US2131836A - Variable choke - Google Patents

Description

Oct. 4, 1938. E. E. DAVIDSON VARIABLE CHOKE Filed May 24, 1937 5. .5. zwwbsom Patented Oct. 4, 1938 UNITED STATES PA Tj ENT-" 'OFFICE 2,131,836 7 VARIABLE onokn Edward E. Davidson, Houstonfllex. v Application May 24,1937, Serial No. 144,384

1 Claim.

flow through a choke so that it will produce only the amount which it has been determined it should produce.

Previously, it has been the custom to insert the standard choke, or such other choke as may be decided upon, by removing a bull plug on one branch of a T or cross, andinserting the choke through the T or cross into an internally threaded section in the flow line on the opposite, side of such fitting. The bull plug is then replaced and the valves opened to flow the well.

The difiiculty with the practice just set forth, however, is that in many instances it is necessary to make numerous and frequent changes in the size of choke employed in order to cause the well to produce at the desired rate. This under the previous practice involved shutting down the well each time by closing the gate valves ahead of the choke, removing the bull plug through which the chokes are inserted, removing the choke from the flow line, inserting the new choke, and replacing the bull plug. This is a job requiring a considerable length of time and involving in each change the necessity for screwing a choke out of position and screwing another choke into position within the flow line. In addition to the time and labor involved in making the changes in the chokes under the previous practice, the threads with which the chokes are engaged within the flow lines after many changes in chokes will deteriorate. until it may become necessary to disconnect the flow line and replace a section thereof with a new internally threaded part. In the past, attempts have been made toprovide variable chokes which could be changed without the necessity for replacing the choke within the flow line in order to vary and regulate the. amount offluid produced by the well.

However, these have for the most part relied upon the principle of the needle valve in' which the valve is moved by means of threads or the like toward or away from a seat within the flow line so as to obstruct flow past. said seat in a greater or lesser degree as desired. However, when used with high pressure wells it has been found that such apparatus will cut out very quickly due to the rapid flow therethrough, and

these chokes have not beengenerally used for this reason. I

'It is an object of this invention to provide a variable choke which willmake possible a change from one size of choke to another without the necessity for dismantling any part. of the apparatus, and without involving any of the defects and shortcomings in the prior art structures. I r 7 It is a further object of this inventionto provide a variable choke'which may be varied to present a choke o fany given size with substantially no loss of time or expenditure of labor.

It is. a further object to provide a variable choke which will not be any more susceptible of cutting out than are the standard chokes customarily employed.

It is a further object to provide a variable choke, the wearing parts of which may be removed and replaced with a minimum of effort and without dismantling the flow lines at any time that replacement may be found necessary.

It is a further object of this invention to provide a variable choke which may be opened to permit free flow without any choking action whatever;

It is a further object to provide a variable choke adapted to receive a standard choke for purposes of testing production.

Qther objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawing, said drawing and descrip tion being by way. of illustration and example only, and not by way of limitation.

In the drawing:

.Fig. 1 is a vertical cross section illustrating a choke constructed in accordance with this invention. i

Fig. 2 is'a horizontal cross section taken along the line 2-2 of Fig. 1. g

r Fig. 3 is a vertical cross section at right angles to that shown in Fig; 1 taken along the line 3--3 of Fig. 1. V

Fig. 4 is an elevation illustrating the choke shown in Fig. 1 connected to a portion of a Christmas tree. 7

The choke illustrated in the drawing consists of a body member I of elongated formation and having a passageway therethrough. At one end,

the body member is externally threaded as illustrated at 2' to receive the cross 3 forming a portion of a Christmas tree. At its other end, it is formed as illustrated at 4 to receive'a flow line 5.

The upper branch of the cross 3 is closed by means of a bull plug 6 to which a pressure gauge 1 is connected in the usual manner. The

is provided with a bull plug 8 and the lower portion of the cross is connected to the portion 9 of the Christmas tree.

The passageway through the body I for the major portion of the length of the body is of an elongated cross section as shown at I0. That is, one dimension is substantially twice the other. At-its intake end, however, the passageway is reduced as indicated at II to a cylindrical bore of substantially the same diameter as the shortest dimension of the remainder of the passageway. The outer end of this bore is threaded at I2 to receive a standard choke such as is used in testing the production of a well to determine the amount it shall be allowed to produce.

