US1902296A - Producing oil from wells and apparatus therefor - Google Patents

Description

INVENTOR:

M arch 21, 1933. s, w. TRAYLOR, JR

PRODUCING OIL FROM WELLS AND APPARATUS THEREFOR Filed ,A April 25 WI TN ESSES:

"n BYJTZL Patented Mar. 2l, 1933 Lamas FFICE PArENr YSAMUEL VWILLIAM TBAYLOR, JE., OE AELENTOWN, PENNSYLVANIA, AssIGNoR 'ro TEAYLOE ENGINEERING a MANUFACTURING, COMPANY, vor

sYLvANIA, A CORPORATION OE DELAWARE I ALLEN'JJOWN, rENN- rEoDUcrNG'orL EEoIir WELLS AND APPARATUS THEEEEOR Y 'Application sled Apin 25,

This invention relates to the takingpof oil from wells, and to apparatus therefor. An important object of the invention is to take oil (or other liquid) from a well without incidental waste or excessive consumption of gas, thereby saving valuable gas; increasing the useful life ofthe well and of the oil field or dome, from which it draws, and also increasing the total ultimate recovery of oil from the well and from the field ;V and diminishing the expense of pumping the oil after pumping does Vbecome necessary. Otherobjects and advantages that can beV realized through this invention will appear-hereinafter. y Y

`The essential geological unit of an oil field maybe conceived of as a subterranean rock dome, containing oil-bearing fsands, `and also, in its top,` natural gas under very high pressure.l Beneath the oil there isgenerally water. When a well is drilled downthrough the rock dome intothe sands, the gas pressure forces the oil up through it, so that it often. spouts into the air with tremendous force. The well continues to iowspontaneously only as long as the gaspressure remains high enough to force the oil to the surfacezafterv this, additional oil can only be recovered by artificial means, such as pumping. The ultimate recovery is generally limited by influx of water when the pressure has been sufficiently relieved,often ruining the well for-all` practical purposes.

In practice, the serious decline of gas pressure results not mainly'from withdrawal of oil through the well, but from blowing ofi' of the gas at the well. The evils'of this are well understood in the oilv industry, and various governmental efforts have been made to compel oil producers to limit their withdrawals of gas to some reasonable ratio to the oil recovered. However, methods of controlling the gas loss have not proved either eliicient or satisfactory.

This invention affords a means of producing or taking oil from a well without loss of any gas except that which is dissolved in the oil. It is-applicable equally to flowing wells and to those for which artificial means are employed to raise the oil, such asv repressurina well entails (in'itself) no waste or confrom one well topump other wells whose-gas i which isconnected a pipe 9: Thisrmay serve either to draw off or vent gas from the well z1932. seria; No. 607,254..

ing with compressed air', or pumping with gas or air, or by 'any desired type of pump, operated electrically, mechanically, or in any other way. While the use of my invention sumption of gas (except that dissolvedinv the oil) it readily permits of pumping a Well with rits own gas, as well as of using the gas pressure maybe inadequate. v 60 In the drawing, Fig. I shows a vertical section through an foil Well `equipped for` operation in accordance with my invention, certain portions being broken out and omit-v ted to bring the depth of the well within the' limits of the'paper. Fig. II is asimplified diagrammaticverticalsection illustrating a modified application of the invention.

In Fig. I, the well is shown with the usual tubular metal lining or casing 4, extending from above the surface of the ground at 5 down to, or into, the oil-bearing sand or stratum 6. As shown,`the well extends belowV the casing 4 into the sands 6. The upper end 75 of the casing 4 is closed or sealed (against f Vdirect escape of gas, etc.)-by the usuall plug 7 screwed into the casing. The plug 7 has a port or elbow passage 8 therethrough, to

