US2825288A - Oil well pumping apparatus - Google Patents

Description

F. w.-P1 E'UGER OIL. WELL PUMPING APPARATUS FiledJuly 1o, 1957 Match 4, 1958 R 6N mfp/W ATTORNEYS mf `E V N u, 7NM 3 .70 7 Z Z 3 Z. 2,2 @Y o V M M /0 A EJ 2 V 4 i y 5. 5 a, H//3% y United States Patent() OIL WELL PUMPING APPARATUS Friedrich Wilhelm Pleuger, Hamburg, Germany Application `Iuly 10, 1957, Serial No. 670,946 Claims priority, application Germany January 11, 1957 6 Claims. (Cl. 103158) This invention relates to pumping apparatus for oil wells and is particularly concerned with pumping equipment for use in the handling of relatively heavy or highly viscous oils.

The invention employs a hollow piston which is slidably mounted on the outer surface of a hollow cylinder, the latter in turn being secured to the well riser. lower end of the piston is provided with a knife-like end for facilitating its entry into the viscous oil. Interiorly the hollow piston also carries a apper valve which is opened during downward motion of the piston and closed tion being imparted by a reciprocating piston rod which extends to the surface. The invention also employs a suitable check valve above the apper valve which check valve opens upwardly to permit passage of the oil and The f seats downwardly to prevent the oil from running back rod is centrally guided in the hollow cylinder and has limited relative movement with respect thereto, the apper valve being alternately'opened and closed upon each reversal of the motion of the piston rod.

YIt is also an object of the invention to provide the rather considerable rod power which is necessary to deliver the heavy viscous oils of the type for which the pump is designed, and, at the same time, to operate the apper valve with a minimum kof wear on the valve and its seat. To this end the invention provides improved articulation between the actuating piston rod on the one hand'and the hollow piston and the flapper valve on the other hand so as to greatly minimize the'strains imparted to the flapper valve and its seat during operation of the pump.

In attaining the objectives above mentioned the piston rod is guided in a cross head which isrrigidly connected to the interior of the hollow piston, through which cross head theY piston rodhas a limited degree of sliding movement with respect thereto. At its lower end the piston rod is also provided with a suitable enlargement for supportingthe hollow piston duringthe upward kstroke of the piston rod after closing movement of the tlapper valve has been initiated. In this way the apper valve and its actuating parts are stressed by the power of the piston rod only during a relatively small part of the delivery stroke, because, immediately following the start of the upward stroke, the hollow piston with its cross head is' supported directly on the piston rod itself.

How the foregoing objectives, together with such other objectives and advantages as are incident to my invention are attained is illustrated in preferred form in the accompanying drawing wherein:

Figure 1 is a vertical longitudinal section through my improved pumping equipment with the parts in the po- 2,825,288 Patented Mar. 4, v 1958 ICC sition they assume during the downward stroke of the piston rod; and

Figure 2 is a similar section on an enlarged scale of the lower portion of the pumping equipment illustrated in Fig. 1 with the parts in the position they assume during the upward or delivery stroke of the piston rod.

The pump housing is formed essentially as a hollow cylinderV 1 which is threaded to a coupling member 2 by means of which it can be connected to the customary riser 3, ythe connection between the coupling and the riser being provided for by a tapering thread 4. The screw connection 5 between the hollow cylinder 1 and the coupling 2 is packed with a gasket 6.

A hollow piston 7 is slidably mounted on the hollow cylinder 1 and at the upper end of the hollow piston there isa stuffing box 8 which can be tightened by means of a screw ring 9. At the lower end of the hollow piston 7 is arranged a cross arm or cross head 10 within which is a guide bushing 11 through which the lower end of the operating piston rod 12 is adapted to slide.

The piston rodV 12 is extended axially through the hollow cylinder 1 and is provided at its upper end with a coupling 13 with which it can be connected to a pump actuating rod of-the usual type of construction. The apertured abutment 14`is a further guide for the piston during upward motion said upward and downward mo .I rod .12 which abutment 1s rigidly secured within the hollow cylinderv 1 and is equippedwith abushing 15 through which .the piston rod reciprocates.` The flap valve within thehollow piston takes the form of a butterfly valve 16 and this valve is arranged near the lower knife-like end 38 of' the hollow piston. The valve 16 is mounted pivotally on a pin 17 mounted at opposite ends in the'walls ofthe hollowpiston 7. Rigid withv the butterilyvalve 16 is a swivel arm 18 is connected and this arm has an oblong hole 19 which cooperates with the pin or bolt 20, the latter being arranged tov move back and forth in the hole 19.. During downward movement of the rod 12 the pin slides into position where a torque is attained around the axis of the pin 17 which torque vopens the buttery valve 16. During downward movement of the rod the bolt-20 slides back into its original position the arrangement being such that there is. little if any stress placed upon the parts so that .deflection or bending of the pump rod12 is avoided.

By means of the bolt 20 and a fork 21 a spring plunger a 22 projects upwardly into a socket 23, which latter is f or toward each other.

closed with a connection nut 24. Between the connection nut 24 and an abutment on the end of the spring plunger 22, a compression spring 25 is inserted which biases the spring plunger 22 and the socket 23 together The socket 23 has a plurality of equalizing openings 26 by which the oil being pumped can enter on both sides of the end of the spring plunger.

The piston rod head 27, which is screwedv to the rfree end of the piston rod by means of a Ythread 28 and is secured in position by means Vof a bolt 29, constitutes the connecting linkbetween the socket 23 and the lower end of the piston rod 12, the lower end of the piston rod head 27 being pivotally connected with the spring socket 23 by the connection bolt 30.

