US2356423A - Bottom hole intermitter - Google Patents

Description

Aug. 22, 1944. c. M. O'LEARY I 5 BOTTOM HOLE INIERMITTER Filed Feb. '1, 1942 2 Sheets-Sheet 1' V IN YENTOR (/2 41 696 flZ OZ 641:9,

U BY 35 a0.

\ ATTORNEY Patented Aug. 22, 1944 UNITED STATES PATENT OFFICE BOTTOM HOLE INTERMITTER Charles M. OLeary, Houston, Tex. Application February 7, 1942, Serial No. 429,939

Claims. The present invention relates generally to a method and means for causing outflow of oil from oil wells of small productive index, and is more particularly suitable for use in wells where, in the interest of steady maximum flow of oil from the producing formation, it i of primary importance to not only eliminate any back pressure on the formation'but to be able to create a low pressure 'area adjacent to the formation, andto keep the fluid level down.

There are many wells capable of producing oil steadily .in relatively small quantities providing that the oil is removed as it accumulates in the bottom of the holei In a great many instances the oil'flows from the producing formation either without gas pressure or with so little gas as not to constitute a practically useable factor in the upflow of the oil to discharge. The lack of gas in such instances means a condition wherein it is extremely important that no back pressure be created against the formation which might interfere with the free'flow of oil therefrom. Also in many instances the creation of a low pressure area adjacent to the formation is of material help 7 in maintaining a steady flow of oil.

The problem of economically causing upflow and discharge of oil from wells of the above type is generally considered to be answered by the use of an intermitter, since the first cost and upkeep of-a rod pump' with a surface pumping unit is,

prohibitive. Various types of intermitters may be used with good results provided there is a high liquid level in the well and fluid-actuated plunger pumps may also be economically employed, but in deep wells of the small productive character set forth, and particularly those having a low liquid level therein, both intermitters and fluidactuated pumps have been found lacking. The intermitters known at the present time fail because the well liquid flows into the same at a rate controlled by well pressure which thus makes it dimcult to accumulate uniform proper heads of oil; because of slow filling operation due to the low levels of liquid, and because of the resulting waste of gas pressure. The fluid-actuated plunger pumps fail mainly because of the great pressure required to lift a long solid column of oil to the surface.

It is, for the above reasons, the primary object of the present invention to provide a method and apparatus which combines the advantages, and eliminates the disadvantages, of both of the above systems, and is economically useable in deep wells of low productivity index and low liquid level without waste of gas pressure; without danger of retarding free flow of oil from the formation, and without requiring high operating pressures. v

It is a further, purpose to provide a method for causing outflow from deep wells of low productivity, and low formation pressure, and especially those having normally a low level of liquid therein, which includes positively and intermittently forming, under fluid pressure from the surface,

' by fluid pressure, cause upflow of each head when it reaches a predetermined economically intermitting weight, in a manner permitting immediate resumption of measured accumulation of the next head or slug following each outflow operation.

' The invention, for this purpose, proposes a method and apparatus which combine an intermitter and a pressure actuated pump so that the pump will lift oil onlyso far as is necessary to form a predetermined head or slug of oil within a filling chamber isolated from pressure communication with the oil producing formation, and the intermitting arrangement will automatically cause upflow of the accumulated head or slug of oil whenever it reaches a predetermined weight value.

It is a furtherobject to'provide such a method and apparatus whereby both the pumping means for thus forming the head or slug, and the intermitting means for discharging the accumulated head or slug, will be controlled by a single pressure or gas supply line wherein the gas maybe fed to the working parts under a constant pressure from the surface, and wherein provision is made for cessation of the pumping action during intermitting and for immediate resumption of pumping operation to form the succeeding head or slug.

The manner inwhich the method is carried out and the apparatus for so doin may be better understood and'more thoroughly appreciated in the course of the following detailed description thereof and by reference to the accompanying drawings, the latter forming a part of this specification and including several flgures illustrative of the invention, of which,

Figure 1 is a general side view, partly in elevation and partly in section, showing the manner in which the apparatus is installed in a well.

