DE1254968B - Hydraulically operated multiple piston pump for pumping oil from deep wells - Google Patents

Description

Hydraulically operated multiple piston pump for pumping crude oil from deep boreholes The invention relates to a hydraulically operated multiple piston pump for the extraction of crude oil from deep wells with at least two coaxial, hydraulically operated pumping devices connected in tandem is. Each of these pumping devices can absorb the load with a pump power, and each can actuate a control valve member that controls the pump output to be applied successively allocate the pumping devices and each of them this pumping capacity can dispose of again after the pumping power of the other of this pumping device has been allocated.

The invention aims to provide a pump for the aforesaid Purpose, with the smallest possible occurring hydraulic shocks very allow high performance to be achieved. Namely, this freedom from hydraulic Shock in particular by establishing an approximately steady flow both the working fluid with which the pump is operated hydraulically, as well as the extracted petroleum can be achieved. In particular, the invention aims to provide a hydraulically operated pump, appropriately referred to as a multiple pump can be and the two or more hydraulically operated pumping devices with drive devices connected in parallel and pump devices connected in tandem possesses, this multiple pump including controls by which these pumping devices, coordinated in time, with previously defined phase relationships can be operated to each other that at any time at least one of the pumping devices executes its working stroke. A related purpose of the invention is the creation of a multiple pump with two or more hydraulically operated Pumping devices in which only one of the pumping devices is at any given moment Performs return stroke while the rest of the pumping device or pumping devices Executes or executes the working stroke or their working strokes.

Another purpose of the invention is to provide a hydraulic operated multiple pump, in which the control valve member the working strokes of the Can pumping devices overlap such that when each pumping device the Approaching the end of its working stroke, the pumping capacity is gradually reduced by a pumping device is transferred to the other. In other words, it is another purpose of the invention to create a multiple pump with a control valve member that controls the working stroke of the acting driving and the pumping device of the next pumping device in the Series initiates when the driving and the pumping device of the previous one The pumping device is approaching the end of its working stroke.

There are already pump types in oil drilling operations where the working cylinders are controlled by main control devices to the auxiliary control devices act in such a way that a results in practically shock-free conveying operation. Also multi-cylinder pumps are without mutual mechanical coupling of the individual pumping devices known in which besides the common main control devices pilot control devices are provided, which are designed partly as regulating and partly as pre-selection organs, of which the the former reverse the main control element in its end positions and the latter within a certain area in which the drive piston approaches its end position, reverse this in such a way that a constant overall performance of the conveyor system is achieved, and provided as control organs and grids and stops are. In the first-mentioned types, however, the pumping devices are not coaxial arranged. which is the rule for a pump system intended for greater depths, and the latter type is suitable for double-acting multi-cylinder pumps, which for the following reasons less for the purposes pursued by the invention in Come into consideration. A double-acting pump does have a single-acting pump compared to the considerable ones Advantage that both strokes are working strokes are so that the piston speed is fully utilized, while with the simple acting pump practically only half the piston speed is used. the However, the displacement of the liquid to be conveyed is usually not twice as much that of a corresponding single-acting pump, since the pistons of a double-acting Pump because of the additional, for the working fluid and the pumped or so-called extraction liquid channels required to be smaller in diameter must than that of a single-acting pump. Enable double-acting pumps on the other hand, a more uniform flow of the working and the recovery liquid and therefore cause hydraulic shocks in the conveyor system less often than single-acting ones Pump. However, the piston devices of double acting pumps must be at each end stop their stroke, causing sudden interruptions in the working and extraction liquid flow and the tendency to the occurrence of hydraulic shocks brings with it. However, these sometimes lead to mechanical damage, such as breaks and underwashes, as well as expensive repairs. All single and all double acting Pumps also have a tendency to run away when the pump cylinder is not completely filled with liquid acting as a compact mass. In the state of the art associated hydraulically operated pumps must be used to avoid such Runaway regulating devices of some kind are provided, adding to the complexity of the plant increased. Although various features of the present invention include both be embodied in a single-acting as well as in a double-acting pump but the invention is preferably applied to a single-acting pump Execution applied as the basic invention with a pump this Art can be achieved and so the complicated design of the double-acting Pump is avoided. However, it remains with the single-acting pump aside from theirs greater tendency to generate hydraulic shocks as a result of intermittent work both the working and the recovery fluid a disadvantage that only one of their strokes is a working stroke and therefore the desired high performance of the system must be achieved by a high piston speed of the pump.

There are also known types of pumps in which cooperating Drive cylinders are controlled by main control devices, which are controlled by a Auxiliary control device controlled by the piston on its working stroke, control fluid is fed; by delaying the return stroke of one cylinder piston, which lasts until the other cylinder piston has been controlled to the delivery stroke is, a uniform delivery of the liquid is brought about. The disadvantage these as well as similar types of pumps with control elements actuated by the pumping devices is that a lot of mechanically operated, sometimes spring-loaded valves must be provided.

The invention has set itself the task of that pursued by it Aim of the most uniform possible promotion of high performance with the simplest possible Means to achieve. In the invention it is proposed to meet this The task of the control valve organ that the pump power to be applied to the pumping devices assigned and disposed of them again, hydraulically actuated and Include valve devices, their number, the number of pumping devices and which control the respective pumping device. Appropriately stands each of the pumping devices for actuating a valve device other than that, from which it is controlled by a liquid with the control valve member in Connection, whereby these valve devices are connected to one another by a liquid Are connected so that one valve device is always actuated by the other can be.

This arrangement has the advantage that by using two or several hydraulically operated pumping devices have a much higher pumping capacity can achieve than it was previously achievable under comparable conditions. Also, since the pumping devices are timed, they move with their strokes partially overlapping relationship to one another and with parallel-connected, driving devices and pump piston devices connected in tandem are operated, the working fluid flowing through the shaft piping and recovery liquid streams connected to the multiple piston pump, on the whole constant and hydraulic shocks only occur to an extremely small extent before. Furthermore, since the pistons of the pumping devices can be connected in tandem and the pump capacity varies in each embodiment, the three or more pumping devices comprises, distributed to the pistons of two or more pumping devices, either the pressure of the working fluid or the surfaces of the driving pump elements, on which the working fluid acts can be reduced.

As for the design options of the hydraulically operated deep well pump concerns, whose working fluid usually pure crude oil is chosen, so are the driving and the piston devices of the pump in a pumping device united, whose control valve member are either combined with the pumping device or a separate body. In the former case there will be a pumping device and control valve element installed together in the borehole or removed from it, while in the second case the pumping device and the control valve member are independent be installed in or removed from the borehole from each other. The deep well pump can also be built as a free or built-in pump; when applying the former embodiment, it can be used from its operating position in the wellbore Earth's surface and vice versa moved through one of the pump tubes of the pipe system so that if the pump needs to be removed, the pipe system does not need to be expanded. When using the second embodiment on the other hand, when the pump is removed, at least part of the pipe system must be removed because the pump is attached to one of the pipe sections.

