河流相储层中夹层类型的定量识别

Quantitative recognition of interbed types in fluvial reservoirs

根据夹层的岩性、物性特征,河流相储层中的夹层一般可分为泥质夹层、灰质(钙质)夹层和物性夹层,由于这3种夹层对流体运移影响程度不同,因此剩余油的分布也有差异。综合利用自然伽马、微梯度、微电位、微电极、声波时差和井径等参数的变化幅度能够较为灵敏地识别夹层性质,并建立了3种夹层的雷达图识别模式,总结出了不同夹层定量识别特征值,适用于程序化批量处理数据。在孤岛油田利用水平井挖潜夹层上部剩余油的过程中,利用这一方法优选泥质夹层及厚度较大的物性夹层发育的区域部署水平井,取得了良好的生产效果,提高采收率达4%。

According to the lithology and physical properties of interbeds,the interbeds in the fluvial reservior could be divided into three types as muddy interbed,calcareous interbed and silty mud interbed. Different type of interbed has different influence on fluid migration,which results in various distribution of remaining oil. Interbed properties could be identified sensitively by variation scope of combination gamma ray neutron laterolog,microinverse,micronormal,microelectrode,acoustic travel time,and wellbore diameter. Recognition model of radar maps for three interbed types was established. Characteristic values for quantitative recognition in various type of were summarized,which is suitable for routinized batch data processing. This method has been applied to tapping the potential of the remaining oil in upper interbeds. After horizontal wells were placed in the zones of muddy interbeds and thick silty mud interbeds,very good production effect was achieved in Dudao Oilfield with EOR up to 4%.