Research On Time-Difference Extraction Algorithm For Acoustic For Logging-while-Drilling

Acoustic logging while drilling(LWD)are widely used recently along with the drilling at the same time logging,can be measured before the onset of the formation of the speed,Logging while drilling(LWD)environment is complex,resulting in the measurement of the waveform data where is a serious dispersion,The time difference-time correlation(STC)method for maturing applications in cable logging does not take into account dispersion when extracting time differences,the extraction of the time difference can not reflect the formation of the real difference.Therefore,it is necessary to research the waveform characteristics of the acoustic logging.In this paper,the finite difference forward modeling is used to simulate the wave fields of the monopole,dipole and quadrupole in hard and soft formation.The various measurement modes are analyzed in different types of formation.WSS method,APES method and Phase Moveout method,were researched.The pure data-driven dispersion correction method were studied.Phase Moveout method was selected by contrast.It is found that the data driven dispersion correction method with curve fitting method can be used to extract the time difference of the logging data,and the time difference extraction process of the logging is analyzed.The processing confirms the effectiveness of the process.