US3126836A - Bottom hole pump - Google Patents

Description

Max-c1131, 1964 A. D. LARsoN BOTTOM HOLE PUMP 3 Sheets-Sheet 1 Filed MalrOh 29, 1961 v W. mm m o um. w w v\ @E T/- a S y W, a nu Q M/ M M Y Y 7 E //M \M/w B L\ .A V ,5/ QU; T M. 3 4 9... 2 ///J 2 lo 6| |V1 ...l 2 3 5. M. .0.. .l .0.. F rl' F H March 3'1, 1964 A. D. LARsoN 3,126,836

BOTTOM HOLE PUMP Filed Manch 29, 1961 3 Sheets-Sheet 2 Fg.4 i" 37 7r y i/ y: n j i i 52 f f?. z

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Albert D. Larson IN VEN TOR. 62` BY awaa'm 7`7 d IWW M@ March 3l, 1964 A. D. LARsoN 3,125,836

` BOTTOM HOLE PUMP Filed March 29, 1961 5 Sheets-Sheet 3 Fig. 5

A/berf D. Larson lN VEN TOR.

38 Y kwa/lfm United States Patent O 3,126,836 BOTTM HLE PUMP Albert D. Larson, 3025 Chapel Hill Road, Oklahoma City, Okla. Filed Mar. 29, 1961, Ser. No. 99,202 2 Claims. (Cl. 193-179) This invention comprises a novel and useful bottom hole pump and more particularly relates to a deep well reciprocating pump adapted to effect an increased delivery of fluid for a given size of pump.

The primary object of this invention is to provide a deep well reciprocating pump which will enable a reduction of the load imposed upon the sucker rod string and the pump jack by the weight of the liuid column being pumped.

A more specific object in accordance with the preceding object is to provide a device wherein a given sucker rod string and pump jack shall be capable of lifting a greater quantity of fluid with the same load thereon or conversely whereby the same amount of fluid may be lifted with less load upon the sucker rod string and pump jack. The attainment of this object enables the pumping operation to be performed on a given quantity of fluid with smaller rods and jack; with the use of less power; and with a lower cost of installation, upkeep and operation.

More specifically it is an important object of this invention to provide a deep well reciprocating pump having a piston assembly with an upper portion together with a lower portion of a relatively greater area than said upper portion in the same tubing string together with means which effect a transfer of a portion of the load of the fluid column to the lower portion.

Yet another object of the invention is to provide an irnproved positive sealing means between the pump and the tubing and between the upper piston portion and the upper cylinder of the pump.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like part throughout, and in which:

FIGURE 1 is a view in vertical section, parts being broken away, and showing a typical deep well pumping installation with a tubing string through which the pumped fluid flows inserted within the well casing of a well bore, the installation being a typical one for carrying out the principles of this invention, with parts being broken away;

FIGURES 2-5 are views in vertical central section taken upon an enlarged scale through the cased well and tubing assembly and the sucker rod and pump assembly therein, these views being taken along the sections indicated by the brackets FIGURE 2, FIGURE 3, FIGURE 4 and FIGURE 5, respectively, of FIGURE l; and

FIGURES 6 and 7 are horizontal sectional Views taken substantially upon the planes indicated by the section lines 6-6 of FIGURE 2 and 7 7 of FIGURE 5 respectively.

Referring first to FIGURE l it will be observed that the numeral 10 indicates a well bore extending through a formation 12 into a productive zone 14 from which it is desired to pump the well fluid. Shown at 16 is a casing for the well bore 1li although it may be understood that in some instances the casing is not necessary for the successful application of this invention. Shown at 18 is a string of tubing which extends to the surface of the ground and by means of which the pump apparatus of this invention is housed and the flow of the pumped fluid to the surface of the ground from the well bore is effected. Inasmuch as the use of a tubing string for this dual purpose cil er' lCe is well known, a further description of the same is deemed to be unnecessary.

It will be understood as set forth hereinafter that the tubing string itself is slightly modified by incorporating therein a series of specifically arranged adapters as at 2t), 22 and 24 whichcooperate with the structure of the pump as set forth hereinafter.

