Features: Multi-array induction tool coil system adopts asymmetry structure with one transmitter coil and eight receiver coils. It works at three frequencies. Multi-dsp and array coil system are adopted in the tool. The multi-channel, multi-frequency weak signal pick-up in the tool is achieved by real-time calibration, digital filtering and digital phase-sensitive detection technology. A lot of mechanical and electronic measures have been taken for reaching the desirerable tool stability and high reliability. Due to the excellent performance, high reliability and high accuracy of multi-array induction tool, many oil companies decide to adopt multi-array induction tool as one important part of their logging program. Specification : Temperature:311 ¨h(155 ) Pressure :14503.8 psi (100 mpa) Data transmission:430 kbps/100 kbps Accuracy: Vertical resolution : 0.75 ms/m or < 2% 1.81 in., 23.62 in., 47.24 in. (30cm, 60cm, 120cm) Investigation depth:9.84 in., 19.69 in., 29.53 in., 59.05 in. 88.58in. (25cm50cm75cm150cm225cm) Applications: Accurate formation resistivity measurement with three vertical resolutions and five investigation depths Accurate oil/water saturation evaluation (both oil saturation and residual oil saturation) Thin layer analyses in laminated reservoirs Oil/water zone identification by resistivity profile images in many difficult cases, like deeply-invaded formations etc. Resistivity measurement in oil-based mud or air-filled boreholes.