US2111177A - Well pump - Google Patents

Description

2,1llgl77 W. F. COX

WELL PUMP March 15, 1938.

Driginal Filed Aug. 29, 1935 www AQ M A Patented Mar. Al5, 1938 UNITED STATES PATENT OFFICE Original application August 29, 1935, Serial No. 38,449. Divided and this application October 31, 1936, Serial No. 108,658

4 Claims.

This invention relates to improvements in well )pumping apparatus and, particularly, to oil well pumps of the type wherein the space between the pump and well wall or casing is sealed at a point 5 along the exterior surface of the pump structure. The sealing of this space is accomplished by means commonly referred to as a packer, which usually comprises a radially expandable sleeve carried by the pump and a tubular mandrel which, under certain conditions, can be moved to a position within the sleeve to expand the latter into sealing engagement with the well casing. In the event the pump is to, be withdrawn from the well for repairs, cleaning out the well, or the like, Ait is necessary to disengage the mandrel from the sleeve, usually by raising the mandrel in the well hole. However, in casing pumps, i. e., that type of pump which flows the liquid through the well casing to the surface of the ground, the liquid above the seal or packer exerts a tremendous pressure on the packer mandrel and to relieve this pressure preliminary to withdrawing said mandrel from the packer sleeve, means are provided for by-passing the liquid from above the packer to a point below the packer. Preferably, one or more by-pass ports are provided in the pump cylinder wall and the flow of liquidl through said ports is controlled by a valve which, in the present invention, is yieldingly urged toward its port-closing position by a spring. When said valve is moved toward its open position, said spring will, of course, be compressed and the primary obiect oi.' the present invention is to provide means for limiting the compression of said spring, or preventing said spring going solid whereby the life thereof is materially prolonged. Briefly, therefore, .the invention may be said to contemplate the provision of means for by-passing liquid from abovethe well sealing devices, such means 40 comprising a spring seated valve for the by-pass or drain port and means for preventing excessive compression of said spring.

With these and other objects in view, the inv vention consists in certain details of construction and combinations and arrangements of parts, all as 'will hereinafter be more fully described and the novel features thereof particularly pointed out in the appended claims.

In the accompanying drawing- Figure 1 is a vertical Lcross-sectional view through the well-casing and a portion of a pump mechanism illustrating the preferred embodiment of the present invention, the parts being in the position they occupy as the pump is lowered into 55 the well; and

Fig. 21s a similar view, illustrating the essential elements of the present invention, in the positions they occupyI when the pump is operatively positioned in the Well.

'I'he present application is a division of appli- 5 cants co-pending ,application Serial No. 38,449, wherein the pump structure proper illustrated in the present instance is more fully disclosed and claimed. The present invention can, of course, be utilized. in various constructions of pumps but l0 in the preferred pump structure illustrated, there is an upper conical member or hollow mandrel 3|, and a lower cylindricalmember 32 which is, in effect, an extension of the pump cylinder or Working barrel 4|, being connected to the work- 15 ing barrel proper by a tubular coupling member 32h. The conical outer surface of mandrel 3| tapers downwardly toward the cylindrical surface of member 32 and these surfaces are coaxially arranged. The bore of cylindrical member 32 20 opens into the interior of the hollow mandrel 3|, the latter being provided with a number of openings 33, through which oil passing upwardly from the pump cylinder will flow into the well casing indicated at 20. Mandrel 3|is provided with a 25 bore 34 for the accommodation of the lower end of the sucker rod string 45 which extends from within the pump cylinder to a point above the ground surface whereby the pump may be raised and lowered in the well and the pump piston 43 30 reciprocated in the pump cylinder. Of course, other means, such as cables, etc., may be utilized for raising and lowering the pump and actuating the piston, if desired. Slidable axially on the working barrel or cylinder of the pump is a cy- 35 lindrical slide 35 to the lower end of which there is connected what is commonly called the shell of the pump. 'I'he shell l's indicated at 2| and at the upper end of said slide 35 there is secured an expansible sleeve 31 of rubber or some similar 40 substance, the lower end of said sleeve being interiorly'grooved and receiving an annular ilange 3B on the upper end of the vslide whereby said expansible sleeve is firmly secured on the slide. Downward movement 'of slide 35 on the pump 45 cylinder is limited by a stop 4|a on the pump barrel, said stop preferably being formed by the collar by which the cylindrical member 32 is secured to coupling member 32h. Said collar 4|a is adapted to be engaged by the lower end of the slide 35 to arrest its downward movement relatively to the pump cylinder. At the lower end of the pump cylinder, there is a standing valve 42 which may be of any desired construction, and the pump piston, which may also be of any wellknown type, carries the traveling valve 43a. As is well known, reciprocation of the sucker rods and piston causes oil to first be sucked through standing valve 42 upon the up stroke of the piston, which oil, on the downward stroke of the piston unseats and passes traveling valve 13e.

