油页岩的地球物理识别和评价方法

利用地球物理方法识别和评价油页岩主要是依靠测井技术,地震方面研究非常薄弱。在现有的油页岩测井响应特征和测井评价方法(ΔlogR重叠法)的基础上对ΔlogR重叠法进行了拓展,引入波阻抗与常规测井响应特征进行重叠来评价油页岩;同时根据油页岩的岩石结构特征,建立油页岩岩石物理模型,提出了一种基于岩石物理模型的由速度反演油页岩有机质含量的方法;最后利用地震多属性预测技术将已知钻井的含油率信息反演外推到地震数据,得到预测的含油率数据。结果表明,波阻抗ΔlogR重叠法、岩石物理反演法和地震多属性预测法都可以有效地评价油页岩的有机碳含量和含油率。

Application of seismic multi-attribute fusion method based on D-S evidence theory in prediction of CBM-enriched area

D-S evidence theory provides a good approach to fuse uncertain inlbrmation. In this article, we introduce seismic multi-attribute fusion based on D-S evidence theory to predict the coalbed methane （CBM） concentrated areas. First, we choose seismic attributes that are most sensitive to CBM content changes with the guidance of CBM content measured at well sites. Then the selected seismic attributes are fused using D-S evidence theory and the fusion results are used to predict CBM-enriched area. The application shows that the predicted CBM content and the measured values are basically consistent. The results indicate that using D-S evidence theory in seismic multi-attribute fusion to predict CBM-enriched areas is feasible.

致密砂岩气藏可拓学评价研究——以渤海湾A气田为例

致密砂岩气藏储层物性差、含气饱和度低,合理评价气藏内有利含气储集体,对于优选动用单元、提高单井产能意义重大。以渤海湾盆地A气田为例,通过开展岩、电、震多尺度资料分析,总结了致密储层成因演化与气藏成藏过程的耦合关系,建立了“先成藏、后致密”的气藏成藏模式和分布规律;在模式指导下,开展致密砂岩储层综合评价,形成了以“致密系数(Tightness Index)”为核心的致密储层物性评价方法,大幅提高了致密砂岩物性解释精度;通过重构含气特征参数,利用基于神经网络的地震多属性拟合方法预测了气藏分布,验证了气藏模式,并通过可拓学方法定量评价优选出了有利目标。