(especially if the gas. pressure is excessive, or for the introduction of gas (sometimes air) under pressure, if the pressure in the well should be or become too low. The plug 7 also has a port or opening l0 therethrough,` to which is vconnected the inner tube (or delivery conduit) 11 in the well. An eXtension of the delivery conduit 11 above ground is alfordedby a'pipe 12 also connected to the plug opening l0.` The conduit 11 extends, asVv v shown, down to a point somewhere near the bottom of the well, and its lower portion includes a tube or casing'l considerably en- Y larged as compared with theportion above. The conduit 11 is completely closed at its bottom 14 and for some distance above,'but has'slots or openings 15 through its vertical wall, preferably at a point withinthp well casing fl. Inside the conduit 1l is an inner 100 i Inthe, conduit 11, beyond the gas anchor,

tliereris interposed al valve 20 for Controlling pipe 16 whose flared upper end joins the outer conduit wall at 17, above the openings 15, and whose open lower end 18 extends down nearly to the closed bottom 14. Gras issuing from the sands 6 cannot enter the lower end of the conduit 11, but bubbles up through the oil around the conduit past the openings 15, l and dis'eiigiiges itself .at the free surface of the oil in the well,- accumu-4 lating thereabove. However, oil entering at the openings 15 can vflow downwardin Vthe conduit 11 around the pipe 16 and then up through the latter quit-e freely. This construction constitutes a convenient forni of trap or gas anchor. (as it is termed in the art) tol prevent gasrfrom entering' and as- (tending in the conduit 11 along with the oil. The conduit 9V is eii'e'ctivelygas-sealed by the entrapped liquid, however, only so long as the liquidvlevel in the well (outside thel conduit) remains above the openin'pfs 15.;

Yfor if these openings are once exposed, vthe gas V,'.ibo'vegthe liquid .will vbe entrained with the oil and escape freely through the trap.

Y .the flow through theconduit and ythereby ings 15;

regulating the` liquid level inthe well,I always maintaining' it .above the highest point of entry of oil into the conduit at the open- Forv openingl and y closing or shifting the. valve 2() for this, purpose, ,any means properly responsive to the liquidlevel in the V well may be. employed,-provided `it is quite Y many oil wells.

reliable in its,k action, and provided ample 'power is ai'oided for positively moving the Vvalve according to the liquid level.4 In order to minimize the necessary opening and closing force, I prefer a balanced type of valve 40 20, such ,as `the double-seated lpoppet valve shown. Made withequal bevelled heads having'A very narrow contact Zones, such a valve is so closely balanced as to be comparatively easily moved; yet rthe slight imbalance due to the diilerence between the pressure-ex- .posed areas of its heads holds it definitely seated until force suiiicient to open it prop- 'erly is brought to bear, and thus. obviates vwire-drawing. As shown, this valve 2O op- ,e'ifates in a chambered and ported structure 21 forming y lower conduit portion 13.

vhe upper-end ofthe enlarged To assure `positive operation ot the valve 20 atrall times, greater Aforce is preferably 1 provided than can be secured from the liquid displacementv of floats' or other moving partsv associated with the valve,-owing to space limitations' and the wall thickness of a` float required'-to stand the enormous pressures in By employing'` liquid-responsive,means` whose force varies with the y height of the liquid in the well, very great- Vvvalve operating power is directly availible;` whereas the buoyancy of a iioat increasesV but very little after it is once fullysubmerged. As here shown, a hydrostatic pressure device 22 is used and is located inside the casing 13, where the parts are protected trom injury, as well as from violent movements of oil that might aect their action. So located, the hydrostatic device 22 responds perfectly to variations of oil level in the welhevei wit-h'the conduit po'i'tion- 13 full 'of liquid to' the e'Xc'lusion' of any gas vwhatt-aver, whereas a float operating within the casing 13 would require the maintenance Vthere ot a constant body of- Vgas (or air) in order VJto act regularly,something that it is not easy to assure.-

"The device 22 consists, preferably, of a (sheetfnietal) bellows, with its movable top wall '23 attached directlyV to the stein 24 of the valve 20, andV its bottom 25 ymounted on an, apertured ,diaphragm or spider. 26'su`itably mounted in the casing` 13 above the openings-15y and the upper end 17 of the inner pipe V16. As shown, theyalvet)A is loose on the reduced upper end ofthe stein 2,4,be-

tween the Stem `Siicmi'titr at aia mit. httal shouldertlib on the upper end of the stein, so-that the stem may have a limited longitudinal movement or play relative toi the valve. The valve-opening,bellows-collapsing action of tite hydrostatic pressure ettside on the device 22 is assisted by a weight mounted on its top4x 23, ar'oiindthe stem A24. The stein 24A has aneirterisioii 28 down inside the bellows, to engage' the bellowsbotjcom 25 and thus prevent Aeil't'iessive 4va'.-lyeA opening movement; AThe devif'jeQ?J isalso subject to a valve-closing, bellows-expanding torce,` so determined as tob always sutlicient to close the valve: Q0 with 'the liquid ioo levelin the well above the tops of the openv ing-s 15. In the present instance, this force is a substantially constant fluid pressure insideV the:V bellows 22, whose interior isI eoiinected throughl a passage ,29 in the parts 25,

