Abstract: Minimizing circulating pressure loss and/or reducing friction in drilling fluid operations to minimize equivalent circulating density (ECD) and maximize flow for borehole cleaning, tool optimization and efficient drilling may be achieved by the addition of friction improvers or drag reducers while circulating drilling fluids. Suitable drag reducers may include, but not necessarily be limited to, poly(alpha-olefins); polyisobutylene; condensation polymers of dicarboxylic acids or anhydrides, or polyols and monocarboxylic acids, addition polymers of unsaturated esters; copolymers of alpha-olefins with unsaturated esters; polystyrene acylated with long chain fatty acids; polyalkylene oxides; copolymers of alkyl acrylates with N-containing olefins; and combinations thereof.