US1536348A - Gas-escape valve for oil wells - Google Patents

Description

May 5, 1925.

P. H. MACK l GAS ESCAPE VALVE FOR OIL WELLS FiledDeo. 20, 1921 Patented May 5, 192552 untrue ortica.

WATREK H. MAGE, 0F BRADFORD, PENNSYLVANIA, ASSGNOR T0 OIL "WELL SUPPLY UMPANY, 0F PITTSBURGH, '.ENNSLvANA, A CORPORATON 0F PENNSYLVANA.

GAS-,ESCAPE 'VALVE EUR OIL WELLS.

Application 'filed December 20, 1921. Serial No. 523,620.

To all 'whom 'it may concern."

Be it lmown that l, PATRICK H. MACK, a citizen of the United States, residing at Bradford, in the county of McKean and State of Pennsylvania, have invented certain new and useful Improvements in a Gras- Escape lValve for Oil Wells, of which the following is a specification.

This invention relates to a gas relief valve for use in connection with oil well tubing for permitting the escape of gas 'from the bore below the anchor or lowermost packer.

After an oil well is drilled, a tubing is inserted through which the sucker rod operates and up through which the eil is pumped. A packer is inserted in this tubing somewhere between the lower end and the surface of the ground, usually a relatively short distance above the oil bearing sand. rlhis packer 7serves to anchor the tubing against movement when pumping and to eX- elude water and dirt from coming down around the pump at the lower end of the tubing.

lt frequently lhappens that natural gas will accumulate in the well below the packer and the pressure thereof will prevent proper functioning of the Valves of the pump. It is accordingly necessary to provide some means for permitting the escape of gas, preferably into the tubing. Various methods of accomplishing this result have been tried, but, for various reasons, could not be used. Difficulty is most frequently encountered in very dee wells where the hole is necessarily of a minimum diameter.

The present invention has for its principal objectto provide a gas relief valve at any point below the packer for permitting the escape of gas into the well tubing and which will be sutiiciently compact and yet strong enough to sustain the weight of the pipe above it or below it. lt is designed for use as 'a part of the packer and in combination therewith, or as a separate unit in the .st-ring of pipe.

My invention may be readily understood by reference to the accompanying drawings, in which:

Fig. l is a vertical section through a string of pipe and packer when set in the well, the valve being also shown in section and in combination with the packer;

Fig. 2 represents a side elevation of the l pipe and packer set in a well with the gas relief valve shown in elevation and separate from the packing, a portion of the pipe and coupling between the pipe and valve being shown in section;

Fig. 3 represents a vertical section on a larger scale of the relief valve;

Fig. 4 shows a horizontal section taken on line IV-IV of Fig. 3.

In the drawings, A represents the well A and B designates generally the tubing. C indicates the packer, and D is the relief valve. l

`The packer may be of any known or preferred construction. As shown, it comprises a tubular-'central ymember 5 having an inside diameter at least equal to the diameter of the tubing B with which it is connected through coupling 6, the lower end of which sets intoa counter-bore in a compressing collar 7 slidable on the upper end of the cen` tra] tube 5. The under face of the collar is recessed to receive the upper end of an annular packing member 8 of rubber or other suitable material surrounding the member 5 on which it is also slidable. y Slidable on the lower portion of the central member `5 is dise 9 having flanges on the upper and lower faces thereof at its periphery. The

`lower end of the packing member 8 is received by the upper face of disc 9, while a packing or sealing ring 10 of similar material is received by the lower face. Telescoping within the flanged inner face of disk 9 for compressing the sealing ringlO is a gland member l1 slidable on the tube 5.

This member is adapted to compress the sealing ring to prevent gas or oil under pressure from working up the inside of the packing member 8, which 1s necessarily v somewhat loose von tube 5, to prevent injury to the packer.

The lower end of tube 5 has a shoulder 5' thereon and a key adapted to extend into a recessin the gland for normally holding the parts against relative rotation before the packer is set. Threaded to the gland is a tubular casing 12 into which the lower ena of tube 5 projects when the packer is set. The lower end of this casing must be con nected with the lower port-ion of the tubing The relief valve D may be here interposed for providing the coupling.

The packer herein described is merely illustrative of the use of my invention, but the relief valve D may obviously be applied to any preferred or suitable form of well packer having a central passage therethrough, through which the oil is pumped.

