强碱三元体系与萨中地区油藏适应性研究

Study on Adaptability of ASP Flooding System to Reservoir in Sazhong Area

为保证强碱三元复合驱在大庆油田萨中地区顺利实施,开展了强碱三元复合体系中聚合物分子线团尺寸及其影响因素、岩心渗透率极限及其影响因素和驱油剂分子线团尺寸与岩石孔喉半径匹配关系实验研究。结果表明,随聚合物相对分子质量增加,聚合物分子线团尺寸Dh增大;随聚合物浓度升高,聚合物溶液中Dh呈“增大—减小—增大”趋势;随剪切强度增大,聚合物溶液中Dh先降低后升高。驱油剂岩心渗透率极限随聚合物相对分子质量和浓度增大而增大,随剪切强度的增大而减小。油藏岩石与驱油剂聚合物的适应性受岩石渗透率、聚合物浓度、相对分子质量以及剪切强度等因素影响,强碱三元复合体系“孔喉半径中值/Dh”范围通常在11~21。

In order to ensure strong base ASP flooding successfuUy implemented in Sazhong area of Daqing Oilfield, the matching relations between rock pore throat radius and polymer molecular group size and its influencing factors, core permeability limit and its influencing factors, oil displacement agent molecular group size were studied by experiments. The results show that, with the polymer relative molecular mass increasing,the molecular group size of polymer in the ASP solution increases;with the concentration of polymer solution increasing, the molecular group size of polymer presents the trend of increasing-decreasing - increasing; with the shear strength increas- ing, the molecular group size of polymer decreases firstly and then increases. The core permeability limit of oil displacement agent in- creases with the polymer relative molecular mass and the polymer solution concentration increasing, and it decreases with shear strength increasing. The adaptability of ASP flooding system to reservoir rock is controlled by rock permeability, polymer solution concentration, polymer relative molecular mass and shear strength. The ratio of median value of pore-throat radius to polymer molecular group size is generally between 11 and 21 for strong base ASP flooding.