Sonic vibration telemetering system

摘要

In accordance with illustrative embodiments of the present invention, a sonic vibration transmitter that is used, for example, in telemetering measurements made while drilling includes a body that mounts a stack of ceramic crystals which generate bursts of sonic vibrations when excited by encoded electrical signals that represent such measurements. The vibrations are coupled into a metal member of a drill string such as a drill collar by a coupling block that is held tightly between a shoulder on the metal member and the outer end of the stack of crystals by a strong spring that also permits longitudinal dimensional changes under high downhole temperatures. The sonic vibrations are sensed at a remote location on another metal member by a transducer that can be constructed substantially identical to the above-mentioned stack of crystals, of an accelerometer. The output signals of the transducer are filtered, amplified, and processed. Preferably the excitation signals are encoded digitally in accordance with repetition rate of the bursts. Adjacent pairs of such transducers can be used as repeater stations at spaced locations in the drill string to transmit signals from downhole toward the surface.