US1573051A - Gas anchor for pumping wells - Google Patents

Description

Feb. 16" 1926.

J. R. GIGNOUX ET AL GAS ANCHOR FOR PUMPING WELLS Filed June 17 1925 2 Sheets-Sheet l narra/Wwf?.

Feb. 16 1926.

J. R. GlGNoUx `Er AL GAS ANCHOR FOR PUMPING WELLS 2 Sheets-Sheet 2 Filed June 17 1925 6. o o R f MM5 m 4 f i; i, M, E m /L ,w MW a 4 @n @f M, 5 5 9 8 @1W v W4/wf 1r Patented F eb. 16, 1926.

UNITED STATES PATENT OFFICE.

JOHN GIGNOUX, OIF LONG BEACH, AND THEODORE E. SWIGABT, 0F LOS ANGELES,

CALIFORNIA, ASSIGNORS TO SHELL COMPANY OF CALIFORNIA, OF VSAN FRAN- CISCO, CALIFOBNIA, A CORPORATION OF CALIFORNIA. i i

i GAS AN CHOB FOR PUMPIN G WELLS.

Application led June 17, 1925. Serial No. 37,697.

` To all whom it may concern.-

Be it known that we, JOHN R. GIGNoUx and THEoDonE E. SWTGART, both citizens of the United States, the former residing at 5 Long Beach, in the county of Los Angeles,

State of California, the4 latter residing at Los An eles, in the county of Los Angeles,

State of California, have invented a new and useful. Gas Anchor for Pumping Wells, of which-the following is a specification.

Our invention relates to oil pumping equipment. I

T e standard oil well pump is secured at the lower end of a pump tubing at the bottom of a well. The pump tubing extends upwardly through the well and has a branch pipe extending from the top thereof to'convey oil to suitable' storage or place of use. The plunger of the pump which is situated in a pump barrel is connected. to a string of sucker rods which extends up through the pump tubing, extending through a stuffing box secured at the upper end of .the pump and being connected to a walking actuated by operating mechanism "and the plunger of the pump is reciprocated in theV valve. During the up-stroke of the plunger oil is drawn lnto the barrel, the standing valve being open. During the down-stroke of the plunger the standing valve closes and oil passes into the barrel from a position below the plunger .to a position above the plunger, the working valve v being open. When'the plunger again rises, the workin valve closes and oil 1s elevated through the pump tubing. Oil carries a certain amount of free gas which, if present in large quantities, may reduce the capacity of the pump, since it tends to accumulate in the pump between the working and standing valves. This gas then expands and compresses with each stroke of the plunger, not lifting the working valve and not allowing the standing valve to lift. The presence of this gas between the valves therefore tends to prevent the operation of the pump. .l

A gas anchor attached to the lower end beam of the derrick. The walking beam is and the pump plunger carries a working g gas openings.

ofthe barrel is a valuable supplementV for any well having an appreciable amount of gas. Gas anchors now in use each com'- prises a tubing securin to the lower end of the barrel, which tu ing is closed at its lower end. Extending downwardly inside the tubing from the barrel is an eduction pipe, the upper end of this pipe being connected to 'a passageA closed by the standing valve. below the standing valve openings are provided through which the gas enters the tubing.l The gas separates from the oil in the gas anchor as the oil flows downwardly towards the lower open end of the eduction pipe, this gas flowlng upwardly and passing outwardly through the same openings that the oil enters. There is much interference at this point and in actual practice it is found that free separated gas tends to move in and out of these openings in the shell and an efficient separation of gas and oil is not accomplished in the space inside the tubing and outside the eduction pipe.

It is an object of our invention to provide a gas anchor adapted to be attached to oil well pumps which will effectively separate gas and oil and prevent gas from accumulating in the pump.

It is also an object of our invention to provide a gas anchor in which the oil and gas do not lnterfere with each other, oil entering at one opening and separated gas leaving at another opening.

It is a further object of our invention to provide a gas anchor having means for preventing a reverse flow of gas through the This prevents a re-entrance of separated gas into the gas anchor after it has been expelled therefrom.

Itis also an object of our invention to provide a gas anchor of this character in which means for preventing a reverse flow comprises valves, which valves are entirely protected from external interferences.`

It is an additional object ofour invention to provide valves which are extremely sensitive.

Other objects and advantages of our invention will be made manifest hereinafter.