The invention will now be explained with reference to the drawings using two embodiments, a duplex and a triple pump. Of the drawings, FIG. 1 shows a diagram of a hydraulically operated duplex pump according to the invention, FIG. 2 shows a representation of a hydraulically operated triple pump according to the invention, also shown diagrammatically. Duplex pump 10 Looking at FIG. 1 it is seen that in this a duplex pump of the invention is 10, the two independent but inter-related, coaxially located and hydraulic pump devices 12a and 12b includes the self again hydraulically operated, connected in tandem pump devices 14 a and 14 b, each of which can absorb the load with a pump power. As will become apparent in the further course of the description, each of these pump devices has its own hydraulically operated, driving device and its own pump devices, the two driving devices being connected in parallel to one another and the two pump devices in tandem. The two pumping devices 14 a and 14 b are actuated by a control valve element 16, which successively allocate the pump output to the pump devices and each of these pump devices can dispose of this pump output again after the pump output of the respective other of these pump devices has been allocated. The control valve member 16 includes independent but interrelated stationary valve devices 16 a and 16 b, where these valve devices represent and parts of the pumping devices 12a and 12b control the pumping devices 14a and 14b, respectively. As can be seen, the number of valve devices is the same as the number of pump devices, and the control valve member 16 is arranged on the longitudinal side of the pump devices and at a distance from them.

The above-listed parts of the deep drilling pump 10 are through a working fluid is actuated, which is supplied through the inlet pipe 18 under pressure will. In the particular execution that this figure represents, the consumed one is used Working fluid returned to the earth's surface through a return pipe 20. A delivery pipe 22 is used to pump up the pumped up by the pumping devices 14 a and 14 b To convey extraction liquid to the surface of the earth.

The pumping devices 14a and 14b comprise each united impulsive acting devices and pump piston or -kolbenvorrichtungen 24 a and 24 b. The pistons 24 a and 24 b again include plungers 26 a and 26 b, which can slide up and down in the cylinders 28 a and 28 b, and also include the shafts 30 a and 30 b, which the plungers 26 a and 26 b with the slidable in the cylinders 34a and 34b in upward and downward directions plungers 32a and 32b connect and through the walls of the bores 36 a and 36 b. pass through them tightly against them.

The pump pistons 24a and 24b are for a liquid that is pumped from an inlet 40 fro in the conveying tube 22, with passing through them in the axial direction of passages 38 a, provided b 38, wherein these passages are connected in series, and a reverse flow of fluid through the working valves 42 a and 42 b is prevented. As will become clear in the further course of the description, each time the working stroke of one of the two pistons 24a, 24b, which represents its upward stroke, is initiated before the end of the working stroke of the other pump piston (so that one of the pump pistons is always on its Working stroke is), one of the working valves 42 a, 42 b closed, so that a backflow of the liquid from the delivery pipe 22 to the inlet 40 is prevented. This eliminates the need for one or more suction valves, which is an important feature of the invention. The desired phase shift of the working strokes of the pistons 24a and 24b against each other is maintained by the control valve member sixteenth

As already said above, during the execution of the working stroke of each of the pistons 24 a and 24 b, the corresponding valve 42 a, 42 b is closed so that the liquid sucked in by the action of the piston in question is pushed up through the delivery pipe 22. During the return stroke of each of the pistons 24a and 24b, the downward stroke of this piston, the corresponding operating valve 42a, 42b open, so that the sucked by pumping action of fluid from the bottom of the respective piston by the respective passage 38 a or 38 b therethrough may over flow in the overlying b cylinder 28a or 28th

The piston 24a is forced to perform its working stroke by applying the pressure of the working fluid in the supply pipe 18 to the lower surface of the plunger 26a and the pressure of the used working fluid or discharge pressure in the return pipe 20 to the upper surface of the plunger 32a, whereupon it goes upward liquid sucked through the conveyor tube 22 through pushing up and other fluid through the axial passage 38 b in the piston 24 b pass aspirates. In the same way, the piston 24b is forced to perform its working stroke, and when it goes up, it pushes sucked liquid up through the axial passage 38a in the piston 24a and sucks in new liquid through inlet 40. The return stroke of the piston 24a is effected by causing the pressure of the working fluid to act on both the lower surface of the plunger 26a and the upper surface of the plunger 32a; the latter area is slightly larger than the former, so that when both surfaces are subjected to the same pressure, the piston 24a moves downward and makes its return stroke. Since it is only necessary to effect the return stroke of the piston 24 a, the mechanical friction between the plungers 26 a and 32 a and the cylinders 28 a and 34 a and the fluid friction to be overcome by the flow of sucked fluid through the axial passage on the working valve 42a arises, the upper surface of the plunger 32a need only be slightly larger than the lower surface of the plunger 26a. The return stroke can, for. B. caused by making the diameter of the cylinder 34a a few thousandths of an inch larger than the diameter of the cylinder 28a. The return stroke of the piston 24 b is generated in exactly the same way, so that it is unnecessary to go into it.

Looking at the manner in which the pressure of the working fluid and the outlet pressure are exerted on the pistons 24 a and 24 b so that the above working strokes are carried out, the working fluid pressure is continuously passed through a main passage 44 and the branch passages 46a and 46b to the lower ones Areas of the plungers 26a and 26b exerted, the main passage being connected to the delivery pipe 18 and the branch passages being in communication with the cylinders 28 a and 28 b. The controlled by the valve devices 16a and 16b, passages 48a and 48 b which are either Arbeitsflüssigkeits- or outlet on the upper surfaces of the plunger 32 a and 32b can be, associated with the cylinders 34a and 34b in connection. If the discharge pressure on the upper surfaces of the plunger exerted 32a and 32b and that the power strokes of the piston 24 a and causes 24b, connect the valve means 16 a, 16 48 b the passages a and 48 b via the channels 50a and 50 b with the Rückströmrohr 20. Conversely, connect the valve devices 16a and 16b, if working fluid pressure is applied to those surfaces, to effect the return strokes of the pistons 24a and 24b, the passages 48a and 48b with the branch passages 52a and 52 b, with the from the conveyor tube 18 coming from the main passage 44 are in communication.

Looking at the control valve member in detail, the valve devices 16a and 16b include known motor valves 56a and 56b , which can be moved up and down by surfaces of different sizes, with plungers 58a and 58b , which are connected to the plungers by the shafts 62a and 62b 60 a and 60 b are connected, the plunger, as shown in FIG. 1 shows, are displaceable in suitable bores or cylinders, on the walls of which they are liquid-tight. The bores for the plungers 58a and 58b are with the reference numbers 64 a and 64 b, the bores for the plungers 60a and 56b with the reference numbers 66a and 66 b and the bores for the shafts 62 a and 62 b with the reference numbers 68a and 68b designated.

