US3114327A - Gravity powered casing pump - Google Patents

Description

Dec. 17, 1963 o. v. REYNOLDS GRAVITY POWERED CASING PUMP 3 Sheets-Sheet 1 Filed March 20, 196 1 arm 1/. Reynolds v INVENTOR.

Dec. 17, 1963 '0, v. YN L 3,114,327

" GRAVITY POWERED CASING PUMP 3 Sheets-Sheet 2 7 Filed March 20. 1961 0270 V. Reynolds INVENTOR. e052.

BY gin 7 0 6 ..I w 4 6 x w 4 2 6 4 I l l I I I I I J 2 2 J l 6 by 0 6 V 6 5 6 4, n 4 3 w Dec. 17, 1963 o. v. REYNOLDS GRAVITY POWERED CASING PUMP 3 Sheets-Sheet 3 Offo l4 Reyna/d5 1N VEN TOR.

Filed March 20, 1961 BY m United States Patent 3,114,327 GRAVITY POWERED CASING PUMP Otto V. Reynolds, Bloomfield, N. Mex, assignor of one-half to L. G. Johnson Filed Mar. 20, 1961, Ser. No. 96,828 17 Claims. (Cl. 103-158) This invention comprises a novel and useful gravity powered casing pump and more particularly relates to a reciprocating pump for producing liquids from deep wells.

In the recovery of fluids such as petroleum or water from well bores, it sometimes occurs that owing. to economical reasons a relatively small bore of five inches or less has been drilled into the productive formation and the fluid produced from pump tubing within the casing of this bore is frequently at a rate of flow which is less than the productive capacity of the formation penetrated by the well bore. When this condition occurs, the well operator fails to obtain the maximum output and therefore the maximum profit from the well owing to the lack of adequate flow capacity.

It is therefore the primary purpose of this invention to provide an apparatus to eflectively overcome the foregoing difficulty and enable a maximum production from the well which is limited only by the volumetric capacity of the casing of the Well.

More specifically, it is an object of the present invention to provide a bottom hole type of reciprocating pump in which the entire Well casing is employed as the pump tubing string so as to obtain the utmost volume of delivery from the well.

It is a further important object of the invention to provide an apparatus in accordance with the foregoing object which is capable of being operated by conventional wire line equipment and will not necessitate the weight of the pumping string as well as the expense thereof which are incident to pumping by a rigid pumping string or sucker rod string.

Still another purpose of the invention is to provide a bottom hole reciprocating pump which shall reduce to a minimum the power requirements for operating the pump and which shall be so constructed that gravity alone may be relied upon as the actuating means to effect the downward pumping stroke while the operation of the wire line is utilized simply to lift the reciprocating mass of the pump assembly in preparation for the next pumping stroke.

In carrying out the principles of this invention there is utilized a novel packer assembly which is appropriately secured and positioned in the lower end of the well casing to completely seal oif the bottom hole from the casing thereabove so that the entire casing above the packing member may be utilized as the pump tubing of the apparatus.

Yet another object of the invention is to provide a packer assembly in accordance with the preceding object which shall be provided with a means for supporting the packer assembly in position from the bottom of the well bore and wherein the packer assembly itself shall support and fixedly carry a stationary piston which cooperates with and is disposed in a reciprocating gravity lowered and wire line lifted pump cylinder.

A still further and very important object of the invention is to provide an apparatus in which the entire arrangement of reciprocating pump barrel, stationary piston, packer assembly and a supporting tailpipe therefor may be connected together as a unitary subassembly whereby they may be lowered into or removed from a well bore by conventional wire line and when positioned in a well bore may be operated as a bottom hole pump by the wire line.

3,114,327 Patented Dec. 17, 1963 "ice A further and more specific object of the invention is to provide in an assembly of the character above set forth a packer construction in which the packer may be expanded into its sealing engagement with the well casing through the weight of the pump as the assembly is lowered into the bottom hole of a well; and whereby the weight of the liquid column from the packer to the surface may be utilized to retain the packer in a fluid tight sealed engagement with the well bore; and whereby the packer and the entire assembly may be readily retrieved by a wire line.

