Abstract: Recognition of the fractures in the wells is a hard problem,the research submits the method of wavelet analysis to decompose the interval transit time information,which makes the microstructure characteristic signal,fluid characteristic signal,despondences of fractures and random disturbance signal separated from lithology,the high frequency signals reflecting fractures are directly reconstructed to avoid the influence of low frequency signal and recognize development of fractures correctly.Also,the same method is used to decompose the microelectrode log signals,reconstruct the low frequency signals that reflect the permeable layer.At last,combination of the high frequency signal of fractures and the low frequency signal of microelectrode log can help to recognize the layer of fracture development.Practice in oil gas field indicates the results from the method are consisting with the results coming from the core inspection.

Key words: wavelet analysis, fracture recognition, log signals, signal decomposition, signal reconstruction