Single borehole reflection imaging is an effective approach to the direct evaluation of geologic structures and reservoirs a-round a borehole using reflected shear waves extracted from array acoustic logging data.To enhance azimuthal resolution and radial depth of investigation,the key to data processing is complete separation of reflections from original data with the minimum loss of signal energy.Existing separation methods suffer from the problems of modes mixing and energy loss of extracted reflections and consequent small resolution and radial depth.We propose a new algorithm of 2D variational mode decomposition for wave separa-tion without great time consumption of recursive iteration.Original signals are decomposed into several inherent modes with differ-ent directions and vibration characteristics,and appropriate modes are used for reconstruction and reflection separation.Reflected waves are extracted from synthetic data with different noise levels and field data using 2D variational mode decomposition,median filtering,and F-K transform;our method performs better than median filtering and F-K transform in effective suppression of mode waves and random noises and extraction of complete reflected signals.Synthetic and field data tests demonstrate the effectiveness and advantages of our method.
remote detection acoustic loggingreflection extraction2D-VMDdipole sonic
维普
万方数据
