US1932480A - Means for gas control for plunger lift devices - Google Patents

Description

Oct. 31, 1933. N} RICKER MEANS FOR GAS CONTROL FOR PLUNGER LIFT DEVICES Filed Feb. 1, 1932 rllllil dlli liillvillt RAAN.

NORMAN H. R\CKER INVENTOR W H W ATTORNEY Patented Got. 31, 1933 stares FOR GAS CONTROL FOR PLUNGER LIFT DEVKCES Norman H. Kicker, Houston, Tex, assignor to I Hughes Tool Company,

poration of Texas Houston, Tex, a cor- Application February 1, 1932. Serial No. 590,074

3 Claims. (or. roe-e2 My invention relates to plunger lift devices for raising liquid from deep wells in which a load of liquid is elevated from the bottom to thesurface through the use of a freely movable plunger. v In devices of this kind it has been found that when the plunger with its load of liquid has reached the upper end of its stroke and discharges its load, the valve is opened in the plung r and the plunger tends to drop, but, due to the fact that accumulated air or gas in the well finds a free entrance to the lower end of the eduction tube, it will blow up through the tube and prevent the plunger from dropping freely and seriously interfere'with the free operation 0 thereof. Such performance also results in a waste of gas necessary for operation of the device.

It is an object of my invention to provide an apparatus in which the pressure fluid is allowed entrance to the lower end of the eduction tube 20 through a restricted passage which controls the flow of the gaseous fluid to the eduction tube and hence prevents the blowing of the gas strongly from behind the plunger and allows the plunger to drop readily to its seat.

I contemplate the provision of a stop or seat for the plunger at the lower end of the eduction tube and to form in connection therewith, an inlet for the pressure fluid below the plunger which. will accurately control the amount of flow thereof.

Inthe drawing herewith Fig. l is a'central longitudinal section through the upper end of a plunger lift installation in which my invention is employed.

Fig. '2 is a similar view showing the lower end of apparatus in position in the well.

In the plunger liit apparatus disclosed in the drawing there is an outer casing 1 which extends from the surface downwardly to a point closely adjacent the lower end thereof. The upper end of the casing is connected with a casing head 2 which has a lateral inlet 3 for the pressure fluid to the well, and has its upper end threaded internally at a for attachment thereto of a bonnet 5, the upper end of which is reduced in diameter threaded at 6 for connection with upper extension 7 upon the eduction tube. Within the casing head is an upwardly presented shoulder 3 upon which the head 9 on the eduction tube 10 may be supported.

The eduction tube 10 is secured at its upper end to the head 9 which fits closely within the casing head and hasa radial flange 11 which is supported upon the shoulder 8 making a fluid tight fit therewith. The upper end of the head 9 plunger may contact in case it is not flange 24 in the collar eduction tube, and has its outer surface threaded at 12 to receive a pipe or seating device by means of which it may be lowered into position.

The extension 'l'fits closely within the head at its lower end and is provided with longitudinal openings 13 through which fluid from the well may flow outwardly into the casing head-and find an outlet through a pipe 14 leading to storage.

The upper end of the eduction tube isextended beyond the bonnet '5 to form a closed chamber within which the plungermay be received, the upper end of the extension being closed by a cap 15. Within the cap 15 I may employ a buffer or shock absorber member 16 against which the stopped by the air and liquid trapped within the said ex tension.

The lower end of packer l7 thereon which may be of any preferred construction and in this case comprises a body ofcompressible material the lower end of which may be held stationary by dogs or jaws 18 adapted to engage with the casing when the device is at the lower end of the well. This packer is to close the space between the eduction tube and the casing and prevent 'the passage of gas from the gas spacel9 between the casing and the eduction tube to the space 39 below the packer.

Below the packer the lower end of the eduction tube is connected to a perforated plug or strainer 20 from which liquid from the well'may enter the tube. Ordinarily the lower end of the tube is placed'at a point well below the fluid level in the well. The liquid therein will tend to rise to a point indicated at 21 in Fig. 2 through the pressure in the formation about the lower end of the tube.

