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Downhole Logging Tools

Stuck/Lost Tools


Stuck and lost tools are a normal occupational hazard of logging. In spite of our best efforts to avoid tool loss, Schlumberger strings have been lost on ODP Legs 101, 113, 117, 122 and 175, and IODP Expeditions 320 and 342. These strings are expensive and therefore are insured against loss in a hole; however, the shipboard loggers try their best to avoid sticking a tool, to recover a stuck tool, and to fish for a lost tool.

If a tool is lost downhole, a reasonable effort must be made to recover it in order to satisfy obligations to Schlumberger and the insurance provider. The recovery effort should follow accepted practices and include multiple recovery attempts if technically feasible. USIO/LDEO must be notified immediately by the Logging Staff Scientist or the drilling superintendent if a tool is stuck or lost.

If all reasonable efforts have been made to recover a stuck or lost tool without success, then the decision to abandon the tool must be made collectively by the Logging Staff Scientist, Operations Superintendent, Rig Superintendent and the Schlumberger engineer.