US2812723A - Jet pump for oil wells - Google Patents

Description

Nov. 12, 1957 y c. J. coBERLY 2,812,723

JET PUMP FOR OIL WELLS Filed July 19, 1954 2 sheets-sheet 1 Nov. 12, 1957 c. J. coal-:RLY 2,812,723

JET PUMP FOR OIL WELLS Filed July 19, 1954 2 Sheets-Sheet 2 rf/? wv.. j-7"`/ LIMA UWE/Veg J 605.94m/

United States Patent y O i JET PUMP FOR OIL WELLS Clarence J. Coberly, San

Kobe,`Inc., California Marino, Calif., assignor to Huntington Park, Calif., a corporation of The present invention relates in general to jet pumping and, more particularly, to a novel jet pumping apparatus and method for oil wells. During the productive life of an oil well which flows initially, there is a period of time after the well stops flowing during which only a slight boost is required either to lift the Well fluid to the surface, or to cause the well to start 4flowing again, since the fluid level in the well is quite close to the surface at this stage. Where a supply of gas is available, it is conventional practice, during this stage, to use a gas lift to maintain production. In many weils the period during which a gas lift is effective is relatively short, and when the formation pressure drops to a value equal to the gas lift pressure no oil can enter the Well and pumping equipment must be installed in the well which does not impose a back pressure on the formation. Gas lifts are inherently inefficient, but may be economical when most of the gas required is produced by the well with the oil. Production of the well in this manner becomes excessively expensive in many instances, particularly since expensive gas compressing equipment is required and the power required is high if all or a large part of the gas must be supplied by the compressor. Furthermore, this equipment has no utility after the gas lift period of the wells life is ended.

Attempts have been made to avoid the foregoing difficulties of gas lift production during the stage in the life of the well in question by setting a jet pump in the well to obtain the necessary boost, the operating fluid preferably being crude oil. However, such attempts have met with no commercial success, first, because of the inherent ineciency of jet pumps, and, second, because of the fact that such pumps operate at their relatively low maximum etliciency only over a very small range of head and cae pacity. If operated outside of this range for which they are designed their eiciency falls off very rapidly. This applies both above and below the uid head for which they are designed. Since, in oil well pumping, the pumping head uctuates widely during the life of the well, and and particularly during the period after the well stops owing, jet pumps set in the well have never met with any commercial success because of the expense involved in changing pumps to meet such changing conditions, or in changing the jet means in the pump, as the fluid head to be pumped against changes, which has been done only by pulling and reinstalling the pump, which is an expensive operation, as is well known in the art.

The present invention provides a way of jet pumping an oil Well which is economically feasible and which thus avoids the foregoing disadvantages of gas lift production and of jet pumping as heretofore practiced, the provision of such a way of `jet pumping an oil well being the primary object of the invention.

More particularly, the primary object of the invention is to provide a jet pumping method and apparatus which involve the use of a jet pump of the so-called free type, a pump of this type being capable of being lowered into and removed from a well Without disturbing the associ- 2,812,723 Patented Nov. 12, 1957 ated tubing system, n contrast to a pump of the so-called set type which requires removal and r'einstallation of its associated tubing system each time it is pulled and reinstalled, an important object of the invention thus being to provide a jet pump of the free type. The free jet pump of the invention may be installed in and removed from the'well in various wayssuch as by means of a wire line, or hydraulically, the latter being considered herein for convenience. With hydraulic installation and removal of the free jet pump of the invention, the pump is installed by lowering it through a tubing into an operating position at the lower end of such tubing, the pump either being permitted to drop through the tubing into its operating position, or being hydraulically displaced down such tubing into its operating position. In hydraulically removing the free jet pump of the invention, the flow of operating Huid through the system is reversed and the pump is hydraulically displaced upwardly through the tubing in which it is disposed. The pump of the invention may be disposed either in the supply tubing through which the pump is supplied with operating liuid under pressure, or in the production tubing through which the production iluid from the well and the spent operating iluid are conveyed to the surface, the former being con` sidered herein for convenience. p

As will be readily apparent, the free jet pump of the invention may be removed from and installed in the well in a matter of minutes and at very little expense. Consequently, it is economically feasible to remove `the pump of the invention frequently, as the uid level in the well drops, for the purpose of substituting for the jet means previously therein a diiferent jet means capable of causing the pump to operate more efficiently at the new fluid head to be pumped against. For example, in jet pumping an 8000 foot well, the present invention makes it perfectly feasible economically to change the jet means several times as the fluid level in the Well drops from near the surface to the 8000 foot level so that the pump of the invention is always operating at, or near, the maximum efficiency attainable therewith. Thus, substituting jet means as the iluid level in the well drops is perfectly feasible, whereas this is out of the question with a conventonal jet pump of the set type.