Figure, 2 is an enlarged detail vertical sectional view through the upperpo'rtion of the housing of the apparatus, showing the construction adjacent to the crossover.

' seen by a comparison latter openings placing in communication with casing ill from which a perforate liner lldepends within the production zone of a well in practice. An elongated, cylindrical to the present invention, lowered into the casing l 9, on production tubing l3, so that the lower portion of housing l2 may suitably depend within the liner I l, and the upper portion of the housing may be suitably packed oil, as by means of packing ll, within the lower portion of easing Ill to thus cut off the space within the casing above the packing, from the space within the liner H and also with respect to the producing formation.

The upper portion of housing l2 which, it will be noted is of substantially greater diameter than vthe tubing l3, includes, above the packing l4, a

crossover section I! around which there is shown a cylindrical filtering screen I6. This section l5, as shown in Figure 2, has a cylindrical wall [1, spaced from screen It, and upper and lowerend walls It and i9, enclosing a central chamber 29. Through the wall l1 are vertical outflow channels 2| which extend through the end walls I8 and I3 and open at their upper ends into the interior of housing l2 above and below the crossover.

The channels 2i are spaced apart in a series circumferentially of wall l1 and alternate with radial openings 22 of Figures 2 and 3, the the central chamber 29 the interior of the well casing above the packing ll. f a

Through a central opening in the lower end wall I! is fixed the upper end of a pressure flow tube 23, the upper end of which is open within the chamber 20. Through this flow tube there extends a much smaller macaroni tube 24, which extends through chamber 29 and has its upper end portion fixed through an opening centrally of the upper end wall i8 so that it opens into the production tubing 13. Facking glands 25 and 26 respectively in the end walls I! and 19 around macaroni tube 24 and pressure flow tube 23 serve to prevent leakage therearound. r

In order to better understand what follows, let it be understood that channels 2| provide for upflow of oil or well liquid only during the continuous lift of a slug of accumulated oil upwardly from the housing l2; flow tube 23:never receives liquid, and provides only for downfiow of fluid pressure or gas from chamber 29 of the crossover I to the intermitter valve and to the fluidactuatedpump, and macaroni tube 23 provides for upward exhaust of pressure into the production tube l3 above the crossover IE only during operation of the pump, when the space within said production tube is at low pressure.

Referring to Figure 4,.it will be seen that the lower end of pressure flow tube 23 enlarges for connection with the upper end of a combined intermitter and pump casing, and that said tube is directly connected to the upper end of a cylindrical valve block 21 constituting the upper secthrough said wall, as plainly the above described figures 7 and particularly to Figure 1, there is shown a well housing I2 is, according tion of this casing. To the lower end. of this valve block 21 is connected the upper end of a cylindrical barrel 28, from the lower endof which a substantially reduced plunger barrel 29 depends to the lowerend 30 of the housing l2.

The valve block 21 has an axially disposed tapering seat 3| at its upper end receiving the lower tapering end 32 of the macaroni The block 21 also has a small axial pressure exhaust channel 33 therethrough opening at its upper end into the macaroni tube 24 and opening at its lower ,end through the lower end of the block. In addition, block 21 has an enlarged upwardly opening bore 34 at one side of its axial channel 33, for a purpose which will presently appear, and is provided at its lower end with a reduced portion 35. To this portion 35 is connected the upper end of av piston cylinder 33, spaced from the wall of barrel 23 to form an annular pressure feed. channel 31. The lower end of cylinder 33 terminates short of the lower end of barrel 23 so that channel 31 is thus in open communication at its lower endwith the lower end of th piston chamber.

Within piston cylinder 36 isa verticallyslidable valved piston 33 on the upper end of a rod 33 which dependswithin the smaller plunger barrel 29 and carries at its lower end a plunger 43 slidable in said barrel 29. It will be understoodthat both piston 33 and plunger 40 will be provided with leak-proof rings, cups and the like.

The lower} end of plunger barrel 29 is tapered at to seat within a conformably tapering opening axially or the lower end 30 of housing l2. An intake or standing valve 42' seats. within the lower end of said barrel 29,, and an outlet valve 43 is providedtherein above the standing valve to control a side opening 44 which outlets into the filling chamber 45 thus formed within the housing i2.- An intake pipe 46 may depend from the lower end of barrel 29 below the lower end of the housing, to extend into the well liquid substantially below its normal level in the well, 7

however low that level may be.