Intermediate its ends and intersecting the passageway I0 the body I is formed with a plurality of slightly tapered lateral openings I3 adapted to receive respectively a series of plug valves which have in thisdisclosure been indicated by the numerals I4 to I8, inclusive. Each of these plugs has a transverse opening I9 therethrough after the manner of the customary plug valve, these openings I9 in the various plugs being of substantially the same size as the bore II and in alignment with that bore and with each other so that when all of the plugs are turned to place their openings I9 in alignment with the passageway I0 a substantially unrestricted passageway will be provided through the body I.

Each of the plugs, however, is provided with a second transverse opening at substantially right angles to the openings I9, these second mentioned transverse openings being designated by the numerals 20 to 24, inclusive, and varying in size depending upon the sizes of the choke openings which it is desired the device shall be capable of providing. As illustrated 'in the drawing, the openings I9 and the bore II are so positioned as to be in alignment with one side portion of the cross section of the passageway I0. The openings 20 and 24 inclusive, are off-set from the openings I9 and are arranged to be in alignment with the other side portion of the opening Ill.

The external surface of the body I adjacent the open ends of the tapered openings I3 is provided with a seat 25 adapted to receive a plate or gasket 26 which serves the dual purpose of forming a seal about the open ends of the openings I3 and of retaining the plugs I4 to I8, inclusive, in position within the body I. Positioned against the exterior of the element 2 5 is a fitting 21 held in place by means of screws 28 or the like and formed with portions 29 providing stufiing boxes adapted to receive packings 30. These packings 30 are compressed by means of gland nuts 3| so as to provide a seal about the stems 32 of the plugs I4' to I8, inclusive. These plugs may be rotated as desired by means of squared portions 33 formed on the external ends of the stems 32.

In operation, the well is first connected with the body I in position as illustrated in Fig. 4, and with a standard choke threaded into the opening I2. All of the plugs I4 to I8, inclusive, are rotated so that the openings I9 will be in alignment with each other and with the openings I I and I2. The well is then permitted to flow through the standard-choke until its capacity is determined and the rate at which it is to be allowed to produce decided upon, The well is then shut down by means of gate valves customarily provided (not shown) and the bull plug 8 is removed. By means of a suitable wrench provided for the purpose which is inserted through the cross fitting 3 the standard choke is then removed from the threaded opening I2 and taken out through the opposite lateral branch of the cross member from which branch the bull plug 8 has been removed. The bull plug 8 is then replaced and whichever one of the plugs I4 to I8, inclusive, is desired is rotated so that the opening I9 therein is at right angles to the passageway I0 and so that the smaller opening 20, 2|, 22, 23 or 24, as the case may be, is placed in alignment with the lower portion of the passageway I 0. The well is then opened and allowed to flow.

Assuming that the opening 22 of the plug I6 has been placed in alignment with the passageway ID as illustrated in Fig. 1, the well will then be in efiect flowing through a choke of the size of the passageway 22. If, however, it be found that the well flowing through this passageway 22 produces oil more rapidly than desired, the plug I1 or the plug I8 may be rotated so as to place the opening 23 or the opening 24, as the case may be, in alignment with the passageway Ii], after which the plug I6 will be rotated to place the opening I9 in alignment with the passageway I0. Similarly, if the flow through the opening 22 be found to be too slow, the plug I4 or the plug I5 may be rotated so as to place the opening 20 or the opening 2I in alignment with the passageway IIJ. Thus, it will be seen that the choke opening provided for the flow of oil or other fluid may be changed at will with substantially no loss of time or expenditure of labor, and without necessity for shutting down the well. It will further be seen that the number of choke openings available is limited only by the number of plugs provided in the body I, and it will be appreciated that this number can be varied to provide either more or less plugs than illustrated, fiepending upon the need which may exist there- It will further be appreciated that inasmuch as the choke openings provided by this invention are not determined by adjustment, but are predetermined when the openings 20 to 24, inclusive, are formed, there will be no errors introduced due to faulty adjustment such as is possible with the needle valve type or adjustable choke, and the wear will be no greater than would exist with the standard choke.

Having described my invention, I claim:

In a choke connection, a body having a relatively large passageway therethrough and a plurality of rotatable plugs extending transversely of and interrupting said passageway, each plug having a relatively large opening, all of which are of substantially the same size and adapted to be arranged in alignment with each other to provide a substantially unrestricted passage through the connection, and each plug having a smaller opening therethrough at a substantial angle to and off-set from and independent of the larger opening, said smaller openings being of varying sizes in the respective plugs whereby one of said plugs may be rotated to move the larger opening out of alignment with. the passageway and the smaller opening into alignment therewith to provide a selective predetermined restriction in said passageway.

EDWARD E. DAVIDSON.

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