Using FIGURE l for the purpose of orientation, and referring specifically to the enlarged detail views of FIG- URES 2-5, it will be seen that there is provided within the tubing string and cooperating therewith a deep well reciprocating pump whose construction and operation form the subject matter of the present invention.

As shown in FIGURE 2, the lowermost section of a sucker rod string as indicated by the numeral 26 is detachably secured as by threaded engagement with the neck 28 of a coupling member 30 to the externally threaded upper end of a hollow sleeve 32 comprising the upper portion of the piston of the pump mechanism. The pump piston upper portion 32 is a hollow sleeve whose open upper end communicates with the hollow interior of the coupler 30 there being provided ports 34 in the latter which constitute the discharge ports for the upper piston portion and which communicate the interior of the upper portion with the interior of the tubing string 1S. It is by means of the annular space between the sucker rod string 26 and the tubing string 18 that the pumped uid is discharged from the well bore to the surface.

As shown in FIGURE 2, the tubing string i8 includes between the two adapter couplers 20 and 22 a tubing string section 36 which also comprises the jacket of the stationary pump barrel in which the pump piston upper portion reciprocates. Referring further to FIGURE 5 it will be seen that the adapter coupler 24 attached to the lower extremity of the tubing string 1S in turn secures thereto a tubing seating shoe 3S having in its upper end a conical internal seating surface 40. As so far described it will now be apparent that the tubing string consisting of the previously mentioned connected sections is hollow and open from its lower end at the tubing seating shoe to the surface of the ground at which the tubing string terminates.

Stationarily but removably seated in the tubing string is a pump barrel assembly which includes a plurality of interconnected elements of specic design and is normally seated in the tubing string upon the tubing seating shoe except that it may be removed from time to time as required for servicing or for other purposes. The stationary pump barrel assembly comprises as shown in FIG- URE 2 a sleeve 42 which comprises a combined guide and iishing neck whereby the stationary pump barrel assembly may be lowered into and seated on the tubing string or removed therefrom. This sleeve 42 has slidably received therethrough with a snug sliding t the previously mentioned upper piston portion 32. Immediately below and carried by the combined guide and fishing neck 42 is a cylindrical body 44 which comprises a packing arbor for receiving thereon a plurality of suitable packing cups or sealing rings 46 which rub against and have a fluid tight engagement with the internal surface of the previously mentioned pump barrel jacket 36. These sealing elements are retained upon the packing arbor or body 44 as by means of a screw threadedly engaged adapter and connector 48 which is screw threadedly engaged upon the lower end of the body 44 as shown in FIGURE 2. Screw threadedly engaged upon the lower end of the adapter or connector 4S is the upper end of the upper pump barrel jacket 50, see FIGURE 3, in which is received and clamped the upper pump barrel S2 in the form of a sleeve whose upper end is sealingly engaged as by a packing ring 54 against the underside of the connector 48, and whose lower end is similarly engaged and retained by a packing ring 56 which is held in place by a further adapter or connector 5S which is internally threadedly engaged in the lower end of the jacket 5t?. The pump barrel 52 has a snug uid tight sliding it with the exterior surface of the cylindrical and tubular upper portion 32 as clearly shown in FIGURE 3.

Threadedly engaged upon the lower end of the connector 53 is a connecting sleeve 66 which in turn is engaged with the upper end of the lower pump barrel 62. The lower pump barrel is of greater internal diameter than the upper pump barrel and at its lower end, as shown in FIGURE 5, is threaded to a connector sleeve 64 whose lower end in turn is threadedly engaged upon a sleeve 66 which constitutes the standing or stationary valve cage, this sleeve in turn carrying a coupler 68 in which is received the pump seat mandrel lll having thereon a cylindrical pump seat gland 72. lt will be observed that the entire weight of the pump organization is supported upon the pump seating surface All) of the tubular seating sleeve 33 by engagement of the pump seat gland 72 upon the surface du.

