US1803683A - Automatic valve for fluid lift devices - Google Patents

Description

May 5, 1931. J. w. TAYLOR AUTOMATIC VALVE FOR FLUID LIFT DEVICES Filed April 9, 1927 i m ad t? Patented May 5, 1 931 UNITED STATES PATENT OFFICE JAMES W. TAYLOR, OF SAN ANTONIOQTEXAS, ASSIGNOB TO ECONOMY PUMP AND OIL TOOL COMPANY, A CORPORATION OF CALIFORNIA AUTOMATIC VALVE FOR FLUID LIFT DEVICES Application filed April 9, 1927. Serial No. 182,283.

My invention relates to a method of and devices for lifting liquids from deep wells through the use of gaseous fluids, and has particular reference to the construction and operation of automatic valves by means of which the gaseous fluid is discharged into the liquid outlet pipe, or flow line.

In raising liquids, particularly oil, from deep wells, I have by way of illustration provided a tubing extending from the surface down to the vicinity of the well bottom, and have connected in said tubing automatic valves, by means of which gaseous fluid may be discharge under pressure into the li uid in thetubing to raise the liquid to the sur ace. The gas produced by the well may be utilized for this purpose, or other gas or air may be forced into the well under the control of pressure devices at the surface; to supply the necessary pressure. 1

The invention involves the principle of using an automatic liquid control means positioned in a flow line so as to control the admission of the liquid to be pumped thereto, and-an entry means for the admission of an actuating fluid spaced from the liquid control means functioning to admit the actuating fluid when there is a lower diflerence in pressure between the column of liquid in the flow line above the entry valve and the pressure of the actuating fluid and stopping the admission when there is a higher difference of pressure.

This principle of lifting liquids from wells by means ofsuch entry means has been dis closed in other prior applications of mine, particularly by Serial Number 15,758, filed March 16th, 1925, now Patent No. 1,572,330,

dated February 9th, 1926. But the valves controlling the use of the gaseous pressure fluid and its entrance into the flow line, have been modified and changed in my present invention to allow entrance of gaseous fluid to the line, even when the fluid pressure within the line at the level of the valve is less than fluid, pressure outside the line, at the same level.

An object of this invention is to provide in a pumping system having a flow line for liquid to be pumped and a chamber for the supply of the liquid to the flow line arranged for submergence of the inlet of the flow line, a liquid control means for said inlet operable to open the inlet to the flow of liquid upon a selected higher submergence and to close the inlet at aselected lower submergence.

Another object of this invention is to provide a system of the character described with means to admit gas to the flow line above the liquid control means whereby to aerate the column of liquid in the flow line and lift it, and to automatically operate said entry means so as to admit gas to the flow line at a higher difference of pressure between the column of liquid in the flow line above said entry means and the gas and to stop the admission of gas at a lower difference in pressure characterized by the gas being supplied to said entry means from a gas space wherein the gas acts upon the liquid tending to move it into the flow line through the inlet of the liquid control means. It will be understood that by gas is meant a fluid as distinguished from a liquid. The purpose of the liquid control means is to prevent gas from passing from the gas space through the liquid control means and wasting through the flow line when suflicient liquid is not present.

A further object of the invention is to provide a device of the character stated wherein the entry valves are adjusted to open under a predetermined static head in the flow line, less in amount than the fluid pressure in the casing at that level.

It is desired to so form the structure that the valves will normally be held open with a predetermined mechanical force, but will tend to close under the fluid pressure in the well when the pressure exerted on the valve from within the casing exceeds the pressure exerted thereon from within theflow line by approximately the amount of said mechanical force.

It is a further object to pro-vide an automatically operating valve to shut off the operation of the fluid lift apparatus before the fluid level in the casing reaches the open lower end of the tubing, and to thus prevent the exhaust of the pressure fluid out through the flow line. g

Referring to the drawings herewith for a more particular understanding of the invention, Fig. 1 is a central vertical section through a well with the well tubing therein equipped with my valves. Fig. 2 is an assembly view showing, in vertical section. the apparatus as equipped for installation in a well with my invention thereon. Fig. 3 is a section as seen on the line 33 Fig. 1.

