K (viscosity) : The consistency index, is the shear stress or viscosity of the fluid at one sec-1 shear rate. An increasing K raises the effective annular viscosity, increases hole cleaning capacity
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}