942 iliii'l STATES FATENT OFFICE WELL FLOWING DEVICE Lester D. Mowrey, Wichita Falls, Tex.v

Application February 21, 1940, Serial N o. 320,210

(Cl. S-232) This invention relates to an apparatus for elevating liquids from a lower level to a higher level, and more particularly to the lifting of water or oil in wells by air or gas pressure.

The present invention is an improvement on that set forth in my prior co-pending application for Gas lift flow devices, Serial No. 278,530, filed June 1G, 1939.

In oil fields there is a certain amount of gas associated with or entrapped in the liquid oil when the re ervoir is first penetrated. This gas functions to lift the oil while the well-is on natural flow. After the well ceases to flow naturally, there is almost as much gas per barrel accompanying the oil from the formation as when the well was owing naturally, but the reservoir pressure has declined until the gas is insufficient to continue the lifting operation. Under these circumstances it is necessary that some means be provided to lift the cil in the well.

Various types of gas pressure lifts have been employed, using both open and closed end floats, but these have depended upon the buoyancy of the float to open a gas or air inlet valve so as to aerate the liquid to cause it to rise Within the tubing.

In this invention, the opposite principle is utilized, i. e., as long as the float has a buoyancy greater than that of the displacement of the liquid, it will have a tendency to rise and close the valve. As long as the liquid does not eXert a hydrostatic pressure on the float to such an extent as to compress the air or gas within the float and the weight of the float is less than the Weight of the liquid which it displaces, the oat will hold the Valve closed. However, when this buoyancy decreases to the extent of being less than the buoyancy of the liquid displaced, the iloat will sink, permitting the valve to open and introduce gas or air into the tubing containing the liquid so as to aerate the liquid and move it upward in the tubing,

This action is entirely automatic in operation, i. e., when predetermined hydrostatic pressure accumulates within the tubing, the apparatus will function, thereby causing the float operated valve to open and discharge a portion of the liquid upward through the tubing under the force of gas introduced from a point eXteriorly of the tubing. Due to the fact that this valve arrangement retains the natural reservoir pressure by preventingthe waste of gas or air, less additional gas or air will be necessary than would be required otherwise to lift the liquid in the Well.

laims.

This invention is an improvement on that set forth in my co-pending application hereinbefore mentioned, inasmuch as I have here provided for keeping the float chamber filled at all times with liquid, thereby excluding substantially all foreign matter from close contact with the operating mechanism and insuring the continued presence of sufcient liquid in the float chamber to operate the float. By having a float chamber always fllled with liquid, the control valve will remain closed even if the pressure in the Well should blow liquid therefrom or if the level of liquid should fall below the flow unit. The float is responsive to a pressure exerted by a column of fluid above the iloat and is not responsive to gas pressure in the casing.

A preferred embodiment of this invention is illustrated in the accompanying drawing, in which- Fig. l is a vertical sectional view through a well showing a plurality of flow units comprising the invention, installed therein;

Fig. 2 is an enlarged vertical section of the upper portion of the ow unit and valve mechanism;

Fig. 3 is similar View of the lower portion of the flow unit, showing the check valve installed in the bottom thereof;

Fig. 4 is a horizontal section taken on the line of Fig. 2, looking in the direction of the arrows;

Fig. 5 is a horizontal section taken on the line 5-5 of Fig. 2, looking in the direction of the arrows; and

Fig. 6 is a horizontal section taken on the line 6 6 of Fig. 3, looking in the direction of the arrows.

In the drawing, the numeral I designates the casing of a conventional deep well having a casing head 2 at its upper end thereof, which casing head is sealed by a cap 3 to prevent escape of pressure from the well.

Within the well casing I is disposed a tubing 4 that extends to a point adjacent the bottom of the well and has the usual perforated pipe 5 on the end thereof.

Flow units 6 may be mounted at spaced intervals in the tubing 4, the number used depending upon the depth and capacity of the well, a sufi-lcient number being employed to effect step by step upward now of liquid to the top of the well.

Each flow unit 6 comprises a tubular member 1 having a head 8 at the upper end thereof and a bottom member 9 attached to lower end thereof and respectively closing said tubular member at the opposite ends thereof. The head 8 and the bottom member 9 are bored and screw threaded to receive the adjacent ends of sections of the flow tubing 4.

Mounted within the tubular member 'I between the head 8 and bottom member 9 is a central iioat chamber I0. The space between the chamber IE) and the tubular member 'I provides an annular ow chamber II through which flows the liquid rising in the well.