In the drawings I have illustrated an equipment for deep wells for the production of oil, water, gas and the like. said casing being of the usual sectional type extending from the surface to the lower end of the well and to the vicinity of the producing stratum. The casing illustrated at 1 is equipped at its lower end with a strainer 2, said strainer having a fluid tight connection with the interior of the casing through a seal or packer member 3 of any desired construction. It is understood that the strainer 2 will he seated within the producing stratum of the well and will filter the liquid entering the lower end of the casing.

The upper end of the casing has the usual casing head 4 with lateral openings 5 and 6 therein, one of these openings 5 having connected therein an actuating fluid supply pipe 7. The opposite opening 6 may be closed by a bull plug 8. A fluid tight fit is made be tween the upper end of the casing head 4 and a flow line 9 by means of a stuffing box indicated at 10.

The flow line 9 is of the same construction as the ordinary pump tubing. It is of smaller diameter than the casing and its upper end is connected to a pipe 11, extending to some container for storage, not shown. The tubing or flow line extends downwardly within the casing and its open lower end projects into the strainer 2.

I contemplate placing in the flow line and preferably at a point toward the lower end thereof a control valve A, controlling the fluid which is to be raised from the well. The said liquid control valve includes an upper section 12 of a valve housing, said section being screwed at its lower end within a coupling member 13, which acts to connect the two parts 12 and 14 of the valve housing, and also closes the space between the said valve housing and the wall of the tubing. The upper section 12 has lateral openings 15 therein to provide passage for liquid. The upper end is closed by a cap 17, the inner face of which is cylindrical and furnishes a chamber 16 in which a plunger 18 uponthe valve rod 19 may move.

The lower part of the valve housing 14 is cylindrical in shape and is connected at its lower end to a plug 20 which has a central passage 21 therethrough into which is connected an L-shaped fitting 22 extending laterally through the side wall of the tubing 9 and secured thereto by welding or otherwise so as to provide a fluid tight fit therewith.

The upper end of the section 14: is screwed within the coupling 13 and has openings 23 through the walls thereof below the attachment with the coupling. Within the housing thus constructed the valve rod 19 is movable. The lower end of said valve rod has thereon a valve 24 and below the valve the rod is extended downwardly somewhat farther and engaged with a piston 25, fitting within the valve housing. The piston has on its lower side a connection at 26 with a weight 27 tending to hold said valve downwardly with a predetermined force. At the upper end of the section 14 of the housing,

the inner wall is extended inwardly to pro- .its open position, as shown in Fig. 1, liquid may pass upwardly between the valve housing A and the tubing and through the openings 23 and past the valve and outwardly through the openings 15 and from thence upwardly in the tubing. The valve will tend to remain in open position due-to the force of the weight 27. When the pressure below the valve exerted on the lower side of the piston through the opening 22 into-the casing, exceeds the downward pressure of the head of liquid above the valve, plus the weight on the valve itself, the valve will tend to close; the pressure below acting to force the piston and valve upwardly and thus move the valve head 24 into the passage 28, and stop the further passage of liquid through the tubing.

Above the liquid control valve A is a fluid actuating entry means which is a pressure fluid control valve B. Said valve has a cylindrical housing having a central partition 30 therein, said partition having an opening axially of the housing to act as a guide for a valve stem 31 and to serve for communication of the chambers aboveand below it. The lower end of the housing has a threaded connection with a plug 32. Said plug has oppositely extending tubes 33 connected with a central chamber 34 in said plug and extending through the side walls of the tubing, as shown in Fig. e

The interior of the valve housing is connected with the lower tubes 33 through a passage 35 leading into a small chamber 36, formed within an upwardly extending -wall on the plug 32, said wall being perforated to allow the passage of liquid therethrough.

The upper end of the housing is connected to the plug 37, which is in turn connected to through the wall of the tubing into the space within the casing.

Within the housing is a piston 39 to which is detachably connected the valve rod 31, previously mentioned, said valve rod having at its lower end a tapered valve 40 adapted to fit within and close the passage 35 in the plug 32. A radial flange on the valve head fits Within the chamber 36 so as to limit the flow of fluid past the valve head. A ring 41 is formed on the valve stem below the partition f and limits the upward movement of the valve. A spring 43 within the housing bears at its lower end upon the partition 30 and at its upper end against the piston 39, tending to hold the piston 39 upwardly with a predetermined force, and thus act to hold the valve normally in open position. The housing ofv the valve has lateral openings 44 therein above the valve to allow the passage of the pressure fluid outwardly into the liquid within the tubing.

