US2077911A - Valved coupling for gas wells - Google Patents

Description

VALVED GOUPLING FOR GAS WELLS Filed Dec. 10, 1934 INVENTOR Aer., ac, resa UNI-TED STATES PATENT oFFlc 1 Claim.

My invention relates to natural gas-wells, and is found in a coupling for use in such wells. Notice is given of my co-pending application Serial No. 73,052, illed April 7, 1936.

5 Ordinarily, a gas-well includes a tubular casing which extends from the earths surface downward and into communication with the upper sand-the tlrst gas-yielding stratum reached during the'drilling oi the well. When in the operaw tion of the well the yield or pay of the upper sand becomes low, the well is drilled deeper, down to the next lower gas-bearlngstratum. Within vthe outer casing a line of tubing is run to this so-called second sand, and the yield of the well then comprises the gas delivered by the second sand. plus the gas delivered by the upper sand. Usually water is present in the gas-bearing strata, and such liquid drains into the passages through which the yielded gas enters the tubing and casing. 'I'he liquid which drains from the second sand and floods the entrance to the inner tubing may be removed in well-known manner, by

operating a bailer within the tubing, but the liquid draining from the upper sand into regions between the tubing and the casing is not always accessible to the bailer, and the removal thereof presents a problem. More particularly my invention relates to improvements in a coupling providing for iiow between the inner and outer passages of -a gas-well.

In the accompanying drawing Fig. I is a diagrammatic, sectional view of a gas-well. showing the inner tubing of the well provided with aI special, adjustable coupling in which the invention is realized; Fig. Il is a fragmentary view of the well, showing to larger scale the coupling in alternate position of adjustment; and Fig. III is a view of the coupling in-side elevation- In Fig. I of the drawing the reference numeral l indicates the upper sand, and 2 the second sand of the well W. In accordance with usual practice the outer casing 3 of the well is sealed in a casing head d at the earths surface and extends downward therefrom and into communication with the upper sand I. The inner tubing 5 of the well is also sealed in casing head 4 (cf. the casing head gland' S), and extends within the`casing 3 downward to or to a point below the second sand 2. The foot of the tubing 50 5 is perforate, and above the stratum 2 the usual packer l is installed.

'Ihe packer 'I is located between the two gasbearing strata, and, in conjunction with the tubing 5, the packer serves as a seal in the bore oi the well, whereby the sole escape oi the gas interval from the sand I to the packer is from yielded by the second sand 2 is by way of the tubing 5, while the escape of the gas from the upper sand is by way of the passage 8 that lies between the tubing 5 and the outer casing or wall ci the well. At the surface the 'two streams 5 of' gas may be fed into a common main, or they may be carried in independent lines. With such details. of common practice, however, the invention' is not immediately concerned, and I shall 4not dwell further upon them, other than to mention 10 that the top of the inner 'tubing 5 isequipped with a gate valve 9 which,I when opened, establlshes communication with the atmosphere.

In the field the' vertical distance between two subterranean gas-bearing strata may vary from V15 a few feet to several hundred feet, and in exemplary way the interval between the strata I and 2 is given as two hundred and fifty feet. In such case, the packer 'l is installed from fty to one hundred feet above the sand 2, and the one hundred and ilfty to two hundred feet.

Between the packer I and the upper sand I, I organize in the tubing 5 an expansible drainage coupling I0, and conveniently the coupling 25 I0 lies from fty to one hundred feet above the packer.

The expansible coupling I0 includes a head I'I which is secured in threaded union I2 to the lower end of the upper portion of the tubing that 30 reaches from the coupling'to the mouth of the well. The external wall of the head II is provided with circumferential serrations or slip rings I Ia, whereby the coupling may bey grappled with shing tools in case it be lost" in the well. 35 'I'he head II carries a cylinder portion I3 which includes a circumferentially extending line of relatively small orifices I4,` and within the cylinder portion I3, a plunger I5 is organized. The plunger is forined with an annular shoulder 15a, 40 and a keeper I6 secured in the lower end of the 4 cylinder portion I3 serves, in cooperation withsuch shoulder, to secure the parts in assembly; from within the cylinder portion I3, the plunger continues downward in a tubular extension I5b 45 which is connected, by an ordinary coupling Il, to the upper end of the lower portion of tubing 5 that extends from coupling I'I downward to the bottom oi.' the well. As the drawing indicates, the head II and plunger I 5 are hollow, pro- 50 viding in conjunction with the tubing 5 a continuous -passage from the bottom of the well to the top-a passage which normally is sealed from and independent oi the outer passage (8) within which it extends. 55

Within the Vcylinder portion I3, the head II of the coupling is provided with an upwardly and inwardly tapering seat IIb, and, advanta-` geously, the seat is provided in an inset block I Ic.

5 The plunger I5 is formed of a relatively noncorrodible metal, such as brass or bronze, and the block IIc is 'formed of a cuprous, nickel alloy, such as is commonly known as monel metal. Otherwise, the coupling may be formed of cast iron or steel. The upper or inner end of the plunger I5 is corneal, providing a tapered -face I5c adapted normally to engage the seat I Ib, and, as shown in Fig. I, when such normal condition prevails, the body of the plunger closes the orilces I4 from within. In the alternate or unseated position of the plunger, the ports I4 are uncovered.