The oat chamber I has a partition plate I2 closing the lower end thereof, whereby the chamber I 0 is adapted to hold a quantity of liquid at all times for a purpose later to be more fully explained. Below the partition plate I2 is an inlet chamber I3 having discharge openings I4 through the sides thereof into the annulail flow chamber for the purpose of directing liquid from the flow tubing 4 into the annular chamber II. The inlet chamber I3 is normally closed at the bottom by a check valve I5. The check Valve I5 has a normal tendency to close under a weak spring tension but the upward pressure of rising fluid readily opens the Valve, the function of which isV to prevent a back iiow or back wash down the tubing 4 to the producing formation during the aerating periods. The valves also serve to hold all liquid that passes above the valves when they are used in series. Fluid communication between the ow chamber II and the central float chamber I9 is provided through orifices I6` at the upper end of the chamber I0. The annular ow chamber I I also communicates with the upper section of tubing 4 through ducts I'I in the head 8.

Thus liquid from the well may pass up through the lower section of flow tubing 4, through the openings I4, into the flow chamber II, and upward through the ducts Il, to the upper section to flow tubing 4 through which it passes as far as the reservoir pressure will carry it until the liquid head becomes static. As the liquid passes upward by the orices I6, the central chamber IIIv will be maintained filled withv liquid sov as to insure the float the proper working liquid and to impart the pressure of the hydrostatic head to the float.

For the purpose of aerating the liquid to assist in raising it from the well, an automatic float mechanism isprovided to admit air or gas thereto which float mechanism operates when the pressure-of the hydrostatic head reaches a predetermined point. This float mechanism is mounted within the central chamber I0 and is operatively connectedwith a valve I3 which controls the flow of gas into the chamber IIJ. through an inlet duct I9 formed in the head 8 and which duct scommunicates at its opposite end with the exterior of the` flow unit B within the well casing I. The gas admitted past valve II'!` into chamber I I escapes through orices I6, aerating the column of static liquid thereabove, causing it to flow upward in the tubing 4.

The float mechanism for operating the valve I8 comprises an operating lever 22) pivotallymounted at 2I on a dependent bracket 22 suspended from the head 8 within the chamber Il. The lever 2i)V underlies the stem of the valve I8 in position for moving said valve to a seated position. The operating lever 2! has integrally formedtherewith an arm 23 which extends downwardly through the float chamber I and has an offset portion 24` at its lower end in position for engagement by a roller 25. The roller 25 is journaled on a leverZS pivotally attached at 2l t0 the dependent bracket 22. A link 28 suspends a float 29 from the free end of the lever 26. A rest S is provided at the bottom of the dependent bracket for limiting the downward swinging movement of lever 25. The float 29 comprises a hollow cylindrical tube closed at its upper end and open at the lower end thereof. rIhe ioat 28 is provided with peripheral projections 3| on the sides thereof for guiding the upward and downward movements of the float in the chamber I0.

A plug 32 is provided in the connecting head 8 whereby the float chamber I may be filled with liquid prior to insertion of the ow unit into the well, which, under normal atmospheric pressure, will cause the float 29 to rise in the chamber and close the valve I8. By lling the chamber with a clean liquid prior to placing in the well, very little foreign matter will nd its way into the chamber through orioes IS, as very little additional liquid will pass into the chamber during the operation thereof.

In operation, the upper portion of the enclosed well casing I will be filled with entrapped air or gas under pressure, and as the liquid rises in the well casing it will pass through the perforated pipe 5 and the lowest section of the tubing 4, thence past the check valve I5, through holes I4 and into the iiow chamber II', thence upwardly through ducts II into the upper section of the tubing l. The liquid continues to pass up through the tubing 4 until it becomes static due to the equalization of pressure.

When the liquid rises to a sucient height above the level of the orices I6 in the float chamber I3, a pressure will be exerted on the liquid contained therein causing a compression of the air or gas. trapped within the upper end of the float 2S. When the compression of the entrapped air or gas reaches that point at which the liquid displacement of the oat is less than the weight thereof, the float moves downward in the liquid. As the float moves downwardly in the oat chamber I0 the lever 28 swings downwardly allowing downward movement of the valve I8 which opens the passageway I9 and admitting air or gas under pressure into the upper end of the iioat chamber I6 above the liquid therein, which airor gas passes outwardly through orioes It and upwardly through said tubing 4.

It is, of course, understood that the weight of theY iioat assembly, without the entrapped gas, is greater than the weight of the liquid which it displaces, and the height of the column of oil isdependent upon the amount of pressure required to sink the float. These factors determine the points at which the aerating valve opens and closes.

