低渗透油藏储层多尺度裂缝的建模方法研究

Study on Simulation Method of Multi-scale Fractures in Low Permeability Reservoirs

低渗透油藏储层中流体的流动是一个横跨致密基质、天然裂缝、水压裂缝、井筒的典型多尺度力学行为明确油藏储层中裂缝的尺度分级,建立精确的低渗透储层多尺度裂缝模型,探究多尺度之间的级联耦合作用过程和内在联系,是低渗透油藏渗流研究的关键,也是实现超低渗透油藏有效开发的重要理论基础。根据复杂学科的多尺度关联方法及油藏多尺度裂缝建模的相关文献资料,明确提出了油藏中多尺度裂缝的尺度分级标准,总结归纳了多尺度关联方法和低渗透油藏储层多尺度裂缝模型,分析了按连续介质思想和离散介质思想构建的几种代表模型的优劣。在此基础上,提出了储层裂缝多尺度建模的建议,并指出了低渗透油藏多尺度裂缝建模研究的趋势。

The flow of fluids in low permeability reservoirs displays typical multi-scale mechanical behavior across dense matrices,natural fractures,hydraulic fractures,and wellbores.Studying the classification of the scale of fractures in reservoirs,establishing an accurate multi-scale fracture model in low permeability reservoirs,and exploring the cascade coupling process and internal correlations between multi-scales are the keys to the study of seepage flow in low permeability reservoirs and provide an important theoretical basis for effective recovery from low permeability reservoirs.Based on the multi-scale correlation method of complex disciplines and the relevant literature on multi-scale fracturing modeling of reservoirs,the scale classification criteria of multi-scale fractures in reservoirs are proposed.In addition,the multi-scale correlation method and multi-scale fracture model in low permeability reservoirs are summarized.The advantages and disadvantages of several representative models constructed from a continuous media perspective and a discrete media perspective were analyzed.Based on the study′s results,recommendations for constructing the multi-scale model of reservoir fractures are proposed and the research trend of multi-scale fracture modeling in low permeability reservoirs is pointed out.