26 with a. standpipe 30 ezrteitidingI up',

, (through the structureA to a height affording adequate hydrostatic pressure, and preferably open into the well at its top. In operatiomthe bellows22 responds to hydrostatic'pressureinerel since the gas pressure ou the liquid in the well acting outside Ithe bellows is always neutralized oi' cancelled by the very same gras pressure on liquid in pipe 30 actingl inside the bellows,

skirt pts-etten f the structure 2i tutti t, ittviie A resistant but ultimately yieldingtifigger stem 24 in the valve 20 vallows the stem to be moved just past the dead-center of the springs 33, 33, each way, before the stem shoulder 24a or 242i vstrikes the valve to open or close it.

The use of some such trigger device 33 to secure intermittent opening and closing of the valve 20 prevents wire-drawing at the valve, and so makes the valve and its seats last considerably longer. While advantageous, however, such a trigger device is not essential to the success of my invention.-

In practice oil entering the well from the sands 6 may be forced or drawn up through p the conduit 11 by any of the natural or artificial means mentioned above: That is tov say, either (in a flowing well) by the natural gas pressure in thev well; or by gas (air) under pressure introducedintoV the well at 8, so as to act on the surface of the liquid around the conduit ll; or by a variety of pumping means, which may be interposed in the conduit ll at any suitable point or points. In many cases, the natural gas pressure will force the oil upa considerable distance, so that it is only necessary to pump it up the rest of the way. However, the operation and utility of my invention are independent of the particular means employed for raising the oil in the conduit 11; i. e., the invention is useful in any well that produces gas in substantial amounts. Assuming, therefore, merely that adequate pressure or other means of raising the oil is present or provided, a mode of operation is as follows:

Oil from the sands 6 accumulates yinfthe well until it reaches a level such that its hydrostatic pressure on thedevice 22 (aided by the weight 27) overcomes the closing pressure from the standpipe 30, aided by the springs 33, 33, and carries the springs 33, 33 past dead center; whereupon the valve 20 snaps wide open, allowing a free flow of oil. As this free flow continues, the oil level inthe well falls until the head of oil in the standpipe 30 is able to overcome the weight 27 and the re.- sistance of the springs 33, 33, together with the hydrostatic well-pressure on the device 22, when the valve 20 snaps tight shut, completely stopping the oil flow. `Accumulation of oil in the well recommences, vinitiating a repetition of the cyeleV-and so on indefinitely. In this cycle of operation, the gas pressure in the vwell plays no part, since it acts equally on the oil surface in the Well and on the liquid in the open-topped standpipe 30.

The. elfectivevalve opening force corresponds to the height of the oil above the device 22,- which, as already mentioned,'is above the openings 15. The liquid in the'standpipe 30 will preferably well.

The foregoing is the usual mode of operation. There may, however, vbe an initial'period in the life of a well when its gas pressure will sufiice to maintain a continuous flow of oil, withoutany periodic drawing down of the oil level to a lpoint wherethe valve 20 would close. I-f at such atime the oil in the well rises above the open top Vof the standpipe 30, this will not affect the subsequent operation as described above later on, after the flow of oil has diminished.

From the foregoing description, it will be seen that by my invention oil can be taken from a well without loss of any gas except that actually dissolved in the oil,-,together with any used for pumpingr the oil, if the gas pressure is insufiicientto render the well ka flowing well. In producing this result, the gas anchor-formed by the trapped oil below the openings l5 and the automatic 'levell regulator consisting fof valve 20 and levelresponsive device 22 have an important coaction; i. e., without the gas anchor, the oilv passing the valve 2O would carry quantitiesk of .entrained and unseparated gas;V while without the level regulator, the oil level in the well would be forced down tothe openings 15, andthe gas anchor emptiedof oil and rendered ineffective,-..after which large quantities of'gas would blow off through the conduit 1l, and comparatively little oil. But when maintained'effective by the level regulator, the gas anchor causes a separation of the gas from the oil, as already described, and

permits the oily to be taken off by itself.l

While gas anchors have heretofore been sometimes used inv wells that had to be pumped, they have been found practically useless in iowingwells, for reasons indicated above. Y

