US2642803A - Dual production zone pump - Google Patents

Description

June 23, 1953 c. A. MoRRls ErAL DUAL Paonuc'rxon zona Puur dA. MoRRls E'rA'i; I

DUAL PRODUCTION ZONE PUIIP June 23, 1953 2 Sheets-Sheet 2 Filed April 27, 1950 @M3U ma;

AVG ENT.

Patented June 23,y 1953A DUAL PRODUCTION ZONE PUMP Charles A. Morris and John D. Exner, Wichita Falls, Tex., assignors, by mesne assignments, to Standard Oil Development Company, Elizabeth, N. J., a. corporation of Delaware Application Aprilk27, 1950, Serial No. 158,368

The present invention relates to deep well pumps of the reciprocating type. More particularly the invention relates to an improved combination of elements forming a unitary pump capable of pumping fluids simultaneously from spaced, subsurface formations while maintaining the pumped fluids segregated from each other.

It is known to pump fluids, such as oil or water, from spaced producing formations either by employing a plurality of single zone pumps arranged in a plurality of different boreholes or by employing a unitary structure employing a plurality of pumps in av single borehole with each pump withdrawing fluid from a dilerent sub# surface formation. Ordinarily it is impractical to pump uid from more than two pay zones by means of a single unitary pump structure.

Deep-well, dual-zone pump structures of the prior art have suiered from the disadvantages of being constructed in such fashion that, if, after installation in a well, it becomes necessary to service the lower zone pump, the entire structure, including the production tubing string, must be withdrawn from the well; or the pump structure has included a complicated and expensive packing arrangement for isolating the internal operating zones of the pumps.

It is one object of the present invention to provide, in a unitary structure, an` improved deep-well pump adapted to pumpk fluids simultaneously from two, spaced subsurface formations without admixing the fluids pumped from the two formations.

It is another object of the present invention to provide a dual-zone pump structure so constructed and arranged that the traveling elements of both pumps may bewithdrawn fromv the well for servicing without disturbing the tubing string on which the pump structure is normally suspended inthe well.

It is a further object of the present invention to provide a simple and inexpensive means for sealing the internal operating zones between two reciprocating pumps aligned in a unitary, deepwell pump assembly.

Still other and further objects of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings in which:

Fig. 1 is an elevation View, partly in section, of the upper portion of one embodiment of a dual-zone pump assembly constructed in accordanceA with our invention, and showing an upper production zone pump;

Fig. 2 is an elevation View, partly in section, of

3v Claims. (C1. 10S-4) Atubing string I1.

'a next lower intermediate portion of the ernbodiment shown in Fig. 1 and showing a seal barrel and plunger in accordance with our invention for sealing the internal operating zones between pumps;

Fig. 3 is an elevation view, partly in section, of a still lower intermediate portion of the embodiment illustrated in Figs. l and 2, and. showing! a casing-tubing packer for sealing between two producing formations;

Fig. 4 is an elevation view, partly in section, of the lower portion of the embodiment Shown in Figs. 1, 2 and 3, and showing particularly a lower production zone pump; and

Fig. 5 is a cross-sectional. view taken along the line V-V of Fig. 1.

In the several Views, like numerals refer to like parts of the assembly.

In the drawing., the numeral. Il designates the walls of aborehole which penetrates subsurface earth formations includingtwo producing formations or zones, such as an upper' zone I2 (Figi) and a lower zonerv I3 (Fig. 4)`. In usual practice, the borehole will be cased by a'casing string I4 which is supported. at the well head (not shown) ra, stationary, production tubing string II which, `similar to casing I4, is supported in the well head in conventional manner.

In accordance with a preferred embodiment of vour invention, a tubular head member or sub I8,

provided with a central longitudinal passage I9, is screw-threadedly engaged to the lower end of The lower end of head member I8 has a substantially larger outside diameter than tubing string I1 and is threadedly secured to the upperend of a rst, or upper, tubular jacketY 20, which also is of larger diameter than tubing I'I. Jacket 20 is constructed of suflicient length to house an upper production zone pump which will be described more fully hereinafter,

