Study On Viscosity Reducing Property Of Polyaspartic Acid

Viscosity-reducer for drilling fluids were mostly used reduced viscosity of drilling fluids and controlled fluidity of drilling fluids. Presently, polymer viscosity-reducer was developing trend of viscosity-reducer for drilling fluids. Polyaspartic acid was green viscosity-reducer.The viscosimetric properties of polyaspartic acid in dilute solution was investigated. The intrinsic viscosity of PASP in DMF solution was measured at 25℃.The perfermance in reducing viscosity of polyaspartic acid used in drilling fluids as viscosity-reducer was studied. The rate of reducing viscosity of polyaspartic acids at different molecular weights of 4000 22000 34000 and 60000 were measured in this experiment. The experimental results showed that the polyaspartic acid having a molecular weight of about 34000 had a better effect in reducing viscosity. It was found that when m(polyaspartic acid) : m(polyethyleneglycol) = 3:1 and the addition of the combination was 0.4%, the rate of reducing viscosity could reach 75%. The studied copolymer meet with the demand of viscosity-reducer in oilfield.