The diffusion coefficient of natural gas in foamy oil is one of the key parameters to evaluate the feasibility of gas injection for enhanced oil recovery in foamy oil reservoirs. In this paper, a PVT cell was used to ...The diffusion coefficient of natural gas in foamy oil is one of the key parameters to evaluate the feasibility of gas injection for enhanced oil recovery in foamy oil reservoirs. In this paper, a PVT cell was used to measure diffusion coefficients of natural gas in Venezuela foamy oil at high pressures, and a new method for deter- mining the diffusion coefficient in the foamy oil was de- veloped on the basis of experimental data. The effects of pressure and the types of the liquid phase on the diffusion coefficient of the natural gas were discussed. The results indicate that the diffusion coefficients of natural gas in foamy oil, saturated oil, and dead oil increase linearly with increasing pressure. The diffusion coefficient of natural gas in the foamy oil at 20 MPa was 2.93 times larger than that at 8.65 MPa. The diffusion coefficient of the natural gas in dead oil was 3.02 and 4.02 times than that of the natural gas in saturated oil and foamy oil when the pressure was 20 MPa. However, the gas content of foamy oil was 16.9 times higher than that of dead oil when the dissolution time and pressure were 20 MPa and 35.22 h, respectively.展开更多
A fiber-array probe is designed to measure the damping behavior of a small perturbed shock wave in an opaque substance, by which the effective viscosity of substance under the condition of high temperature and high pr...A fiber-array probe is designed to measure the damping behavior of a small perturbed shock wave in an opaque substance, by which the effective viscosity of substance under the condition of high temperature and high pressure can be constrained according to the flyer-impact technique. It shows that the measurement precision of the shock arrival time by using this technique is within 2 ns. To easily compare with the results given by electrical pin technique, the newly developed method is used to investigate the effective viscosity of aluminum （Al）. The shear viscosity coefficient of A1 is determined to be 1700 Pa.s at 71 GPa with a strain rate of 3.6× 10^6 s-1, which is in good agreement with the results of other methods. The advantage of the new technique over the electrical pin one is that it is applicable for studying the non-conductive substances.展开更多
The effect of reverse pressure.on theological behavior has been studied. The apparatus is a capillary rheometer with counter pressure chamber being held at a high reverse pressure by means of a cock. The results show ...The effect of reverse pressure.on theological behavior has been studied. The apparatus is a capillary rheometer with counter pressure chamber being held at a high reverse pressure by means of a cock. The results show that with the increase in temperature, the shear viscosity of hydrophilic PET is reduced. It is different that the effect of temperature on shear viscosity is varied under the condition of all shear rates or all pressures, and the effect is more prominent at 50 MPa or at 216 s^-1. At the same time, the pressure coefficients decrease with increasing the shear rate and the temperature and tend to reach a constant value nearly at the temperature of 290 ℃.展开更多
This paper is concerned with the free boundary value problem（FBVP） for the cylindrically symmetric barotropic compressible Navier-Stokes equations（CNS） with density-dependent viscosity coefficients in the case tha...This paper is concerned with the free boundary value problem（FBVP） for the cylindrically symmetric barotropic compressible Navier-Stokes equations（CNS） with density-dependent viscosity coefficients in the case that across the free surface stress tensor is balanced by a constant exterior pressure. Under certain assumptions imposed on the initial data, the unique cylindrically symmetric strong solution is shown to exist globally in time and tend to a non-vacuum equilibrium state exponentially as time tends to infinity.展开更多
采用毛细管流变仪及其配套的反向压力腔组件控制毛细管出口压力,在平均压力为5~50 MPa下研究了3种不同特性黏度的聚酯（PET）的流变行为。结果表明：PET的剪切黏度随着平均压力的增大都呈指数增加,符合Barus方程。压力系数随着特性黏度...采用毛细管流变仪及其配套的反向压力腔组件控制毛细管出口压力,在平均压力为5~50 MPa下研究了3种不同特性黏度的聚酯（PET）的流变行为。结果表明：PET的剪切黏度随着平均压力的增大都呈指数增加,符合Barus方程。压力系数随着特性黏度的增大而减小,当特性黏度由0.48增加至0.67 d L/g时,压力系数显著减小,且这种变化随着剪切速率的增大而衰减,当特性黏度≥0.67 d L/g时,压力系数随剪切速率的变化不大。压力系数随剪切速率的增大而减小,特性黏度为0.48 d L/g时变化显著,当特性黏度≥0.67 d L/g时,压力系数随剪切速率的变化不大。压力系数随着温度的升高而减小,且变化率随着温度的升高显著减小。不同特性黏度PET压力系数的变化表明,特性黏度较低时,自由体积较大,表现在玻璃化转变温度低,受压力的影响显著;当特性黏度为0.67和1.00 d L/g时,自由体积的减小不再明显,因此受压力的影响也不再明显。展开更多
