油气微渗漏的垂向结构与地面地电化学油气检测

油气微渗漏现象是现代油气地球化学勘探、地球物理勘探和遥感地质勘探的重要依据之一。在研究油气微渗漏特点的基础上，根据油气微泡迁移模型和流体力势概念，建立了油气微渗漏动力学参数与地层孔隙结构的函数关系。按作用在油气微泡上势力的性质和特点提出了油气藏微渗漏的垂向分区结构，即划分为渗漏区、阻隔区、聚集区和迁移区。这种分区结构主要是由油气藏和围岩的孔隙结构及地质构造等因素决定的。根据在俄罗斯伏尔加乌拉尔成油区和在中国内蒙陆西坳陷两地油藏上方的金属有机相态地电化学油气检测结果，揭示了油气微渗漏的地表晕环状结构，表明了油气微渗漏特征与油气藏空间分布和地质构造的必然联系，证实了地电化学方法对确定油气藏边界的有效性。图３ 参７ （文百红摘）

Vertical structure of hydrocarbon microseepage and its surface geoelectrochemical detection.

Hydrocarbon microseepage is one of important criteria for modern geochemical, geophysical and remote sensing hydrocarbon exploration. Based on concepts of microbubble transport model and fluid potential, a function of dynamical parameters of hydrocarbon microseepage and stratum porosity is established. According to nature and characteristics of potential force, exerting on microbubble, a four zone vertical structure of microseepage is determined, i.e. zones of seeping, partition, accumulation and transportation. The vertical zoning structure is determined by stratum porosity, geological structure and other factors of hydrocarbon reservoir and host rocks. By geoelectrochemical surveys over one oil deposit in Ural Volga of Russia and over one in Luxi depression in Inner Mongolia of China, the circular halo surface structure of hydrocarbon microseepage is revealed and the close relationship between the features of hydrocarbon microseepage and spatial distribution and geological structure of hydrocarbon reservoir is presented. The results verify effectiveness of geoelectrochemical detection of boundaries of hydrocarbon deposits.