STUDY OF HYDROGEL MODIFIED DRILLING FLUID: PREPARATION, RHEOLOGICAL PROPERTIES AND SWELLING BEHAVIORS OF CHITOSAN N-ISOPROPYLACRYLAMIDE HYDROGEL

Abstract

Chitosan N-Isopropylacrylamide hydrogels were synthesized by thermal and gamma radiation methods. The thermal method used an initiator and a crosslinker while the gamma radiation process was done in absence of any kind of initiator or crosslinker agent. The study found that the gamma radiation method produced hydrogels with higher water swelling ratio. The rheological properties of the hydrogels used in the preparation of drilling fluids were investigated. Properties such as apparent viscosity, plastic viscosity, gel strength, and yield point were compared with those of Carboxymethyl Cellulose (CMC) and Xanthenes (XC) resins, which are widely used in drilling fluids. The hydrogel synthesized by gamma radiation improved rheological properties of drilling fluids better than CMC, XC, and thermal prepared hydrogel. Also, comparison results show that whereas linear polymer effects on mud properties are more significant in low polymer concentration, prepared crosslinked hydrogel effects are more prominent at high concentrations.