Screw-threadedly engaged to the. lower end of jacket 20' is a first coupling member 2| which,

as will' become apparent from subsequent description, serves also as an anchor member for the upper zone pump. Depending from, and screw-threadedly engaged to, the lower end of member 2`I is va second, or intermediate ltubular seal barrel which will be subsequently described. At the lower end of jacket 22, a second coupling member or sub 23 is screw-threadedly engaged thereon. Coupling member 23 is provided with a central longitudinal passage 24 and, preferably, is tapered at its lower end to a smaller external diameter than jacket 22. Secured to the lower end of member 23, as by screw threads, is a third, or lower, tubular jacket 25 which -terminates in a conventional bottom-lock releasable pump hold-down device 26 provided with a longitudinal iiuid passage 21 such, for example, as the pump anchor shown and described in the Kelly et al. Patent, 2,298,567. Tubular jacket 25 is constructed at least of sufficient length to house a lower zone pump, which will be described hereinafter, and will preferably terminate adjacent or below lower producing formation I3. If desired, any suitable form of well screen or mud anchor may be secured to the lower end of pump anchor 2S. In the drawing, a perforated tubing nipple 28 has been shown to represent such a means for admitting lower zone fluid.

It will be understood that jackets 20, 22, and 25 may be constructed of convenient lengths of suitable diameter tubing coupled together at intermediate points, as needed, by conventional collars not specifically pointed out hereinabove. Although, for convenience in description, mernbers 20, 22 and 25 have been described as three different jackets, it will be apparent that these members are so joined together that they may also be considered as forming a single jacket assembly for a unitary structure. While the members 22, 23, and 25 form parts of a single jacket assembly, upon consideration it may be seen that these members, in combination with the pump anchor 26, also serve as means for supporting the lower pump at a selected distance below the upper pump. As may be seen from the drawing, all of these members are aligned along a common central axis.

Around the jacket structure, at a position between producing formations |2 and I3, and preferably within casing |4, there is disposed a conventional packer means 29, as shown in Figure 3. Although a cup-type casing-tubing packer has been illustrated in the drawing, it will be understood that packer means 29 may be any suitable packer adapted to seal between the jacket and the casing I4, or between the jacket and the walls of an uncased borehole intermediate between producing formations I2 and I3 to prevent intermixing of formation fluids external to the pump assembly.

Secured to pump anchor 26, as by means of pull tube 30 and collar 3|, is a lower tubular plunger 32 provided with suitable circumferential packing rings, or cups, 33 and a conventional standing valve means 34. Reciprocatably sliding over plunger 32 and packing means 33, is a lower pump traveling barrel provided at its upper end with a conventional traveling valve means 36 and open valve cage 31. Secured 'to the lower end of barrel 35 and concentrically around pull tube 30 is a sleeve or bushing 38, adapted to engage against collar 3l during an extreme upward pull transmitted to barrel 35 when it is desired to release hold-down means 26 from its anchored position and thereby remove plunger 32 from its normal operating position. Since the structure and the operation of a suitable pump anchor 25 is well known in the prior art, further description thereof is omitted herein.

From the foregoing description it may be seen that the working barrel 35 and its associated traveling valve structure 36, 31 form a cylindrical reciprocating element in the lower pump, while the plunger 32, with associated packing means 33 and standing valve means 34, form a cylindrical stationary element which co-operates with the reciprocating element to pump a fluid. It will be apparent to workers in the art, however, that by suitable rearrangement of the standing and traveling valves, the above-described pump may be inverted so that the working barrel is held stationary by anchor means 26, and the plunger 32 may be caused to reciprocate therein. The plunger will then be the cylindrical reciprocating element in the lower pump.

As may be seen from Fig. 4 of the drawing, an upward stroke of barrel 35 causes lower formation fiuid to be drawn through well screen or tubing nipple 28, fluid passage 21, the bore of pull tube 30, the bore of tubular plunger 32, and thence through standing valve means 34 into the interior of barrel 35. When barrel 35 is forced downward, valve means 34 closes, valve means 36 opens, and the fluid within barrel 35 is forced into the bore of tubular jacket 25 above valve 36.

In order to impart longitudinal reciprocating motion to barrel 35, a first sucker rod string 39, arranged substantially concentrically within jacket 25 and the central passage 24 of coupling member 23, is threadedly secured to cage 31 which, in turn, is suitably secured to barrel 35. The upper end of rod string 39 is threadedly secured to the lower end of a valveless blind plunger 40.

Plunger 4] is constructed with a slightly1 larger outside diameter than the outside diameter of traveling barrel 35, and is provided with suitable circumferential packing rings or cups 4|. Plunger 4I! and packing means 4| are arranged to reciprocate longitudinally in an elongated tubular seal barrel 42 and, in combination with the latter, to provide an effective, movable seal between the internal operating zones of the lower pump, described hereinabove, and an upper pump, to be described hereinafter.

