High Resolution Reflection Separation Method for Dipole Acoustic Logging

To image the formation structure outside the borehole with reflected wave of dipole acoustic logging has attracted widespread attentions in recent years in the area of heterogeneous reservoir evaluation, due to its directivity and deep detecting depth. To obtain the reflected wave from the whole waveform of dipole acoustic logging, a new reflection separation method based on high resolution Radon transform is developed to adapt to the borehole environment. Instead of using the least square method, which can cause trails in Radon domain, the high resolution method is employed for its ability to make the different wave field focus in the Radon domain respectively. Moreover, through combining the principles of maximum entropy and Bayesian, the high resolution can be achieved. The processing results of simulation data show that the new method can be used to extract the desired wave field under complicated situations. Compared to the least square method and the F-K filtering, high resolution Radon transform can make the direct wave strongly focused into an approximate point within the Radon domain, which makes it easier to extract reflection. Finally, applications of field data to separate reflection were implemented to further verify the validity and accuracy of this method.