In the operation of the device, it is contemplated that the two valves thus described v will be placed in arbitrarily selected spaced relation adjacent the lower end of the well. Entry valve B will preferably be located above the normal level of the well liquid and control valve A submerged. However, entry valve B should always be located above control valve A. If the well generates suflicient gas pressure, the valve in pipe 7 may be closed. If the well does not generate, the pumping action may be developed by opening the valve in pipe 7 and delivering actuating fluid or gas under pressure from a suitable source of supply, as from a pump or other wells developing gas under pressure. Initially and before actuating gas pressure is built up, atmospheric pressure acts through the flow line and in the casing so that the level of well liquid or actuated fluid in the casing and in the flow line is the same, assuming control valve A is submerged. As soon asactuating gas pressure is built up in the casing, the level of the liquid in the flow line is raised. The pressure on top of piston 39 of the entry valve is that exertedby the actuating gas and the area acted upon is equal to the total effective area on the lower side of the piston and valve subject to action by fluid pressure. Spring 43 tends to lift the entry valve against the gravitative action of the piston and attached parts and its force is designed to preponderate over the gravitative action an amount which is later set forth. Before the initiation of operation, the fluid pressure exerted on both sides of piston 39, considering the pressure exerted on valve stem 31 and valve 40 as applied to the piston, is equal and the entry valve is open. However, upon initiation of actuating gas pressure in sufficient amount for operation, the pressure above piston 39 due to the actuating gas overbalances the forces from below tending to maintain the valve open. The pressures from below are the atmospheric pressure and the spring pressure less the weight of the piston and valve. Thereupon, the entry valve closes preventing wastage of gas. The level of the column of actuating fluid is lowered and the level of the column of actuated fluid in the flow line is raised until the static head of the latter acting on the lower side of piston 39 together with the force exerted by spring 43 is sufficient to raise piston 39 and open the entry valve. The force of spring 39 is so designed that ittogether with the static pressure of a column of aerated well liquid above the entry valve and reaching to the discharge pipe 7 will be sufficient to raise the piston 39 against the action of the actuating gas pressure maintaining such column. The aeration selected is that due to admission of actuating gas through entry ports 33. The unaerated column exerting an equal static head will be lower thanthe level of discharge pipe 7. However, at this point in events, the entry valve opens, the actuating gas enters the flow line, lifts the flow column to the discharge level and inaugurates pumping which is continued as long as suflicient well or actuated liquid is supplied to the flow line. If the supply is such that the flow line column lowers below the discharge level,pressure on the underside of piston 39 decreases to the point that the entry valve is closed and wastage of gas is prevented. When the supply of actuated fluid by the well is insuflicient to maintain sub-v mergence of valve A, the latter closes. When stoppage of delivery has occurred, well liquid will enter the well hole until a sufficient volume has passed the control valve into the flow line for another cycle of pumping events. If the supply of the well is suflicient to maintain pumping continuously, both valves A and B remain open. If the level of well liquld r1ses above the entry valve, it may either open or close de ending upon difference of pressures within t e flow line and within the casing, gas not entering through the entry valve.

The gaseous fluid entering the flow line will a fluid being under pressure as it enters the tub-g ing will gradually expand as it passes upwardly in the li uid due to the decrease 1n liquid pressure 0 the fluid head 1n the tub.- ing. It will gradually form bubbles of sulficient size to entirely fill the tubing, thus acting as air pistons forcing the l1qu1d upwardly and discharging it through the outlet pipe 11 from the well. When, the l1qu1d 1n the well becomes depleted to such an extent that the level 42 of the liquid the easing is forced downwardly to the vicinit of the lower valve A, there will. gradually e a preponderance of pressure through the tubing 22 leading to the valve from the casing, and as this preponderance of pressure builds up sufficient to overcome the force of the 5 weight 27 and the liquid head in the flow line,

the piston 25 will carry the valve 24 upwardly so as to close the passage 28.

The liquid within the well will gradually accumulate after the operation of the pressure fluid has ceased valve A will be opened and liquid will pass slowly by the valve 24 so as to raise the level within the tubing and when this level has been raised to a suflicient head, the valve 40 will be opened and the pressure fluid will then be forced past the valve into the liquid within the tubing and the operation of discharging the liquid from the well will then again be initiated. The pressureof the fluid within the casing will be lowered as the operation is started and more pressure fluid will be delivered to the casing. In the same manner the pressures upon the lower valve A will be reduced to normal and the weight 27 will serve to open the valve 24 and allow the passage of further liquid through the tubing.