The working fluid pressure is through the branch passages 70a and 70b, which lead from the main passage 44 to the upper ends of the bores 64a and 64b. continuously exercised on the upper ends of the valves 56 a and 56 b. The passages 52 a and 52b are connected to the lower ends of the bores 64a and 64b in combination, so that the working fluid pressure is continuously exerted on the annular surfaces at the lower ends of the plungers 58a and 58b. The annular surfaces at the upper ends of the plungers 60 a and 60 b are continuously exposed to the outlet pressure through the branch passages 72a and 72b, which are in communication with the passages 50a and 50b coming from the return pipe 20, the latter also being exposed to the between the ends of the same lying bores 64a and 64b are in communication. The pressures mentioned in the preceding continuously a applied to the upper ends of the plungers 58a and 58b Ringflächer_ at the lower ends of the plunger and the annular surfaces at the upper ends of the plungers 60 and 60b, so the valves 56a and 56b move upward, when the pressure of the working fluid is applied to the lower ends of the plungers 60a and 60b, and move downward when the discharge pressure is applied thereto. When the lower ends of valves 56a and 56b are exposed to the outlet pressure in bores 66a and 66b, the downward usable force exerted on each valve is equal to the product of the cross-sectional area of the corresponding stem 62a or 62b and the pressure difference between unused and used Working fluid. The lower ends of the plunger exposed b 60a and 60b to the working fluid pressure in the bores 66 a and 66, it is again applied to each of the valves 56 a and 56 b applied, usable upward force equal to the product of the difference between Arbeitsflüssigkeits- and outlet times the cross-sectional difference between the respective stem 62a or 62b and the corresponding plunger, provided that both plungers of the valve in question have the same cross-sectional area.

If one also considers the type of liquid and outlet pressure exerted on the lower ends of the valves 56a and 56b , the channels 74 a and 74 b are with the lower ends of the bores 66 b and 66 a and thus with the lower ones Ends of the plunger 60 b and 60 a in connection. The channels 74 a and 74 b are in communication with channels 76 a and 76 b , which lead to the bores 36 a and 36 b, in which the shafts 30 a and 30 b of the pump device pistons 24 a and 24 b are arranged; the latter channels will always be referred to as control channels in the further course of the description. The channels 76 a and 76 b can be connected through control slots 80 a and 80 b in the shafts 30 a and 30 b when the pistons 24 a and 24 b approach the end of their working stroke, even before reaching this end with channels 78 a and 78 b. The channels 78a and 78 b, which also represent control channels, communicating with the bores 64a and 64b in connection and are uninterrupted annular channels 82 a and which are formed of the plungers 58a and 58b 82b. The latter channels are also continuously connected to the channels 50a and 50b , which lead to the return pipe 20, so that the pressure of the used working fluid prevails in the first-mentioned channels without interruption. Are the valves 56a and 56b in their lower position, so the channels 82a and 82b are even with the pump means to the cylinders 34 a and 34 b carrying channels 48 a and 48 b in connection. However, the valves 56a and 56b in their upper positions are located, so are the channels 82a and 82b with channels 84a and 84b in compound b from the bores 64a and 64 via the orifices 86 a and 86 b to the channels 74 a and 74 b.

The above-mentioned connections between the pump and valve devices 14a and 14b and 16a and 16b relate the work of these organs to one another in such a way that the flow of the extraction liquid flowing through the delivery pipe 22 and the streams flowing through the delivery pipe 18 and return pipe 20 exert pressure or consumed working fluid remain approximately the same in strength and that shocks are avoided as a result. This mutual relationship will become clear from the following description of the operation of the Duplexpump-10.

Operation of the duplex pump 10 The operation of this duplex pump is easier to understand if one keeps in mind that, as far as the operation of the pumping devices 14 a and 14 b is concerned, the valves 56 a and 56 b, the working and return strokes of the pistons 24 a and 24 b cause these pistons to perform their upward strokes when the valves are in their lower position and perform their return strokes when they are in their upper position. What 56a and 56b regards the upward movement of the valves, controls the valve 56 b, the valve 56 a and the valve 56a, the valve 56b. During the downward movement of the valves 56a and 56b 24a controls the piston valve 56 b and piston 24 b the valve 56 a.

It is assumed that the pistons 24 a and 24 b and the valves 56 a and 56 b are the ones shown in FIG. 1 assume the position shown. Under these circumstances, the piston sets 24a, as indicated by the arrow 88a, its taking place in an upward direction stroke and the piston 24 b, as indicated b by arrow 88 just reaches its taking place in the downward direction return stroke back, or has the end of its return stroke. The working stroke of the piston 24a is brought about by exerting outlet pressure via channel 48a, the annular channel 82a in the valve 56a and the channel 50a on the upper side of the plunger 32a. The return stroke of the piston 24b is through the exercise of working fluid pressure across the conduits 44 and 52b, the lower end of the bore 64 b and the Kana148 b on top of the plunger 32b causes. During the working stroke of the piston 24a, the working valve 42a is closed, so that liquid sucked in is pushed up in the delivery pipe 22. At the same time, the working valve 42b is open, since the piston 24b completes its return stroke, so that liquid sucked in flows from the inlet 40 through the piston 24b into the space between the two pistons.

As soon as the piston 24a approaches the end of its working stroke, the control slot 80a bridges the control channels 76 a and 78 a. When this occurs, the lower end of the valve 56 b is exposed to the outlet pressure via channel 74 a, control channel 76 a, control slot 80 a, control channel 78 a, annular channel 82 a in valve 56 a and channel 50 a. As a result, the valve 56 b goes into its lower position, which has two consequences: First, it blocks the upper surface of the plunger 32 b of the piston 24 b from the delivery pipe 18 and connects them via channel 48 b, ring channel 82 b in valve 56 b and Channel 50 b with the return pipe 20. This initiates the working stroke of the piston 24 b, so that the liquid sucked in is pushed up, the working stroke of this piston being initiated before the piston 24a has finished its working stroke, so that the pump output gradually from the piston 24a is displaced onto the piston 24b and a hydraulic shock is avoided, which is an important feature of the invention.

The second thing that happens when the valve 56b moves down to its lower position, is that 44 and 70 b to the working fluid pressure via passage hole 64b via the valve 56b, bore 84 b, throttle point 86 b and channel 74b lower to the Let the end of the valve 56a act. This exercise of working fluid pressure on the lower end of the valve 56 a via the choke coil 86 b leaves the valve 56a with a velocity in its upper position pass, which is determined by the throttle point and which is so great that the end of the working stroke of the piston 24a is delayed until the piston 24 reaches the full speed b on its power stroke. When the valve 56a reaches its upper position, it blocks the upper surface of the plunger 32a of the plunger 24a from the Rückströmrohr 20 and connects them via channel 44 and 52 a, under the plunger 58 a of the valve 56 a opposite bore 64 a and Channel 48 a with the supply pipe 18. As a result, the return stroke of the piston 24 a is initiated. This piston moves downward at a generally uniform speed which is quite high due to the fact that only mechanical and fluid friction has to be overcome on the way through the axial passage 38a and past the working valve 42a. The piston 24a therefore reaches the end of its return stroke before the piston 24b has finished its working stroke, and remains in its lower position until the piston 24b approaches the end of its working stroke. The desired speed of the piston 24a during its return stroke can easily be achieved by making the upper surface of the plunger 32a sufficiently larger than the lower surface of the plunger 26a.