It will be understood that while I have referred to changing jet means in the free jet pump of the invention, changing theentire pump is regarded as being equivalent thereto and, consequently, when I speak hereinafter and in the claims of changing jet means in a particular pump,A I intend to include, by such terminology, changing the entire pump as well.

Another important feature of the present invention is that, when the fluid level in the well has dropped to such a point that jet pumping of the well in accordance with the present invention is no longer practical, all the pro. ducer of the well nee-ds do is remove the free jet pump of the invention from the well and substitute a conven-V tional free pump of the reciprocating type, this being accomplished with no changes whatsoever in' the tubing system, or associated equipment, which arecapable of operating either with the free jet pump of theinvention, or with a conventional free Another object is to provide a jet pump which includes` pump of the reciprocatingV type. Thus, the only expense to the producer is the ini# a barrel, a fitting threadedly connected to one end ofn the barrel, and-'a' jet assembly or jet rneans arried by such Vfitting so that the jet means may be removed from the barrel by merely unscrewing the fitting from the barrel. A related object is to provide another fitting carried by the barrel with which the jet means is telescopi'cally enL gageable so that such other fitting supports the j et `Vmeans without, however, interfering with removal of the jet means by merely unscrewing from the barrel the first fitting mentioned. Y l

Another object `of the invention is to provide a jet pump wherein the jet or jets produced by the jet means are di rected downwardly. e i ,t I Another object is to provide a jet pump having a check valve for preventing reverse flow `into the supply tubing, such check valve being located either in an intake passage means for supplying operating fluid under pressure to the jet means, or in anvoutlet passage means for conveying production fluid and spent operating fluid from theA jet means to an outlet leading to the production tubing of the tubing systemi Y Another object is to providel a jet pump having, in addition tothe aforementioned check valve, a standing valve in an inlet passage means for conveying fluid from the wellto the jet means. n

The foregoing objects, advantages and features of the present invention, together with various other objects, advantages and features thereof which willA become apparent, may be attained with the exemplary embodiments of the invention illustrated in the accompanying drawings and described in detail hereinafter. Referring to the draw# ings:

Fig. l is a utility view in vertical section illustrating the invention installed in a well;

Figs. 2 and 3 are enlarged, fragmentary vertical sectional views of the free jet pump of the invention and are'- taken along the arrowed lines 2 2 and 3 3 of Fig. l of the drawings, Fig. 3 being a downward continuation of Fig. 2;

Fig. 4 is an enlarged, fragmentary vertical sectional View similar to a portion of Fig. 2, but illustrating another form of jet means for the free jet pump of the invention;-

Fig. 5 is an enlarged, transverse sectional view taken along the arrowed line 5--5 of Fig. 2; a'nd Figs. 6 and 7 are enlarged, transverse sectional views taken along the arrowed lines 6-6y and 7-7,- respectively, of Fig. 3 of the drawings.

