Mud Tracer 2 : A material such a grain, dye, flakes or other material that can be circulated with the mud to track how quickly and to what extent the hole is circulated
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}