Underground Engineering Signal Processing Methods

Because of the working conditions and the complicated background of the well, and the results is the signals are badly disturbed. How to remove kinds of noises in well drilling parameter processing process and how to improve the SNR of well drilling parameter are main task. The main idea of this thesis is reach on the processing methods of well drilling parameter.Wavelet transform is a new mathematic analysis tool. It is a signal processing methods which was rapidly developed in late 1980s. Owe to its multi-resolution analysis on time-frequency, because of its ability, the localization of the signal is analyzed both in the time domains and the frequency domain, so it is suitable to analyze un-steady station signal and observe signal observed in different scales. The method has been used in many fields such as signal processing, image processing, speech processing, pattern recognition, and quantum physics and so on. It is considered as a key breakthrough in tools and methods in recently years.According to the processing results of the real will-engineering signal, analysis the application of wavelet transform in signal processing process with a detailed, the thesis mainly researches wavelet threshold de-noising and modulus maximum de-noising applications, and other signal processing applications, wavelet transform has played an important role in signal processing through the display and analyze of their respective application processing resultsIn this thesis, the drilling pressure signal is processed with the wavelet modulus maximum de-noising method, the torque signal is processed with the wavelet threshold de-noising method, and the bending moment signals is processed with the wavelet modulus maximum de-noising method and the wavelet threshold de-noising method. Though the combination of two methods of different emphases, and a large number of analyzed of processing results, a conclusion is proposed that the results of wavelet modulus maximum de-noising is better in well drilling parameter processing.In this thesis, the spectrum and feature of the drilling pressure signals is analysised in well drilling parameter, and display frequency spectrum and power density spectrum of the drilling pressure signals through and not through wavelet transform were compared though MATLAB.