Monopole acoustic logging while drilling instrument used together with bottom hole assembly, method for measuring shear wave velocity of slow formations

摘要

A monopole acoustic logging while drilling instrument used together with a bottom hole assembly and a method for measuring a shear wave velocity of slow formations, wherein the bottom hole assembly includes a drill collar and a drill bit, wherein the monopole acoustic logging while drilling instrument is installed on the drill collar. The monopole acoustic logging while drilling instrument comprises: an acoustic receiver array installed on the drill collar; a monopole acoustic source arranged at the drill collar, wherein the monopole acoustic source is configured to emit acoustic waves with a frequency in a preset frequency range, and the ratio of the outer diameter D1 of the drill collar to the outer diameter D2 of the drill bit is d, and 0.75d1.