两种长源距声波波形特征及其时差提取方法

Characteristics of Two Kinds of Long-spaced Sonic Waveform and Methods for Determining Slowness from Waveform

Based on the analysis and comparison of two kinds of full sonic waveform and their spectrum from Schlumberger's and Dresser-Atlas' acoustilog tools, thecharacteristics and difference of two kinds of waveform are discussed. According to the information, several kinds of methods for determining slowness from waveform are proposed, and computer programs are made for these methods. The processed results with some field examples show that the square deviation ratio method, Hilbert transform method for picking first break, the method of following the tracks of semblance peak and the method of direct phase determination for the slowness of S wave and Stoneley wave have achieved good results. K-L transform is useful for determining the slowness from full sonic waveform by improving the signal to noise retio of sonic waveform and for suppressing incoherent staked waves.