METHODOLOGY FOR CALCULATING THE COMBINED SYSTEM FOR BALANCING THE DRIVE OF A ROD INSTALLATION WITH FLUCTUATIONS IN THE DYNAMIC LEVEL

Abstract

Relevance. Drive balance is one of the key factors determining the efficiency of well operation by downhole rod pump units. This is of particular importance for stripper wells, which operate at the margin of profitability due to low flow rates and high energy consumption. Transferring them to a periodic mode leads to systemic fluctuations in the dynamic level. A change in the dynamic level causes a change in the loads acting on the rod string and balancer drive. To maintain the balance of the pumping unit under these conditions, it is necessary to adjust the position of the balancing counterweights. Objective: analysis of the automatic balancing system of the pumping unit, including an additional balancing counterweight, with the inclusion of automatic switching, which provides balance control by turning on the auxiliary electric motor; development of a methodology for calculating the parameters of a dynamic balancing system, which makes it possible to carry out calculations of the deflection balancing mechanism. Methods: express method for estimating the parameters of counterweights, taking into account the static components of the loads on the plunger and drive, and detailed method, taking into account the dynamic components of the loads. Results. It is shown that both methods of calculation give acceptable results in terms of providing a minimum torque on the crankshaft to equalize the degree of loading of the shaft and the electric motor during the pumping cycle. Conclusions. It was established that the required (to maintain dynamic balance) weight of the additional balancing counterweight grows to a large extent as the difference in the dynamic level increases during pumping and decreases with the growth in the «stroke length» of the counterweight along the balancer. The shoulder of the crank load with the increase in the weight of the additional balancing counterweight decreases due to decrease in the contribution of the crank component in the combined balancing system.

Keywords

• rod pumping unit
• periodic pumping mode
• dynamic level
• modeling
• pumping unit
• additional balancing weight
• balancing