BOREHOLE LIQUID ACOUSTIC WAVE TRANSDUCER

摘要

The transducer is used to send an acoustic wave between a down-hole end and the surface to convey measurement signals and also to receive control signals from the surface, the single transducer thus acting selectively as a transmitter or receiver. The transducer comprises a piston 37 moving within a chamber 38 which causes acoustic waves to propagate via windows radially into the borehole liquid. A resonator 36 communicates with the piston 37 via a horn structure 41. The piston is driven by a moving coil, permanent magnet arrangement (Fig. 4).