US2138719A - Blow-out preventer - Google Patents

Description

Nov. 29, 1938. c. B. WR|GHT 2,138,719

BLOW-OUT PREVENTER Filed May 15, 1957 2 Sheets-Sheet l awe/Mm L Mz'gki Q KM' anal/Mill Nov. 29, 1.938. I c, w HT 2,138,719

BLOW-OUT PREVENTER Filed May 15, 1937 2 Sheets-Sheet 2 Patented Nov. 29, 1938 BLOW-OUT PREVENTER Charles Braxton Wright, McFaddin, Tex., assignor of one-half to Charles Bryan Wright, McFadd'in, Tex.

Application May 13, 1937, Serial No. 142,510

1 Claim.

This invention relates to an automatic gas well control and blow-out preventer and provides a novel means that is operable upon a difierential in pressure Within the tubing or line.

In producing gas or oil from high pressure Wells, it has frequently happened that the valve which regulates the flow of gas or fluid passing through the system at the high pressure causes the same to cut out, resulting in the increase of flow beyond the capacity of the well, lowering pressure in the well and thus causing sand and water to enter, which when passing out at the point where the pressure is greatly reduced, causes friction and the cutting out of the tubing and regulating valve, resulting in the loss of the well and endangering the life of workmen in attempting to close the same. As a result of the condition mentioned, many wells have been lost, and even the loss of fields by fluid entering prolducing fans by pressure being lowered in the we The invention enables the control and blowout preventer to operate automatically beyond the regulated capacity, and provides a construction wherein the choke is interchangeable or regulable as to size, permitting any desired capacity to be used.

The more specific objects and advantages will become apparent from a consideration of the description following taken in connection with accompanying drawings illustrating an operative embodiment.

In said drawings:-

Figure 1 is a view in elevation, partly in section, showing my improvements applied to a well discharge or outlet assembly;

Figure 2 is a vertical sectional view through a control and blow-out preventer alone;

Figure 3 is a cross sectional view taken on the line 3-3 of Figure 2;

Figure 4 is a side elevation of the choke;

Figure 5 is a side elevation of the barrel or piston;

Figure 6 is a side elevation of the stud bolt employed in the control and blow-out preventer, and

Figure 7 is a detailed side elevation of the needle valve for such well control and blow-out preventer.

Referring specifically to the drawings wherein like reference characters designate like or similar parts, It designates a well casing of an oil or gas well from which tubing ll leads to the pipe line, the gas and liquid taking the course designated by the arrows l2 under control of operating gas well control and blow-out preventing device is used and which is generally designated 25 and detailed in Figures 2 to 7.

Aside from thesaid device 25 and its connections in the system, the remainder of the system is conventional.

Saiddevice 25 includes anipple 26 screwthreaded 'to tubing branching from the well tubing l1 and which nipple 26 has apressure release valve 21, connected therein and adapted for manual opening and closing. Acollar 29 is screwthreaded at 30 to the nipple and at 3| to a pipe, cylinder orcasing 32. Asimilar collar 33 is screwthreaded to thecylinder 32 at 34 and at 35, it is screwthreaded to anipple 36 in turn screwthreaded at 31 in thetubing connection 24.

Slidably disposed in thecylinder 32 is a tubular barrel orpiston 38. Said barrel preferably hasexpansive packing rings 39 disposed inperipheral grooves 40 thereof and adapted to wipe the bore of thecylinder 32. An expansive coil spring 4| is located within the cylinder, bearing at one end on thecollar 33 and at its other end on thebarrel 38.

A choke fitting ortube 42 is detachably screwthreaded at 43, in the bore of thebarrel 38. Such nipple has a laterally extendingflange 44 at its upper end adapted to overlap and engage the barrel. The nipple extends only partly through the barrel and through the same, the bore of the barrel communicates withdiagonal passages 45 for the outlet of the gas into the cylinder, around aneedle valve member 46 which is removably suspended from the barrel as through the medium of astud bolt 41 detachably screwthreaded at 48 to theneedle valve 46 and at 49 to the barrel.

Saidnipple 36 at the upper portion thereof is provided with aconical valve seat 49 for engagement by the conical valve portion of theneedle valve 46, at the desired time.

Attention is called to the fact that in connec- 50 tion with the device, different sizes ofchoke members 42 will be employed so as to be interchangeable, according to the capacity or quantity of production desired from the well.

Presuming use of the invention, with the well flowing and the valves opened so that flow transpires in the path shown by the various arrows, with theproper size choke 42 in place parts of thedevice 25 will remain in the position of'Figure 2, with the pressure at the inlet and outlet of such device the same, whereby thevalve 46 remains inactive in such position of Figure 2. However, if the regulatingvalve 23 should be cut out by friction referred to, causing more gas to be produced than thechoke 42 will allow, pressure will be reduced on the down throw side of Y the barrel andvalve 46 and at the same time, such valve will have well pressure on its up throw side, causing greater pressure in the barrel proper 33, forcing thevalve 46 onto the seat49 closing off the well automatically. The spring 4| is of such tension that it prevents thevalve 46 closing with the normal passage of gas or fluid when the pressure remains equal on both sides of the plunger orbarrel 38.

For example, if there is a working pressure of fifteen hundred pounds to the square inch in the well and it is wished to produce in the line with three hundred pounds pressure and the well-would produce fifty thousand cubic feet of gas per hour without lowering the pressure in the well to the danger point, or below working pressure, the workmen would use achoke 38 to permit passage of this amount of gas and open theregulator valve 23. If such regulator valve cut out to produce more than capacity of thechoke 38, the pressure would be reduced between theregulator valve 23 and thebarrel 33, causing thevalve 46 to automatically close on its seat by the greater pressure on the barrel proper.

Various changes may be resorted to provided they fall within the spirit and scope of the invention.

While I have shown and described herein an embodiment of the present improvement which I believe to be entirely satisfactory and practical for the purpose in view, nevertheless it is to be A device of the class described having a cylinderQa barrel operable in the cylinder, said barrel being tubular and having a removable choke in its bore, a valve extending from the barrel, passages in the barrel communicating with the bore thereof and having outlets outwardly ofthe valve, a collar on the cylinder, a spring engaging the collarand the barrel to maintain the valve normally in open position, and a nipple secured to the collar having a seat engageable by said valve and a stud bolt secured to the barrel and to the valve member.

CHARLES B. WRIGHT.

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