Seal barrel 42, as may be seen from Figs. 1 and 2, is screw-threadedly secured in the lower portion of centralpassage 43 in coupling member 2|, and is seated, or otherwise suitably retained, in an enlarged upper portion of central passage 24 in coupling member 23. Adjacent to coupling member 23 and the lower end of seal barrel 42, the latter is provided with one or more iiuid ports 44 adapted to pass the pumped lower zone iiuid from the bore of jacket 25 and central passage 24 into a first annular passage 45 defined between the outer walls of seal barrel 42 and the inner walls of jacket 22. As may be seen from Figs. l and 2, annular passage 45 extends throughout the length of jacket 22 between coupling members 2| and 23.

Secured to the upper end of blind plunger 40, as by screw threads or other suitable means, is a second sucker rod string 46 which passes upwardly through central passage 43 in coupling member 2| and terminates in a yoke 41.

In the drawing of Fig. l, coupling member 2| has been shown in section taken along the section line I-I of Fig. 5. Similarly, in the drawing of Fig. 5, coupling member 2| has been shown as a section taken along the line V-V of Fig. l. As may be seen from these figures, coupling member 2| is provided with a plurality of bypass passages 48 extending longitudinally therethrough and providing communication between iirst annularpassage 45 andv a, second annular passage 49 dened. between the outer wal-1sV of a stationary upper pump working barrel 5I)v and the inner wal-ls. of jacket 26. The lower end of upper pump working barrel 5111 is" screw-threadedly Secured, Vand thereby anchored,v in. coupling member 2|` intheav upper endv of central passage'43, whilev the upper-endA of said barrel. is seatech4 or otherwise secured, inthe central. passage I9 of head member I6. One or more' iluid re-entry ports5l. areprovided adjacent the upper end of work-ing barrel 5B to provide means fori passing pumped lower zone flu-id. out of annular-passage 49 into passage I9 and thence into tubingstring I1.

The outer walls of' coupling member 2| are pierced by a plurality of upper zoney uid entry ports 52. which communicate,r through suitable screens 53- and upper pumpstanding valve.` means 54, with a plurality of ports 55 entering central passage 43. Thus, upper zone V fluidy. drawn through perforations I6 in casing stringk I4, enters ports 52., passesI through. screensl 53` and standing valves 54, and. enters central passage-'43 through ports 55.

Although, for convenience of description, the member 2J hasbeen termed a coupling member by virtue. of: its utilization tocouple jacketpump. When considered thus,- vthe threaded juncture between seal barrel'. 4,2. and;l member 2l provides. a means for sealing saidY seal barrel to said cylinder structure. I

Arranged' for longitudinal reciprocating move;- ment in working barrel 5llis ai movable upper pump plunger 56 provided with circumferential packing rings or cups; 51;. Blunger 56 istubular, thereby permitting passage.I ofy uidpgthrough, central. bore 5BV therein. At.: its lower'end'fplunger `56 is secured to yokeV 4l., as bylSuitable.l screw threads. Ports 59. are provided in. yoke. 4lv so that uid in the lower. part of working barret 5.0 mayv enter.v bore. 58 of. plungeri5'6r Arranged along bore58 orplunger anduit.- ably secured thereim isa traveling. valve means 60. Secured to the upper end. of plunger tfand above-,valve meansV 60,A is a, bushing' 6i which .com nects. theplunger to amovable tubingxstring: 62, Tubing 6,2 passes. upwardlyrr through passage [9. in head member I8., and, thencegsub'stantially con.- centrically within and through-.stationary tubing string II.

The upperv end of movabletubingHr string .6.2 passes through a conventional Stuffingbox' above the well head and may be connected; through a flexible connectionto a ilow line. Tubing string gitudinally, the` resulting reciprocating movement is imparted to pump plunger 5.6,v second sucker rod string 46, blind plunger-41),.iirstsuck,- er rod string. 3.9 andlower pump traveling barrel 35, simultaneously. 'IlxeseA elemente; taken as a 6 unit; 'formy ak common reciprocatingl lmember which.. is operatively connected vto each of. tw@ pum-ps.. In theoperation-of the. pump.- assembly of our invention.. lower zone fluid which has beenrforced intol the-.bore of lower jacket 25, ask has been hereinbefore described, is forced upward through central passage 2.4- in coupling member 23, through fluid ports 44 in` seal barrel 42., and into annular passage 45. Continued operation .of the pump assembly forces.. the iluid in. annular passage 45 upward through by-pass` passages 48 in. coupling member 2 I, then through they second annular passage 49, fluid re-entry ports 5iI in working barrel 50, and thence into stationary production tubing I.'I.. Because of the presence of. seal; barrel 42, blindL plunger 40. therein, upper pumpV working barrel 50, and upper pump plunger 56. lower zonev fluid cannot intermix `with uid drawn into the upper zone pump.

