Development Of Balance Performance Monitor

Pumping unit are ground driving equipment of sucker rod pumping system in oilfield. Their quantity is over ninety percents of the whole quantity of the oil extraction equipments in oilfield. Among these pumping units, the beam pumping unit is the most widely used type. This paper takes the beam pumping unit as the research object, analyzes the theoretical analysis and field testing method of sub nodes efficiency of the beam pumping unit, and in order to meet the oilfield needs, the balance performance monitor is developed。Firstly, based on the geometric structure and motion characteristics of the four bar linkage of beam pumping unit, a dynamics analysis model for the beam pumping unit is established. We give the calculation method of sub nodes efficiency of the beam pumping unit, the instaneous transmission efficiency of the beam pumping unit system is analyzed. Based on the structure of theoretical analysis, the sub nodes efficiency test of beam pumping unit is made.Secondly, we set up the relation between the current(voltage) change of driving motor and crack torque of the beam pumping unit, and set up the theoretical method to judging the balance performance of the beam pumping unit. According to the oilfield needs, we propose general design scheme of the balance performance monitor, including the choice of sensor and data acquisition module。Thirdly, the balance test software is programmed by Visual Basic 6.0, which can realize real-time data collection and control, data store, query and process, report generation and print.Finally, the sub nodes efficiency test and the performance verification of balance performance monitor is carried out by many pumping units, the results showed that the balance performance monitor can meet the objective of judging balance property and giving balance adjustment quantity and dynamometer card of polished rod by testing drive motor electrical characteristics. It can overcome the deficiency balance test at present. It greatly improved the accuracy and the efficiency of the balance test.