The valve 56b is maintained during the working stroke of the piston 24b in the following manner in its lower position: When the valve 56a, as it is described in the foregoing, is in its upper position, the channel 84a through the annular channel 82 in the valve 56 a and channel 50 a with the return pipe 20 in connection. As a result, the outlet pressure prevailing in the return pipe 20 via channel 50 a, the annular channel 82 a in the valve 56 a, channel 84 a, throttle point 86 a and channel 74 a, since the channel 76 a is closed by the shaft 30 a, to the lower end of the b exerted valve 56 and thereby closing a hydraulic b toward created over the entire working stroke of the piston 24 that receives the valve 56b is in its lower position.

Summarizing what has been said, the piston 24 a, when it approaches the end of its working stroke, moves the valve 56 b downward, causing a working stroke of the piston 24 b before the piston 24a has completed its working stroke. The valve 56b moves the valve 56a upwards and thus initiates the return stroke of the piston 24a. Similarly, piston 24b controls valve 56a, which in turn controls valve 56b. In other words, when the piston 24b approaches the end of its working stroke, it moved the valve 56 a downwardly and thus initiates the working stroke of the piston 24 a, a. The valve 56a also moves the valve 56b upward and thus initiates the return stroke of the piston 24 a b. If one takes a closer look at how what has been said above takes place, the control slot 80 b bridges when the piston 24 b approaches the end of its working stroke, but before it is completed, the control channels 76 b and 78 b, so that via channel 50 b, the annular channel 82 b in the valve 56 b, 78 b control channel, control slot 80 b, 76 b and channel control channel is applied 74 b outlet to the lower end of the valve 56a. Therefore, the valve 56a goes down because the induced drag b through the orifice 86 is large enough so that, although the valve under these circumstances the main passage 44, channel 70 b, the bore located b the valve 56 64 b and channel 84 b is open to the working fluid pressure present in the supply pipe 18, even this does not raise the pressure exerted on the end of valve 56a significantly above the outlet pressure. Is the valve 56 a in the manner just described in its lower position on, so two will take place: First, the upper surface of the plunger 32a of the piston 24 is a separated from the supply pipe 18 and through passage 50 a, the annular channel 82 a in the valve 56 a and the channel 48 a connected to the return pipe 20 . Characterized the stroke of the piston 24a is introduced, which takes place b of the piston 24 before completion of the working stroke, so that again the pump performance gradually from the piston 24b on the piston 24a is transmitted and hydraulic shocks are avoided.

The second thing that happens during the downward path of the valve 56a in its lower position is that this is the lower end of the valve 56 b via the main passage 44, passage 70a, the bore located above plunger 58a 64 a, channel 84a, orifice 86 a and passage 74 a with the inlet pipe 18 connects. Thereby, the valve is converted into its upper position 56b, the upper surface of the plunger 32 separates b of the piston 24 b from Rückströmrohr 20 and connects it via the main passage 44, channel 52 b, under the Planger 58 b bore located 64 b and channel 48 b with the supply pipe 18. This causes the downward or return stroke of the piston 24 b, the latter moving downward at a sufficiently high speed that it still reaches the end of the return stroke before the piston 24 a reaches the end of its working stroke, as in the preceding has been said in connection with piston 24a. The desired return stroke is rather high for the piston 24 b achieved in that one well 32b of the lower surface of the plunger increases the upper surface of the plunger 26b against.

As already stated, the valve 56b is held in its lower position by the fact that, when valve 56a is in its upper position, the outlet pressure via channel 50a, annular channel 82a, channel 84a, throttle point 86a and channel 74a to the lower end of the valve 56b is exercised. The valve 56 a is, when the valve 56 b is in its upper position, held in its lower position that outlet pressure via channel 50 b, annular channel 82 b, channel 84 b, throttle point 86 b and channel 74 b to the lower End of the valve 56 a is exercised. The valve @ b is 56 when valve 56a is in its lower position, thereby held in its upper position, that working fluid pressure across the main passage 44, channel 70a, the upper end of the hole 64a, channel 84a, orifice 86a and duct 74a to the lower end of valve 56b is exerted. The valve 56a, when the valve is 56b in its lower position, thereby held in its upper position, that working fluid pressure across the main passage 44, channel 70 b, the upper end of the bore 64 b, channel 84 b, the throttle point 86 b and channel 74 b is exerted on the lower end of the valve 56 a.

From the foregoing it follows that in the pumping cycle of the duplex pump 10, which represents an embodiment of a deep drilling pump built according to the invention, each time one of the pumping devices 14 a or 14 b is connected to the control valve member 16 by a liquid, which another valve device 16 a or 16 b of the same as from which it is controlled, actuated; it always moves the valve of this other valve device in a certain direction. The valve devices 16 a and 16 b are again connected to one another by a liquid, one valve device always actuating the other and both devices being switched so that each moves the valve of the other device in the direction opposite to the aforementioned. The valve devices are controlled by the pump devices in such a way that when one of the latter approaches the end of its working stroke, they initiate the working stroke of the other pump device. As a result, a steady flow of the extraction liquid is achieved and hydraulic shocks both in the delivery pipe 22 and in the supply pipe 18 and return pipe 20 are avoided.

The length of time by which each of the pumping devices 14 a and 14 b precedes the other when initiating the working stroke of their piston 24 a or 24 b, depends on the attachment point of the control slots 80 a and 80 b on the shafts 30 a and 30 b away. These slots are positioned so that the second piston can reach its normal speed before the first piston has completed its power stroke. The time by which the working strokes of the two pistons 42 a and 42 b overlap is also determined in part by the throttling points 86 a and 86 b , since these throttling points also determine the speeds of the upward movement of the valves 56 a and 56 b and therefore also the Determine the times at which the working strokes of the pistons 24 a and 24 b are completed and the return strokes of the pistons are initiated. The phase shift of the working strokes of the two pistons 24 a and 24 b is therefore determined both by the attachment point of the control slots 80 a and 80 b and by the flow resistances of the throttling points 86 a and 86 b.