' Various means, well known in the art, may be provided for supporting the pump proper at the desired pumping elevation in the well hole, but as these means form no part of the present invention, they are not shown or described. Sufiice .it/to say that the pump lar-supported 'on the y ucker rod 45 while it is being lowered into the working position with the pump barrel and, as will be later described, the by-pass will be sealed oil, so that the pump is ready for operation. Should it be desirable to removethe pump, or to adjust its position in the Well, it is only necessary to open the by-pass, as will be later described, in order to relieve the pressures above the mandrel 3|, after which the sucker rod is raised to remove mandrel 3| from the packing member 31.

As before mentioned, it is quite advantageous to by-pass oil from above the mandrel 3| when lt is desired to raise the pump, because the pressures imposed upon the mandrel, particularly in the deep wells of today, are such that it is quite difcult to break out the sealing or packing element so long as those pressures exist and the force required may be great enough to cause breakingof the sucker rod string. The particular arrangements for by-passing the oil above the mandrel are shownand described in detail in my ,copendlng application, Serial N o. 38,449. scribed briey, these means consist of ports 90 in the cylindrical extension 32 of the pump barrel and ports 9| in member 35 and a sliding tubular valve carried on the sucker rod 35 for controlling the ow of oil from within the pump to the exterior thereof. As shown in Fig. 2, when the pump is in pumping position, a coil spring 92 surrounding the sucker'rod and-interposed between the upper endof the mandrel 3| and sliding valve 00 holds said valve depressed so that the cups |0| at -the upper end of the valve and. the cups |02 at the lower end of the valve prevent oil in the pump cylinder or in the interior of the mandrel gaining access to the ports 90, 9|'. In other words, oil drawn into the pump barrel will be forced upward through the tubular valve or sleeve |00 and into the interior ofthe mandrel and then through openings 33 into casing 20.

However, if it is desired to pull the pump, the

sucker rod is raised until collar Mb engages valve |00-and elevats it to a point where the cups |0| will be moved out of the cylinder 32, under which conditions, ,oil above the packing elements will dif-ainx baclnldwn through'therlmular space bel tween the 'tubular sleeve wl'id cylinder 32 and through ports 90, 9|, into the space between the pump shell 2| and well casing 20. Although not essential, itis highly desirable to provide a spring `92 for the purpose of depressing, or seating, the tubular valve |00. However, when the pump is being lowered or raised, the entire weight thereof is carried on the sucker rod and if the spring 92 `going solid.

gages the cross member |00a of the slide 4valve is so positioned with respect to the upper end of sleeve 52 on the sucker rod that the latter will come into contact with the bushing 34B in the mandrel head before spring 92 can go solid. In other words, the sleeve 52 which is fast on the sucker rod forms an enlargement yadapted to function as a stop for limiting the lcompression of spring 92 by abutting against bushing illl before said spring goes solid. In this way, damage to the spring by excessive pressures, particularly during-the lowering and raising of the pump, is absolutely precluded.

What I claim is:

1. In an oil well pump, a pump cylinder, means for sealing oi the well ata point along the cylinder wall, said cylinde having a port therein for by-passing liquid from above said seal to a point below theseal, a slide valve for said port, a sucker rod, an enlargement on said rod engageable with a member carried by said cylinder for raising said cylinder, a coil spring on said rod for moving said slide valve to port-closing position, one end of said spring engaging said member, and means on said sucker rod for moving said valve from its portclosing position against the pressure of said spring, the spring, the spacing of said last-mentioned means and said enlargement axially of the rod being such that said enlargement will contact said member in advance of said coil spring 2. In an oil well pump, a pump cylinder, means for sealing o the well at a point along the cylin'- der wall, said cylinder having a port therein for by-passing liquid from above said seal to a point below the seal, a slide valve for said port, a sucker rod, an enlargement on said rod engageable with a member carried by said cylinder for raising said cylinder, a coil spring on said rod for moving said slide valve to port-closing position, and means for moving said valve from its port-closing position against the pressure of said spring, the spacing of said last-mentioned means and said enlargement axially of -the rod being such that said enlargement Will contact said member in advance of for sealing oi the well at apoint along the cylinder wall, said cylinder having a port therein for by-passing liquid from above said seal to a point below the seal, a sucker rod, an abutment on said rod engageable against a portion of the pump structure for supporting the pump in the well, a slide valve for controlling flow of liquid through said port, a'spring urging said valve toward its port-closing position, and means operable by movement of said rod longitudinally of the pump cylinderifor moving said valve toward its portopening position against the pressure of said spring, the compression of said spring being limited by the engagement of said abutment with said pump structure.

4. In an oil well pump, a pump cylinder having a drain port in the wall thereof, a valve controlling the flow of liquid through said port, a spring for urging said valve toward its port-closing position, means for opening said vvalve against the pressure of said spring, and means for limiting compression of said spring when said valve is moved toward its open position.

WILLIAM FRED COX.

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