Two versions of the compressional sonic device are available: the compensated sonic and the full waveform sonic (FWS). The full waveform sonic contains an array of receivers that are used to determine both compressional and shear velocities. Sonics are available in a variety of transmitter-to-receiver spacings from 3 to [[length::12 ft]] or more. The longer spacings are capable of investigating deeper into the formation. Both the conventional sonic and the full waveform sonic devices are used to measure compressional velocity. A typical presentation of compressional sonic measurements is shown in the log in Figure 1. | Two versions of the compressional sonic device are available: the compensated sonic and the full waveform sonic (FWS). The full waveform sonic contains an array of receivers that are used to determine both compressional and shear velocities. Sonics are available in a variety of transmitter-to-receiver spacings from 3 to [[length::12 ft]] or more. The longer spacings are capable of investigating deeper into the formation. Both the conventional sonic and the full waveform sonic devices are used to measure compressional velocity. A typical presentation of compressional sonic measurements is shown in the log in Figure 1. |