Study on the Application of Starch Derivatives as the Regulators of Potassium Drilling Fluids Filtration

Derivatives of starch, such as graft copolymer of acrylamide onto starch, carbamoylethylated starch, carbamoylethyl-dihydroxypropylated starch, and dihydroxypropylated starch have been tested for their properties as components of drilling fluids used for clay inhibition and for the regulation of their rheology. The influence of modified starch and their blends with tylose as protective agents in the filtration of drilling fluids, as well as replacement of tylose, by modified starch were investigated. The viscosity, flow limit, filtration, pH, and dispersion as factors of the properties of potassium drilling fluids with the addition of starch derivatives were determined.