CARBOXY METHYL STARCH

CMS is an effective "economical" Fluid Loss Control agent for water-based drilling fluids. Increasing additions of CMS can cause an increase in desired viscosity. Used of CMS does not require any biocide treatment in normal drilling fluid operations. CMS is typically unaffected by normal solids concentrations and products a tough, slick filter cake, which promotes a reduction in friction and potentially increases drilling rates. CMS may be less effective in high levels of Mg and Ca ions and it is recommended that all "high hardness" be treated out prior to CMS addition. The normal dosage is 0.3 0.5 percentages.