海上低渗透油藏压驱精细数值模拟表征方法及其应用OA

In order to further upgrade current fracture-flooding technology and solve the problems of insufficient un-derstanding of existing oil enhancement mechanism,incomplete consideration of numerical simulation models and low accuracy in production prediction,physical modeling experiments are conducted to study oil enhancement mechanisms of fracture-flooding.Combined with numerical simulation,multi-physics field characterization models for fracture-flooding process are established to develop a fine characterization method for numerical simulation of fracture-flooding in low-permeability reservoirs.Variations of permeability and conductivity with time are taken into account by the model,reducing human intervention and improving the accuracy of fracture-flooding simulation.The results show that the fracture-flooding process is influenced by multiple mechanisms including stress evolution,fracture initiation and propagation,porosity and permeability evolution,relative permeability variation,surfactant effect and imbibition effect.Among them,fracture initiation and propagation are the dominant mechanisms for frac-ture-flooding,with contribution rate of 50.7%to incremental oil production,while surfactant and imbibition effects contribute 29.7%and 19.6%,respectively.The accuracy of developed multi-physics field characterization model for fracture-flooding is validated using data from multiple wells in W oilfield in South China Sea.This model can be used to optimize the parameters such as injection volume,displacement rate and soaking time for fracture-flooding engineering design.The research provides systematic guidance for technical iteration and program formulation in the development of low-permeability reservoirs.