Airor gas may also be introducedl on the outside a-t the upper end* of the casing I in order to furnish any addi-tional pressure required. A

kvoir pressure canbe utilized for flowing. after it has declined below the point where the well'will flow naturally. This pressure will elevate the liquid in the flow tubing to a point where the gas lift flow device may be installed to utilize the reservoir pressure to lift the liquid to the surface l 'either directly or by stages.

If necessary, a series of these devices may be installed, as shown in Fig. 1 of the drawing.

When a series of flow units are installed, a hydrostatic head is built up above a second of the additional flow units, and the same operation will occur as has just been decribed, each unit giving additional aeration to the liquid. With the present device the second or additional ow units will not allow any escape of gas pressure until successive hydrostatic heads are built up above the ow units in turn.

A further advantage to be gained by using a oat as described herein is that this float will not collapse under pressure as the pressure is always equal inside and outside at any point on the float.

It will be noted that in the operation of the device, the casing or lifting pressure has nothing to do With the automatic control of the device, as it is controlled by the hydrostatic pressure within the float chamber.` Therefore, the casing or lifting pressure can have a wide variance without affecting the operation of the device.

I claim:

1. In a flow device, a chamber having an inlet and an outlet adapted for flow of liquid therethrough, a second chamber adjacent the firstmentioned chamber having a fluid passage connecting the same with the first-mentioned chamber, the liquid inlet of the rst-mentioned chamber being arranged out of communication with the second-mentioned chamber, said second chamber having a fluid inlet, and means for controlling said luid inlet, said controlling means being constructed for trapping compressible uid therein with said compressible fluid in communication with the liquid in said second chamber, said liquid outlet of the first-mentioned chamber being separate from the second chamber for discharging the liquid from the firstmentioned chamber independently of the second chamber.

2. In a flow device, a chamber having an inlet and an outlet adapted for flow of liquid therethrough, a second chamber adjacent the nrstmentioned chamber having a iluid passage connecting the same with the rst-mentioned chamber, said second chamber having a fluid inlet, and means movably mounted in said second chamber for controlling said fluid inlet, said controlling means being constructed for trapping compressible uid therein with said compressible iiuid in communication with the liquid in said second chamber and movable in response to the compression thereof by hydrostatic pressure of the liquid to permit opening movement of the inlet controlling means, said liquid outlet of the iirstmentioned chamber being separate from the second chamber for discharging the liquid from the first-mentioned chamber independently of the second chamber. Y Y

3. In a flow device, a chamber adapted for flow of liquid therethrough, a second chamber enclosed within the first-mentioned chamber and having a fluid passage connecting the same with the rstmentioned chamber, said second chamber having a gaseous fluid inlet communicating with the exterior of said flow device, means for closing said uid inlet, and means movably mounted in said second chamber and operatively connected with said inlet closing means, said movable means being constructed for trapping compressible iluid therein in open communication with the liquid contained in said second chamber and holding the inlet closed by fluid contained in said second chamber, said means CII moving in response to the compression of the fluid by the hydrostatic pressure of the liquid thereon to permit opening of the uid inlet.

4. In a flow device, a chamber adapted for iiow of liquid therethrough, a second chamber mounted within said first-mentioned chamber and having communication with said outer chamber, said inner chamber being adapted to contain fluid and having a gas inlet communicating with the exterior of said flow device, a valve for controlling said gas inlet, and means mounted within said inner chamber for actuating the valve, said means being movable by the liquid contained in said inner chamber normally to hold the valve closed and having a compressible fluid therein, said means being movable in response to a compression of the iiuid by the liquid in the inner chamber for permitting opening movement of the valve.

5. In a flow device, a chamber adapted for flow of liquid therethrough, a second chamber mounted within said first-mentioned chamber and having its upper end in open communication with the outer chamber, said inner chamber being closed at the lower portion whereby iiuid is contained therein at all times, said inner chamber having a gas inlet communicating with the exterior of said flow device, a valve for controlling said gas inlet, and float means within said inner chamber for actuating the valve, said float means being movable by the liquid contained in said inner chamber normally to hold the valve closed and having a compressible uid therein in communication with the inner chamber for compression by the hydrostatic pressure of the liquid.

6. In a flow device, a chamber adapted for flow of liquid therethrough, a second chamber mounted within said rst-mentioned chamber and having its upper end in open communication with the outer chamber, said inner chamber being closed at the lower portion thereof whereby liquid is adapted to be contained therein, said inner chamber having a gas inlet communicating with the exterior of said flow device, a valve' for controlling said gas inlet, and float means within said inner chamber for actuating the valve, said float means being movable by the liquid contained in said inner chamber normally .to hold the valve closed and having a compressible fluid therein in l communication with'the inner chamber for compression by the hydrostatic pressure of the liquid, said float means being movable in response to a compression of the fluid for permitting opening of the valve.

