Intelligent energy-saving pumping unit and its automatic control method

Abstract

A smart energy-saving pumping unit comprises a walking beam, a horsehead, a tail beam, a support, a base, a main motor, a crank, a connecting rod, a beam hanger, an intelligent control cabinet and a plurality of working condition sensors, wherein the main motor is a low-speed constant-torque permanent magnetic direct drive motor; a motor shaft is connected with the crank; the centrifugal end of the crank is connected with the walking beam through the connecting rod; the walking beam is provided with an external accurate adjustment balancing device or an internal accurate adjustment balancing device; the tail end of the walking beam is provided with a tail beam balancing device; an electronic control unit and a remote terminal intelligent unit are arranged in the intelligent control cabinet; the remote terminal intelligent unit is in wired connection with the electronic control unit; and the remote terminal intelligent unit is wirelessly connected with all the working condition sensors. The smart energy-saving pumping unit disclosed by the invention is high in intelligent automation degree, high in power factor, accurate in adjustment on degree of balance and good in energy-saving effect, and is capable of effectively saving energy by more than 40 percent in comparison with a traditional walking-beam pumping unit.

Description

technical field [0001] The invention belongs to the technical field of oil pumping equipment, and in particular relates to an intelligent energy-saving oil pumping unit and an automatic control method thereof. Background technique [0002] The pumping unit is the main energy-consuming equipment in the oil field. At present, most of the pumping units used in the oil field are beam pumping units. This pumping unit is driven by a common motor, and reciprocates through a multi-stage reduction box and a connecting rod and a beam. Since the pumping unit is a periodic alternating load with impact, in order to ensure sufficient overload capacity during operation, the drive motor with the largest capacity is often used, and the problem of "big horse and small cart" is common, and the motor When running, it needs to be output through a multi-stage reduction box and a linkage mechanism, which consumes a lot of power, resulting in low operating efficiency and power factor. Generally, t...

AI Technical Summary

Problems solved by technology

Since the pumping unit is a periodic alternating load with impact, in order to ensure sufficient overload capacity during operation, the drive motor with the largest capacity is often used, and the problem of "big horse and small cart" is common, and the motor When running, it needs to be output through a multi-stage gearbox and a connecting rod mechanism, which consumes a lot of power, resulting in very low operating efficiency and power factor. Generally, the overall efficiency of the system is only 30% to 40%.

In addition, when the beam pumping unit is working, due to the unevenness of the load change at the suspension point, the balance effect of the pumping unit is poor, resulting in high wear and energy consumption and poor stability. In order to reduce the unevenness of the load, the beam pumping The type pumping unit is generally equipped with a balance device, and some pumping units are equipped with a counterweight and fixed on the crank, but the load and centrifugal force of this method are relatively large, and some pumping units are equipped with a balance device on the beam. Or balance the counterweight, adjust the balance by manually moving the position of the counterweight or manually adding or subtracting the mass of the counterweight to change the balance moment. These two balancing methods or the composite balance formed by the two still have cumbersome, time-consuming, labor-intensive, and balancing problems. Too light or too heavy balance leads to extremely limited adjustment range, poor balance accuracy and high maintenance cost. Therefore, the existing beam pumping unit cannot adapt to the dynamic change of load well, and generally relies on increasing the output of the motor. power to make up for it, which increases the energy consumption of the pumping unit, and the operating noise of the pumping unit is huge

In addition, the intelligent automation control level of the pumping unit also has lag defects. The ground and downhole conditions cannot be included in the intelligent control system in a real-time and effective manner. There are obvious limitations under the complex working conditions of oilfield production, especially the number of strokes and balance. Automatic and loss-free or low-loss adjustment cannot be achieved, and the balance accuracy is far from adapting to load changes

For example, on July 15, 2015, the publication number is CN 104775792 A patent application for the invention of an intelligent pumping unit. Although the intelligent pumping unit realizes the function of automatically adjusting the balance, it is limited by its transmission mechanism and ordinary motors. The balance adjustment of the machine is rough, not precise enough, and the adjustment range is limited

At the same time, the pumping unit also has the defects of small motor power factor, long transmission chain, complex structure and large energy loss

And in the oil pumping operation in the oil field, the situation of slight jamming of the sucker rod occurs from time to time. Once the slight jamming of the sucker rod occurs, the falling speed of the sucker rod is slower than the falling speed of the donkey head, and an over-balance phenomenon will occur, which will cause the motor to The load increases sharply, the energy consumption is huge, and it may cause shutdown or motor burnout, seriously affecting oil field operations

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