A bellows type of hydrostatic liquidlevel responsive device 22 can be used under a pressure difference of as high as lbs. per sq. in. for a double-walled sheet metal bellows, thus affording kan availableforce as high as 350 lbs. for'moving the valve 20 each way. The mechanism shown is almost without 'friction, and is unaffected by either sand or dry` gas. A hydrostaticdevice 22 will'operate perfectly ina sloping well, where a float device could scarcely be made'to work at all.

Fig. II illustrates in simplified diagram the'use of artificially suppliedgas pressure to raise oill in a well equipped with theV apparatus of Fig. I, especially on'the air-lift principle. Various parts and Afeatures here shown diagrammatically may correspond in construction with the showing in Fig. I, and

be some of the oil inthe are here marked with similar reference characters as a means of dispensing withv repetitive description; and it will be understood that accessory features of Fig. I (suoli as the 5 gas anchor) may in practice be used-with the device of Fig. II.

Fig. II shows a reversal of the arrangement shown in Fig. I; i. e., gas .(or air) from the supply pipe Sluis introduced through the inner tube or conduit lla, and oil rises .in the well casing l around said conduit 11a to the delivery connection 12a, which is here made into the casing 4l instead of to the conduit lla. Accordingly, the level-responsive device 22 controls the admission of gas pressure from the pipe lla into the bottom of the well to force oil up around the pipe lla. As shown, the conduit lla has an annular row of small holes 41a located at an intermediate level between the valve 2() and the subjacent hydrostatic device 22, and below the minimum liquid level at Z, so as to allow gas to pass out into the well when the valve 20 is open,and assist in raising the oil on the air-lift principle. lV hen the valve 20 is closed, however, the gas is prevented from escaping, as in Fig. I. Here, again, the device 22 responds tothe liquid level in the well, -as in Fig.`I-always maintaining a level above the point of escape of gas at Ala to mingle with the oil.

Having thus described my invention, I claim: Y

- l. A process or method of takingv liquid from a well while preventing the loss of gas, which method comprises opening and closing passage through aV delivery conduit for the liquid according to variations of hydrostatic pressure of the-liquid in the well, re

gardless of gas pressure, and thereby always maintaining in the well outside of said conduit, a liquid level above the highestvpoint oi entry of liquid 'into said conduit.

2. A process or method according to the preceding claim, including the further step u oi" maintaining the conduit gas-sealed. with entrapped liquid below the lowest point of entry of liquid into the conduit.

8. A- process or method of raising liquid Afrom a well on the air-lift principle while preventing the escape of gas, which comprises admitting and cutting ofi air-lift gas pressure from the delivery conduit according to the variations of hydrostatic pressure of the liquid in the well outside of the conduit, and thereby always maintaining in the well' a to mingle with the liquid in the well.

A process or method of raising liquid `from a well on the air-liftfprinciple, which comprises admit-ting and shutting` oil vthe airlift gas according to variations of the liquid level in the well, and thereby always main- `taining in the well a liquid level ,above the point of escape of gas to mingle with the C3 `liquid in the well.

5 fApparatus of the character described comprising the combination with an oil Well and means for introducing gas under pressure to mingle with the oil and thereby raise it 'on. the air-lift principle, of means con- `70 trolled by the liquid level in the well for admitting the gas as aforesaid and cutting it oil, .and thus always'maintaining a liquid level. abovethe point of escape of gas .to mingle with the oil'.

. f6. Apparatus of the characterdescribed comprising an inner oil well tube, valve means for controlling passage therethrough, means also controlled by said valve means for introducing gas under pressure to mingle 'S0 with the oil andv thereby raise it on the airlift principle, and Vmeans controlled by the liquid level in the well for opening and closing said valve means and thus always maintaining a liquid level Vabove the point of85 escape ofjgas to mingle with .the oil.`

7. Apparatus of the character described Vcomprising an inner oil well tube for supplying. gas under pressure to mingle with the oil and thereby raise it on the air-lift prin- 90 ciple, valve means controlling the supply oliv gas, and means controlled by the Vliquid level in the well for opening and closing said valve means and thus always maintaining a liquid level above the point of `escape of gas to 95 mingle with the oil.