And a final important object of the invention to be specifically enumerated herein resides in the provision of a pumping apparatus in accordance with the foregoing objects wherein an automatically operated venting or dumping valve is incorporated into the packer construction which valve will be closed when the device is in normal pumping position, and which valve will be opened during reset of the device into a well bore by the wire line and during withdrawal of the device from the well bore by the wire line to thereby permit the flow of fluid through the packer assembly and facilitate such lowering or lifting of the device.

FIGURE 1 is a view in central elevation through a portion of a cased well bore and showing the position of the parts of the pump subassembly in accordance with this invention during vertical travel of the assembly by a wire line in the well casing;

FIGURE 2 is a view similar to FIGURE 1 but showing the position of the parts when the pumping subassembly is installed in a cased well bore and is in readiness for pumping operations;

FIGURE 3 is a view similar to FIGURES l and 2 but shows the position of the parts during operation of the pump and when the latter is in the upper position of reciprocation of the pump barrel in readiness for beginning of the gravity operated pumping stroke;

FIGURES 4 and 5 are enlarged detailed views in central vertical section of the upper and lower portions respectively of the reciprocating pump and the packer component of the assembly in the position assumed by these parts during their vertical travel into or out of the well bore;

FIGURES 6 and 7 are horizontal sectional detailed views taken respectively substantially upon the plane indicated by the section lines 66 and 7-7 of FIGURES 3 and 4; and

FIGURE 8 is an exploded group perspective view showing the various components of this pump subassembly in their disassembled relation.

In the accompanying drawings the numeral 10 designates a portion of a well casing for a well bore extending from the surface to any suitable subterranean formation for producing liquids therefrom such as oil or water. The pump assembly or subassembly of this invention is adapted for use in a well casing of this character and is particularly advantageous in its effects when the well casing is one of a relatively small or narrow diameter. The basic concept of this invention resides in the using of the well casing itself as the pump tubing through which the liquid from the formation is produced, thus dispensing with the usual pump tubing which is ordinarily disposed in such a Well casing and which pump tubing therefore restricts the maximum flow of liquid from the formation to a rate of flow which is considerably less than that which could be accommodated by the well casing. In some instances it will be preferred to initially install the casing pump of this invention in the well casing 10-' when the well is initially produced, while in other instances it will be advantageous to convert a well of this character from the employment of a relatively small in diameter pump tubing to the use of the well casing as the pump tubing. In this latter event, the conventional pump tubing and bottom hole pump are pulled from the Well and are then replaced by the pump subassembly of this invention which is carried by and is manipulated by a conventional wire line rather than by a rigid sucker rod or pumping string, and is both inserted into the well bore and withdrawn from the 'Well bore by the use of the wire line.

FIGURE 1 and FIGURES 4 and 5 illustrate the construction and arrangement of the components of the bottom hole pump subassembly in accordance with this invention with these components to be illustrated in the position which they assume when the device is being lowered into or withdrawn from a well casing.

Shown at 12 is the lower end of a wire line by which the device is to be lifted, lowered and operated, it being understood that a conventional rope socket, not shown, is utilized for securing the wire line to the pump assembly.

The pump assembly includes as its main components a reciprocating pump barrel 14 which may be of any size desired which can be loosely received in the well casing for reciprocation therein as Well as for trips into and out of the well casing. Supported and carried by the pump barrel 14 in a manner to be subsequently set forth is a packer assembly indicated generally by the numeral 16, while a tailpipe 18 comprises a support means or anchor for the packer assembly and performs certain other functions as subsequently set forth. A centralizer 20 is disposed between the Wire line or rope socket which is designated generally by the numeral 22 and the pump barrel 14.

Referring now especially to FIGURE 4 it will be observed that the pump barrel 14 has a relatively large cylindrical chamber or bore 24 opening upwardly through its lower end and which provides the cylindrical working chamber 26 of the pump. The lower end of this barrel is closed as by a closure cap or end plug 28 having an aperture or bore 30 therethrough which guidingly accommodates the hollow tubular piston rod 32. Freely slidable within the chamber 26 is the pump piston 34 having an axial passage 36 therethrough in which is secured in any suitable manner the upper open end of the piston rod 32. A standing valve assembly 38 is provided for controlling the communication between the upper open end of the piston rod 32 and the chamber 26 above the piston 34. By way of example, this standing valve assembly includes a counterbore 40 in the upper end of the piston 34 in which is received a plate or disk 42 comprising a valve seat and an upwardly opening ball-type of check valve 44 cooperates therewith, being retained in association with the seat by a slotted valve cage 46 which is screw-threadedly engaged in the counterbore.