Referring first to Fig. l of the drawings; illustrated therein is an oil well casing 10 which isperforatedv adjacent its lower end toA admit oil andy other fluids, hereinafter collectively termed the well fluidi The casing 10" isprovided at its upper end with a casing head 12` which supports supply and production tubings 1'4 andV 16; the former being adapted to convey an operating fluid, such as clean crude oil, under pressure downwardlyinto the well and the latter being adapted. to convey upwardly to the -surface a miXtureof spent operatingV fluid andy pumped well fluid,` also referred to herein as production; fluid. The supply and production tubings 14' and 16 are' connected at their lower ends to a foot member 18, the latter having therein a'passage or passage means 2'0 which interconnects the supply and production tubings in liuid communication. Disposed below the passage means `is an inlet member 22 seated on a seat 24 carried bythe foot memberthe inlet member 22 being provided therein with acheckfvalve, not shown, for preventing reverse flow into the well while permitting flow through the inlet member from the well. Thev inlet member 22 is aligned with the supply tubing 14k in the particular construction illustrated and serves as aaseat for a fluid operated, free pump`26 of tlie.: jet type, the provision of such a pump'being one of the'fobjects of. the invention. The pump` 26- is'=` provided withzan-intake-28, Fig. 2*, `for operatingfuid?under'presy sure from the supply tubing 14, the intake 28 communicatingiw'ith: the interior of thev supply` tubing?7 througha nose assembly 30 connected to the upper end of the pump, this nose assembly having at its upper end a head 32 for engagement with a pump catching means, not shown, when the pump 26 is hydraulically moved upwardly in the supply tubing 14 to the surface as hereinafter described. The pump 26 is also provided, adjacent its lower end, with an inlet 34, Fig. 3, through which the pump 26 receives fluid from the well by way of the inlet member 22 when the pump is seated thereon in its operating posifion. The pump 26 is also provided with an outlet 36, Figs. l and 3, between the intake 28 and the inlet 34, the outlet being adapted to discharge production fluid and spent operating fluid into the interior of the supply tubing 14, from which such fluids flow into the production tubing 16 by way of the interconnecting passage means 20 in the foot member 18. The pump 26 carries a sealing means 3S, Vsuch as an O-ring, which is engageable with a sealing collar 40 interposed in the supplyV tubing 14, the sealing means 38 being located between the intake 28 and the outlet 36 to separate the two. As will be apparent, the outlet 36 is separated from the inlet 34 by virtue of the fact that the pump 26 is seated on the inlet member 22 when in its operating position.

The supply and production tubings 14 and 16 are coni nected at their upper ends to a valve head 42 having therein a valve means, not shown, controlled by a handle 44 for diverting operating uid under pressure, supplied to the valve head through a line 46 by a pump 48, into either the supply tubing 14 or the production tubing 16. Normally, when the pump 26 is in operation, the handle 44 is so positioned that the valve means in the valve head 42 delivers the operating fluid under pressurek into` the supply tubing 14 to operate the pumpv 26 in a' manner hereinafter described. When it is desired to remove the pump 26 from the well, the handle 44 is moved to cause the valve means in the valve head 42 to deliver the oper; ating fiuid under pressure into the production tubing 16'; from which it passes to the underside of the pump' 26, by way of the interconnecting passage means 20, to hydraulically displace the pump 26 upwardly throughthe supply tubing 14 tothe surface. In installing the' pump 26, it is either merely dropped through the supply tubing 1'4 into itsl operating position wherein it is' seated on the inlet member 22, fluid in the supply' tubing offeringsufficient resistance to cause the pump' to drop' slowly, or the pump is' hydraulically displaced downwardly into its operating position'by a downward flow of operating fluid' under pressure through the' supplyv tubing 14 acting? on; the upper endV of the pump.Y Thus', it' willv begs'een that' the pump 26` can be installed in and removed from the wellreaclily in a minimum of timey and without disturb"-` ing the tubingsystem in any way, which is' an important feature of the" invention. j

Considering. the4 free jet'- pump 26 of the invention" in: more deta-iL'it includes an outer tubular barrel 50 com? prising'two seetior'is` 52T- and 54, an' intake fitting-56 being threaded into the upper end of the-upper section 52 ofthe barrel 50; an' outlet fitting S8 being threaded into".

the lower end of the upper section 52 of the barrell` and into the upper end of the lower section 54: of theV barrel to interconnect the two" sections, and an inlet*f fitting 60 being threaded into the lower end of the lowerV section 54 of the barrel. The intake 28 is formed inthe intake fitting 56 and comprisesV a' central bore therein the outlet 36 being formed in the outlet fitting 5,8 and, as best shown in Fig. 6, comprising a plurality of radial ports 62 communicating with a` central bore 64f in? the* outlet fitting. The inlet 34 is formed'in the'inlet fitting'f 60 and comprises a central bore therein.

