In this paper, the effects of shear rate on the intrinsic viscosity measurement of partially Hydrolysed Polyacrylamide (HPAM) in salt solution were studied with homemade multibulb viscometer and low shear rate rheomet...In this paper, the effects of shear rate on the intrinsic viscosity measurement of partially Hydrolysed Polyacrylamide (HPAM) in salt solution were studied with homemade multibulb viscometer and low shear rate rheometer. The critical shear rate of HPAM in salt solution for high molecular weight HPAM was determined. A low shear rate capillary viscometer was designed in which the [eta] approached to value at zero shear rate can be obtained for HPAM -salt system. The effect of molecular weight on shear rate dependence of viscosity was also studied.展开更多
This paper describes the experimental study of viscosity measurement error in the vibrational type viscometer, which measures viscous damping of the oscillating circular plate in a fluid in continuously increasing tem...This paper describes the experimental study of viscosity measurement error in the vibrational type viscometer, which measures viscous damping of the oscillating circular plate in a fluid in continuously increasing temperatures. The experiments are carried out to measure non-uniformity of the temperature field in the test cup of the vibrational viscometer in continuously increasing temperatures, while changing the viscosity of the target fluids. Experimental outcomes show that non-uniformity of the temperature grows in the cup and results in viscosity measurement error, when the viscosity of the fluid increases. In order to understand this phenomenon, velocity measurement by particle image velocimetry is conducted in the test cup for fluids of varying viscosity. The results indicate that mixing is enhanced in the low-viscosity fluid by the occurrence of unsteady thermal convection, while weaker convection appears in the high-viscosity fluid.展开更多
Based on a conventional torsion pendulum,we develop a forced oscillation viscometer with ultra-high viscosity sensitivity of 2×10^（-7）Pa·s working at frequencies near the resonance.The viscosity is achieve...Based on a conventional torsion pendulum,we develop a forced oscillation viscometer with ultra-high viscosity sensitivity of 2×10^（-7）Pa·s working at frequencies near the resonance.The viscosity is achieved by exploiting the phase lag for the angle displacement behind the torque,instead of the resonant curve,i.e.,the variation of angle displacement amplitude versus frequency.The general formula for the measurement of the visco-elasticit.y of complex fluids is also presented.With such precision it is easy to measure tiny change in viscosity result from circumstantial influences.Deionized water and two kinds of NaCl aqueous solutions are chosen to demonstrate the performance of our home-made torsion pendulum-based viscometer.展开更多
为了准确测量油藏条件下气体、液体和气液混合物的运移黏度,依据泊肃叶定律设计了毛细管黏度计。毛细管黏度计主要包括注入系统、测量系统、回压控制系统和辅助系统4个部分。针对气体、液体和气液混合物的特性,分别设计了气体注入系统...为了准确测量油藏条件下气体、液体和气液混合物的运移黏度,依据泊肃叶定律设计了毛细管黏度计。毛细管黏度计主要包括注入系统、测量系统、回压控制系统和辅助系统4个部分。针对气体、液体和气液混合物的特性,分别设计了气体注入系统、液体注入系统和气液混合注入系统,并研制了不同内径的毛细管和不同渗透率的孔隙介质模型模拟油藏孔隙。结果表明,毛细管黏度计实现了气体、液体和气液混合物的注入速度准确计量和黏度测量,回压控制系统采用回压式位移量化控制系统精准控制回压,提高了毛细管黏度计测量的准确度和精度。在模拟油藏条件氮气黏度非常低,仅为0.018 mPa·s,而聚合物和泡沫体系毛细管黏度较高,分别为78 m Pa·s和126 m Pa·s。展开更多
基金This work ws supported by the National Natural Science Foundation of China and Polymer Physics Laboratory,Institute of Chemistry,Academia Sinica.
文摘In this paper, the effects of shear rate on the intrinsic viscosity measurement of partially Hydrolysed Polyacrylamide (HPAM) in salt solution were studied with homemade multibulb viscometer and low shear rate rheometer. The critical shear rate of HPAM in salt solution for high molecular weight HPAM was determined. A low shear rate capillary viscometer was designed in which the [eta] approached to value at zero shear rate can be obtained for HPAM -salt system. The effect of molecular weight on shear rate dependence of viscosity was also studied.
文摘This paper describes the experimental study of viscosity measurement error in the vibrational type viscometer, which measures viscous damping of the oscillating circular plate in a fluid in continuously increasing temperatures. The experiments are carried out to measure non-uniformity of the temperature field in the test cup of the vibrational viscometer in continuously increasing temperatures, while changing the viscosity of the target fluids. Experimental outcomes show that non-uniformity of the temperature grows in the cup and results in viscosity measurement error, when the viscosity of the fluid increases. In order to understand this phenomenon, velocity measurement by particle image velocimetry is conducted in the test cup for fluids of varying viscosity. The results indicate that mixing is enhanced in the low-viscosity fluid by the occurrence of unsteady thermal convection, while weaker convection appears in the high-viscosity fluid.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10974259,11274391 and 11104357the Science and Technology Planning Project of Guangdong Province under Grant No 20128060100003the Fundamental Research Funds for the Central Universities under Grant Nos 121gpy36 and 09lgpy29
文摘Based on a conventional torsion pendulum,we develop a forced oscillation viscometer with ultra-high viscosity sensitivity of 2×10^（-7）Pa·s working at frequencies near the resonance.The viscosity is achieved by exploiting the phase lag for the angle displacement behind the torque,instead of the resonant curve,i.e.,the variation of angle displacement amplitude versus frequency.The general formula for the measurement of the visco-elasticit.y of complex fluids is also presented.With such precision it is easy to measure tiny change in viscosity result from circumstantial influences.Deionized water and two kinds of NaCl aqueous solutions are chosen to demonstrate the performance of our home-made torsion pendulum-based viscometer.
文摘为了准确测量油藏条件下气体、液体和气液混合物的运移黏度,依据泊肃叶定律设计了毛细管黏度计。毛细管黏度计主要包括注入系统、测量系统、回压控制系统和辅助系统4个部分。针对气体、液体和气液混合物的特性,分别设计了气体注入系统、液体注入系统和气液混合注入系统,并研制了不同内径的毛细管和不同渗透率的孔隙介质模型模拟油藏孔隙。结果表明,毛细管黏度计实现了气体、液体和气液混合物的注入速度准确计量和黏度测量,回压控制系统采用回压式位移量化控制系统精准控制回压,提高了毛细管黏度计测量的准确度和精度。在模拟油藏条件氮气黏度非常低,仅为0.018 mPa·s,而聚合物和泡沫体系毛细管黏度较高,分别为78 m Pa·s和126 m Pa·s。