Referring to the two sheets of drawings In the bottom `of the tubing justv `in which we illustrate a referred embodiment ofour invention an which are solely for purposes" of illustration:

Fig. 1 is a very diagrammatic view illustratin the application' ofour invention to a stan ard oil well ump.

g. 2 is a view ko the upper end of a gas anchor o f our invention.

discha l Fig. 3 is a view of the lower end of the gas anchor of our invention. v

Fig. 4 is anenlarged sectional view7 of the body of the gas anc ior of our invention.

Fig. 5 is-a section taken on the line 55 of Fig. 4. Y A

Fig. 6 is a section taken on theline 6,-6

of Fi :4. -A o In Fig. 1 of the drawing a gas anchor 1l the stuing box 17 is a' string of sucker rods 18 which is connected at its upper end-to a walking beam 19 and .at its lower end to a pump plunger 20 in the pump barrel 12.

- With' reference to Fi ..2 the nipple 13 is threaded at 23 in a llower collar 24 of the pump barrel 12. The lower end of-the nipple 13 is threaded at 25 in a coupling 26. One end 27 of a body 28 is threaded into the lower end of the coupling 26, as

clearly shown inV Fig. 4. The body 28 has a reduced part 30' which is surrounded by a cylindrical housing 31. The housing 31 engages a' cylindrica face 32 of the body 28 at its upper eiid and engages a- 'cylindrical face 33 of the body at its lower end. Threaded screws 34 and 35 are provided for securing the Ahousing 31 in place on the bod 28.

(gimmunicating between a bore 37 of the body 28 and an annular chamber 38 formed inside the housing 31 is a plurality of gas openings 39. Semi-spherical valve closures 40 supported by flexible valve supporting arms 41 arenadapted to engage seating faces 42 formed around the openings 39 for preventing a flow from the exterior to the iiiterior of the body. The upper ends of these flexible valve' supporting arms 41 are secured to flat faces 44 `of the body 28 by screws 45.

A lower coupling 48 is threadedly secured to a lower threaded projection 49 ofthe body 28. A reduced end 50 of a shell 51 is vthreadabl secured to the lower coupling 48. At t e lower end of the shell 51 there is secured a cup 53, this cup 53 being secured to the shell 51 by arms 54 in such a manner that an annular space 55 is the lower end of an opening 6l of a stand- Y ing valve body 62 of the pump 12. This eduction tube 60 extends through the bore 37 which is reduced at 65 so that it is only slightl larger than the tube 60. AThe lower end o the eduction tube 60 extends into the cup 53. v

The method of operation is as follows: When the gas. anchor is situated in a well, as shown in Fig. 1 oil .flows .upwardly in the shell 51 through the annular space 55 formed between the ,shell and the cu'p 53 due to'the suction of the pump. Oil iows into the cup 53 and downwardly around the eduction tube 60 and into the lower end of the eduction tube through openings 64 provided near the lower end thereof. During the up-'stroke of the plunger 20 a suction is created therebelow inthe barrel 12 and the standing valve 62 opens. This draws oil through the eduction tube 60,. thisoil pass- Ving'from the exterior of the shell 51 through the annular space 55 into the cup 53 and through the openings 64 into the eduction pipe. During the down-stroke of the pump the standing valve 62 is closed and there is no flow through the eduction tube 60. 'lhei'e is a tendency for\ a slight reverse flow or back flow through the eduction tube 60 on the initial downward movementl of the plunger before the standingl valve has completely closed.

With particular reference to Fig. 3, in order toppass into the eduction tube 60, it is necessar for the oil to pass up around the top vo the cup 53 and then down to the bottom thereof. This oil as previously mentioned carries a certain amount of gas, this gas being much lighter thanl the oil. When the gas and oil reach the upper end of the cup 53 the oil, due to suction, is pulled into the cup. However, the gas being so li ht is not greatly affected by this suction, iut flows upwardly' to the upper end of the shell 51 and into an enlarged pbrtion 69 of the bore 37.

In actual practice it is found that by causing the oil to flow up and around and then to the .bottom of the cup 53 a very thorough separation of the oil from the gas is acquired. The as accumulates at the upper end of the s ell 51 and in the portion 69 of the bore 37.