The intake fitting 56 is provided at its upper end with an externallyy threaded tubular boss 66 onto which the nose" assembly 30 is` threaded, operating fluidunderpresll asia/:fas

which is threaded the upper end of a jet assembly or jet means 70 so that the jet means is carried by the intake fitting. The lower end of the jet means 70 is telescoped over a tubular projection 72 on the outlet fitting 5S through which the bore 64 extends, a fluid tight seal between the lower end of the jet means 70and the tubular projection '72 being provided by an O-ring 74. With this construction, it will be apparent that the jet means 70 may be removed from the barrel t) for substitution of another jet means, or for other purposes, merely by unscrewing the intake fitting S6 from the barrel, which is an important feature of the invention.

IThe jet means 7d is merely typical of one of a set of jet means which may be used in the pu-mp 26 of the invention, each jet means in the set being designed to pump against a different fluid head. The particular jet means 7f3 illustrated includes, at its upper end, a tubular fitting 76 which is threaded into the counterbore 63 in the intake fitting 56. Threaded onto the lower end of the fitting 76 is a sleeve '73 into the lower end of which is threaded a tube @il counterbored at its lower end to fit over the tubular projection 72 on the outlet fitting 58. Seated against the lower end of the fitting 76 is a jet or orifice element 32, this element being spaced from a second jet or orifice element 84 Within the sleeve 7S by a tubular spacer 86. Another tubular spacer 83 separates the jet element 84 from the upper part 9i) of a two-part diffuser 92, the lower part of this diffuser being identified by the numeral 94 and being seated against the upper end of the tube 80. Thus, it will be apparent that, by threading the fitting 76 and the tube 80 into the sleeve 78, the elements 82, 84, 86, 88, 90 and 94 are all held in assembled relation within the sleeve 78. g

The jet means 7i? is supplied with operating fluid under pressure from the intake 28 through an intake passage means 96 which includes the counterbore 63 in the intake fitting 56 and the interior of the tubular fitting 76. Well fluid to be pumped is admitted to the jet means 70 from the inlet 3d in the inlet fitting 60 by an inlet passage means 98 which includes the interiors of threadedly connected tubular fitting members 100 and 102 forming the inlet fitting 60, the interior of the lower section 54 of the barrel 50, passages 104, Figs. 3 and 6, through the outlet fitting S3, the annular space between the upper section 52 of the barrel 5t? and the sleeve 78 of the jet means 7d, and ports 166 and 108 respectively communieating with the interior of the jet means 7i) downstream from the jet elements S2 and 84. The ports 106 extend through the sleeve 78 and the spacer 86 and the ports 108 extend through the sleeve 7S and the spacer 88. The mixture of production fluid and spent operating fluid discharged by the jet means 76 flows to the outlet 36 by way of an outlet passage means 1l() which includes the interior of the tube 8l) and the bore 64 in the outlet fitting 5S.

It will be recognized that the jet means 70 is a twostage one, a single-stage jet means designed for different pumping conditions, i. e., designed for pumping against a different fluid head being illustrated in Fig. 4 of the drawings and being identified by the numeral 112. Most of the parts of the jet means 112 are the same as the jet means 70 so that identical reference numerals are applied Wherever applicable. The jet element 82 has been replaced by a jet element 114, the same spacer 86 being disposed below the jet element 114. In the jet means 112, the spacer 86 engages the upper end of the diffuser 92, which closes the ports 108 through the sleeve 78,. The new location of the diffuser 92 is maintained by a tubular spacer 116 which engages the tube 30. Thus, by a slight rearrangement of parts, the two-stage jet means 70 is converted to the single-stage jet means 112. Various other jet means for still other pumping conditions may also be provided to make up a complete set of jet means for the pump 26 for a particular set of operating conditions therefor.

The inlet fitting 60 carries a standing valve 118 for preventing reverse flow into the well, the standing valve 118 including a ball valve 120 which is vertically movable in a bore 122 in the fitting member 102, this bore communicating with passages 124, Figs. 3 and 7, which lead to the interior of the lower section S4 of the barrel 50 and which form part of the aforementioned inlet passage means 98. The ball valve 120 is adapted to engage an annular seat 126 which is clamped between the fitting members and 102 making up the inlet fitting 60.

