Tractor 8 : An electrically or hydraulically powered downhole tool with driven wheels or slip and hydraulic extension capability that can pull a tool string along a highly deviated well
George E. King Engineering, 5000 Oilfield Terms: A Glossary of Petroleum Engineering Terms, Abbreviations and Acronyms, US 2010. http://gekengineering.com/Downloads/Free_Downloads /Glossary_of_Petroleum_Engineering_Terms_25_August _2010.pdf, (Oil - Amer) {593}