基于小波分解的油井加速度信号的周期计算

Calculation of Pumping Unit Acceleration Signal Period Based on Wavelet Decomposition

抽油机运动周期作为示功图的重要参数,其准确性直接影响示功图的精度。针对悬点加速度信号周期难确定等问题,以及小波分解对信号进行时域和频域分析的强大功能。本文提出采用Meyer小波对加速度信号进行处理的方法。首先通过小波分解提取有效低频信号,再利用最小二乘原理对有效信号进行周期函数的拟合,仿真结果验证了算法的可靠性。最后以中原油田某油井80组加速度数据为依据,通过对比低通滤波后曲线拟合所得加速度周期和小波分解后计算的周期的标准差,得出基于Meyer小波分解的方法得到周期更准确的结论。

Pumping motion period is an important parameter of the dynamometer card, whose exactitude affects the accuracy of the dynamometer card directly. Aiming at the problem that （it is hard to determine the signal period） the signal period is difficult to be determined and the advantage that the wavelet decomposition has in signal time domain and frequency domain analysis, th paper proposed a method using Meyer wavelet to process the acceleration signal. Firstly, the effective low frequency signal was extracted by wavelet decomposition, then the least square principle was used to fit the effective signal. The simulation results show the reliability of the algorithm. At last, according to the 80 group acceleration data of the oil well in Zhongyuan Oilfield, a contrast experiment was taken using low - pass filtering method and the wavelet decomposition method. The standard difference results of the period show that the method based on Meyer wavelet decomposition can get more accurate conclusion period.