7. In a flow device, a chamber adapted for flow of liquid therethrough, a second chamber mounted within said first-mentioned chamber and having its upper end in open communication with the outlet chamber, said inner chamber having the lower portion thereof closed whereby liquid is contained therein at all times, said inner chamber having a gas inlet communicating with the exterior of said iiow device, a valve for controlling said gas inlet, and a float in said inner chamber operatively connected with said valve for actuating the same and in position for movement by the liquid in the chamber normally to hold the valve closed, said float comprising a chamber with its upper portion closed and its lower portion in communication with the said inner chamber in position to trap compressible uid therein by the liquid, said float being constructed for movement upon compression of the uid by the hydrostatic pressure of the liquid to permit opening of the valve.

81 In a flow device, the combination of a casing, flow tubing' therein, means for confining gas under pressure in the casing around the tubing, a chamber in the casing connected with the tubing and adapted for flow of liquid therethrough, a second chamber mounted within said first-mentioned chamber and having its upper end in open communication with the outer chamber, said inner chamber having the lower portion thereof closed whereby liquid iscontained therein, means forming a gas inlet for admitting gas from the casing to the inner chamber, means for controlling said gas inlet, and means movable within .the inner chamber for actuating said controlling means, said movable means being constructed for trapping compressible fluid therein for compression by the hydrostatic head of liquid in said ow tubing, said movable means being movable in response to a compression of the fluid for permitting opening of the inlet controlling means to admit gas to the inner chamber for passage therethrough to the outer chamber and flow tubing.

9. In a flow device, the combination of a casing, flow tubing therein, means for confining gas under pressure in the casing around the tubing, a chamber in the casing connected with the tubing and adapted for ow of liquid therethrough, a second chamber mounted Within said nrst-mentioned chamber and having its upper end in open f communication with the outer chamber, said inner chamber having the lower portion thereof closed whereby liquid is contained therein, means forming a gas inlet for admitting gas under pressure to the inner chamber, means for controlling said gas inlet, and float means within the inner chamber for actuating said controlling means, said float means being constructed for trapping compressible uid therein in communication with the liquid in the chamber for compression by the hydrostatic head in the flow tubing, said oat means being movable in response to compression of the fluid therein for permitting opening of the inlet controlling means to admit gas to the inner chamber for passage to the outer chamber and flow tubing.

10. In a flow device, a chamber adapted for flow of liquid therethrough, a second chamber having its upper end in communication with the firstmentioned chamber, said second chamber having the lower portion thereof closed whereby liquid may be contained therein, said second chamber having a gas inlet communicating with the exterior of said ilow device, a valve for controlling said gas inlet, and a float mounted within said second chamber enclosing a compressible fluid and so constructed and arranged as to permit operation of the valve at a predetermined loss in the buoyancy thereof, said gas inlet being located externally of the float and admitting gas to the second chamber outside of said float.

11. In a ow device, a chamber adapted for ow of liquid therethrough, a second chamber mounted within said nist-mentioned chamber and having its upper end in open communication with the outer chamber, said inner chamber having the lower portion thereof closed whereby liquid may be contained therein, said inner chamber having a gas inlet communicating with the exterior of said flow device, a iioat mounted in said inner chamber and operatively connected with said valve normally to hold said valve in closed position, said float comprising a tube closed at its upper end and open at its lower end to allow entrance of a liquid head to entrap compressible iiuid therein, said float being adapted to loose buoyancy as the pressure of the liquid head lncreases and compresses the fluid therein causing the iioat to drop at a predetermined pressure and permit said valve to open.

12. In a flow device, the combination of the casing, flow tubing therein, means for coniining gas under pressure in the casing around the tubing, a chamber in the casing connected with the tubing adapted for flow of liquid therethrough, a

, second chamber mounted within said rst-mentioned chamber and having its upper end in open communication with the outer chamber, said inner chamber having the lower portion thereof closed whereby liquid is contained therein, said flow unit having an inlet port connecting the interior of said inner chamber with the casing, a valve for controlling said inlet port, and means within said inner chamber for holding said valve normally closed until a predetermined pressure is applied to said means, said means comprising a float so constructed and arranged as to act to permit opening of said valve as the buoyancy of said float is decreased a predetermined amount by action of said predetermined pressure.

LESTER D. MOWREY.

Images