With continuing reference to FlGURE 5 and also to FIGURE 7 it will be observed that the standing valve cage 66 has a spider 7d therein which limits upward travel of the ball valve 76 in the valve chamber 78, the valve cooperating with an annulus or ring 3@ comprising a valve seat which is retained within the open lower end of the valve cage 66 by the screw threaded engagement of the upper extremity S2 of the connector 68. The latter also has radially extending ports 34 therethrough which establish communication from the interior of the stationary pump barrel assembly to the annular space between the latter and the tubing 18, this annular space still further having communication with the exterior of the tubing and the interior of the well casing by means of ports, see FGURE 3, shown at 86 in the pump barrel assembly and at S8 in the tubing string 18. Thus, the well fluid rising within the well bore casing and between the latter and the tubing string 18 is at all times in free communication with the annular space between the stationary pump barrel assembly and the tubing string and through the ports S3, 86 and 811 with the interior of the pump barrel assembly. The liquid level of the fluid standing within the well bore and the well casing is indicated in FIGURE 2 by the numeral 9@ and it will be understood that the major portion of the pump barrel and piston assemblies lie below this liquid level.

Attention is now directed to FIGURES 2-5 for an understanding of the construction of the pump piston upper and lower portions and their cooperation with the upper and lower pump barrel assemblies. As previously mentioned, the upper piston portion 32 is directly connected to the sucker rod string for reciprocation thereby, and extends downwardly through the upper barrel assembly in a sliding liuid tight engagement therewith and to all practical purposes may consist of a single unitary tubular pipe or sleeve extending through the length indicated in FIGURES 2 and 3 until its lower end is threadedly engaged in a connecting joint at 1li@ as shown in FlGURE 4. Connected to and supported by the connector 16) is a cylindrical element 102 or lower piston portion comprising a continuation of the upper piston portion 32 and which as shown in FIG- URE 5 is screw threadedly engaged upon the interior surface of the upstanding sleeve 19d of a further connector 166. Upon the exterior surface of the sleeve 164i is threadedly engaged an upstanding sleeve 1198 which comprises with the sleeve 192 and the connector 1M- the lower portion of the pump piston assembly. As will be apparent from FIGURE 4, the major portion of the lower portion sleeve 1618 has a uid tight t'it with the interior of the lower pump barrel 62 for sliding therein.

Also carried by the lower end of the connector 10o by a screw threaded engagement is the traveling Valve cage 119 which likewise is Yin the form of a sleeve having a valve retaining spider 112 wherein together with a valve chamber 114 in which is received a ball valve 116. This valve cooperates with a valve annulus or seat 118 retained by the screw threaded gland 12@ therein.

The foregoing completes the structure of this reciprocating type deep well pump. As so far described it will now be appreciated that the reciprocating elements of this pump include the upper portion 32, the connector securing the upper portion to the lower portion with the latter consisting of an inner sleeve 162 and an outer sleeve 163, the two sleeves of the lower portion at their lower ends being secured together by the connector element 166 which latter in turn carries the traveling valve cage for reciprocation therewith. Fluid can thus enter the hollow upper portion upon its downstroke by lifting and unseating the traveling valve 116 and passing upwardly into the hollow interior of the valve cage,

- through the connector 106, the lower portion inner sleeve 162, the connector 166 and the upper portion 32 from whence this fluid can emerge through the ports 34.- into the interior of the tubing string above the packing means formed by the liuid tight sliding engagement of the members d6 with the tubing section 36 at the upper end of the pump barrel assembly.

The stationary barrel assembly of this pump includes the connector and fishing neck 42, the packing arbor or body 414 with the packing or sealing elements 46 carried thereby, the adapter or connector 48, the upper pump barrel jacket 56 with the upper pump barrel 52 therein, the upper and lower packing rings 54 and 56, the adapter 58, the connecting sleeve 6@ and the lower pump barrel 62 carried thereby, the lower pump barrel connector sleeve 64, the stationary or standing valve cage 66, the connector 68, the pump seat mandrel '70 and the pump seat gland 72 by which the entire pump barrel assembly is supported upon the tubing string upon the seating surface du of the tubing seating shoe 38.

