关键词: 高盐油藏, 物理模拟, 储层孔喉尺寸, 匹配关系, 聚合物分子聚集体, 机理分析

Abstract: At present, the application demand of polymer flooding technology is shifting from low⁃salt reservoirs to high⁃salt and extra⁃high salt reservoirs. Improving the adaptability of polymers in high⁃salt reservoirs has become a technical problem that petroleum science and technology workers need to solve urgently. In order to improve the recovery rate of the target reservoirs, the “Chang 4+5” high⁃salt oil reservoir block of Changqing Oilfield was mainly based on the knowledge of physical chemistry, polymer materials science and reservoir engineering, through instrument detection and chemical analysis and physical simulation and other experimental methods, under the conditions of high salinity solvent water, the polymer solution reservoir adaptability study. The results show that the core permeability limit of the polymer solution is Kg=(25～40)×10-3 μm2 when the relative molecular mass is M=800×104 under the conditions of polymer concentration of CP=300～900 mg/L, permeability limit Kg=(30～55)×10-3 μm2 when M=1 400×104, Kg=(35～70)×10-3 μm2 when M=1 700×104 ,when M=2 000×104, Kg=(45～80)×10-3 μm2. Under the conditions of water and keep temperature injection in the target reservoir, the adaptability between reservoir rock and polymer solution is affected by rock permeability, polymer relative molecular mass and concentration. The top of the correlation curve is the compatibility area, and the lower part is the blocking area. The "hole throat radius median/Dh " ranged from 3.02 to 5.76 in the target reservoir.

Key words: High?salt reservoir, Physical simulation, Reservoir pore throat size, Matching relationship, Polymer molecular aggregate, Mechanism analysis