The pressure fluid which is forced into the chamber 19 will enter the lower end of the eduction tube through an opening or openings 22 above the packer. Within the tube adjacent the openings 22 is a sleeve or core 23 which forms a stop for the plunger in its downward movement. This sleeve rests upon an inwardly extending 25 upon the tube. The sleeve is formed with a circumferential groove 25 adjacent the openings 22 to receive pressure fluid entering to the tube. From the groove 25 a single constricted orifice 26 allows the passage of the pressure fluid to the channel 27 extending longitudinally of the sleeve. The upper end of the said sleeve is tapered at 28 to inter-fit with a wedging device 29 which fits over the upper end thereof and is adapted to wedge between the has a close fit with the extension '7 upon the the eduction tube has a same and the tube and hold the sleeve 23 rigidly in position. The upper end of the wedge member is formed with a seat 30 to receive the lower end of the plunger 31.

A plunger 31 is shown as being one now in ordinary use. It comprises a body portion which is connected at 32 to the supporting member 33 which is spaced from the lower end of the body by means of legs 34 allowing the passage of liquid to the plunger through the openings 35. The supporting block 33 is smaller in diameter than the body of the plunger and has a recess on its upper side to receive the valve which fits upwardly within a seat 36. There is a guide stem 37 on the valve sliding within the support and openings 38 are formed below the valve stem to allow fluid to enter below the same in order to assist in moving the valve to its seat.

In the operation of this devicethe plunger in moving downwardly in the tube to its seat 30 will pass through the liquid which has accumulated about the seat. When it has reached the seat the pressure fluid in the shape of gas or air from the chamber 19 will enter at a predetermined rate through the constricted opening 26. This opening is arranged at a proper size to allow the entrance of air or gas in suitable volume to accommodate the conditions of the particular well being operated. This pressure fluid will pass upwardlybelow the plunger and will encounter the back pressure of the head of liquid above the seat and when this head of liquid exerts sufficient back pressure the air will be enabled to lift the valve 37 to its seatand the plunger will then be moved upwardly to the surface with its load of liquid. As it rises the pressure fluid will continue to enter through the opening 26 and when the plunger has reached the upper end of the tube and has discharged its load of liquid, the pressure fluid will force the plunger past the openings 13 into' the closed'upper end of the tube. The valve in the plunger will then be forced open and the plunger will start on its downward movement.

After the plunger has passed the openings 13 the pressure fluid will exhaust behind the plunger and it will drop downwardly to its seat and in thus dropping it will not be seriously impeded in its passage by the air or gas flowing up through the eduction tube. This will be due to the fact that the entrance of the pressure fluid at the lower end of the eduction tube is so restricted as to prevent its rapid movement. Thus the plunger will drop to the bottom of the well striking within the liquid which has risen in the tube, and

sink to its seat ready to repeat the movement. The advantage of this construction lies in the manner in which the pressure fluid is fed to the eduction tube in such quantities as to make the operation of the plunger accurate and uniform. I V

The operation of this control device is based on the principle of critical flow. This to say, if a high pressure gas supply is maintained upstream of the orifice, then the rate of supply of gas through the orifice will be independent of the downstream pressure provided the downstream pressure does not exceed .56 times the upstream pressure. Since in normal operation the operating pressure of the plunger lift is low, it is possible in this manner to secure a uniform rate of flow of the pressure fluid into the system.

Having described my invention, what I claim is:

1. In a plunger lift device, a well casing, an eduction tube spaced concentrically within'said casing, a packer closing the space between said tube and easing adjacent the lower end of said tube, means to admit pressure fluid at the upper end of said casing, a plunger seat in said tube above the level of said packer, a plunger above said seat, and means to control a predetermined restricted flow of pressure fluid through said tube and seat below said plunger.

2. In a plunger lift device, a well casing, an eduction tube spaced concentrically within said casing, a packer closing the space between said tube and casing adjacent the lower end of said tube, means to admit pressure fluidat the upper end of said casing, a sleeve in said tube above the level of said packer, said sleeve having a single lateral choke opening therein positioned to connect with an opening in said tube, a plunger in said tube, and a seat for said plunger on said sleeve.

3. In a device of the character described, an eduction tube adapted to extend into a well to a point below the liquid level therein, a packer on said tube adjacent the lower end thereof, means to conduct gaseous pressure fluid to the space in said well above said packer, a plunger operating approximately fromend to end of said tube, a seat for said plunger adjacent said' packer, a tubular sleeve below said seat andheld in position by said seat, said sleeve having a single lateral restricted orifice therein communicating with an opening in said tube to admit a uniform flow of pressure fluid below said plunger.

NORIVIAN H; RICKER.

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