The operation of this pump is as follows. With the pump positioned within the tubing string the lluid accumula 'ng in the well bore will stand at its natural level as indicated at @il thus immersing the lower portion of the pump barrel assembly. The registering ports 88 and 86 in the tubing string and in the pump barrel assembly serve to maintain the pressure of this standing lluid in the well bore in communication with the annular space lying between the plunger and the pump barrel assemblies and above the lower piston portion 162 and below the packing means 46, and further through the annular space lying between the lower portion 162 and the lower pump barrel 62 and the ports 84 with the interior of the lower barrel below the standing valve 76. Upon each upstroke of the piston assembly, therefore, the well iiuid is drawn into the chamber lying between the two valve assemblies and within the lower pump barrel. The volume displaced by this upward travel of the upper piston portion 32 constitutes the volume of fluid delivered at each working stroke of the reciprocating pump. This incoming charge of uid passes the standing check Valve 76 by lifting the latter until this chamber is filled. Upon the following down stroke of the upper plunger assembly, the standing valve '76 will be closed and the liuid within this chamber will bypass the traveling valve 116 and move up into the interior of the hollow upper plunger, filling the latter and passing out through the ports 34 at the upper end of the upper plunger into the tubing string.

lt is to be particularly noted that by this construction the eliective area of the upper piston portion 32 is substantially one-half that of the lower piston portion 1132 inasmuch as the external diameter of the lower outer sleeve 166 and the connection of the connector 106 with the outer sleeve 1% and the inner sleeve 162 of the lower piston portion comprises an effective working area of the lower portion which is substantially twice that of the upper portion.

As a result of this arrangement, and of the iluid tight sealing engagement between the pump barrel with the tubing by means of the seal members 44, 46, the column of fluid lifted by the pump and which lies above the liquid level 90 in the well bore thereby lessen the power required to eiect the downward delivery stroke of the pump. Upon the down stroke of the pump, the weight of the column upon the upper piston portion assists in effecting the downward stroke. In the operation of the present invention, about one-half of the fluid column weight is transferred from the piston portion 32 to the top of the stationary part of the pump barrel assembly. This transfer of weight is accomplished by the lower piston portion 102 being of a cross sectional area double that of the upper portion 32. The lower portion, when stroked upward, creates a void between the standing and traveling valve assemblies '76, 116 equal to its cross sectional area times the length of its stroke. This void is illed by incoming fluid from the bore hole and this is the amount of iluid pumped on each stroke of the pump, and since the annulus, between the upper portion and the bore of the lower cylinder or barrel is not subjected to the iluid column pressure within the tubing string because of the provision of the sealing or packing members 44, 46 previously described, but is subjected only to the bore hole pressure of the fluid level 90 through the ports 88, S6, it results on the up stroke that the bore hole pressure pushes against both the bottom and the annulus at the top of the lower piston portion and the fluid column pressure pushes against the top of the smaller upper portion 32. On the down stroke, the uid trapped in the larger lower cylinder is forced upwardly through both the lower and upper piston portion into the tubing string through the ports 34 above the sealing means 44, 46.

Some of the sucker rod string weight is used to lift the extra iluid brought into the lower cylinder below the lower piston portion. This may be calculated as follows: on the down stroke of the piston assembly the cross sectional area of the lower piston portion minus the cross sectional area of the upper piston portion times the fluid column pressure equals the rod string weight employed to force the piston assembly down and deliver the trapped fluid up through the piston assembly and into the tubing.

This action is made possible by the seal between the tubing and the members 44, 46 at the top of the pump assembly and the seal between the upper piston portion 32 and upper cylinder. By means of the port hole system, the bore hole iluid can pass into the top of the lower cylinder on the down stroke and on the up stroke this lluid can pass back out through the port holes into the bore hole.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