Since the pumping work performing parts or means of the two pumping devices 14 a and 14 b are connected in tandem to have a largely steady flow of oil as a result, it is easy to see that with the same overall diameter of the pump, the performance of the same a pump of previous design is greatly increased, which is an important advantage of the invention. Conversely, with the same pump performance as that which is volibrachi from a pump of a previous design with a larger diameter, the overall diameter of the pump can be greatly reduced. This is often very desirable from an economic point of view as the use of a smaller diameter pump allows the use of narrower tubing for the pump and hence the use of a narrower borehole and casing, thereby reducing drilling costs, well casing costs and tubing costs. This results in very large savings in investment costs. Triple pump 110 The in F i g. 2 of the drawing documents shown, built-in triple pump according to the invention, which is generally designated by the reference number 10 in this figure, comprises three pumping devices 112 a, 112 b and 112 c, which the coaxially lying pumping devices 114 a, 114 b and 114 c with one behind the other, Include parts or means performing pumping work and driving parts or means connected in parallel to one another. The pumping devices 114 a to 114 c are again controlled by a control valve member, the member 116, which in this embodiment of the invention has coaxial valve devices 116 a, 116 b and 116 c, each of which controls the corresponding pumping device 114 a, 114 b or 114 c. The number of valve devices is again the same as that of the pumping devices, and the control valve element 116 is also arranged here on the longitudinal side of the pumping devices 114 a to 114 c and is at a distance from them.

The triple pump 110 is again supplied with pressure-exerting working fluid through the supply pipe 118. In the particular construction shown, which is a closed system, the used working fluid is brought through the return pipe 120 to the surface of the earth. The liquid emerging from the pumping devices 114 a to 114 c is pumped through the delivery pipe 120 to the surface of the earth.

The pumping devices 114a to 114c are all identical to one another and essentially the same as the pumping devices 14 a and 14 b of the duplex pump 10 described above, only that two of them are provided instead of the simple control slots 80 a and 80 b of the pumping devices 14 a and 14 b. Those parts of the pumping devices 114a and 114 b, which are identical to corresponding parts of the pump devices 14 a and 14 b will be referred to below by reference numbers, in which to the respective in connection with the pumping devices 14 a and 14 number used always b Number 100 has been added. Also, since the pumping device 114 c is identical to the pumping devices 14 a and 14 b , the designation numbers for the parts thereof will only differ from the designation numbers for corresponding parts of the last-mentioned devices that instead of the index "a" or "b" the index "c" will be set. The inlet corresponding to inlet 40 of the duplex pump shall be designated by reference numeral 140 .

As the lower surfaces of the plungers are at the pistons 24a and 24b of the pump devices 14 a and 14 b also 126 a, 126 b and 126 124 c of the piston a, 124 b and 124 c through a main passage 144, and branch passages 146 a, 146 b and 146 c continuously exposed to the pressure of the working fluid in the supply pipe 118. The upper surfaces of the plungers 132 a, 132 b and 132 c are alternately controlled by the valve devices 116 a, 116 b and 116 c channels 150 a, 150 b and 150 e to the pressure of the working fluid in the supply pipe 118 and the pressure of the used working fluid or exposed to outlet pressure in return tube 120. The valve devices 116a, 116 b and 116 c close engine valves 152 a, 152 b and 152 c, which are movable between an upper and a lower position, these valves when they are in their upper positions, the channels 150a, 150 b and 150 c with the ducts 154 a, 154 b and 154 c leading to the return pipe 120 and, when they are in their lower position, the ducts 150 a, 150 b and 150 c with branches 156 a, 156 b and 156 c of a main channel 158 leading to the inflow pipe 118 . The valves 152a to 152c therefore initiate the upward or working stroke of the pistons 124 a, 124 b and 124 c in their upper positions and the downward or return stroke of these pistons in their lower positions. In the case of the triple pump 110, the relationship between the valve position and the piston stroke is therefore the opposite of that in the case of the duplex pump 10.

The valves 152 a, 152 b and 152 c are valves with differently large impact surfaces, each of which has a three-turn effect during its upward movement, during which it determines the acceleration of the corresponding piston 124a, 124 b and 124 c at the beginning of its upward or working stroke has a two-speed effect during its downward movement, during which it monitors the initiation of the downward or return stroke of the corresponding piston. The valves 152a, 152b and 152c include slightly smaller plungers 160 a, 160 b and 160c and slightly larger plungers 162 a, 162 b and 162 c, the smaller plungers in the bores 164 a, 164 b and 164 c and the larger ones Plungers in bores 166 a, 166 b and 166 c can be moved up and down and are connected to the smaller plungers by shafts or spindles 168 a, 168 b and 168 c of reduced diameter. When the valves 152 a, 152 b and 152 c are in their upper positions, the channels 150 a, 150 b and 150 c through the existing around the shafts or spindles 168 a, 168 b and 168 c around annular spaces with the channels 154a, 154 b, and c connected 154, whereby the strokes of the pistons 124 a, 124 b, and c are effected 124th If, on the other hand, the valves are in their lower position, the channels 150 a, 150 b and 150 c are connected to the branch channels 156 a, 156 b and 156 through the bores 164 a, 164 b and 164 c located above the plungers 160 a, 160 b and 160 c c connected, whereby the return strokes of the pistons 124 a, 124 b and 124 c are brought about.

The plungers 162 a, 162 b and 162 c of the valves 152 a to 152 c are provided in the vicinity of their upper ends with external annular channels 170 a, 170 b and 170 c. When the valves 152a to 152c are in their upper positions and when they pass from their lower to their upper positions, these channels communicate with the branch channels 172a, 172b and 172c of the main channel 158 which leads to the inlet pipe 118 and thus supplies working fluid under pressure to the channels 170a to 170c under the stated conditions. The lower ends of the channels 170 a to 170 c are connected to external, helically wound speed control grooves or threads 174 a, 174 b and 174 c in the plungers 162 a, 162 b and 162 c, these grooves at their lower ends with external ones annular grooves 176a, 176b and 176c are in communication, again through the radial passages 180a, 180b and 180c in the plungers 162 a, 162 b and 162 c with the axial channels 178 a, 178 b, and c are connected 178th These axial channels extend to the lower ends of the valves 152 a, 152 b and 152 c. When these valves are in their lower positions, the annular grooves 176a, 176b and 176c are connected to the branch channels 182 a, 182 b and 182 184 c of the control channels a, 184b and 184c in communication of the pump device holes 136a, 136b and 136c to to the lower ends of the valve device holes 164 a, 164 b and 164c extend. As will be appreciated, the branch and control channels just mentioned are by the valve spindles 168a to 168c around existing annular spaces and channels 154 a to 154 c with the constant Rückströmrohr 120 in conjunction, so that continuously in these channels, the outlet pressure prevails .

The plungers 162 a, 162 b and 162 c of the valves 152 a to 152 c are provided below the grooves 176 a, 176 b and 176c with external annular grooves 186a, 186b and 186 c, which are provided via radial passages 188 a, 188 b and 188 c are in communication with the axial passages 178 a, 178 b and 178 c and which, in intermediate positions of the valves 152 a, 152 b and 152 c , cover the branches 190a, 190 b and 190c of the main channel 158, the latter, like already said, is in communication with the supply pipe 118 and thus always contains working fluid which is under pressure.

