Study On Extracting And Application Of The Multifractal Characteristic Parameters Of Cement Bond Logging

Much attention has been paid to cementing evaluation since directly effects the well recovery life and normal production along the injection and producing periods. No effective methodology for cementing evaluation, especially for identification of second interface cementation and annulus cement packing on account of formation media difference and the characteristic complexity for wave propagation. By using real axis integration method, the responsese of acoustic logging are calculated with different wave velocity and attenuations of formation; the responsese of acoustic logging are tested in three typical different cement bond quality in miniature well models; Based on the multifractal theory, the multifractal characteristic parameters are extracted from the responsese of numerical and physical simulation for acoustic logging using multifractal parameters calculation progrem. The relationship between multifractal characteristic and cement bond quality of the first and second interface in cased holes is built. By using the VDL data, the figures of multifractal evaluation results of the field cementing data are shown, the evaluating results are in good agreement with actual results.