The upper end of the pump barrel 14 is provided with a delivery passage 50 extending axially therethrough whose upper end is provided with a counterbore 52. The traveling valve assembly indicated generally by the numeral 54 is engaged in this counterbore, consisting of a fiat plate or disk 56, apertured as at 58 and which is controlled by the upwardly opening non-return ball valve 60. A cylindrical hollow tubular body or sleeve 62 has its lower end threadedly engaged in the counterbore 52 and constitutes a cage or closure for the traveling valve. This sleeve is provided with a series of apertures or ports 64 which establish communication between the pump chamber 26 through the traveling valve assembly and into the casing above the pump barrel.

As will be understood, the rope socket 22 is fixedly secured to or may constitute an integral part of the member 62.

A centralizer 66 in the form of a cylindrical body of rubber or other similar yieldable and wear-resisting material is bonded or otherwise fixedly secured to and surrounds the member 62 and is of sufficient diameter to slidably engage the well casing to act as a guide for the upper end of the pump barrel during travel of the latter into and out of the well bore. As shown best in FIGURE 8, the centralizer body 66 is provided with a plurality of axially extending longitudinal channels or grooves 68 in its periphery which constitute and are of sufiicient size and total cross-sectional area to permit substantially unrestricted flow of the fluid discharged from the traveling valve upwardly past the centralizer and up the casing to the surface.

By virtue of its rigid connection to the upper end of the reciprocating pump barrel the centralizer acts as a guide to prevent rubbing of the pump barrel against the well casing during its passage therethrough.

Referring now specifically to FIGURE 5 it will be observed that the packer assembly 16 has a conical upper section 70 which is of a resiliently deformable material such as rubber or the like and is bonded to or fixedly secured to and surrounds the hollow piston rod 32 being retained between upper and lower retaining members such as the upper plate 72 having a hub 74 suitably rigidly attached to the piston rod 32, and a lower retainer 76 in the form of a collar which is fixedly secured to the piston rod and is received in a recess 78 in the lower end of the upper packer section 70. It is particularly to be noted that the exterior surface of the packer section '70 is conical in shape, and has a downwardly convergent tapering conical exterior surface 80 thereon.

The lower packer section consists of a main body portion 82 likewise of a resiliently deformable material such as rubber and whose external diameter is such as to be slidable in the well casing 10 in close proximity to the latter during travel of the device into and out of a well casing. The lower section is provided with a conical recess or cavity 84 which is upwardly divergent and which is sufficiently complementary to the conical exterior surface 80 of the upper section to wedgingly receive the latter therein. The bottom surface of the lower section is recessed or counterbored as at 86 to receive therein and to bondingly engage upon a metallic body or plug 88. This plug has a bore or passage 90 therethrough for slidingly receiving the piston rod 32 so that the lower section is thus slidingly mounted upon the piston rod while the upper section 70 is fixedly secured upon the latter.

A stop means is provided for limiting relative sliding movement of the piston rod through the lower packer section, and for this purpose there is provided a nut 92 threadingly engaged upon the lower threaded end of the piston rod and which nut is adapted to abut against the bottom surface 24 of an internally threaded recess 96 in the bottom face of the body 88. A tailpipe or anchor means for the packer assembly is provided consisting of a tubular member 98 whose upper end is threadedly engaged in the counterbore 96, whose lower end is adapted to rest upon the bottom of the well bore as shown in FIGURES 2 and 3 for supporting the packer assembly in a fixed position adjacent the bottom of the well bore, while the tailpipe is further provided with a plurality of apertures or ports therethrough as at 100 which establish continuous communication between the interior of the tailpipe and the interior of the piston rod 32 and the bottom of the well bore below the packer assembly.

