基于 F⁃J 法微动探测的表层结构调查

3D seismic exploration is typically employed in areas where micro logging and other static correction methods cannot be implemented，such as towns and roads. Recently researchers have tried to replace existing static correction methods with microtremor surveys and yielded some achievements. At present，in petroleum exploration，microtremor survey mainly employs surface wave dispersion curves to invert formation velocity structures. This method is still in its infancy in petroleum exploration. As the core technology，dispersion imaging methods can be classfied into many types，such as the frequency‐Bessel（F‐J）transformation method proposed in 2019，which has attracted the attention of geophysicists. Compared with the spatial autocorrelation method（SPAC），the F ‐ J method has great advantages in adopting ambient noise for higher‐mode surface wave imaging. To better study the applicability of F‐J method，this paper first analyzes the influence of different observation systems and acquisition param ‐ eters on F‐J imaging using synthetic data. Then，the effect of different observation systems and acquisition time on FJ dispersion imaging is analyzed through the field ambient noise data of an area in Sichuan. In practical application，the dispersion spectrum obtained by subsection optimization superposition can effectively improve the imaging quality of the dispersion spectrum and provide a data basis for the accurate extraction of dispersion curves. Finally，logging data comparison shows that multi ‐ mode joint inversion using fundamental mode and higher ‐ mode dispersion curves can accurately invert formation structures，thus making it possible to obtain surface structures economically and efficiently.