RU2493433C1 - Oil well pumping unit - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: oil well pumping unit comprises a pumping unit for installation near the well, having a beam with a rotary head, a pump for installation in the well, comprising a cylinder with suction valves and a plunger with injection valves, installed inside the cylinder as capable of reciprocal movement. In the upper part of the plunger there is a head stem connected by means of a flexible link to the rotary head. On the upper part of the head stem there is a movable part of the electromagnet covered with the stator part of the electromagnet with the winding. The beam is made as capable of closing the electric circuit of the electromagnet winding with the possibility to excite the electromagnetic force acting at the movable part of the electromagnet and directed along the axis of the head stem.

EFFECT: higher reliability of plant operation, increased service life, reduced overload surges acting at a system of power units, provision of smooth travel of a head stem.

3 cl, 5 dwg

Description

The invention relates to the petrochemical industry of mechanical engineering and can be used in the design of well-pumping units.

Known borehole pump installation containing a rocking machine for installation near the well, having a balancer with a rotary head, a pump for installation in the well, including a cylinder with suction valves and a plunger with discharge valves mounted inside the cylinder with the possibility of reciprocating motion, in the wellhead stock is formed on the upper part of the plunger, connected by flexible connection with a rotary head (see the advertising sheet of TsINTIkhimneftemash, PMB, 119048, Moscow, G-48, 12 Dovatora St., Subp. 28.03.79, UDC 622.276.53-83; catalog "Well sucker-rod pumps for oil production" TsINTIkhimneftemash, 119048, Moscow, G-48, Dovatora St., 12, NIIMash printing house, Shcherbinka, Subp. 14.01.80. , UDC 622.276.054.22 (085)).

A disadvantage of the known device is that the working force on the wellhead when lifting the plunger of the pump is quite significant and reaches several tons. This effort is due to the mass of the plunger, wellhead and the mass of the oil column supplied to the pipeline, moving vertically in the well with acceleration, the value of which is not constant when the balancer rolls and reaches its maximum values when the balancer passes through the extreme positions. In this case, a dynamic load arises on the wellhead rod and on all power units connected to it, which can reach a double value, which requires a corresponding increase in the safety factor and, consequently, a heavier structure.

Closest to the proposed is a device for driving in the forward direction of the rod in the pump unit with a piston rod (downhole pumping unit), containing an electric linear motor including an armature, stators and a base installed in the desired position relative to the working axis of the pump with a piston rod while the motor armature is connected to the upper end of the stem, a balancing mechanism in contact with the upper end of the armature (see US Pat. No. 6,213,722).

A disadvantage of the known solution is the complex circuit design and construction of a linear electric motor, the need to use a complex electronic frequency converter with a set of rod position sensors controlling the linear electric motor; the need for continuous operation of electric motor elements having large dimensions, which causes large economic costs, has a large power consumption, overload surges are possible, which causes the emergence of large stress concentrations; complexity of repair in case of failure of the linear electric motor; the need for the most accurate positioning of the electric motor relative to the rod, strict adherence to alignment; in case of failure of the counterweight, it is necessary to completely dismantle the structure to replace it, the presence of complex balancing mechanisms that require additional calculations, the choice of installation location, complicated installation using special technical means, additional maintenance, which reduces the maintainability of the installation as a whole .

The technical result of the invention is the provision of the possibility of damping (reduction) of the dynamic loads of the nodes and parts of the device in the extreme positions of the rod, eliminating jumps in overloads, ensuring a smooth stroke of the wellhead.

The technical result of the invention is achieved due to the fact that the well-pump installation includes a rocking machine for installation near the well, a pump with a plunger for installation in the well, in the upper part of the plunger a wellhead rod is formed, on the upper part of which is fixed the movable part of the electromagnet covered by the stator part of an electromagnet with a winding, while the rocking machine has a balancer with a rotary head, which is connected through a flexible connection with the wellhead rod, and the balancer is made with the possibility of closing of the electric circuit of the electromagnet coil, with the excitation of the electromagnetic force acting on the movable part of the electromagnet and directed along the axis of the stem wellhead.

In addition, the movable part of the electromagnet can be made in the form of a steel core.

In addition, the movable part of the electromagnet and its stator part can be made in the form of detachable semi-ring blocks.

The invention is illustrated by drawings, where figure 1 shows the proposed device; figure 2 shows the node of the electromagnet with its movable and stator parts, the takeaway A in figure 1; figure 3 shows the node of the electromagnet with its movable and stator parts, section BB in figure 2; figure 4 shows the node of the electromagnet with its movable and stator parts, made in the form of detachable half-ring blocks, a section view BB in figure 2; figure 5 shows a diagram of the inclusion of an electromagnet.

The downhole pumping unit includes a rocking machine, which includes a support frame 1 mounted on a pre-prepared foundation 2 near the well 3. A gear 4 with a drive motor 5 and a stand 6 with a swinging balancer 7 are mounted on the support frame 1 a two-arm beam, at one end of which a pivoting head is formed 8. A crank 9 with a counterweight 10 is fixed to the output shaft of the gearbox 4, while the crank 9 is movably connected to the connecting rod 11, the crosshead 12 and the free end of the balancer 7 (Fig. 1).