基金financial support from the Major Subject of National Science and Technology (2011ZX05032-001)the Fundamental Research Funds for the Central Universities(NO.11CX06022A)
文摘The diffusion coefficient of natural gas in foamy oil is one of the key parameters to evaluate the feasibility of gas injection for enhanced oil recovery in foamy oil reservoirs. In this paper, a PVT cell was used to measure diffusion coefficients of natural gas in Venezuela foamy oil at high pressures, and a new method for deter- mining the diffusion coefficient in the foamy oil was de- veloped on the basis of experimental data. The effects of pressure and the types of the liquid phase on the diffusion coefficient of the natural gas were discussed. The results indicate that the diffusion coefficients of natural gas in foamy oil, saturated oil, and dead oil increase linearly with increasing pressure. The diffusion coefficient of natural gas in the foamy oil at 20 MPa was 2.93 times larger than that at 8.65 MPa. The diffusion coefficient of the natural gas in dead oil was 3.02 and 4.02 times than that of the natural gas in saturated oil and foamy oil when the pressure was 20 MPa. However, the gas content of foamy oil was 16.9 times higher than that of dead oil when the dissolution time and pressure were 20 MPa and 35.22 h, respectively.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10974160 and 11002120)the Fundamental Research Funds for the Central Universities (Grant No.SWJTU12CX085)
文摘A fiber-array probe is designed to measure the damping behavior of a small perturbed shock wave in an opaque substance, by which the effective viscosity of substance under the condition of high temperature and high pressure can be constrained according to the flyer-impact technique. It shows that the measurement precision of the shock arrival time by using this technique is within 2 ns. To easily compare with the results given by electrical pin technique, the newly developed method is used to investigate the effective viscosity of aluminum （Al）. The shear viscosity coefficient of A1 is determined to be 1700 Pa.s at 71 GPa with a strain rate of 3.6× 10^6 s-1, which is in good agreement with the results of other methods. The advantage of the new technique over the electrical pin one is that it is applicable for studying the non-conductive substances.
基金financially supported by the National "Twelfth Five-Year" Plan for Science&Technology(2011BAE05B00)the State Key Laboratory of Hollow Fiber Membrane Materials and Processes
文摘The effect of reverse pressure.on theological behavior has been studied. The apparatus is a capillary rheometer with counter pressure chamber being held at a high reverse pressure by means of a cock. The results show that with the increase in temperature, the shear viscosity of hydrophilic PET is reduced. It is different that the effect of temperature on shear viscosity is varied under the condition of all shear rates or all pressures, and the effect is more prominent at 50 MPa or at 216 s^-1. At the same time, the pressure coefficients decrease with increasing the shear rate and the temperature and tend to reach a constant value nearly at the temperature of 290 ℃.
基金supported by National Natural Science Foundation of China(No.41630530),National Natural Science Foundation of China(No.41575109)Key Research Program of Frontier Sciences,CAS(Grant No.QYZDY-SSW-DQC002)
文摘This paper is concerned with the free boundary value problem（FBVP） for the cylindrically symmetric barotropic compressible Navier-Stokes equations（CNS） with density-dependent viscosity coefficients in the case that across the free surface stress tensor is balanced by a constant exterior pressure. Under certain assumptions imposed on the initial data, the unique cylindrically symmetric strong solution is shown to exist globally in time and tend to a non-vacuum equilibrium state exponentially as time tends to infinity.
文摘采用毛细管流变仪及其配套的反向压力腔组件控制毛细管出口压力,在平均压力为5~50 MPa下研究了3种不同特性黏度的聚酯（PET）的流变行为。结果表明：PET的剪切黏度随着平均压力的增大都呈指数增加,符合Barus方程。压力系数随着特性黏度的增大而减小,当特性黏度由0.48增加至0.67 d L/g时,压力系数显著减小,且这种变化随着剪切速率的增大而衰减,当特性黏度≥0.67 d L/g时,压力系数随剪切速率的变化不大。压力系数随剪切速率的增大而减小,特性黏度为0.48 d L/g时变化显著,当特性黏度≥0.67 d L/g时,压力系数随剪切速率的变化不大。压力系数随着温度的升高而减小,且变化率随着温度的升高显著减小。不同特性黏度PET压力系数的变化表明,特性黏度较低时,自由体积较大,表现在玻璃化转变温度低,受压力的影响显著;当特性黏度为0.67和1.00 d L/g时,自由体积的减小不再明显,因此受压力的影响也不再明显。
