基于小波变换分析牙轮钻头磨损状态的研究

发布时间：2018-03-28 01:04

本文选题：三牙轮钻头　切入点：小波变换　出处：《西安石油大学》2015年硕士论文

【摘要】：钻井质量、钻井效率和钻井成本都与钻头的磨损状况息息相关。由于井底情况的复杂性,使得难于对钻头磨损状况进行准确判断,若钻头尚能工作而提前取出钻头,将会造成人力物力的浪费,若钻头磨损过于严重而未取出钻头,将会影响钻井效率,因此需准确地、实时地对钻头磨损状况进行判断,才能避免发生钻井事故,提高钻井质量和钻井效率,减少钻井成本。针对钻柱振动信号中含有大量时变、短时冲击、突发性质的噪音信号的问题,本文提出了小波变换原理的去噪和时频特征提取方法,首先利用小波包去噪方法将采集到的钻柱振动信号去噪,然后利用时频法对去噪后的振动信号进行特征提取,提取出钻头磨损的敏感特征集,作为适合于BP神经网络的输入特征向量,经网络分析处理后,得到最终诊断结果。基于Lab VIEW平台开发了三牙轮钻头磨损程度诊断系统,实现了对三牙轮钻头磨损程度的诊断。系统包括信号输入模块、信号处理模块、BP神经网络诊断模块和诊断记录查询模块,详细介绍了各个模块的开发过程、功能说明和界面。通过对现场数据的处理分析,表明该系统能满足钻头振动信号的测试和诊断需求,为钻头起下钻时间的确定提供了重要的理论基础,为钻头的合理使用以及科学管理提供了重要的理论和实践基础。
[Abstract]:Drilling quality, drilling efficiency and drilling cost are closely related to bit wear. Due to the complexity of bottom hole conditions, it is difficult to accurately judge the bit wear. It will cause waste of manpower and material resources. If the bit wear is too serious to take out the bit, it will affect the drilling efficiency. Therefore, it is necessary to judge the drill bit wear condition accurately and in real time in order to avoid drilling accidents. In order to improve drilling quality and drilling efficiency and reduce drilling cost, aiming at the problem that the vibration signal of drill string contains a large number of time-varying, short-time impulse and burst noise signals, this paper presents a method of de-noising and time-frequency feature extraction based on wavelet transform principle. Firstly, the vibration signal of drill string is de-noised by wavelet packet denoising method, and then the feature extraction of the de-noised vibration signal is carried out by time-frequency method, and the sensitive feature set of bit wear is extracted. As the input feature vector suitable for BP neural network, the final diagnosis result is obtained after the network analysis and processing. Based on the Lab VIEW platform, a three-cone bit wear diagnosis system is developed. The system includes signal input module, signal processing module BP neural network diagnosis module and diagnostic record inquiry module. The development process of each module is introduced in detail. Function description and interface. Through processing and analyzing the field data, it is shown that the system can meet the requirements of testing and diagnosis of bit vibration signal, and provides an important theoretical basis for determining the drilling time of drill bit. It provides an important theoretical and practical basis for the rational use of bit and scientific management.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE921.1

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