抽油机井系统效率的计算机仿真模型

根据油井的静态与动态参数,建立了以波动方程为基础的抽油机悬点与泵示功图的计算机仿真模型。以仿真示功图为基础,建立了抽油机井系统效率的仿真模型,并重点改进了有效功率与电动机输入功率的仿真模型,其中包括:(1)考虑了泵余隙容积内气体的压缩与膨胀,改进了排量系数的计算模型;(2)考虑了地面传动系统能量流动方向的变化与传动效率的影响,改进了曲柄轴净扭矩与电动机输出功率的计算模型;(3)考虑了电动机瞬时负载率对电动机运行效率的影响,改进了电动机输入功率的计算模型。所建立的系统效率仿真模型具有较高的仿真精度和广泛的适应性。

Computer Simulation Model of the System Efficiency of Rod Pumping Wells

According to the static and running parameters of rod pumping wells, the methods of simulating dynamometer cards of the polished rod and pump on the basis of wave equation were setup. On the basis of the simulated cards, the model of simulating system efficiency of rod pumping wells was setup, and particularly the simulating models of the system effective power and input power were improved. The following improvements in simulating system dynamic parameters were made: (1) with the compressing and expanding of gas in the pump clearance volume considered, the formula of calculating the displacement coefficient was improved; (2) with the energy fluid direction changing and transmission efficiency of the driving mechanisms considered, the formulas of calculating the net crank torque and the motor output power were improved; (3) with the influence of the momentary load ratio on the motor running efficiency considered, the formula of calculating the motor input power was improved. The established model of simulating the system efficiency is suit to all kinds of rod pumping systems which consist of various types of pumping units and different working states of the pumps. The model is of high simulating accuracy and of wide adaptability.