-When the piston 33 is moved up-and down bypressure. against-its. lower and upp r surfaces in a manner tobe presently described, the. relatively smaller plunger 49 followssuch movements, and liquid is alternately drawn upwardly into the barrel around the standing valve 42, and'dlscharged from the barrel. around the outlet valve l3 and through outlet opening 44 into the filling chamber 35 to fill the latter in substantially measured quantities to a predetermined point above the valve block 21 for the formation of an economically dischargeable head or slug as we shall hereinafter see.

Referring to Figures 4 and 5, it, will be seen.

' that the valve block 21 has an angular pressure eflective area of the new channel 41 of substantial size whose upper end opens into the bore 34 to receive pressure feddownwardly therein from the pressure flow tube 23,.and whose lower end opens into the upper end of the feed channel 31. between piston cylinder 26 and barrel 23. In this way fluid pressure is fed into the lower portion of the piston chamber and is active against the relatively greater I piston 33 ascompared to plunger 40. ,I I

As best seen in Figure .7, the piston "has therethrough a valve bor e 49,. intermediatexthe ends of which is an annular internalv rib 49 forming a valve seat. ,A valve member 50, intermeseat upwardly against seat 49. The opposite ends tube 24..

cages '52 and. Upperandlower angular chan- 'nels 54am! '55, liave" their inner ends opening 'into' the bore 48 respectively above -and'below' valve seat 49, and have their outer ends opening,

respectively, throughthe' upper and' lower sur- .facesof thepiston V Withvalv'e 50 seated, .as in Figure 7, pressure fed into thelower end of the piston chamber,

actsagainst'the lower surface of the piston38 to move the same upwardly." During thisjmov ment any pressure above the piston is relieved by exhausting through the'exhaustchannel 33 and'exhaust or macaroni tube into the production" tubing l3 above the crossover I5, since the production tubing I3 is at low pressure during pump operation. With valve 50 open the pressure passes thro'ughfbore 48 and channels 54 and 55 and accumulatesabove the piston forlaction 1 against the preponderantly greater effective upper surface of the piston. This accumulation of pressure above the piston results from its upflow through the larger channels 55 and of thepiston substantially faster than it can possibly escape through the relatively smallexhaust channel 33. two surfaces of the piston is the diameter of piston rod 39, andit is to be noted that the effective area of valve bore 48 and channels 54 and 55' is substantially greater than the'area of .pressure exhaust channel -33 which forms an outlet forpressure from the chamber above the piston 88 whenthelatter moves upwardly.

- The upper and lower portions of valvestem 5| project movably throughthe inner ends of the The diflerence between the cages 52 and 53 and have end heads 58 and 51 opposed to the inner ends of plungers 58 and 59 whose function is to shift the valve stem' .5]

axially in the bore 48 upon contactwlth the valve block 21 and the bottom of barrel 28 when the piston approaches the upper and lower limits of its travel. s v v I The plungers 58 and 59 have outer heads 60 and are provided with inner coil springs 6| and 62 disposed thereai'ound and: normally projecting inwardly therebeyond. The stem 5| also has, near its lower end, an enlarged portion provided with lengthwise spaced annular grooves 58 and 54. Spring-pressed latch balls 85 are carried within the lower cage'f58 for movement into grooves 63 and 54respectively as the valve isshifted' to open'and closed positions.