Above the cross head 10, there is provided a ring shaped valve seat 31 within the hollow cylinder 1 and this valve seat cooperates with a cone-shaped valve member 32 having a central opening by means of which it is arranged to surround the piston rod 12 and slide with respect thereto. To provide for satisfactory packing of the valve member 32 with respect to the piston rod 12, a stuffing box is arranged in the interior of the valve member 32 which consists of C-ring packing 33 and a screw nipple 34. The screw nipple 34 is provided with a sleeve-like projection 35 on which the closing spring 36' of the check valve is guided. The abutment 14 is provided with openings for passage ofthe oil, and this abutment serves as a support for one end of the closing spring 36,as well as forl guiding lthe piston rod,12 in its .bushing 15.

The abutment 14 serves additionally as a means. for limiting the pump stroke in the lower dead center. On the upper side of the abutment piece 14', a crown-shaped projection 39 is provided which cooperates with a crownshaped projection 40 on the upper end of `the rod in the immediate t vicinity of the rod screw connection 13. These two crown-shaped projections are arranged to prevent initial angular movement in installation and disassembly of the pump. This provides a safety factor in that in loosening the screw connections of the rods, the turning or twisting movement of the piston rod 12 with respect to the remaining parts of the pump, is prevented.

Operation of the equipment may be summarized as follows. The pump is introduced in vertical position into the petroleum bore hole and the coupling 2 is screwed to the lower end of the customary well riser. The coupling 13 of the piston rod is connected with a motor driven upwardly and downwardly reciprocating actuating rod in the usualmanner.

In the downward motion of the piston rod 12 the parts of the pump assume the positions indicated in Figure 1. Here` thepiston rod head 27 is separated from the cross head and by means of the two-piece inter mediate lever 22,23 the buttery valve 16 is swung until itcomes to its fully opened position against its stop 37 in the hollow piston. By virtue of the power transmitted from the piston rod 12 by means of the inter,- mediate lever 22, 23 as well as by the buttery valve pin 17 and also by its own weight, the hollow piston 7 is moved downward to press its sharpened end `38 into the viscous heavy oil to be delivered from the well.

After the piston rod reaches `its lowest point the direction of movement changes and it begins to move upwardly and the initial upward movement occurs without` takingl along the hollow piston 7 because the piston rod head 27 is not yet in position at the cross head 10. In this initial movement of the piston rod, the buttery valve 16 is moved from its open `position shown in Fig. 1 toward the closed position shown in Fig. 2. Because the viscous oil offers considerable resistance to movement of the buttery valve 16, the closing of this valve can occur somewhat more slowly than it would in the event that the parts were rigidly fixed to each other. The difference of speed between the rotating movement of the buttery valve 16 and the stroke movement of the piston rodis compensated for by the compression spring 25 in the two-part intermediate lever 22, 23'.` By virtue of this spring arrangement 25, the closing ofthe buttery valve can occur somewhat delayed and can be continued after the piston rod head 27 has already engaged the cross head 10. The stud bolt connection 19, 20 compensates for relative movement and serves to assure satisfactory closing of the butterfly valve 16 under the influence of the spring 25.

After the tlap valve 16 is closed and the piston rod y 4 head 27 actuates the cross 7 together with the quantity of heavy oil trapped therein by the buttery valve 16 is moved upward with respect to the stationary hollow cylinder 1. This forces the heavy oil past the cross head 10, through the central valve seat 31, and raises the valve cone 32 against the pressure of the spring 36, the valve 32 seating downwardly to prevent runback after reversal of the piston rod stroke. Above the `valve conek 32, the oil moves upward through the bore in the abutment 14 and then along side of the piston rod 12 and past the connection 13 to and through the riser 3 until it reaches the surface.

I claim:

1. Pumping apparatus for an oil well having a riser and a piston rod, `comprising a hollow cylinder secured to the riser, a hollow piston slidably mounted on the outer surface of the cylinder, a cross head for the piston rod secured to the inner wall of the hollow piston, said piston rod being mounted to project through and to slide with respect` to the cross head, an enlargement securedV to the piston rod below the` cross head, which enlargement is adapted to be moved away from the cross head on the downward stroke of the piston rod and to be returned to engage the cross head on the upward stroke of the piston rod, whereby the hollow cylinder is supportedby the piston rod, a ap valve in thehollow piston below the cross head, said tlap valve being adapted to control ow through the hollow piston, a resilient operating connection between the ap valve and the end of the pistonrod, said Hap valve and its operating connection being constructed and arranged to effect openingof the valve upondownward movement of the piston rodgand closing thereof upon `upward movement of the piston rod, and an upwardly opening check valve above the cross, head.

2.` Pumping apparatus according to claim 1 wherein the flap valve is formed as a butterfly valve and wherein the operating connection includes a pair of telescoping members with resilient means biasing them toward each other.

@Pumping apparatus according to claim 2 wherein one telescoping member is joined to the `butterfly valve by a pin guided in an elongated hole.

4. Pumping apparatus according to claim l wherein the check valveslides on the piston rod and seats on a ring-shaped seat secured to the hollow cylinder.

5. Pumping apparatus according to claim 4 wherein the check valve is provided with a stuing box and packingarourid` the piston rod.

6. Pumping apparatus according to claim 4 wherein an` abutment member is fixed in the hollow cylinder above the checktvalve and, further, wherein a spring reacts between said abutment member and the check valve.

vReferences Cited `in the le of this patent STATES PATENTS 2,630,757 Cartier Mar. l0, 1953 FOREIGN PATENTS 23,271 Great Britain Nov. 30, 1894 head 10, the whole piston`

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