Below the annular grooves 186a, 186b and 186c, the plungers are wide 162a to 162c with fairly, outer annular channels 192 a, 192 b and is provided 192c via radial passages 194a are 194b and 194c with the axial passages 178a to 178c in connection and when the valves 152a to 152c are in their lower positions and when they are in intermediate positions, they coincide with control channels 196a, 196b and 196c. The control channel 196a leading to the bore 136 b b of the pumping device 114, is that provided for control of the valve 152a by the piston 124b. Likewise, the control channel 196b leads to the bore 136c of the pumping device 114c, so that the piston 124c exercises control over the valve 152b . The control channel 196c leads to the bore 136a of the pumping device 114a, which means that the piston 124a exercises control over the valve 152c. Thus, the highest pumping device 114a exercises control over the lowest valve device 116 c, while the middle and the lowest pumping device 114 b and 114 c exercise control over the highest and the middle valve device 116 a and 116 b , so that As will be explained in more detail below, the desired time relationship or phase shift is established between the pumping devices. Further control channels 198 a, 198 b and 198 c go from the bores 136a, 136b and 136c of the pump devices 114 a, 114 b and 114 c to the lower ends of the larger bores 166 a, 166b and 166c of the corresponding valve devices 116a, 116b and 116c . As will be described in more detail below, the control channels 198a to 198c enable the pump devices 114a to 114c to exercise control over the respective valve devices 116a to 116c. Thus, a control of the valve devices 116a to 116c not only by other pumping devices other than the devices 114 a, 114 b and 114c of the respective valve devices 116 a, 116 b or controlled 116c, but also by the pumping devices 114a to 114c even which are controlled by the respective valve devices 116a to 116c.

The shafts 130 a, 130 b and 130 124 c the piston a to 124c are connected to control openings 200 a and 200 b and 200c and control ports 202a and 202 b and c provided 202nd When the pistons 124 a near its working stroke to 124c to the end, this but have not yet fully reached, 200a connect the control openings 200c, the control channels 196 c, 196 a and 196 b with the cylinders 128a and 128b and 128e. As a result of their connection with the supply pipe 118 via the branch channels 146 a, 146 b and 146 c and the main channel 144, these cylinders contain working fluid which is always under pressure. At the same time when the control openings 200 a, 200 b and 200 c that connect above or shortly after they have done this, but before the pistons 124a, 124b and 124c reach the end of its working stroke, bridges the control orifice 202a the control channels 184 a and 198 a, the control opening 202b bridges the control channels 184 b and 198 b, and the control opening 202c bridges the control channels 184c and 198c. As will be appreciated, therefore, the control apertures 200 a to 200 c to the cause that the pumping devices 114a to 114c control over certain other of the valve devices 116a to 116c as the exercise, of which the respective pump means is controlled, while the control ports 202 a , 202 b and 202 c to the reason for this will be that the pumping devices 114a to 114c, a control of the respective valve devices 116 a, 116 b or 116 c exert, by which they are controlled. Operation of the triple pump 110 In order to facilitate the consideration of the operation of the triple pump 110, the operation of the valves 152 a, 152 b and 152 c should first be examined in detail. Next, consider the overall operation of the pump 110 including the relationships between the pumping devices 114a, 114b, and 114c and the valve devices 116a, 116b, and 116c. Since the valve members 152a, 152 b and 152c are identical to each other, they all work in exactly the same manner, and it should therefore be described in more detail 152a, only the operation of the valve member.

As can be readily seen, the upper end of the valve 152 via a main channel 158 and branch 156a always of the same exposed to the pressure of the working fluid in the supply pipe 118th Likewise, the annular surfaces at the lower end of the plunger 160 a and at the upper end of the plunger 162 a are always exposed to the outlet pressure prevailing in the return pipe 120 via the channel 154 a. Thus, the pressure of the working fluid on the surface of the plunger 160a and the discharge pressure on the difference of the surfaces have the plunger 160 a and 162 a continuously downward. Therefore, when outlet pressure is exerted on the lower end of valve 152a, this valve descends, the downward force causing this movement being the product of the area of plunger 160 times the difference between the pressure of the working fluid and the outlet pressure. Conversely, an upward movement of valve 152a occurs when the lower end thereof is exposed to working fluid pressure, the useful upward force being the result of exerting the difference between working fluid and outlet pressure on the difference in areas of plungers 162a and 160a.

This movement radial opening Referring now first upward movement of the valve member 152 from its lower position, so is by the application of working fluid pressure via control channel 196 a, annular channel 192 a, 194 initiated a and axial passage 178a and the lower end of the valve member. All of these fluid paths offer quite little resistance to the flow of the working fluid so that the valve member 152a moves upward at a fairly high initial velocity. At the end, the annular channel 192a no longer coincides with the control channel 196a during its upward movement, which marks the end of the upward movement of the valve member 152a at its initial speed. At this moment, the channel 170 a coincides with the branch 172 a of the main channel 158 leading to the inflow pipe 118 , whereupon the working fluid pressure prevailing in the inflow line via the main channel 158, branch 172 a, channel 170 a, the helical groove or the thread 174 a , Annular groove 176 a, radial opening 180a and axial passage 178 is exerted on the lower end of the valve 152a . Under these circumstances, the valve member 152a continues its upward movement at a rather slow rate of time, which is determined by the flow capacity of the helical thread 174a . When the valve member 152 with its relatively small time speed moved upward, the plunger 160 begins a channel 150 A expose and thus the cylinder 134 above the plunger 132 a through around the shaft 168a around existing annular space and the channel 154a with the Rückströmrohr 120 to connect. This compound of the above of the plunger 132a horizontal cylinder 134 a with the Rückströmrohr 120 is thus introduced slowly so that the working stroke of the piston 124 a slowly introduced, thus avoiding a hydraulic thrust and a runaway of the piston 124a in the event that he is not on a compact liquid works, is prevented.

After the plunger 160 a has exposed the channel 150 a and thus started to initiate the working stroke of the piston 124 a in the manner described above, the annular groove 186 a with the branch 190 a leading via the main channel 158 to the inflow pipe 118 to cover, whereupon under pressure a can standing working fluid from the supply pipe forth through the main passage 158, the branch 190a, the annular groove 186a, the radial opening 188 a and the axial passage 178 to the lower end of the valve 152 a flow. The opening 188a offers a much lower resistance to the flow than the helical turns 174a, so that the valve member 152a moves upwards at a fairly high third speed. Usually, the radial opening 188 a so large that it provides sufficiently working fluid, an upward speed of the valve member 152 a to give rise of about three times the speed that would be solely accessible by the helical coils 174a. Hence the fairly high third speed of valve member 152a is somewhat four times its fairly low second speed. The rather high third speed of this valve member makes it possible that the complete connection between the return pipe 120 and the cylinder 134a lying above the plunger 132a comes about at a fairly high speed, after a connection has been made slowly at the beginning in the manner described above, so that the piston 124 a can come to the normal speed of its working stroke as quickly as possible, this slow production of an initial connection preventing hydraulic shocks at the beginning of the working stroke of the piston 124a .