The pump 26 of the invention also includes a check valve 130 for preventing reverse flow into the supply tubing 14. The check valve 130 may be located either in the intake passage means 96 leading to the jet means, or in the outlet passage means leading from the jet means, the check valve being shown as located in the intake passage means 96 and preferably being located therein so that it will operate in the operating fluid, instead of in the mixture of production fluid and spent operating fluid, the operating fluid being clean, whereas the production fluid may contain contaminants, such as abrasive particles.

The check valve 130 is shown as disposed. in the counterbore` 68 in the intake fitting 56 and as being retained therein by being clamped between a shoulder formed at the junction of the counterbore 68 with the intake bore 28 and the fitting 76 at the upper end of the jet means 70. The check valve 130 includes a seat 132 for a ball valve 134 which is disposed in a counterbore 136 in a member 138, the ball valvebeing carried by an element which is reciprocable in a bore 142 in the member 138 and which is biased toward the seat 132 by a compression spring 144. The` member 138 is provided with one or more passages 146 therethrough for the operating fluid under pressure.

It is thought that the operation of the free jet pump 26 of the invention will be apparent, the jet means 70 and 112 operating in conventional fashion. Considering the over-all operation of the invention, it will be apparent that when the fluid level in the well changes sufficiently to make a jet means other than the jet means with which the pump 26 is equipped more efficient, it is a very simple matter to run the pump 26 to the surface for a jet means substitution, the jet means in the pump being readily removable for replacement by another jet means. This process is repeated each time the pumping conditions change sufliciently to make another jet means more efficient than the one with which the pump 26 is equipped at the moment. Eventually, when the fluid level in the well decreases to such an extent that the jet pump 26 of the invention no longer attains a satisfactory degree of pumping effectiveness, it is then a simple matter to remove the pump 26 of 'the invention from the well and substitute therefor a conventional fluid operated, free pump of the reciprocating type, no changes whatsoever in the installation being required to accomplish this. Thus, it is merely necessary for the producer to substitute a reciprocating-type free pump for the jettype free pump of the invention and go on pumping, the changeover being accomplished in a matter of minutes.

lt will be understood that various changes, modifications and substitutions may be incorporated in the particular embodiments of the invention herein disclosed without departing from the spirit of the invention as defined by the claims which follow.

I claim as my invention:

1. In a fluid-operated free-pump system for a Well, the combination of: a supply tubing set in the well and adapted to convey operating fluid under pressure downwardly into the well from the surface; a production tubing set in the Well and adapted to convey production fluid produced by the well and spent operating fluid upwardly in the well to the surface; means interconnecting the lower ends of said tubings in fluid communication with eachl other and witntheweii; anda free pump movb lin one df `said. tubirigs between the surface and an pperating positon at the lower end of said one tubing, said pump havingV an intake for operating fluid under pressure, an inlet for fluid from the well and an outlet for production u'id and spent operating fluid which communicate with said supply tubing, the well and said production tubing, respectively, when said pump is in said operating position, said pump' being provided therein with noizlle means communicating with said intake for forming within the interior of said pump a jet of the operating`, fluid ,Y said inletcominunicating with the interioi of said pump downstream frm said nozzle means.

The system Adefined in claim 1 wherein said one tubing issaid supply tubing. l 3.` A Vfluid-operated free-pump system according to claim 1 including a seat for said pump at the lower end o fsa'idone tubing, and including passage means communicating between said onetubing above said seat and the other of said, tubings s'o that fluid flowing downwardly I through said other tubing will move said pump upwardly through said one tubing to the surface. Y t

4. A nuid-operated free-pump system according to claim l includingl means for preventing direct fluid flow among saidqtubi'ngs and the well when said pump is in sain operating pesition.

5. fi'e'e fluid-operated well pump for use in a fiuid operated free-pump system which includes two tubings set in a' well, said pump being of a Vsize to pass through one of Vsaid tubings to an operating positionat the lower end thereof and being operable by operating fiuid under pressure supplied thereto through one of saidtubingsto discharge a mixture of production fluid producedbby the well andspent operating fluid into the otherofsaid tubings, said pump having therein nozzle means for producing within the interior thereof a jet of the operatingpfluid, and haying an inlet for the production fluid produced by the well which communicateswiththe interior of said pump' downstream frornsaid nozzle means.