l. A reciprocating bottom hole pump assembly comprising a tubing string opening at its lower end into the bottom of a well bore, a stationary pump barrel assembly in said tubing string and having its lower end opening into said well bore, sealing means establishing a iluid tight seal between the tubing string and said barrel assembly intermediate the ends of the latter, a tubular pump plunger assembly slidably disposed in and having a fluid tight seal with said barrel assembly, said plunger assembly including an upper plunger and a lower plunger of greater effective cross sectional area than that of the former, said upper plunger having continuous communication between its interior and the interior of said tubing string above said sealing means, a traveling valve assembly at the lower end of said lower plunger allowing flow of Well uid upwardly only into the interior of said plunger assembly, a standing valve assembly in said pump barrel assembly below said traveling valve assembly and allowing ilow of well iluid from the interior of said pump barrel assembly upwardly only to said traveling valve assembly, means establishing continuous communication between said interior of said barrel assembly below said standing valve assembly and the space between said barrel assembly and said tubing string below said sealing means and between the latter and said well bore, a connector, a pair of concentric sleeves secured to the upper end of said connector and forming said lower plunger, the inner of said concentric sleeves being secured to the lower end of said upper plunger.

2. A reciprocating bottom hole pump assembly comprising a tubing string opening at its lower end into the bottom of a well bore, a stationary pump barrel assembly in said tubing string and having its lower end opening into said well bore, sealing means establishing a iiuid tight seal between the tubing string and said barrel assembly intermediate the ends of the latter, a tubular pump plunger assembly slidably disposed in and having a fluid tight seal with said barrel assembly, said plunger assembly including an upper plunger and a lower plunger of greater effective cross sectional area than that of the former, said upper plunger having continuous communication between its interior and the interior of said tubing string above said sealing means, a traveling valve assembly at the lower end of said lower plunger allowing flow of well fluid upwardly only into the interior of said plunger assembly, a standing valve assembly in said pump barrel assembly below said traveling valve assembly and allowing flow of well fluid from the interior of said pump barrel assembly upwardly only to said traveling valve assembly, means establishing continuous communication between said interior of said barrel assembly below said standing valve assembly and the space between said barrel assembly and said tubing string below said sealing means and between the latter and said well bore, a connector, a pair of concentric sleeves secured to the upper end of said connector and forming said lower plunger, the inner of said concentric sleeves being secured to the lower end of said upper plunger, said traveling valve being carried by the lower end of said connector.

References Cited in the file of this patent UNITED STATES PATENTS 2,061,252 Peters Nov. 17, 1936 2,068,729 Basher Jan. 26, 1937 2,166,612 Scott July 18, 1939

Claims (1)

1. A RECIPROCATING BOTTOM HOLE PUMP ASSEMBLY COMPRISING A TUBING STRING OPENING AT ITS LOWER END INTO THE BOTTOM OF A WELL BORE, A STATIONARY PUMP BARREL ASSEMBLY IN SAID TUBING STRING AND HAVING ITS LOWER END OPENING INTO SAID WELL BORE, SEALING MEANS ESTABLISHING A FLUID TIGHT SEAL BETWEEN THE TUBING STRING AND SAID BARREL ASSEMBLY INTERMEDIATE THE ENDS OF THE LATTER, A TUBULAR PUMP PLUNGER ASSEMBLY SLIDABLY DISPOSED IN AND HAVING A FLUID TIGHT SEAL WITH SAID BARREL ASSEMBLY, SAID PLUNGER ASSEMBLY INCLUDING AN UPPER PLUNGER AND A LOWER PLUNGER OF GREATER EFFECTIVE CROSS SECTIONAL AREA THAN THAT OF THE FORMER, SAID UPPER PLUNGER HAVING CONTINUOUS COMMUNICATION BETWEEN ITS INTERIOR AND THE INTERIOR OF SAID TUBING STRING ABOVE SAID SEALING MEANS, A TRAVELING VALVE ASSEMBLY AT THE LOWER END OF SAID LOWER PLUNGER ALLOWING FLOW OF WELL FLUID UPWARDLY ONLY INTO THE INTERIOR OF SAID PLUNGER ASSEMBLY, A STANDING VALVE ASSEMBLY IN SAID PUMP BARREL ASSEMBLY BELOW SAID TRAVELING VALVE ASSMBLY AND ALLOWING FLOW OF WELL FLUID FROM THE INTERIOR OF SAID PUMP BARREL ASSEMBLY UPWARDLY ONLY TO SAID TRAVELING VALVE ASSEMBLY, MEANS ESTABLISHING CONTINUOUS COMMUNICATION

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