Wave-Arriving-Point Detecting Of Logging Signal On Energy Operator

Acoustic logging signals include the information of stratum velocity, stratigraphic absorption frequencies, stratigraphic absorbing intensity. These information can be obtained through digital signal processing. Then it is flexible to carry out the research of oil and gas, stratigraphic permeability, which is helpful to expand the sonic logging in the oil exploration. The starting point of the signal arriving point is the signal of arriving points,which is strong with energy and the earliest taking-off time. Meanwhile the arriving time can also reflct the porosity of the rock, the acoustic velocity in the formation and so on. In the acoustic logging data, the arriving point of signal is very important. Extracting the time of signal's arrival can provide favorable data for the further treatment of acoustic logging. The traditional methods of extracting acoustic logging signal can only extract the arriving points of different wave patterns, such as p-wave, shear wave and Stoneley wave. But very few scholars cover the signal arrival from logging signal containing serious time-frequency overlap P-wave or shear wave.Firstly, the situation of study about the extraction of signal arrival from acoustic logging signal was analyzed, then the present extraction methods for the signal arrival of acoustic logging signal was introduced, after that the basic knowledge of wavelet transform and energy operator.In the third chapter, the suitable theory model signal was established according to the characteristics of the acoustic logging signal. Energy operator was used to extract the arriving-time of the model signal. The calculation based on energy operator is simple, and has good temporal resolution. Firstly find out the envelope signal amplitude results chart, Each amplitude envelope components of the starting time of the corresponding signal. Used energy operator to extract the wave-arriving time, signal moments of priori information do not need to know, and has good adaptability.In the fourth chapter, energy operator method was used to extract acoustic logging waves and longitudinal wave moment for actual logging to signal. An lowpass filter to eliminate interference signals is needed to draw the arrival time of each signal accurately, then can obtain the singal arrival of the acoustic logging signal. Through the simulation, analysised the test results, the method based on energy operator has certain correctness.