This tool can be lowered by wireline or dropped through the drill pipe onto a landing ring located at the bottom of a non-magnetic drill collar. The non-magnet drill collar isolates the tool from magnetic interference from the drill pipe. The survey instrument (battery pack, camera, timer and compass angle unit) records one record of the direction and angle of the well bore on a film disc. The tool is used to monitor the location of the well bore during drilling. The single shot operates on 4 C or 4 AA alkaline batteries and has a temperature limitation of 82°C [180° F] without a Heat Shield. The tool is available in 1-3/8" (1.0375")OD and 1-3/4" (1.75") OD running gear.
