Experimental research on affects the viscosity of carboxymethylcelluloses

The factors that affect the viscosity of CMC in drilling operation and provide technical guidance for fields were cleared.The factors,such as swelling time,temperature,shear rate,dosage of Na2CO3 and its adding sequence were studied.Experiment results showed that the best swelling time was 120 min;in the range of 30~ 90 ℃,with the temperature increasing,the viscosity of CMC hydrosol decreased,this kind of viscosity change can recover 97% with the temperature down.Furthermore,the linear relationship was presented between the logarithm of viscosity and the reciprocal of temperature.High-speed shearing was greatly impact on viscosity,when the shearing rate reached 12 000 r/min,viscosity can only recover 65%and dosage of Na2CO3 and its adding sequence all can cause the viscosity of CMC decreases.However,the influence that adding the Na2CO3 to CMC hydrosol was smaller than adding the CMC to Na2CO3 on the viscosity of CMC hydrosol.