The valve member 152 approaches its upper position, the annular groove 186 comes in a its upward movement out of register with the branch 190a, so that the upward final movement of the valve member is controlled again by the helical coils 174a. Therefore, these helical windings also hold the valve member 152a in its upper position, since under the circumstances existing at this stage of the process, the lower end of the valve member via channel 158, branch 172a, annular channel 170a, helical windings 174a, annular groove 176a, radial opening 180 a and axial passage 178a is exposed to the working fluid pressure prevailing in the supply pipe 118.

Considering now the downward movement of the valve member 152a, so that the same starts as soon as the outlet pressure on channel 198 is a applied to the lower end of the valve member, to go down with a fairly high Erstgeschwindigkeit. The channel 198a communicates with the bore 166a approximately above the lower end thereof, so that the plunger 162a of the valve member 152a finally covers in connection the channel 198a, the plunger begins 162a to cover this channel when the plunger 160 a passage 150 a expose begins. Thereafter, the valve member 152a moves downwards at a fairly low second speed and slowly establishes the connection between the inlet pipe 118 and the cylinder 134 a via the plunger 132 a , whereby the return stroke of the piston 124 a is slowly initiated and thus a hydraulic shock is avoided. The fairly small downward second speed of the valve body 152a is generated through the radial opening 180a by means of the lower end of the valve member of the channel 154 a, of about the shaft 168a around existing annular space, a portion of the control channel 184 a, the branch passage 182 a , the annular groove 176 a, the opening 180 a and the axial passage 178 a with the return pipe 120 is connected. Preferably, the radial opening 180a, which determines the rather low downwardly directed second speed of the valve member 152a, is approximately the same size as the radial opening 188a, which determines the upwardly directed third speed of the valve member. As soon as the valve member 152a reaches its lower position, the lower end of the same via channel 154a, the annular space around the shaft 168a, part of the control channel 184a , the branch channel 182a , the annular groove 176a, the radial opening 180a and the axial Passage 178 a further exposed to the outlet pressure in the return pipe 120. The opening 180a therefore acts as a hydraulic closure for the valve element 152a when it assumes its lower position.

As already stated above, the valve members 152b and 152c work exactly in the same way as the valve member 152a in that they move from their lower to their upper position and vice versa. A description of the mode of operation of these two valve members is therefore unnecessary.

If one now considers the overall operation of the triple pump 110, the valve members 152a and 152c are shown in their upper positions and the valve member 152b is shown in its lower position, so that the pistons 124a and 124c perform their working strokes, as indicated by the arrows 204a and 204c is indicated, and the piston 124b is on its return stroke, as indicated by arrow 204b, or has reached the end of its return stroke. The piston 124c informs the piston 124a by about 120 °, the piston 124a of the piston 124 b also by about 120 ° and the piston 124b to the piston 124c by about 120 ° before, if it is assumed that the working stroke and the return stroke of the piston represent a conveying cycle of 360 °, measured in radians. The following description shows how this time setting or this phase shift of the movements of the pistons 124 a to 124 c comes about.

If one looks at the piston 124c, one sees that it is approaching the end of its working stroke and that the control opening 200c will immediately thereafter connect the cylinder 128c to the control channel 196b. If this is bombarded flows pressurized working fluid from supply pipe 118 through the main channel 144, branch passage 146c, cylinders 128c, control port 200e, the control channel 196b, annular channel 192 b in the valve member 152 b, the radial opening 194 b in this valve member and the axial likewise in this existing passage 178b into the bore 166b under the valve member 152b. The working liquid pressure is thus exerted on the lower end of the valve member and moves the same in the described in the preceding example, upwardly, whereupon the valve member 152 b, the upper surface of the plunger 132b from the supply pipe 118 separates and via channel 150b, the existing around the shaft 168b around annular space and the channel 154b connects to the Rückströmrohr 120, b is initiated whereby the stroke of the piston 124th Thus, the piston 124 c, when it approaches the end of its working stroke, transfers the valve member 152 b from its lower and into its upper position and thus initiates the working stroke of the piston 124 b, thereby gradually shifting the pump output from the piston 124 c causes the piston 124 b. The piston 124c of the pump device 114c thus actuates another valve member - namely, the valve member 152 b - as that from which it is itself operated, namely, the valve member c 152nd

The piston 124c of the pumping device 114c actuates the same valve element as that by which it is controlled, namely the valve element 152c. More precisely: as when the control port 200c connects the control channel 196b to the cylinder 128 c, or immediately thereafter, 202c connects the control port, the control channels 184c and 198c with each other. When this happens, the outlet pressure is exerted on the lower end of the valve member 152c via the channel 154c, the annular space existing around the shaft 168c, the channel 184c, the control opening 202c and the channel 198c. The exertion of outlet pressure on the lower end of the valve member 152c results, as described above, in a downward movement of this valve member into its lower position. This downward movement terminates the connection of the upper surface of the plunger 132c with the return pipe 120 and connects this upper surface to the inflow pipe 118 via channel 158, branch 156c, the bore 164c and channel 150c located above the valve organ plunger 160c. As a result, the return stroke of the piston 124c is initiated, which only takes place after the working stroke of the piston 124b has been initiated, so that the above-described transfer of pump power from the piston 124c to the piston 124b takes place.

In a similar manner , when the piston 124a has approximately reached the end of its working stroke, the control opening 200a causes the valve member 152c to move upwards via the control channel 196c, whereby the working stroke of the piston 124c is initiated, and the control opening 202a effects via the control channel 198a a downward movement of the valve member 152a into its lower position, whereby the return stroke of the piston 124a is initiated. As a result, there is a gradual transfer of the pump output from piston 124a to piston 124c. Again in the same way can b the control port 200 when the piston 124 b nears the end of its working stroke, the valve member 152a go beyond control channel 196a upward and 124a initiate the working stroke of the piston and the control port 202b can via control channel 198b, the valve member 152 b go down, so that the return stroke of the piston 124 b is initiated, which again causes a gradual transition of the pump output from the piston 124 b to the piston 124 a . The conveyor game is terminated when, as has been described in detail in the foregoing, the piston 124c, the valve body 152b moves upward, which initiates the power stroke of the piston 124 b and the valve body 152c is moved downward, whereby its own return stroke is initiated. The piston 124 a controls the valve members 152c and 152a and the piston 124b, the valve members 152a and 152b in exactly the same manner as the piston 124c and the valve members 152 b 152c, so that a detailed description is omitted.