In normal operation the ll \wer end of the tubing 5 rests upon the bottom of the well; subject zo to the weight of the tubing 5 above, the head II of the coupling bears in seated position upon the upper, tapered end of the plunger I5, and accordingly the oriiices I4 are closed, as shown in Fig. I. The water or oil draining from the sand 2 collects in the bottom of the well and in the bottom portion 50 of the tubing 5; when the liquid rises to such level in the well as to retard unduly the yield 'of the sand, a bailer is lowered in the tubing 5 and is operated in well-known manner to remove the liquid.

The liquid seeping from the upper sand IY drains into the bore of the well above the packer 1, and is separated from the gas yielded by said upper sand and flowing-upward through outer passage 8. The packer serves normallyto prevent such liquid from running to the bottom of the well and flooding the second sand 2. I'he liquid is collected in passage 8 between the sand stratum I and the packer. During the con- 40 tinued operation of the well, the liquid collected in passage 8 gradually increases in volume and, unless it is removed, it eventually reaches and floods the upper sand, in such manner as to retard or throttle the yield of stratum I. As has been alreadyl mentioned, the problem in mind involves the removal of this so-called upper liquid.

In removing such liquid, the casing head gland 6 is released or set ajar, and: the usual anchor rods (not shown) are loosened; the valve 8 is opened, causing the high-pressure gas from the second sand 2 to iiow violently upward through the tubing and to discharge into the open atmosphere (or into a suitable closed receiver); then the tubing 5 is elevated a few inches and stayed, whereby the head II and the cylinder portion I3 oi the coupling III are moved upward relatively to the plunger I5; and thus the seat Ilb is removed from. the conical face I5c of the K 50 plunger, and the orices I4 are uncovered, as indicated in Fig. II. In consequence the liquid, which is conned above the packer 1, is caused to spurt inwardly through the oriiices I4.' whereupon it is'entrained in the gas flowing upward through closed; the casing head gland Sis tightened, the valve 9. is closed, and normal operation of the well is again conducted. Thus, it will be understood that the normal operation of the well may be interrupted from time to time, and the liquid 5 .draining from the upper sand I may be removed in the above-described manner. Of course, the vertical interval between the coupling I0 and the packer 1 is always ilooded, but this condition does no harm-indeed it is desirable, inas- 10 much as it advantageously provides a pool in which solid particles of sand or other material entering the passage 8 may settle below the oriiices I4. That is to say, particles of solid matter will not enter the coupling and interfere with 15 tight seating of the plunger.

It will be observed of my expansible coupling that, when the ports I4 are uncovered, a region R is afforded between the seat IIb and the face I5c of the plunger; this region R. comprises a 20 passage which is inclined upward, toward the course of gaseous iiow. within the tubing 5, whereby the gas streaming through the coupling produces a substantial aspirating effect. The orifices I4 are relatively small, and, when brought 25 into play, they squirt relatively iine streams of liquid into the region R. Due to the relatively small orifices and such aspirating efi'ect, the liquid spurting into the coupling is broken up into small globules which are readily entrained 30 with and carried upward by the ilowing gas.

It has been found that the inwardly spurting liquid, in washing over the tapered surface IBc of the plunger and the tapered surface IIb o! the block IIc, serves to cleanse the surfaces oi' 55 such dirt and grit as normally tend to collect thereon, whereby, when the upper section of tubing is again lowered, to close the orifices I4,

a snug lengagement of the` surfaces (I Ib, llc) is insured. 40

I have found in a practical installation that,

when the outer casing 3 comprises six inch pipe and the inner tubing 5 comprises two inch pipe, the orlnces 14 may be four in number, and each may be 1*; of an inch in diameter. 45'

It may so happen that the pressure of the gas yielded by the lower sand 2 is insufcient to produce the necessary energy to carry the entrained liquid to the top of the well. In such case the liquid entering the coupling is allowed 50 to collect at the bottom of the tubing 5. whence it is removed by a bailer in the usual way.

. It will be understood that no special tools or rods need be run down the well, to open or close the orifices I4. The manipulation of the upper 55 reach of the tubing 5 is all that is required.

I contemplate that my expanslble coupling may be used in a water well which is fed by two or more water-bearing strata. When the lower stratum runs dry, the coupling may be expando ed, to feed water from the upper stratum into the well tubing. And. additionally, the coupling may be employed with advantage in multiple strata oil wells, or wells having an oil stratum and a. gas stratum. 65

I claim as my invention:

A coupling for joining upper and lower sec-1 tions of well-tubing, said coupling comprising aA head for attachment to the'end of one of said sections of tubing, a passage extending through said head and adapted to communicate with the b'ore of said section of tubing, a tapered seat of special material embodied in said head adjacent to one end of said passage, a cylinder portion inv tegrated with and extending from said head, said cylinder portion being of greater radial extent than said seat, a hollow plunger adapted to be secured to the end of said other section of tubing and to comprise a continuation of the bore thereof, said plunger extending into said cylinder portion and including a conical end cooperating with said seat, said plunger including a shoulder within said cylinder portion, and meansv carried by said cylinder portion and cooperating withA said shoulder to secure the parts in assembly, the taper of said seat and the conical end of said plunger being inclined upward and inward relaysaid cylinder portion including an inlet port normally closed by said plunger and communicating with said aspirating passage when said upper-section of tubing is moved, as described. l0

GEORGE E. VAN VOORHIS.

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