US2244051A - Casing pump for oil wells and the like - Google Patents

Description

HUBERTl D. COLLINS x Y ATTORNEYS g i i V412l! lNvENToR* Filed'llay 22, 1949 H. D. COLLINS CASING PUMP VFUI- OIL WELLS' AND THE LIKE iN n Patented June 3, 19,41

UNITED `STATES PATENT OFFICE CASIN G PUMP FOR OIL WELLS AND THE LIKE Hubert D. Collins, Tulsa, Okla..

Application May 22, 1940, Serial No.' 336,501

(Cl. S- 221) 3 Claims.

This invention relates to new and useful improvements in pumping mechanisms for flowing oil wells and the like. It deals particularly with well pumps of the type known as casing pumps, which are located in place inside of the usual well casing and make use of the casing for conducting oil to the `ground surface.

A desirable type of casing pump construction, as employed heretofore in oil well flowing operations, includes a working barrel for the pump piston, an expansible packer of rubber composition or vthe like connected through a drain sleeve with the working barrel, a pump headcarrying a mandrel that is movable into the packer to expand the same into sealing engagement'with the well casing, a drain tube depending from the mandrel toward the working barrel, and the usual string. of sucker rods connected with the piston. The pump mechanism is lowered intothe well casing by the sucker rods, and when it reaches the desired pumping position (after having been located in place by suitable means provided for that purpose) the mandrel is moved into the packer to seal the pump in the well.

Thereafter, the sucker rods are reciprocated to move the piston in the working barrel and thus force oil upwardly through the working barrel, the drain tube, the pump head and the well casing.

type from the well, it is necessary to lift the mandrel out of the packer so that the seal between the latter and the well casing may be broken. The column of oil lying between the pump proper and the ground surface, however,

' still bears on the packer and hinders withdrawal of the pump. It will be understood that a large amount of oil is held in the casing of a deep weil, so that the hydrostatic pressure may be very great. Although it has been proposed to overcome the attendant diilculties by providing drainage ports below the packer, this expedient is of limited eilectiveness due to the restricted space which may be available, the resilient or flexible construction of the packer and the high hydrostatic pressures that may prevail.

Y It is therefore the object of this invention to provide a new and improved casing pump construction which equalizes hydrostatic pressure on the packer and gives positive drainage of liquid through the pump itself after the mandrel has been unseated, thereby increasing the emciency of the pump while retaining all of the desirable features of the aforesaid known type of' pump construction.

When it is desired to remove a pump of this Other objects and advantages of my invention will be apparent from the following detailed description of a preferred embodiment thereof, when considered in connection withthe accompanying drawing, in which Figure 1 and Figure 1a are longitudinal views. partly in cross section, showing, respectively. upper and lower portions of an illustrative pump mechanism as located in a well casingvwith the packer unsealed;

v Figure 2 is a transverse cross section substantially along line 2-2 of Figure 1;

Figure 3 is a transverse cross section substantially along line 3--3 of Figure 1; and v Figure 4 is an enlarged longitudinal cross section showing part of the mechanism of Figure 1 with the packer sealed against the well casing, as when the pump is ready for operation.

I have found that the eiiiciency of casing pumps may be improved and that diiilculties incident to the withdrawal of such pumps from oil wells may be substantially reduced by providing the pump with means for effecting positive well; but when the mandrel is raised out of the packer to break the seal between the latter and the casing, a new arrangement of drainage facilities comes into operation which gives positive drainage of liquid from the drain tube and avoids the objectionable pressure conditions and the ineilicient drainage that have been characteristics of known casing pump constructions.

The new pump construction is illustrated in Figures 1 and la as the parts are associated when the pump is ready to be sealed in the well, casing I 0, or to be withdrawn from the casing after the completion of pumping opera.- tions. A pump rod I2 extending into the pump is connected with the usual string of sucker rods (not shown), or the equivalent. 'I'he lower end of the pump rod (Figure 1a) is connected to a pump piston or sucker Il which carries a travelling valve I6 and sealing rings or gaskets I8 and which is reciprocable by rod i2 in a working barrel 20. A valve housing 22 at the lower end of the working barrel encloses a standing valve 24 through which oil is admitted from the well into the working barrel on the upward stroke of piston Il.

An expansible packer l0, of rubber or other similar resilient material, is located near the upper end of the pump and is connected with the upper end of the Working barrel 20 by tubular means including, in the illustrated form, a flanged ring 32, a. drain sleeve 34 and suitable tubular coupling sleeves 36 and 38. The packer 30, as shown in Figure 1, is normally spaced inwardly from the inside surface of the well casing I0. Above the packer and surrounding rod I2 is a pump head 48 which terminates at its lower end in a mandrel 42 having a tapered cam surface. The head 40 provides a hollow space 44 surrounding the pump rod, which space communicates with the well casing above the packer through lateral ports 46. The mandrel 42 is adapted to enter packer 30 and to force the same into sealing engagement with the casing I0, as shown in Figure 4. Depending from mandrel 42 in spaced relation to the pump rod I2 is a drain tube 48, which is of such length as to extend substantially to the working barrel 23 when the pump is located and sealed in operating position. It will be observed that the drain tube 48 extends downwardly from mandrel 42l inside of the packer 30 and inside of the tubular means 32, 34, 36 and 38.

As shown in Figures 1, 3 and 4, cooperating means are providedon drain tube 43 and drain sleeve 34 for limiting axial movement of the mandrel relative to the`packer. In the illustrated form, such means includes spaced recesses or slots 50 in sleeve 34 and fitting tongues or lugs 52, on drain tube 48, which are movable vertically to a limited extent in the slots 50. At a location above slots 50, the drain sleeve 34 carries a sealing ring or packing 54 which engagesthe outer wall of the draintube 48 and prevents entrance of liquid into the underlying intervening space. Further sealing means are provided between the drain tube 48 and the aforesaid tubular means, in the form of a packing ring 56 that is located in an annular recess between sleeves 36 and v38 in position to engage the outer surface of the drain tube. The pack-y ing 56 is preferably a chevron packing.