During the up stroke of the pump the pressure in the space 69 is a little lower than the pressure outside the tubing 51 at this It is obvious'that were the valves 40 entirely `omitted the oil would flow inwardly through the openings 39 on the up-stroke `of the plunger and that little or no upward :low would take place in the space between the tubing l and the cupD 53. By providing the valves 40 to close the openings 39 on the up-st-roke of the pump we are able to utilize this space. v

The valves 40 are held very lightly on their seats and as soon as any gas accumulates inthe space 69 and the standing valvel 62closes an unbalancing of pressure occurs which opens to valves 40 and allows this gas to escape. This `unbalancing of pressure 1s due to thefact that the gas forces the oil level down -in tubing 51 and that, since this gas has no weicht, the pressure of this gas is that at the oi surface which it establishes directly below it. The pressure at this level is the same'inside and outside the tubing 51 and is greater than the pressure at .the higher level at which the valves 40 are situ.-

ated. The di'erence between these two levels represents the static head available to produce pressure to open the valves 40 and since the pressure of the valves 40 on the1r seats due to the springs 41 is very slight, a small p'ressure or difference in the head 1s suiicient to openthe valves and allow the gas to escape.

The gas passes from the annular chamber 38 through openings 71 of the housing 31.`

These valves 40l immediately close when the pressure of the portion 69 of the bore 37 and the exterior of thegas anchor equalizes, or when the plunger 20 moves upwardly and there is a suction on the interior of the shell 51. The valve arrangement entirely prevents a re-entrance of separated gas and therefore makes room for gas separated of oil entering the annular space 55 around the cup 53 when the plunger 20 elevates.

The valve arran ement of our invention is greatly responsible for the success of our invention. In lFig. 4 it will be noted that the valves 40 are suspended and retained at the ends of valve holding arms 41 y which are preferably made from thin strips of phosphor-bronze. These arms are very sensitive to pressure and respond quickly when an excess pressure is present on either side thereof.. It should be noted that the arms 41 are surrounded on all sides by oil in the annular chamber' 38, and the pressure thereon is equal in all directions. This makes the valves 40 very sensitive to 'an excessive pressure inside the portion 69 of the bore 37. By providing separate oil entrances and gas exits, it is possible to eliminate any interference and to eliminate an inward and outward movement of separated gas which obviously reduces the separating efliciency of a gas anchor. The valves are entirely protected by the housing '31 so that there will be n-o interference to their operation due to external impediments.

Vire' claim as our invention:

1. In combination: a pump; an eduction tube extending from said pump; a shell supported by' said pump around said eduction tube.;- a ycup secured 1n said shell into which said eduction tube extends, there being a space between said' cup and said shell through which oil passes through said shell, and there being gas openings near the upper end of said shell through which gas escapes from said shell; and means for preventing a reverse flow through said gas openings.

2. In combination: a pump; an eduction tube extending from said pump; a shellsupported by said pump around said eduction tube; a cup secured in said shell into which said eduction tube extends, there being a space between said cup and said shell through which oil passes through said shell, and there being gas openings near the upper end of said shell through which gas escapes from said Shell; and valves adapted to close said gas openings for preventing a reverse flow through said gas openings.

3. A gas anchor comprising: a body having a gas opening connecting from the interior to the exterior thereof; a shell extending from said body; a cup secured at the lower end of said shell, there being an annular space in said shell around said cup; an eduction pipe extending through said body, Saidshell and into said cup; and a valve adapted to close said gas opening, said valve allowing an outward flow, but preventing an inward flow therethrough.

4. A gas anchor comprising: a body having a gas opening connecting from the interior to the exterior thereof; a shell-extending from said body; a cup secured at the lower end of said shell, there being an annular space in said shell around sa1d cup; an eduction pipe extending through said body, said shell and into said cup.; a valve adapted to close said gas opening, said valve allowing an outward flow, but preventing an inward flow therethrough; and means for enclosing said valve. f

5. A gas anchor comprising: a body having a bore, gas openings formed in a reduced part of said body, said gas openings extending between the bore and the exterior of said body; a housing carried by said body, said housing surrounding said reduced part of said body thus forming an annular chamber; valves secured to said( body in said annular chamber, said valves allowing an outward flow through said gas opening, but preventing a reverse flow therethrough; a shell extending from seid body; a cup secured in said sl1ell ;-and 'an educton pipe extending through seid body into said cup.-

6. A gus anchor comprising: n, body heving a bore, gas openings formed in a reduced part of said body, said gas openings extending between-the bore and the exterior of said body; a housing carried by said body, said honsngfsurrounding said reduced part of said body thus forming an annular cham-` ber; flexible valve holders secured to said body in said annular chamber; valves carried by said valve holders, said volves allowing an outward flow through saidgasopenlng, but 'preventing a reverse flow therethrough; a, shell extending from said body;

:L cup secured in said shell; and an eduetion pipe extending through said body into said cup., V

In testimonywhereof, we have hereunto set `our` hands at Los Angeles, California, this 11th day of June1925.

-THEODOREE SWIGART JOHN R. GIGNOUX.

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