Study On The Experiment Of Binary System Flooding Relative Permeability In Bohai Oilfield

Water flooding and polymer flooding have been used in the Bohai offshore oilfield, and now the scheme of surfactant/polymer combination flooding is studied. Meanwhile, the surfactant/polymer combination flooding relative permeability curves is of great importance in the development plan, oilfield production performance prediction and reservoir numerical simulation. In this paper, the measuring methods and influence factors of the surfactant/polymer combination flooding relative permeability curves have been studied.The increasing viscosity capacity, salt resistant, temperature resistant, thermal stability and shear resistance of some common polymer have been measured to choose the optimal polymer. For the sake of selecting the suitable surfactant, the capacity to improve the surface of water and oil and thermal stability of the surfactant has been studied. Also, the matching ability of the polymer and surfactant has been measured.For a more accurate relative permeability, different binary systems On the basis of the optimal system, have been inject into the core with and without crude oil. And the viscosity variation of binary systems with different polymer concentration, the whole process of injecting, and different position of the core have been studied.Combining with the viscosity variation of binary system, the method to calculate the viscosity is modified in the SP flooding relative permeability curve by non-steady-state method. Determine the relative permeability curve under different capillary number, different core permeability and different injection rate, and analyze the influence of the three factors on the relative permeability curve during binary system flooding. The result shows that: The bigger the capillary number is, the less the saturation of residual oil and the effective of oil displacement are. The bigger the concentration of polymer is, the less the water relative permeability and the saturation of residual oil are. The bigger the concentration of surfactant is, the bigger the water and the oil relative permeability are, and the less the saturation of residual oil is. The higher the core permeability is, the higher the water relative permeability is, and the less the saturation of residual oil is. The oil relative permeability also increases to some extent. When the injection rate increases from 0.5m/d to 3m/d, the water and the oil relative permeability both increase to some extent, and the saturation of residual oil decreases. When the injection rate increases from 3m/d to 8m/d, the phenomenon is just opposite.