6. A fluid-'operated wellpiimp of the jet type having upper aridV lower ends andoijiented generally vertically in awell with saidupper end thereofuppermost when said pump is in its operatingposition in the well, Vsaid pump having anpintake f oi operating fiuid underpressure an' inlet for fluid frornthe well andan outlet for ,huidprodiiced by the `well and spent operating fluid, ysaid pump having jet means communicating with said intake and said inlet and discharginginto said outlet, said jet means ,being directed downwardly whensaid pump is in its operating position in the well, sad `intakejbeing,` at said upper endV of said p ump;` said inlet being atA said lower end of said pump, and4 outlet being between said ends of said pump, said pump havingpassage means connecting said intake and said inletJto said jet means and connecting said' jet means to said outlet. p

j 7. A uidoperated well pump of` the jet type having upper and lower ends, having an intake for operating fluid under pressure adjacent said upperend thereof, having an inletfor fluid from the well adjacent said lower end thereof, and having any outlet for fluid produced by the wellv and spent operating fluid intermediate said ends thereof, said pump having downwardly directed jetmeans and haVirigiiiletY passage means connecting said inlet to said j et means, intake passage means connecting said'intake to said jet means and outletpassage means connecting said jet means to said outlet, saidpump includingajcheck valyerin one of the last ltwo passage means mentioned.V

8 A` pump as" defined in claim 7 in which said check valve isinsaid ke'p'assa'ge means.

9. A fluid-operated well pump of the jet type having upper and lower ends., having an intake for operating fluid under pressure adjacent s'a'id upper end thereof, having an inlet for uid from the well adjacent said lower end thereof, and having an outlet for fluid produced by the well and spent operating fluid intermediate said ends thereof, said pump having downwardly directed jet means and having inlet passage means connecting said inlet to said jet means, intake passage means connecting said intake to said jet means and Aoutlet passage means connecting said jet means to said outlet, said pump including a standing valve in said inlet passage means and a check valve in one of the other two passage means recited.

l0. pump as defined in claim 9 in which said check valve is in said intake passage means.

1l. A huid-operated well pump of the jet type, including: a barrel; a first fitting threadedly connected to one end of said barrel; jet means in said barrel and carried by said first fitting, said rst fitting providing for removal of said jet means from said barrel by merely unscrewing said first fitting from said barrel; and a second fitting .carried by said barrel, said jet means being disposed in said barrel between said fittings and being telescopically connected to said second fitting so that said second tting supports said jet means while still providingfor removal of said jet means from said barrel by merely unscrewing said first fitting from said barrel.

j 12. A Huid-operated well pump of the jet type, including: a barrel having upper and lower ends; an intake fitting threade'dly connected to the upper end of said barrel and providing an intake for operating fluid under pressure@ means providing an intake passage communicating with said intake; jet means in s aid barrel and carried by said intake fitting and communicating with said intake passage;

an inlet fitting connected to thelower end of said barrel and providing an inlet for uid from the well; means providing an inlet passage which .communicates with said inlet and with which said` jet means communicates; an outlet fitting carried byI said barrel between said intake and inlet fittings and providing an outlet; and means providing an outlet passage which communicates with said jet means and said outlet, said jet means being between said intake and outlet fittings and being telescopically connected to said outlet fitting so that said outlet fitting supports said jet means while providing for removal of said jet means from said barrel by merely unscrewing said intake fitting from said barrel.

13. A pump as defined in claim 12 including a standing valve in said inlet passage and carried by said inlet fitting and including a check` valve in said intake passage and carried by said intake fitting.

l`4. In a free fluidoperated well pump assembly, ythe' combination of: a fluid-operated well pump operableby' an operating fluid under pressure to pump a well fluid,

said pump having nozzle means therein for producing a jet o f 4 the operating, fluid within the interior thereof and havin an' inl'etifoi thefwell fluid which communicates with d'pur'np downstream from said nczl'e` m an Pur. packer nose assembly connected to said' upper end4 of said4 Pump References Cited in the file of this patent UNITED sTATEs PATENTS 1,782,310 Overstreet Q Nov. 1S, 2,004,337 Murphey .lune 1l, 1235 2,080,623" McMahon May 18.195,1 2,582,059 l os e an..8, 195,2 2,653,545 D einpsey Sept. 22, 125,3, 2,674,202 Kelley Api'. 6, 1954 pf having upper and lower ends; ,and a

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