It will be seen that I have thus provided a device whose operation is automatic in its nature and which will function to raise the liquid from the well at a lower difference in pressure at the valve level between the pressure of the gaseous fluid in the casing and the pressure due to the head of liquid above the valve'in the tubing.

It is to be noted that when the valve A is spaced properly above the lower end of the casing, it will be impossible for the liquid level in the casing to be carried down low enough to allow the gaseous pressure fluid to escape through the lower end of the tubing. The valve A may be closly adjacent the lower end of the flow line, yet the level of the liquid will not pass below the level adjacent the valve A when the said valve is closed by the preponderance in the pressure below the valve piston 25, as described.

While the lower valve 25 has been shown as controlled by means of a weight, it is obvione that any equivalent means such as a spring, may be employed, the object being to hold the valve open with a certain predetermined mechanical force.

The advantages of this structure lie in the fact that the liquid may be raised from the well without the necessity of the usual pumpmg means involving moving parts liable to wear and breakage. Liquid having a material amount of sand and sediment therein may be raised from the well by means of this device without material wear of the parts.

Furthermore, the operation may be made automatic and the services of an operator will be necessary only to a limited extent, so that a large number of wells may be handled by one I operator in an obvious manner.

It is to beunderstood, of course, that if there is suflicient gas pressure in the well, no gas under pressure need be supplied by artificial means. If the pressure is increased, the difference in level between the liquid in the casing and that in the tubing will be greater but the operation of the valve will be the same as it would with a smaller gaseous pressure, and the valve will only close when the pressure of the head of liquid in the tubing above the valve attains the proper proportion to the pressure of the gaseous fluid in the casing, the pressure differential remaining the same.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. In a device of the character described including a well casing, a flow tubing therein, said casing being closed about said tubing at its upper end, the combination of a valve housing in said tubing, a piston in said housing, a valve connected with said piston, means to conduct pressure fluid into said casing, a passage from the outside of said tubing adapted to be closed by said valve, a second passage from without said tubing connecting with the side of said housing away from said valve, and means tending to hold said valve in open position with a predetermined pressure.

2. In a device of the character described including a well casing, a flow tubing therein, said casing being closed about said tubing at its upper end, the combination of a valve housing in said tubing, a piston in said housing, a valve connected with said piston, means to conduct pressure fluid into said casing, a passage from the outside of said tubing adapted to be closed by said valve, a second passage from without said tubing connecting with the side of said housing away from said valve, and mechanical means cooperating with said piston and tending to hold said valve in open position with a predetermined pressure.

3. In a fluid lift device for raising liquid from wells, a control valve for the pressure fluid comprising a valve housing having upper and lower openings connected with the interior of the casing, a valve controlling one of said openings, mechanical means tending to hold said valve normally open with a predetermined force, and fluid pressure controlled means responsive to changes in fluid pressure in the flow pipe to close said valve when a predetermined pressure difl'erential on said pressure controlled means has been reached, and means below said control valve to limit the flow of liquid in the flow line when the liquid above said means has reached a predetermined level.

4. A method of raising liquid from wells, which comprises sealing the upper end of the casing about the flow line, introducing a aseous lifting fluid into the well casing, un er a predetermined pressure to raise the level of the liquid in the flow line, and introducing I said pressure fluid into the liquid in said flow line at a level at which the pressure of the pressure fluid in the casing exceeds the amount ofpressure of the liquid head at the point of introduction by a predetermined amount and checking the upward passage of liquid in the flow line when said liquid head above said point of introduction has bee substantially exhausted.

5. The method of raising liquid from wells which comprises providing a chamber for the flow therein of liquid from the well and a flow line for normal submergence of its inlet end in the liquid in said chamber, introducing an actuating fluid into said chamber and acting upon the surface of the liquid therein, admitting liquidfrom said chamber to said flow line at a higher submergence and stopping said flow of liquid at a lower submergence, admitting said actuating fluid from said chamber into said flow line at a higher pressure diflerential between the pressure in said flow line and said actuating fluid pressure and stopping the admission of actuating fluid to said flow line at a lower pressure differential. I

In testimony whereof I hereunto-aifix my signature this 18th day of March, A. D. 1927.

JAMES W. TAYLOR.

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