基于动态驱替扫描技术的特低渗储层微观剩余油赋存状态的研究

Research on Occurrence States of Microscopic Remaining Oil in Ultra-low PermeabilityReservoirs Based on Dynamic Displacement Scanning Technology

为厘清安塞油田长6特低渗油藏微观剩余油赋存特征,明确后续开展三次采油技术方向,基于动态驱替扫描技术监测真实岩心水驱过程微观剩余油赋存特征及动态变化规律。结果表明,基于动态驱替扫描技术及计算机重建技术能够获取不同水驱阶段岩心孔隙内部不同流体的赋存状态信息与实际三维形貌,依据微观剩余油分布形态、位置、赋存量及可动用程度等特征信息,将其分为粒间吸附状、团簇状、喉道状、角隅状、颗粒吸附状及孔表薄膜状剩余油。建立了微观剩余油赋存类型定量判别方法与标准。此外,系统地梳理了不同水驱阶段微观剩余油类型及其变化规律,提出针对性的动用方法与建议,为后续开展化学驱提高油田采收率奠定基础。

In order to determine tertiary oil recovery technology for the Chang 6 ultra-low permeability reservoir of Ansai Oilfield,the micro occurrence characteristics and dynamic varying of residual oil in water flooding process of real cores are monitored by means of dynamic oil displacement scanning technology.The results indicate that the information on the occurrence status and actual three-dimensional morphology of different fluids inside the core pores in different stages of water flooding can be obtained by using dynamic oil displacement scanning technology and computer reconstruction technology.Based on the micro distribution characteristics,location,accumulation capacity and displaceable degree of residual oil,the occurrence status of remaining oil can be classified into intergranular adsorption,cluster,throat,corner,particle adsorption,and pore surface film residual oil.A quantitative discrimination method and standard for micro occurrence types of residual oil have been established.The micro occurrence types of residual oil and their variation patterns in different stages of water flooding are systematically sorted out,the targeted residual oil utilization methods and suggestions are proposed,which lays a solid foundation for subsequent chemical flooding to improve oilfield recovery.