As can be seen from the above, the phase shift or time setting of the working and return strokes of the pistons 124 a, 124 b and 124 c is selected so that at any time two of these pistons perform their working strokes, since the pump output taken over by each piston when it approaches the end of its working stroke, it is transferred to a piston that has already completed its return stroke.

While two of the pistons 124 a to 124 c, out of phase with each other, cover their working strokes in the upward direction, with one leading the other by about 120 °, the third piston must cover its return stroke in the downward direction, or it has finished it and is at the lower end of its Travel, waiting for the next piston in the series to approach that of its working stroke. In order for this to happen, the speed of each piston in its return stroke must obviously be at least twice the speed in its working stroke. This is easily achieved by reacting 132 a sufficiently larger, 126b or 126c makes the upper surface of each plunger 132c to as the lower surface of the corresponding plunger 126a. Since the pistons 124 a, 124 b and 124 c only have to overcome mechanical friction and friction of the fluid flowing through the axial passages 138 a, 138 b and 138 c on their return stroke, the aforementioned high return stroke speed can be achieved by changing the diameter makes cylinder 134 a, 134 b and 134 c a few thousandths of an inch larger than the diameter of cylinder 128 a, 128 b and 128 c.

If one looks at some of the advantages of the triple pump I10, it is because the pupil output is always transferred from the piston 124a, 124b and 124c, which is approaching the end of its working stroke, to the piston, which is at the lower end of its working path, before nor has the first-mentioned piston reached the end of its working stroke, on the whole there is no tendency to introduce hydraulic shocks into the liquid sucked in by the pumping action. Also, since the driving parts or means of the pumping devices 114 a, 114 b and 114 c are connected in parallel to one another, the pressurized working fluid flows coming from the supply pipe 118 and the flows of used fluid flowing to the return pipe 120 are essentially constant, so that both no hydraulic shocks occur in the working fluid column as well as in the column formed by the used fluid.

Since the load with the pump output is always borne by two of the pistons 124 a to 124 c and these pistons are preferably identical to one another, the pump output is apparently always evenly distributed over two pistons. Therefore, the pressure of the working fluid required for a given pump output is only half as great as the pressure that would have to be applied if only one of the pistons performed its working stroke at any given moment. Conversely, the size of the impulsive-operating surfaces, the upper surfaces ie the plunger 132 a to 132c and the lower surfaces of the plunger 126a, lowered to 126C at the same pump power to half a reduction of the working fluid pressure to half has the advantage that The strength requirements that are to be placed on the overall construction of the pump system can be reduced, while reducing the driving surfaces by half with the same working fluid pressure has the advantage of reducing the pump size without any reduction in pump performance. The economic advantages of reducing the size of the pump in this way have already been pointed out when discussing the duplex pump 10.

If, on the other hand, when using the triple pump 110 constructed according to the invention, the greatest possible working fluid pressure is applied and the pump is made as large as possible, then very large increases in pump performance can be achieved compared to pumps of previous designs. A triple pump 110 built according to the invention z. B., which operates at the same pressure as a comparable prior art pump and which has the same overall diameter as this, will have an almost five times greater pump capacity compared to it.

The triple pump 110 thus also has the advantages that have been ascribed to the duplex pump 10 above. For example, the coaxially arranged passages 138 a to 138 c for the conveyed liquid greatly reduce the liquid friction. Also, since two of the pistons 124 a to 124 c always carry out their working stroke, while the third is in its return stroke or at the lower end of its working path, no suction valve or no suction valves are required because the respective pistons worn working valves 142 a to 142 c make such valves unnecessary. The straight axial flow flowing through the pistons 124 a to 124 c and the lack of suction valves contribute significantly to the increase in performance when the deep drilling pump 110 is used due to the great reduction in the flow resistance of the pumped liquid.

The invention can also be applied very easily to four-fold, five-fold pump operation, etc., in that further pump devices which are similar or identical to them are used between any two of the pump devices 112 a, 112 b or 112 c. The triple pump 110 can e.g. For example, by inserting a pumping means 112 a to 112 c the same or similar pump means between said pump means 112a and converted into a quadruple pump 112b, said additional pump means b in the same relationship to the pumping device 112 such as the device 112a to device 112b and the pump means 112a stands in the same relationship as the device 112b to the device 112a. By using two such pump devices in the manner indicated, a five-fold pump can also be created. In any such multiple pump, all but one of the pistons would perform their working strokes at any moment. Assuming a multiple pump with n pumping devices, the pump load will always be borne by n-1 pistons. Therefore, either the pressure of the working fluid or the driving surfaces can be reduced nI-fold or the pump output can be increased accordingly by keeping the working fluid pressure and the driving surfaces at the maximum possible values for both . As is easy to see, one can also reduce the working fluid pressure or the driving areas to any desired amount or increase the pump output in the desired manner by increasing the value n.

Claims (6)

Claims: 1. Hydraulically operated multiple piston pump for Extraction of crude oil from deep wells with at least two coaxial, hydraulically operated pumping devices that are connected in tandem and each of which can take the load with a pump capacity, and one of these pumping devices actuatable control valve member, which is to be applied Allocate pump power to the pump devices one after the other and each of these pump devices can get rid of this pump output again after the pump output of the other this pumping device has been assigned, characterized in that the control valve member (16) is hydraulically operated and includes valve devices (16a, 16b) which correspond to the number after the number of pumping devices and the respective pumping device steer. 2. Hydraulically operated multiple deep well pump according to claim 1, characterized in that each of these pumping devices (14a, 14b) for actuating a different valve device (16 a, 16 b) than that by which it is controlled, through a liquid with the control valve member (16) , these valve devices being in communication with one another for actuation of one of these valve devices by another of these valve devices by a liquid. 3. Hydraulically operated multiple deep well pump according to claim 1 or 2, characterized in that each of these valve devices (16 a, 16 b) includes a known, reciprocating valve (56a and 566), each of the Pump devices (14 a, 14 b) is so connected to the control valve member (16) that it moves the valve of another valve device (16a, 16b) than the valve device controlling them in a certain direction and each of the valve devices (16a, 16b) so is connected to move the valve of another of these valve devices in the opposite direction. 4. Hydraulically operated multiple deep well pump according to claim 1, 2 or 3, characterized in that the valve devices (16a, 16b) are controlled by the pumping devices so that when one of these pumping devices approaches the end of its working stroke, the working stroke the other of these pumping devices. 5. Hydraulically operated multiple deep drilling pump according to one of claims 1 to 4, characterized in that the control valve member (16) is arranged on the longitudinal side of and at a distance from the pumping devices (14 a, 14 b). 6. Hydraulically operated multiple deep drilling pump according to one of the preceding claims, characterized in that the valve devices (16 a, 16 b) are coaxial and are connected in series. Considered publications: German Patent Nos. 644 378, 357 550, 93127; German Auslegeschrift No. 1019 563; U.S. Patent No. 2,780,171.