Well logging with battery-powered downhole logging tools and data recording in downwhole memory.
The tool perform autonomously without getting a power from surface and without data communication with surface.
This requires the tools to be programmed for specific recording cycles (called cyclogram) at surface by field engineer and there will be no communication with tool after RIH.
Once the tool is retrieved from borehole up to the surface, a field engineer connects the tool to desktop computer and download the recorded data.
Usually conveyed with slick-line (for vertical sections), wire-line (without electrical transmissions), coil-tubing (in horizontal and severely inclined wells) and drill-strings (for surveillance while drilling)