The piston rod is further provided below the upper packer section 70 with a series of ports 102 which in the separated position of the two packer sections as shown in FIGURE 5 establish free communication with the space above the lower packer section and the interior of the tailpipe 98 and thus through the ports 100 with the interior of the well casing below the packer assembly. These ports and their cooperation with the packer assembly constitute an unloading valve which forms a further important component of this invention.

The operation of this bottom hole pump subassembly is as follows:

When the components of the device are assembled together in the position shown in FIGURES 1, 4 and 5 in readiness for lowering in a well bore upon the lower end of a wire line, it will be observed that the pump barrel 14 depends from the member 62 which latter is carried by the wire line. A piston is at the bottom of the pump chamber 26 and is thus carried by and rests upon the end plug 28. The pump rod in turn by means of the stop member 92 supports the lower packer section 82 as shown in FIGURE 5 so that at this time the unloading ports 102 are exposed to the space above the lower packer, with the tailpipe 98 depending therebeneath. In this position as the device is lowered into a well bore the fluid in the well can freely pass upwardly through the openings in the tailpipe, through the open lower end of the piston rod, then up through the unloading ports 102 and about the upper packer section 80, then upwardly around the pump barrel and by means of the channel 68 can pass above the centralizer. Thus there is substantially no obstruction or resistance to downward travel of the subassembly into a well bore. In a similar manner, when the pump assembly is being pulled from the well bore, the parts will assume the same position so that the fluid column above the packer assembly will thus be vented through the unloading valve formed by the ports 162, the lower end of the piston rod 32 and the openings 100 in the tailpipe 98. Thus there will be no resistance or swabbing action efiected during withdrawal of the device from the well bore.

From the position of FIGURE 1, the device is lowered into the well 'oore until the anchor or packer support means 98 has its lower end engaging the bottom of the well bore as shown in FIGURES 2 and 3. It will be understood that for this purpose the tailpipe is of sufficient length to position the packer above the productive formation from which fluids are to be pumped to the surface. As soon as the anchor means engages the bottom of the well bore, the lower packer section ceases its downward movement. Thereupon, continued lowering of the Wire line through the weight of the pump barrel 14 continues to lower the latter and with it the piston 34 and the piston rod 32. As the piston rod lowers, the upper packer section 78 engages in the recess 84 of the lower packer section 82, so that a wedging engagement is now effected. At the same time the unloading ports 192 now lie below the cavity 84 and thus are no longer effective to permit the flow of fluid between the tailpipe and the cavity 84.

As the pump barrel continues to lower, from the 'views as shown in FIGURE 2 to that shown in FIGURE 3, the pump barrel gradually slides downwardly upon the now stationary piston until the latter reaches its uppermost position in the pump barrel, as shown in FIGURE 3, at which time the weight of the pump barrel now forcibly pushes the upper packer section 79 into a tight wedging engagement with the lower packer section 82 thus radially expanding the latter into a fluid tight seal with the wall of the casing. At this time, the weight of the parts and the weight of any fluid column subsequently supported by the packer will maintzu'n a secure fluid tight seal of the packer with the wall of the casing during the vertical reciprocation of the pump barrel in the pumping action. The pump is now ready for use, and the wire line is now raised and lowered through a sufiicient movement to effect a reciprocation of the pump barrel so as to cause a relative travel of the pump piston, which remains stationary, throughout the desired operative stroke within the pump barrel. 7

At this point it should be emphasized that the pump barrel is of sufiicient weight so that by gravity alone, when released by the wire line, it will descend upon its operating or pumping stroke, will compress the fluid in the pump chamber 26 and force the same through the passage Sii, the traveling valve 54 and the port 64 into the well casing 1% above the packer and thus to the surface. After the downward travel of the barrel and the pumping stroke has been completed, the wire line then lifts the barrel to its upper position. This upward travel enlarging the chamber 26 produces a suction which opens the standing valve 38 and takes in a new charge of liquid from the well bore below the packer through the tailpipe. At the same time, the traveling valve is closed.

