| Abstrakt: |
ABSTRACT Aiming at good thickening ability and temperature resistance in water-based drilling fluid, a novel copolymer viscosifier (SDKP) of sodium 2-acrylamido-2-methylpropane sulfonate (NaAMPS) with N-vinylcaprolactam (NVCL) and cross-linking divinylbenzene (DVB) was prepared by micellar radical polymerization. The composition and molecular structure of optimal SDKP under the optimum reaction conditions was characterized by FT-IR, 1H-NMR, and elemental analysis, and the molecular weight was determined by GPC. Thermal gravimetric analysis showed that the SDKP was even stable when the temperature was not higher than 330 °C. The performance of SDKP as viscosifier for aqueous, brines, and saturated brine bentonite drilling fluid was evaluated before and after aging tests at 230 °C for 16 h. The evaluation results indicated that the SDKP had excellent thickening ability, thermal resistant, and salt tolerance. HTHP rheology test showed that the SDKP containing drilling fluids displayed a thermo-thickening effect in temperature range of 150 to 180 °C, which was beneficial to increase the viscosity and strength of fluids at high temperatures. Shear test showed that the SDKP illustrated a similar shear thinning to xanthan gum. ESEM observations demonstrated that the continuous three-dimensional network was formed in the SDKP aqueous and brines solution, which was probably the main reason for its excellent thickening properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44140. [ABSTRACT FROM AUTHOR] |
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