' The foregoing piston valve thus has its parts relatively arranged sothat with the valve 50 closed as in Figure '-7, the piston will move upwardly in cylinder 36-until plunger 58 comes into contact with the end of the lowerreduced end portion of valve block 21. Plunger 58' will thus be'depressed until its) lower or inner end engages the head 58 of the valve stem and shifts the latter downwardly with the springs holding balls 85 within groove 64. During this movement the spring 5| is placed under compression so that immediately upon displacement'of the latch balls 65, said spring will shift the valve stem downwardly until the balls engage in the upper groove 83. This movement opens the valve 50 and permits fluid'pressure to pass through the 'valve bore for causing downward movement of the piston due to the accumulation of' pressureabove the piston. A similar operation takes place when the piston'reaches the lower limit of its travel and plunger 59 comes into contact with the bottom of the 'piston barrel 7 a force overcoming ment of the piston upwardly in its ,cylinden j best seenin Fig ure 6, the intermitter valve 1 bo're 34 communicates at its lower end through a reduced opening 68witha cavity 61 in the valve block 21. This cavity 81 opens exteriorly of the block into'the liquid space of the housing, and the shoulder at the upper end of, opening 86 forms a valve'seat 68'on which a valve 69 is normally seated by fluid pressure on its upper surface. Valve 69 is in sealed connection with the lower end of a bellows which-is less than that of the seat 68. The upper end of bellows I0 is in sealed connection with a head block H which is stationarily supportedin the upper portion of bore 34, as by means of a snap ring 12. --This block has openings 13, permitting fluid pressure'to feed downwardly into the bore 34, and is provided with a depending tubular supporting member 14 internally of the f latter is sealed under atmosbellows I0, which pheric pressure;

Pressurefed from the 'well casing in inwardly throughcrossover I5 and downwardly through pressureflow tube 23 into the bore 34 normally acts against the upper surface of intermitter valve 69 to close the same and hold the jsame closed until there is a force, created by the weight of that portion of theicolumn of wellfliquid' in the housing l2 above the level of the'valve, and acting,"against the lower surface of the valve I within its seat, which is sufl icientfto overcome or slug accumulated in the housing l2 above the intermitter valve definitely and precisely of a weight which may be economically raised by the available pressure. This is accomplished by the pumping of the oil into the filling chamber 45 in a positive manner which may be readily predetermined as totime and volume in accordance with the existing naturalilo'w of'oil from the'producing'zone', The main purpose is to accomplish the accumulation of a head'of oil which may be economically intermitted under available-pressure and never reaches the height of the crossover l5; which will always be of substantially the same volume, and which may be steadilydrawn from a low head'of liquid in thewell with ut regard to changing formation pressures. V

It is thus assured that each head or slug approaches a predetermined weight valueby meas-' ured quantities of liquid pumped into the filling chamber, thus assuring that all heads or slugs so-formed will be uniformly brought to just the weight value required to force the in termitter valve 69 upwardly from its seat 68. When unacting against the greater exposed lower surface of the valve holds the same upwardly and and cavity 61, into causing upfiowof the fluid head or slug above the level of cavity 61. vIn so doing, back pressure on'the body of liquid in the filling chamber l2 below the'level of cavity 61 prevents operation of the pumping means previously described.

During upfiow of the head or slugof oilunder the expanding gas pressure, there is a drop in pressure, known as a blow-down, and when this 10, the effective area of well conditions, that is, the.

passes through opening 68 l the filling chamber 45, for

ures-i and 7, occurs only during those periods,

in which, after blow down, the intermitter valve ly from the well casing l0, through crossover l and downwardly through pressure flow tube 23, is used solely for pump operation through bore andvalve block channel 411. During these pump operating periods the interior of production tube ll above the crossover ll of Figure 2, is at low pressure following a previous blow down, and there is never any appreciable quantity of oil above the upper end of exhaust tube It Any oil draining downwardly within production tube ll, during pump operation, continues downwardly through channels 2|, and joins the accumulating slug or head being formed in the housing l2.

'As previously describedpeach measured slug or head of oil is accumulated in the housing I! around the outside of tube 23, to a predetermined height, but never reaches the height of the crossover l5. When the intermitter valve 69 is opened by the weight of thehead of oil above the level of said valve, a slug of oil is forced upwardly from the housing l2, in a continuous movement through the crossover channels 2|, and up the production tubing l3 until there is a blow down. 'I'hereupon, the intermitter valve 88 closes and pump operation starts the accumulation of another head or slug of oil in the housing II, which will b similarly discharged when the intermitter valve again opens.