It will be observed that during this reciprocation of the reciprocating pump barrel relative to the stationary piston, only Slli'llClCllt vertical reciprocation is provided through the wire line to etfect the desired length of pumping stroke, but this stroke terminates short of engagement of the piston with the bottom plug 28 of the pump barrel. Consequently, the pumping stroke does not in any way loosen the wedging action of the two packer sections and this wedging action is therefore continuously maintained by the weight of the fluid column in the well casing above the packer.

When it is desired to withdraw the device from the well bore for, any reason, it is merely necessary to pull the wire line a sufficient extent to cause the upwardly rising pump barrel to engage and lift the piston 34. This in turn through the piston rod 32 will lift the upper packer section 70 from the lower packer section and thus uncover the unloading ports 1&2 to the interior of the cavity S4 and permit dumping or venting of the fluid column through the packer assembly and through the tailpipe. With the lifting of the upper section, the radial wedging action upon the lower section is released and the latter now contracts sufliciently so that when the stop means 92 on the lower end of the piston rod engages the body 88, the entire assembly can be withdrawn as a unit to the surface.

It should be noted that in this construction, the rigid construction of the centralizer 26 in extra spaced relation above the upper end of the pump barrel and rigidly secured thereto as well as the lower packer section and its sliding engagement upon the interior of the well casing it operates as a sliding guide at both ends of the assembly which thereby prevents rubbing of the pump barrel against the casing thus avoiding damaging wear therebetween.

As will be seen from FIGURE 8, the bore 3% in the end plug 28 is provided with channels or grooves 31 which establish continuous communication with the cylinder below the piston to permit free flow of fluid. However, these grooves do not interfere with an adequate guiding engagement of the bore with the rod 32.

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:

1. A gravity operated bottom hole casing pump assembly comprising in combination a reciprocating pump, a packer assembly and an unloading valve, said pump including a relatively stationary piston and a reciprocating cylinder barrel slidably surrounding said piston and slidably received in a well casing, a piston rod secured to said piston and slidably received in said packer assembly, means for fixedly supporting said packer assembly in fixed position in a well casing, said piston rod comprising a hollow tube with an upper end opening into said cylinder barrel and having its lower end opening into a well casing below said packer assembly, said piston rod including discharge ports slidable through and controlled by said packer assembly and constituting said unloading valve.

2. The combination of claim 1 including a centralizer rigidly secured to and disposed in axially spaced relation above said pump barrel and said packer assembly being disposed in axially spaced relation below said pump barrel, said centralizer and packer assembly comprising guides for said pump barrel during insertion and withdrawal of the latter in a casing.

3. The combination of claim 1 including a standing valve controlling communication between said upper end of said piston rod and the interior of said pump barrel, a traveling valve upon said pump barrel and controlling communication between the latter and the well casing above said packer assembly.

4. The combination of claim 3 including a centralizer slidable in said casing and rigidly connected to said pump barrel for slidably guiding the latter in said casing while allowing liquid flow between said centralizer and said casing.

5. A gravity operated bottom hole casing pump assembly comprising in combination a reciprocating pump, a packer assembly and an unloading valve, said pump including a relatively stationary piston and a reciprocating cylinder barrel slidably surrounding said piston and slidably received in a well casing, a piston rod slidably received in said packer assembly, means for fixedly supporting said packer assembly in fixed position in a well casing, said piston rod comprising a hollow tube with an upper end opening into said cylinder barrel and having its lower end opening into a well casing below said packer assembly, said piston rod including discharge ports slidable through and controlled by said packer assembly and constituting said unloading valve, a centralizer slidable in said casing and rigidly connected to said pump barrel for slidably guiding the latter in said casing and allowing continuous liquid flow between the centralizer and easing.

6. The combination of claim 5 wherein said packer assembly includes a pair of cooperating inner and outer packer section, said outer packer section being of a deformable material capable of radial expansion into sealing engagement with a well casing and being fixedly mounted upon said packer assembly supporting means, said outer packer section having a central cavity which is downwardly convergent from its open upper end, said inner packer section having a conical exterior surface wedgingly receivable in said cavity for thereby radially expanding the outer packer section, said piston rod being fixedly secured to said inner packer section and being slidable through said outer packer section.

