The DSI combines new dipole-based technology with the latest monopole developments into one system, providing the best method available today for obtaining borehole compressional, shear and Stoneley slownesses. Dipole tools overcome this fluid velocity barrier. The DSI tool is a multireceiver tool with a linear array of eight receiver stations, a monopole transmitter and two dipole transmitters. The receiver array provides more spatial samples of the propagating wavefield for full waveform analysis. The arrangement of the transmitters and receivers allows measurement of wave components propagating deeper into the formation.
Frequency determines the wavelength that drives the depth of investigation of the measurement.
Low frequency penetrates deeper into the formation and helps read beyond altered zones. The DSI tool has several data acquisition operating modes, any of which may be combined to acquire digitized waveforms over each 6-in. logging interval. For waveforms, eight channels are digitized simultaneously with a 12-bit dynamic range.