Droplet spatial distribution is the basic information for the calculation of pressure drop and void fraction of gas-liquid two-phase flow. Based on a detailed analysis of the forces acting on the entrained droplets, o...Droplet spatial distribution is the basic information for the calculation of pressure drop and void fraction of gas-liquid two-phase flow. Based on a detailed analysis of the forces acting on the entrained droplets, one method taking account of the correction of droplet terminal settling velocity due to shear lift force was proposed to modify the droplet turbulent diffusion model. By such a modification the calculated errors of decay coefficient for horizontal oil/gas two-phase separated flow was reduced greatly. As a result, the lift force is one of the important factors to be considered reasonably during the study of droplet diffusion and spatial distribution for oil/gas transport.展开更多
Foam fracturing is an important technology in the development of low permeability oil/gas reservoirs. The heat transfer characteristics of foam fracturing fluid are directly relevant to the calculation of pressure dro...Foam fracturing is an important technology in the development of low permeability oil/gas reservoirs. The heat transfer characteristics of foam fracturing fluid are directly relevant to the calculation of pressure drop in the well, the optimum choice of fracturing parameters and the accurate evaluation of fracturing results. CO 2 foam fracturing fluid behaves as a non-Newtonian fluid. The convective heat transfer characteristics of CO 2 foam fracturing fluid were experimentally investigated on the newly constructed large-scale test loop under downhole conditions with CO 2 in supercritical state, the pressure up to 40 MPa. From the test data, corresponding correlations for convective heat transfer were obtained and the influences of pressure, temperature and flow rate were also studied. The convective heat transfer coefficient increased with the increase of temperature and flow rate, while the effect of pressure was much more complicated.In most cases, with the increase of pressure the coefficient tended to decrease.展开更多
文摘Droplet spatial distribution is the basic information for the calculation of pressure drop and void fraction of gas-liquid two-phase flow. Based on a detailed analysis of the forces acting on the entrained droplets, one method taking account of the correction of droplet terminal settling velocity due to shear lift force was proposed to modify the droplet turbulent diffusion model. By such a modification the calculated errors of decay coefficient for horizontal oil/gas two-phase separated flow was reduced greatly. As a result, the lift force is one of the important factors to be considered reasonably during the study of droplet diffusion and spatial distribution for oil/gas transport.
文摘Foam fracturing is an important technology in the development of low permeability oil/gas reservoirs. The heat transfer characteristics of foam fracturing fluid are directly relevant to the calculation of pressure drop in the well, the optimum choice of fracturing parameters and the accurate evaluation of fracturing results. CO 2 foam fracturing fluid behaves as a non-Newtonian fluid. The convective heat transfer characteristics of CO 2 foam fracturing fluid were experimentally investigated on the newly constructed large-scale test loop under downhole conditions with CO 2 in supercritical state, the pressure up to 40 MPa. From the test data, corresponding correlations for convective heat transfer were obtained and the influences of pressure, temperature and flow rate were also studied. The convective heat transfer coefficient increased with the increase of temperature and flow rate, while the effect of pressure was much more complicated.In most cases, with the increase of pressure the coefficient tended to decrease.