The relief or escape valve D preferably comprises an integral body having an upper reduced portion 15 which is exterlorly threaded to extend into the lower end ol housing or casing 12. The central part of the bo y has a maximum diameter and has a diameter equal to the diameter of the member 12. The lower end portion 16 is reduced and interiori-y threaded to receive the end of the bottom section of the well tubing B An annular flat surface 17 is preferably provided on the bottom of the central portion, while a tapered surface 18 is formed between it and the reduced portion 16.

A passageway 19 extends through the body and has a diameter equal to that of the tubing B. Spaced between the outer edge of the body and the wall of the central opening are one or more vertically extending holes 20. I have shown four such holes. They extend only vpart way through the body, as shown. Communicating with the bottom of each hole is a restricted passageway 21` of smaller diameter that opens out into the tapered surface 18. 'The body is counterbored between its ends to provide a chamber 22 of slightly greater diameter than the central bore or passage 19, the counterbore being of such a depth as to extend into holes 2O and form elongated vertical parts 23.

i Screw plugs 20 are inserted in the tops of holes 20. These holes serve as a cage for a ball valve or check valve coinprismg a ball 24 adapted to normally seat over the top of passageway 21. A spring 25 may` if desired, be inserted in each hole. This spring normally is under no compression and is very light and yieldable. Its purpose is to insure seating of the balls after they have been lifted.

The annular fiat surface -17 may rest on the top of a bottom casing 26 without tending to spread it, while the inclined or conical face 1S serves to properly center the tubing relatively thereto. The bottom casing rests on the bottom of the well and resists the downward pressure of casing member 12 and the packer due to the weight-of the superimposed tubing to effect the compressio'n of the packing member 8 in a manner well understood. This bottom casing is not always used, but its use is often desirable.

meeste Such casings are perforated some distance above the bottom of the well so that oil and gas may pass therethrough into the pump.

l/Vith the apparatus as described, the gas pressure accumulating in the well below the packer, lifts the balls 24 and escapes into the up-ilowing stream of oil. Upon the pressure being relieved, the balls seat themselves and prevent the back-flow of oil from the pipe to the well.

The construction-is such that there is a substantial body of metal in the packer to support the weight of the suspended string ot' pipe or to resist any crushing strain that may be transmitted ownwardly. This is due to the shape of the body member, particularly in providing a portion of a diameter which may be substantially the saine as that of the packer and a reduced portion of suiiicient diameter to receive the tubing, with an intervening shoulder through which the gas-escape passages extend.

ln Fig. 2, the relief valve is shown in use as a separate unit, rather than` a part in combination with the packer. In this instance, the relief valveis coupled in the tubing at some distance below the packer. The construction ofthe valve is no different than that described. Instead of screwing into the casing member 12 at the bottom ot' the packer, the upper end of the body is threaded into acoupling member 30 having a reduced upper portion into which the tubing is threaded and an enlarged lower portion threaded over the valve carrying body. The coupling is so shaped as to clear the heads of the screw plugs 20. It will be apparent, therefore, that the gas relief valve may be placed at any suitable point in the tubing below the casing.

The valve can be made for use in wells of the smallest size now generally drilled and in the successively larger sizes. Inasmuch as the smallest size of packers is generally not more than four and ive-eighths inches in diameter while the' standard tubing has an inside diameter of two inches, and the diameter of the valve body must not exceed the diameter of the packer, it will be obvious that the valve is very compact.y and yet provides an ample body of metal at every point without unduly restricting or limiting the sizes of the various passageways.

I claim:

1. A gas-escape valve for wells comprising a body havinga central opening therethrough and having a reduced upper portion which is threaded exteriorly, a downwardly extending reduced portion threaded for connection with tubing, a conical shoulder between the reduced lower extension and the body, a gas passage from the shoulder to the central opening, and an inwardly opening check valve in the passageway.

2. A. gas-escepe valve for wells com risand the body, a Het surface at the outside .ing a body having a central opening tiereof the conical surface, a gas passage from through and having' a reduced upper porthe shoulder to the IcentralI opening, and an tion which is threaded exteriorly,y a down inwardly ,opering cheek valve in the pas- 5 wardly extendingreduced portion threaded sageway.

for connection withl tubing; e conical shoul- In testimony whereof etx my signature. der between the reduced lower extension 1 PATRICK H. MACK.

Images