Study On The Residual Oil Distribution After Polymer Flooding And Feasibility Of Secondary Polymer Driving

In view of characteristics that water cut increased rapidly and oil rate declined quickly after polymer flooding in Gudao oilfield,with the distribution of remaining oil and the way to enhance oil recovery as center, in accordance with the "systems engineering" principle and taking the technical route of combining geology and exploitation, reservoir static prediction and dynamical analysis,reservoir performance research and numerical simulation,the paper makes an integrative study of building the geological model,making reservoir simulation, affecting factors research, optimization of parameters and economic evaluation.Reservoir characteristics are geological foundation of remaining oil distribution in the later stage of the exploitation. for this reason, combining with the well history file and logging data,the paper firstly describes the current status of simulated domain, set up fine geological model, studies the distribution of remaining oil and surplus reserves, then, in the two aspects of geologic factor and development genesis,the paper analysed formation mechanism and the control factors of residual oil, at the same time, the distribution pattern of residual oil was studied. Secondly, by reusing the model has been set up,the paper studied the sensitivity factors of injection-production parameters and physico-chemical parameters of the three methord.the results provide a scientific basis to extract potential remaining oil. Finally, the paper make comprehensive comparison of flooding effects through parameter optimization and economic evaluation of the three EOR methods, and make dynamic prediction according to eventually optimized program, thus made important awareness in chemical flooding of Gudao oilfield after polymer-flooding. Studies shows that the second injection of poly chemical flooding in Gudao Central can further enhance recovery.