In accordance with this invention, as shown in Figures 1, 2 and 4, the tubular means connect-v ing the packer 30 with the Working barrelii'n this instance at sleeve 36), is provided above the packing ring 56 with a series of radial drainage ports 60 which lead from the inside of sleeve 36 to the annular space between the outer surface of sleeve 36 and the well casing I0. For' cooperation with these drainage ports 60, the drain tube 48 also Iis provided with a series of radial drainage ports 62. As shown in Figures l, these ports 62 are so located that when the tongues 52 are positioned near the upper ends of their respective slots 50, thatis, when the pump head 40 and mandrel 42 have been withdrawn from the packer 30, the ports 62 of the drain tube register with the ports 60 of sleeve 36 and thus provide openings for positive drainage of liquid from the drain tube through the same and sleeve 60 and into' the surrounding space of the well casing. When, however, the pump head and mandrel are moved downwardly to a position sealing packer 30 against the casing I8, the drainage ports 62 of the drain tube pass downwardly to a position below the packing 56. This position of the pump, which corresponds to the operating position, is shown in Figure 4. It will be understood that the packing 56 then serves to block ow of liquid from ports 82 to ports 60 and that the pump. when so assembled and operated, causes liquid to be forced upwardly through the working barrel, the drain tube, the pump head and the well casing without leakage or loss of pressure.

In the use of the new pump construction, the pump is lowered into the well casing by a string of sucker rods in the usual manner, mandrel 42 being spaced from packer 38 with tongues 52 at the upper limits of slots 50, as shown in Figure 1. When the pump has reached the desired pumpl0 ing position, it is located in place either by resting upon a suitable preformed obstruction or by the use of a suitable anchoring device of conventional construction (not shown). The weight of the working barrel assembly is then removed from the tongues 52, and upon further downward movement ot the rods the tapered mandrel 42 moves into packer 30 and seals the same against the casing. In this position, as shown in Figure 4, the drain tube 48 also is sealed with respect to the surrounding tubular means 32, 34.

rel 26 through standing valve 24, and from the working barrel the liquid is forced through travelling valve I6 and upwardly through the drain tube, pump head and well casing.

Upon termination ot pumping operations, the

pump assembly may be removed from the Well by lifting the pump rods abovey their normal working position so that certain lugs I3 on rod I2 strike the upper part 'of head 40. Further lifting of the rods raises head 48 and drain tube 48 and forces mandrel 42 out of packer 30, allowing the seal between the packer and the well ycasing to be broken. As the drain tube moves independent of the working barrel assembly until the tongues 52 reach the upper limits of slots 50, the drainage ports 62 of the drain tube pass above packing 56 and thereupon establish direct communication between the inside of the drain tube and the surrounding casing through the drainage ports 60 in sleeve 35. This positive drainage o1' liquid from the drain tube equalizes hydrostatic pressure on the packer and effects a `comparatively napid drainage of liquid from the pump, thereby permitting the pump readily to be withdrawn from the well and avoiding difliculties that have been encountered heretofore.

As shown in Figures 1 and 4, the drain sleeve 34 may include drainage ports 'I0 at a point located above the sealing'ring 54. These ports may accommodate a certain amount of drainage inside the packer 30 after the mandrel has been unseated, according to known practice.

While I have illustrated and described details of a particular embodiment of my invention, I understand that the invention may be embodied in other forms of construction without restriction to these particular details. I therefore desire that the invention be accorded a scope comi mensurate with its novel contributions to the art, as intended to be set forth in the appended claims.

I claim:

l. In a well pump, a working barrel having a standing valve adjacent its lower end and a piston with travelling valve reciprocable therein by means of a suitable pump rod. an expansible paoker and said tubular means, drainage means opening through the wall of said tubular means;r

sealing means between the drain tube and the tubular means below said drainage means, and

drainage means opening through the wall of said drain tube, the last-recited drainage vmeansA being located below said sealing means when vthe mandrel is positioned within the packer and above said sealing means when-the mandrel is withdrawn from the packer.

2. In a well pump including a working barrel,

a -pump piston reciprocable in the barrel by a suitable pump rod, an expansibie packer con-j nected with the upper end of said `working' bar-A rel by intermediate tubular means, a mandrel.n movable into said packer for expandingv thefsame'* into sealing engagement with aw'ell-c asiifrg,'andr a drain tube depending from theman'drel into said tubular means, cooperating mean's'onv saidv drain tube and `said tubular means `tnrlimiting axial movement of the mandrel relative tothe Y, packer, liquid drainage ports in the wall oi vsaid tubular means, sealing means between'rsaid vdrain and liquid drainage ports in the wall of said drain tube, said last-recited ports being located below said sealing means when the mandrel is positioned within the packer and above said sealing means when the mandrel is withdrawn from the packer. i

3. In a well pump having a mandrel, a drain tube depending from the mandrel. tubular means surrounding the drain tube and an expansible packer carried by the upper, end of said tubular means to be expanded into sealing engagement .with a well casing by downward movement of said mandrel. `cooperating tongue and slot means on said drain tube and tubular means for limiting axial movement o1' the former relative to thel latter, radial drainage ports in said tubular means below said tongue and slot means, sealing means between said tubular means and said drain tube below said drainage ports. and radial drainage ports in said drain tube positioned to register with the aforesaid drainage ports when said mandrel is located above said packer.

tube and said tubular means below said ports,J

HUBERT D. COLLINS.

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