7. The combination of claim 6 wherein said piston rod is hollow and establishes communication between said well casing below said packer assembly and the pump barrel above the pump piston, said piston rod having ports opening into said cavity and controlled by said inner packer section to comprise said unloading valve.

8. The combination of claim 1 including a tail pipe secured to said packer assembly for supporting the latter from the bottom of a Well bore.

9. The combination of claim 8 wherein said tail pipe has perforations in its side wall, said piston rod having its lower end slidable in and continuously communicating with the interior of said tail pipe.

10. The combination of claim 9 wherein said piston rod has stop means on its lower end limiting its withdrawal from and for supporting said packer assembly.

11. The combination of claim 1 wherein said packer u assembly includes complementary inner and outer radially deformable sections, said sections having conical, wedgingly engaged surfaces, one section being fixedly secured to a packer anchoring means and the other section being fixedly secured to said piston rod.

12. The combination of claim 11 wherein said lower section is fixedly secured to said packer anchoring means and has an upwardly divergent concave conical surface, said upper section being fixedly secured to said piston rod and having a conical outer surface wedgingl'y received in said concave conical surface.

13. A gravity operated bottom hole casing pump assembly comprising a reciprocating pump barrel slidably received in a well casing together with a wire line connected to said barrel for lifting the latter on its idle stroke, a stationary pump piston slidable within said barrel, :1 piston rod secured to said piston and extending beneath said barrel, a pair of complementary, cooperating and relatively movable packer sections mounted on said piston rod beneath said barrel, one of said packer sections being fixedly secured to said piston rod and the other packer section slidably embracing said piston rod, said piston rod being hollow and establishing communication between the interior of said pump barrel above said piston and the well casing below said packer sections, a valve chamber provided between cooperating surfaces of said packer sections and open to the well casing above the packer sections when the latter are disengaged, unloading ports in said piston rod opening into said valve chamber, standing and traveling valve assemblies controlling through said pump barrel.

14. The combination of claim 13 wherein said standing valve assembly is disposed in said pump barrel and is mounted upon said pump piston and controls flow from said piston rod into said pump barrel.

15. The combination of claim 13 wherein said traveling valve assembly is mounted upon said pump barrel upon the exterior thereof.

16. The combination of claim 13 including a perforated sleeve secured to and depending from said other packer section for supporting the latter in a well bore, said piston rod having its lower end freely slidable in said sleeve.

17. The combination of claim 16 including a stop means on the lower end of said piston rod beneath said other packer section and engageable with the latter to limit movement of said other packer section from said one packer section.

References Cited in the file of this patent UNITED STATES PATENTS 249,228 Dower Nov. 8, 1881 604,202 Wright May 17, 1898 663,029 Horsley Dec. 4, 1900 1,601,676 Burright Sept. 28, 1926 1,637,629 Winsor Aug. 21,, 1927 1,698,797 Howe Jan. 15, 1929 2,111,173 Cox Mar. 15, 1938 2,247,325 Wagner June 24, 1941 2,876,708 Frost Mar. 10, 1959 2,885,011 Frost May 5, 1959

Claims (1)

1. A GRAVITY OPERATED BOTTOM HOLE CASING PUMP ASSEMBLY COMPRISING IN COMBINATION A RECIPROCATING PUMP, A PACKER ASSEMBLY AND AN UNLOADING VALVE, SAID PUMP INCLUDING A RELATIVELY STATIONARY PISTON AND A RECIPROCATING CYLINDER BARREL SLIDABLY SURROUNDING SAID PISTON AND SLIDABLY RECEIVED IN A WELL CASING, A PISTON ROD SECURED TO SAID PISTON AND SLIDABLY RECEIVED IN SAID PACKER ASSEMBLY, MEANS FOR FIXEDLY SUPPORTING SAID PACKER ASSEMBLY IN FIXED POSITION IN A WELL CASING, SAID PISTON ROD COMPRISING A HOLLOW TUBE WITH AN UPPER END OPENING INTO SAID CYLINDER BARREL AND HAVING ITS LOWER END OPENING INTO A WELL CASING BELOW SAID PACKER ASSEMBLY, SAID PISTON ROD INCLUDING DISCHARGE PORTS SLIDABLE THROUGH AND CONTROLLED BY

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