According to the presentmethod, theintermitter head of liquid may be positively accumulated-from a low head of well liquid in a manner which is not influenced by possible changing pressures in the well; which may be regulated,

by the pressure used, strictly in accordance with normal flow of liquid from the formation, and which will not tend to'create any change in the normal pressure, if any, existing in the well beyond its tendency to create a low pressure area adjacent to the producing formation. Further, the formation of the economically intermittable head of liquid is not left to chance according to the present method, nor does it depend in any sense upon a high level of liquid in the well or upon formationpressure as in the usual intermitter, but on the other hand assures accumulation of uniform heads of liquid, to be intermitted to the surface, by an arrangement which tends to create a low pressure area within the producing zone, and a means which steadily operates between intermitting periods to build up such heads of liquid without regard to the level of liquid in the well and entirely independent of any formation pressure or change thereof.

It will be understood that, since the accumulation of liquid in the filling chamber, is by means of a pumping operation, the flowable head is an accumulation of measured quantities of liquid, and that regulation of the pressure from the surface provides foraocumulation substantially in accordance with well production, to

- 69 is closed, and fluid pressure passing inwardthus avoid undesirable increase in the level of liquid in the well, as well as waste of gas pressure.

Having thus fully disclosed the present invention, what is claimed is:

l. A bottom hole intermitter including means forming outflow tubing, means adapted to be lowered into a well on said outflow tubing and positioned above the liquid level in the well, having a fllling chamber therein, a member within said chamber having channels for receiving pressure from the surface including a passage opening into said filling chamber, a suction pumping mechanism in said member actuated by pressure through said channels and positively raising well liquid into the fllling chamber whereby to gradually build up a head of liquid therein independent of well pressure, and create, by its suction, an area of reduced pressure adjacent the producing formation of the well, "and means actuated by weight of the head of liquid for admitting pressure from said member into the filling chamber for causing u'pflow of said head.

2. A bottom hole intermitter including means forming outflow tubing, means forming a fllling chamber adapted'to be lowered into a well on said outflow tubing, pressure-actuated suction pumping means for lifting well liquid frombelow the chamber into the same to positively, gradually build up a head of liquid therein of predetermined weight value independent of the level of liquidwithin the well and well pressure, and create, by itssuction, an area. of reduced pressure adjacent the producing formation of the well, means within the chamber receiving pressure from the surface for actuating said liquid lifting means and having a pressure outlet which opens into th filling chamber for pressure upflow of a head of liquid of predetermined weight value, and a pressure controlled valve in said outlet and arranged to be opened by the weight of liquid.

3. A bottom hole intermitter including means forming outflow tubing, means forming a filling chamber adapted to be lowered into a well on said outflow tubing,means in said chamber receiving pressure from the surface and having an outlet opening into the chamber, an intermitter valve normally pressure seated to close said outlet and exposedto the liquid in said chamber, to be opened by a head of liquid of predetermined weight value, and a pressure actuated suction pumping mechanism receiving its actuatingpressure from said pressure receiving means, having a suction pipe depending substantially below the chamber and having its discharge opening into the chamber, whereby to gradually and positively raise liquid into the chamber for building up a head of liquid from the well within the chamber independent of the level of liquid in the well and of the well pressure and create, by its suction, an area of reduced pressure adjacent the producing formation of the. well.

4. A bottom hole intermitter including means forming outflow tubing, means forming a filling chamber adapted to be lowered into a well on said outflow tubing, means in said chamber receiving pressure from the surface and having an outlet opening into the chamber, an intermitter valve normally seated by pressure from said means to close said outlet and exposed to the liquid in said chamber, to be opened by a head of liquid of predetermined weight value, and a pressure actuated pumping means receiving its actuating pressure from said pressure receiving plunger barrel below said piston chamber'and 20 2,356,428 I j V 5 means, having an intake opening exteriorly of having a valved outlet opening into the filling the chamber and having its dlscharge opening chamber, a suction pipe depending below the filling chamber; piston cylinder for actuating the piston, and a r In a bottom hole intermitter, outflow tubpressure flow passage opening therefrom into the ing, means forming a filling chamber for lowfilling chamber and having therein a valve seat,

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