The downhole pump installation also includes a pump installed in the well 3, including a cylinder 13, in the lower part of which suction valves 14 are formed, and a plunger 15 with pressure valves 16, mounted inside the cylinder 13 with the possibility of reciprocating motion. In the upper part of the cylinder 13, holes 17 are made, and in the upper part of the plunger 15, holes 18 are made for transferring oil into the cavity of the cylinder 13 (Fig. 1).

In the upper part of the plunger 15, a wellhead rod 19 is formed, connected by flexible connection 20, for example, cable, to the pivoting head 8 of the balancer 7 of the rocking machine. The wellhead rod 19 interacts with an electromagnet, while on the upper part of the wellhead rod 19 a movable part of the electromagnet is fixed, made in the form of a steel core 21 of a cylindrical shape (FIG. 2). The core 21 is located inside the stator part 22 of the electromagnet, made in the form of a ring, covering with the formation of an annular gap 23 (Fig.3) a steel core 21. The stator part 22 of the electromagnet is mounted motionless on a previously prepared foundation 2.

The movable part 21 and the stator part 22 of the electromagnet can be made with a diametrical connector 24, dividing them into composite semi-ring blocks, respectively 25, 26, 27 and 28 (figure 4).

The installation works as follows.

During oil production, the well pump is lowered into the well 3 on a string of tubing and sucker rods (not shown). The plunger 15 has the ability to make translational movements up and down, following the swing of the balancer 7 of the rocking machine. When the plunger 15 is moved from its lowest position upward, oil is sucked from the borehole 3 into the cavity of the cylinder 13 through the open suction valves 14. From the upper position, the plunger 15 is lowered, while the suction valves 14 of the cylinder are closed and the discharge valves 16 of the plunger 15 open, providing the flow of oil from the cavity of the cylinder 13 into the cavity of the plunger 15. The next time the plunger 15 moves up, the process repeats, again the cavity of the cylinder 13 is filled with oil through the suction valves 14. Next , with the next movement of the plunger 15 down, the suction valves 14 of the cylinder 13 are closed, and the discharge valves 16 of the plunger 15 open, through which oil from the cavity of the cylinder 13 flows into the cavity of the plunger 15. Thus, the subsequent movement of the plunger 15 up and down excess oil through the holes 18 , 17 in the upper part of the plunger 15 and cylinder 13 fills the well 3 and through the branch 29 in its upper part enters the highway 30.

Introduction to the device of an electromagnet driven at certain points, allows you to significantly change the power load of the nodes and parts of the pumping unit.

An analysis of the movement made by the pump plunger 15 during its operation shows that, at short intervals when passing the lowest point, the entire mass of the suspension of the wellhead rod 19 (plunger 15 and oil supplied to the line above the plunger 15) experiences a double overload transmitted through wellhead rod 19 to all power nodes and parts of the rocking machine due to maximum acceleration in this zone.

Introduction to the installation of an electromagnet, the stator part 22 of which rests on the foundation 2, and the movable part 21 is mounted on the wellhead rod 19, allows in the extreme lower zone of movement of the plunger 15 to turn on the electromagnet in a timely manner to create a counteracting damping force on the wellhead rod 19, removing excess load from the nodes and the details of the rocking machine and transferring it to the foundation 2. The turning on and off of the electromagnet is carried out mainly by limit switches 31 installed, for example, on the stand 6 and closed by alternating current The balance bar 7. The circuit of the inclusion of an electromagnet is shown in figure 5. However, this circuit is not the only option for closing the circuit.

The balancer 7, moving in the direction of the arrow 32, at the moment of acceleration increase with the limit switch 31 closes the power circuit of the electromagnet, exciting the induction winding 33, and there is an electromagnetic force 34 acting on the moving part of the electromagnet - a steel core 21, enclosed on the wellhead rod 19.

The electromagnetic force 34 is directed against the action of the mass forces 35 of the device and significantly reduces them, and the reaction from the influence of electromagnetic force by the stator part 22 of the electromagnet is transmitted to the foundation 2. The electromagnet is turned off at the right time in the same way as it is turned on.

The introduction into the device of the diametrical connectors of the moving part and the stator part of the electromagnet (Fig. 5), dividing them into composite semi-ring blocks 25, 26, 27, 28 does not impair the operation of the device, but increases its operational characteristics, providing ease of installation and dismantling of the electromagnet, if necessary without removing the pump from the well 3.

Thus, the proposed device can significantly smooth out the jumps of overloads acting on the entire system of power units connected to the wellhead rod when the balancer passes through the extreme positions by creating a damping electromagnetic force that counteracts inertial mass loads - wellhead rod 19, plunger 15 and column of supplied oil, which, undoubtedly, increases the reliability of the device and increases its service life.

Claims (3)

1. A downhole pumping unit comprising a rocking machine for installation near a well, a pump with a plunger for installation in a well, a wellhead rod is formed in the upper part of the plunger, on the upper part of which a movable part of an electromagnet is fixed, covered by a stator part of an electromagnet with a winding, characterized the fact that the rocking machine has a balancer with a rotary head, which is connected through flexible communication with the wellhead rod, while the balancer is made with the possibility of closing the electric circuit of the electromagnet winding and with the possibility of an electrical circuit of the electromagnet winding, with the possibility of excitation of the electromagnetic force acting on the movable part of the electromagnet and directed along the axis of the stem wellhead. 2. Installation according to claim 1, characterized in that the movable part of the electromagnet is made in the form of a steel core. 3. Installation according to claim 1, characterized in that the movable part of the electromagnet and its stator part are made in the form of detachable semi-ring blocks.

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