US1871319A - Oil well flow control device - Google Patents

Description

ug. 9, i932. E. H. GRISWOLD ET AL OIL WELL FLOW CONTROL DEVICE Filed March 26 I N V EN TORS fawn/V H 6/73/4/0/0 70a Joh/7 /V/'c/f/as Patented Aug. 9,1932

UNTTED STATES PATENT Orr-ICE TO CONTINENTAL OIL COMPANY, OF '.PONCA CITY, OKLAHOMA, A CORPORATION OF DELAWARE OIL WELL FLOW CONTROL DEVICE Application tiled March 26, 1932. Serial N0. 601,408.

Our invention relates to improvements in an oil well iiow control device for controlhng the flow of fluids from oil wells and more particularly to a nozzle arrangement which is.

regulated from the surface to increase or decrease the effective area which governs the iiow of oil and gas from the well.

This invention is an improvement on our previous inventionl as set forth in United States Letters Patent 1,837,542, dated December 22, 1931. Y

In our previous invention, the nozzle valve which controlled the flow of the oil Was provided with a threaded spindle which operated the valve. It was found that a certain amount of torsion would be absorbed by the operating rods.

One object of our invention is to provide a choke device which operates by sliding movements so as to eliminate the effect of the torsion.

Another object of our invention is to provide a sliding device which is easy to open.

Another object of our invention is to provide a flow control device in which the stresses transmitted by the rods are cheiiy tensional ones.

Another object of our invention is to provide a iiow control device which is easy to adjust to a desired position.

In the drawings which form part of this specification and are to be read in conjunction therewith andv iny which like reference numerals are used to indicate like parts sliding movement by means of a screw jack positioned on the surface. It is to be understood, of course, that any suitable means may be used for obtaining the operating force, though we prefer to use a screw jack. i Referring more particularly to the drawlng, the oil well casing 1 houses oil well tubing 2 provided with a bottom hole choke 3 with which valve 4 cooperates to govern the rate of flow of oil from the well. Valve 4 carries secured thereto a piston 5 working in cylinder 6, the purpose of which will be hereinafter more fully described. Holes 7 are provided in oil well tubing 2 for the passage of oil through the choke 3 up through tubing 2 and out of the well through outlet pipe 8. The valve 4 is operated by rod 9 which terminates in a swivel 10 above the surface. Connected to swivel 10 is a screw jack 11 which is operated by rod 12 which passes through stuffing boX 13. The casinghead of the oil well tubing 1 is indicated at 14.

Referring now toFigure 2, it will be seen that the choke 3 is provided with a valve seat 15 against which inclined shoulder 16 of the i EDWARD :EL GRISWOLD AND JOHN G. NIOKLOS, OF PONGA CITY, OKLAHOMA, ASSIGNORS valve 4 is adapted to seat to shut olf the iow provided with tapering grooves 17 as may be readilyvseen with reference to Figures 3 and 4. It will be readily appreciated that as the valve 4 is moved downwardly, the effective space through which the oil may leave the well is increased. As the valve 4 is moved upwardly the grooves 17 progressively de` crease in depth throughout the eii'ective oil outlet space until finally surface 16 is seated o nvalve seat 15 when the oil flow will be entirely cut off. The principal portion of valve 4 is secured to rods 9 at 18 in any suitable manner. Connected to the lower portion of valve 4 in any suitable manner, as for example by mandrel 19, is a piston rod 20 carrying a plurality of pistons 21 'having packing members 22 directed upwardly and a plurality of pistons 23 having packing members 24 directed downwardly. The pistons 21 Aand 23 are secured to the piston rod 2O by means of a lock nut 25. The lower portion of the tubing 2 is capped by a cap blank 26 to form a closed cylinder in which the piston travels. The valve 4 is bored axially by a passageway 27 which joins a similar passageway 28 in the mandrel which in turn connects to a similar passageway 29 in the piston rod and communicates with a cylinder space 30. The passageway 27 of the valve 4 is in communication with the eduction tubing 2 by means of axially bored holes 31.

In operation, assuming that the valve is closed, oil from the well entering tubing 2 through holes 7 is prevented from flowing out through eduction tubing 2 due to the fact that shoulder 16 is seated on seat 15. The oil ressure acts upon the upper pistons 21 tendlng to open the valve and placing a tension upon the rod 9 which is transmitted through the swivel 10 to the screw jack. It will be readily appreciated that but little force is required to open the valve. As the valve is opened the effective outlet area is progres sively increased, due to the tapered grooves 17 in the side of the valve 4. Oil flowing between the grooves and choke 3 nds its way out of the well through eduction tubing 2. Part of the oil pressure existing above the choke 3 communicates through openings 31 through bores 27, 28 and 29 and into the cylinder 30 where this pressure Will act upon t e lower piston members 23 to counter balance the pressure on the upper piston members 21. Thus it will be seen that, as long as the valve is open, but slight pressure will have to be overcome due to 'the balancing eiect vof the piston to` move the valve to anyv desired position. Inasmuch as the pressure existing above the choke will of necessity be less than that below the choke, the operating rod 9 will be constantly in tension so that no compression stresses will have to be transmitted by rod 9. lt will be obvious, therefore, that rod 9 may be ofi: smaller thickness inasmuch as it will be constantly in tension during the operation.

It will be appreciated that I have overcome the disadvantages existing in the necessity of transmitting a torsional stress through a long rod. No specially designed rods are necessary to operate my choke device. The operation of my choke device is not dependent upon the depth of the well. The ease of adjusting my device is manifest and results from the balancing of the pressures. Likewise, no compressional stresses are transmittedby the rod eliminating the necessity for a heavy transmitting rod.

llt will be understood that certain features and sub-combinations are of utility and may be employed without reference to other eatures and sub-combinations. This is contemplated by and is within the scope o-our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. lt is, therefore, to be understood that our invention is not to be limited to the specific details shown and described.

Having thus described our invention, what we claim is:

1. An oil well flow control device includingin combination a valve, a valve seat, a piston secured to said valve, a cylinder surrounding said piston, one side of said piston being exposed to oil pressure within said well, means for communicating the pressure above said valve seat tothe other side of said piston and means for operating said valve rom the surface.

2. A device according to claim 1 in which said pressure communication means includes a bore extending axially of said valve.

3. An oil well flow device including in combination a choke positioned in an oil well, a. valve for cooperating with said choke adapted to control the eduction flow of oil' and gas out of said well, a. hydrostatic piston secured to said valve and means for positioningusad valve operable from without said we 4. A device according to claim 3 wherein the pressure on said piston tending to open the valve is always greater than the pressure tending to close the valve whereby .said valve positioning means is constantly under tension.

5. A device according to claim 3 wherein said valveoperating means includes a rod secured to said valve, a screw jack and a swiveled connection therebetween.

In testimony' whereof we ailix our signatures.

EDWARD H. GRISWOLD. JOHN C. NIGKLOS.

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