8. Apparatus ofthe character Vdescribed comprising an oil well conduit, valve vmeans controlling flow throughv said conduit, and meanscontrolled by the liquid in the well for 11.00 exerting on said valve. means opening and closing :torce 'substantially exceeding that 'due to liquid displacement of moving parts operatively associated with the valve, and thus positively moving the valve according-L-1 to the liquid level in the well, and always maintaining the liquid level above the highest point of. entry of liquid into said conduit. 9. .Apparatus of the character described comprising an oil well conduit, valve means"- controlling iiow through said conduit, and means vfor automatically closing and opening said valve means aifected by the liquid level in the well witha valve-opening force 11,. proportionalA to the height of the liquid abovei o la level higher than the highest point of entry of liquid into said conduit, however 'great such height of the liquid above such level, and thus maintaining in the well a minimum li `uid level above such point of entry.

liquid level above the point of escape of gas "sure therein, for opening'and closing said valve lmeans and thus always maintaining in the well aliquid level above the highest point of entry of liquid into said conduit.

11. Apparatus of the character' described comprising an oil well conduit, valve means controlling flow through said conduit, and a pressure-responsive device for opening and closing said valve substantially unaffected by gas pressure,but exposed on its one side to the hydrostatic pressure of the liquid in the Well and on its other side to a hydrostatic pressure always suflicient to close the valve with the liquid level in the well above its highest point of entry into said conduit.

12. Apparatus of the character described comprising an oil well conduit, valve means controlling flow through said conduit, a chamber with a pressure-responsive movable wall substantially unaffected by gas pressure, but exposed to the hydrostatic pressure of the liquid in the well and operatively connected to open the valve when collapsed by such pressure, and an open stand-pipe connected to said chamber and extending to a height in the well aiiording suiicient hydrostatic pressure to expand said wall and close said valve with the liquid level in the well above the highest point of entry of liquid into said conduit.

13. Apparatus of the character described comprising an oil well conduit, valve means.

controllingflow through said conduit, means controlled by the liquid in the well, regardless of gas pressure, for exerting on said valve means opening and closing force substantially exceeding that due to liquid displacement of moving parts operatively associated with the valve, and trigger means for holding said valve definitely open or shut until said trigger means is overcome by substantial change in the relative opening and closing forces.

14. Apparatus of the character described comprising an oil well conduit, valve means controlling flow through said conduit, means` for automatically closing and opening said valve means responsive to the liquid level in the well, and affected thereby with 'a-valveopening force proportional to the height of the liquid above a level higher than the highest point of entry of liquid into said conduit, however great such height of the liquid above such level, thus maintaining in the well a minimum liquid level above such point of entry, and trigger means for holding said valve denitely shut until said trigger means is overcome by substantial rise of the liquid level, and vice-versa.

15. Apparatus of the character described comprising an oil well conduit, valve means controlling flow through said conduit, and liquid-level-responsive means in said conduit responsive to the liquid level in the well, even with the conduit full of liquid to the exclusion of gas, for opening and closing said valve means and thus maintaining in the well a liquid level above the highest point'of entry of liquid into said conduit. Y

16. Apparatus of the character described anchor for preventing entry of'gas thereinto,V

valve means controlling flow through said conduit, and means responsive to the liquid level in the wellV for opening and closingV said valve means and thus maintainingin the well a liquid level above the highest point of entry of liquid into said conduit. Y

18. Apparatus of the character described comprisingan oil wellconduit with a gas anchor for preventing entry of gas thereinto, valve means controlling flow through said conduit, and means insaid -conduit responsive, notwithstanding the exclusion of gas therefrom, to the liquid level in the well, for opening andl closing said valve means and thus Vmaintaining 'in the well a liquid level above the highest point of entry of liquid into said conduit.

19. Apparatus of the character described comprising an oil well conduit with a gas anchor for preventing entry of gas thereinto,

valvermeans controllingi'iovv through said,l

-this 22d Iday of April, 1932.

SAMUEL WILLIAM TRAYLOR, JR. Y

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