As may be seen from Fig. l, when plunger 56 isY movedupward, upper zone fluid enters through perforations I 6, entry ports 52, screens 53, standing valve means 5.4, ports 55, central passage 4.3 and. into the b ore of working barrel 50.. 'Thereafter, when plunger 56I is moved downward, valve means 54 closes, traveling valve means 60 opens and upper zone Iluid is forced upward through ports 59, central borev 58,. valve means 60. and thence into the bore of tubing 62.

From. an examination. of Figs. 1 and 2, it may be seen that the upper zone pump operates on the principle of differential displacement of the two plungers, 40 and 56, on opposite sides of a valved, fluid-entry port 55. The bore of'workingy barrel 50 must be greater than the bore of seal barrel 42 in order'to obtain fluid delivery from. the upper zone. pump. By lsuitable choice of the internal diameters of these barrels, the volumetric delivery of. the upper zone pump may be adjusted.

`In accordance with one objective of the device of our invention, thebore of tubing string II is. also constructed of greater diameter than the. outside-- diameter of upper pump plunger 56, thehoreof workingy barrel 50 vis of greater diameter than the outside diameter of blind plunger 40, and the bore. of central passage 43, seal barrel. 42, and central passage 24 are greater than the outside diameter of lower pump traveling barrely 35 so that, when it is desired to serv- 4ice either the upper zone pump traveling elements or thelower zonev pump, the movable tubingstring 62 may be pulled. upward for a greater distance. than the normal operatingk stroke'. Thereafter, tubing string 62 may be drawn upward out of the well. followed by the other elements includingplunger 56, sucker rods 46,l blind plunger 40,.sucker rods 35, traveling. barrel .35,

plunger 32., and the releasable portion ofv pump anchor 26..

It, may be Vseen that, by lemploying moving blind plunger 40 sealingly reciprocatable in iixed seal barrel 42, expensive and troublesome latching means,` for retaining inter-pump packing means in position is. eliminated and the lower zone. pump` may be. removed from the well; with.- out withdrawing the; tubing string I.'I andthe pump jacketsv depending therefrom.

As will be apparent the lengthstof tubingV H, jacket 20, jacket 22, jacket 25., sucker rod string 39, sucker rod string 46, and movabletubing string 62. may be varied to suit theparticular ydepths and spacingl of producing. formations I2 and"|3 lbeneath the surface ofthe earth. First coupling member 2l ordinarily will be installed above packer 29 and below the normal standing level of liquid derived from formation I2, while the lower zone pump, and especially the standing valve therein, will generally be installed below the normal standing level of liquid derived from formation I3.

Although our invention has been described with respect to a single embodiment thereof, it will be understood that modifications and changes may be made without departing from the scope of the appended claims. `It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described herein.

Having thus described our invention, what we claim as novel, and desire to secure by Letters Patent. is:

1. A dual zone pump assembly adapted to pump fluid simultaneously from lower and upper subsurface zones without intermixing the fluid from said zones comprising, in combination, a tubular head member, defining a central passage therethrough, adapted to be threadedly secured to the lower end or" a stationary tubing string within a suitably perforated casing string in a borehole; a first tubular jacket threadedly secured dependently from said head member; a first coupling member defining a central longitudinal passage and at least one longitudinal by-pass passage therethrough, and also defining an upper zone entry port arranged to provide ingress of fluid from said upper zone into said central passage, said coupling member threadedly joining the upper end of a second tubular jacket coliinearly to the lower end of said rst jacket; a

