示功图频谱分析新方法

示功图分析法是目前常用的抽油井故障诊断方法.由于受到复杂的井下工况的影响,示功图时域信号往往会出现极大变形,从而令示功图分析结果出现错误.为解决这一问题,对示功图时域信号进行了频谱分析.利用将时域信号转换为频域信号的方法,研究了各种频率的能量分布及信号的规律性.分析了示功图频谱的影响因素以及典型工况频谱特征,建立了示功图模糊数学识别模型,并给出了示功图频谱分析方法的步骤.用40多口油井示功图进行了验证,结果表明,频谱分析新方法可用于示功图的识别.

Frequency spectrum analysis method for recognition of dynamometer card

The dynamometer card analysis is a popular method for diagnosis of failure in pumping wells.However,the complicated bottom-hole conditions often lead to distortion of dynamometer cards and wrong recognition results. A new recognition method was developed and thus the time domain signals were transferred into the frequency domain signals. The distribution of energy at different frequency and the rules of signals were analyzed. The affecting factors and typical characteristics of operating conditions for frequency spectrum of dynamometer cards were discussed. A new fuzzy mathematical recognition model was established and its procedure was developed. The method was used to recognize the behaviors of more than 40 wells. The result shows that the method is applicable to analyze the dynamometer cards.