Rheological Properties And Rheo-kinetics Of CMHEC/CTAB Systems

In this paper, aiming at synergistic interaction between carboxymethyl hydroxyethyl cellulose (CMHEC) and cetyltrimethyl ammonium bromide (CTAB), mixtures of CMHEC and CTAB solutions were investigated, employing relative viscosity and rheological measurements. Rheological properties of CMHEC/CTAB systems during the crosslinking and gel-breaking processes were studied, and corresponding rheo-kinetics equations were established. Further, micro-rheolaser was applied to study micro-rheological properties of CMHEC/CTAB systems during the static crosslinking and gel-breaking processes, and corresponding intrinsic crosslinking and gel-breaking rheo-kinetics equations were established. Main conclusions were made as followed:1) It is proved that there exsits synergistic interaction between CMHEC and CTAB solutions. Viscosity, storage modulus and loss modulus of CMHEC/CTAB solutions is greater than that of CMHEC solutions. Shear viscosity, storage modulus and loss modulus of CMHEC/CTAB cross-linked gels is greater than that of CMHEC cross-linked gels.2) The effects of shear rate and temperature on rheological properties (viscosity, storage modulus and loss modulus) of CMHEC/CTAB systems during the isothermal and non-isothermal crosslinking processes were defined. First-order crosslinking rheo-kinetics equation was established, which could describe the viscosity curves during the isothermal crosslinking process. Four-parameter crosslinking rheo-kinetics equation was established, which could describe the viscosity curves during the non-isothermal crosslinking process.3) The effects of the mass ratio, the amount of pH-adjustor and cross-linker, concentration and temperature on micro-rheological properties (Solid Liquid Balance-SLB, Macroscopic Viscosity Index-MVI, Elasticity Index-EI) of CMHEC/CTAB systems during the static crosslinking process were defined. First-order intrinsic crosslinking rheo-kinetics equation was established, which could describe the El curves during the static crosslinking process.4) The effects of the amount of ammonium persulfate and temperature on micro-rheological properties (Solid-Liquid Balance) of CMHEC/CTAB and Guar gum systems during the static gel-breaking processes were defined. First-order intrinsic gel-breaking rheo-kinetics equation was established, which could describe the Elasticity Index curves of CMHEC/CTAB systems during the static gel-breaking process. Four-parameter intrinsic gel-breaking rheo-kinetics equation was established, which could describe the Elasticity Index curves of Guar gum systems during the static gel-breaking process. Further, the effects of the amount of ammonium persulfate and temperature on rheological properties of CMHEC/CTAB systems during the gel-breaking process in small amplitude oscillatory flow were defined. First-order gel-breaking rheo-kinetics equation was established, which could describe the storage modulus curves during the gel-breaking process in small amplitude oscillatory flow. Model parameters were defined and reasonable.The studies provide rheological basis for the application of cellulose-based fracturing fluid.