second coupling member, defining a central longitudinal passage therethrough, threadedly joining the upper end of a third tubular jacket collinearly to the lower end of said second jacket; means adjacent the lower end of said third jacket for admitting fluid from said lower Zone into the interior of said third jacket; a releasable lock hold-down means, provided with a longitudinal fluid passage therethrough, positioned within said third jacket and above said fluid admitting means; a lower tubular plunger', provided with suitable circumferential packing rings in the outer walls thereof, secured to said hold-down means coaxially within, and spaced from, said third jacket; a lower pump barrel arranged for reciprocating movement concentrically over said lower plunger; standing valve means in said lower plunger and traveling valve means in said lower pump barrel constructed and arranged to cooperate and deliver fluid above said lower pump barrel upon downward movement of the latter; packer means secured circumferentially around said third jacket below the upper extremity thereof and adapted to seal olf an annular space defined between said third jacket and said casing string; a tubular seal barrel, defining at least one fluid port through the wall and adjacent the lower end thereof, seated in the central passage of said second coupling member and threadedly secured in the central passage of said first coupling member whereby an annular passage is provided between said seal barrel and said second jacket; a blind plunger, provided with suitable circumferential packing means slidably engaging inner walls of said seal barrel, arranged for longitudinal reciprocating movement concentrically within said seal barrel; a rst sucker rod string securing the lower extremity of said blind plunger to the upper extremity-of said lower pump barrel; a stationary upper pump barrel, defining at least one fluid reentry port adjacent its upper extremity, threadedly secured at its lower end in thel central passage of said first coupling member and seated at its upper end in the central passage of said head member whereby an annular passage is provided between said pump barrel and the rst tubular jacket; a movable upper pump plunger', defining a central bore and having suitable circumferential packing means in the outer walls thereof slidably engaging inner walls of said upper pump barrel, arranged for reciprocating movement concentrically within said upper pump barrel; standing valve means in the upper zone entry port of said first coupling member and traveling valve means in said upper pump plunger constructed and arranged to cooperate and deliver fluid above said traveling valve upon downward movement of the uper pump plunger; a second sucker rod string securing the upper end of the blind plunger to the lower end of the upper pump plunger; and a movable tubing string adapted to reciprocate substantially conoentrically within said stationary tubing string, threadedly secured to said upper pump plunger above the traveling valve means therein.

2. In a dual zone pump assembly adapted to be' secured to the lower end of a tubing string in a well having upper and lower fluid-producing zones wherein said pump assembly comprises an elongated jacket assembly carrying an upper reciprocating pump and a lower reciprocating pump therein; and wherein said upper pump includes a cylindrical working barrel secured to the jacket assembly, a valved piston slidably engaging the interior walls of the working barrel, and upper standing valve means carried in fluidentry ports formed in said jacket assembly below the working barrel and above the lower pump; and wherein said lower pump includes a reciprocating part carrying a traveling valve, a stationary part carrying a lower standing valve, and releasable anchor means for anchoring the stationary part to the lower end of the jacket assembly; the improved means for segregating internal operating zones of said upper and lower pumps which includes an elongated cylindrical seal barrel secured to the jacket assembly below the upper standing valve and above the lower reciprocating pump, said seal barrel having an internal diameter smaller than the external diameter of said valved piston and larger than the external diameter of said lower pump, a blind plunger slidably engaging interior walls of the seal barrel; rod members securing the blind plunger, in suitable spaced relation, to the valved piston in the upper pump and to the reciprocating part in the lower pump; said tubing string, said upper pump working barrel, said seal barrel, and the lower portion of said jacket assembly dening an unimpeded passageway whose internal diameter is proportioned stepwisely smaller in the downward direction whereby said valved piston, blind plunger, and lower reciprocating pump may be withdrawn upwardly from the jacket assembly upon release 0f the anchor means of the lower pump.

3. A deep-well pump assembly including, in combination, a rst reciprocating pump comprising an elongated cylinder structure and a piston slidably engaging interior walls thereof; a seoond reciprocating pump comprising a cylindrical reciprocating element and a concentric stationary element co-operatively associated therewith 9 to pump a fluid; means supporting said second pump coaxially at a selected distance below said first pump along a central axis common to both pumps; a rod member secured axially to the lower end of said piston and to the upper end of said cylindrical reciprocating element for transmitting reciprocating movement of the former simultaneously to the latter; an elongated cylindrical seal barrel spaced concentrically around said rod member between said first and second pumps, the internal diameter of said seal barrel being greater than the external diameter of said second pump and less than the internal diameter of said cylinder structure; means sealing the upper end of said seal barrel to the lower end of said cylinder structure; and a blind plunger se- 10 cured coaxially around said rod member Within said seal barrel and slidably engaging interior walls of the latter.

CHARLES A. MORRIS.

JOHN D. EXNER.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,281,899 White May `5, 1942 2,499,356 Coberly Mar. '7, 1950 2,499,357 Coberly Mar. 7, 1950 2,513,869 Hofer July 4, 1950 2,522,825 Hoier Sept. 19, 1950

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