碳酸盐岩缝洞型储层“弱反射”特征的地震多属性识别

利用常规的振幅类地震属性难以有效识别塔河油田奥陶系碳酸盐岩缝洞型储层的“弱反射”特征。为此,首先建立了几种不同类型的缝洞储层数值模型,通过正演模拟明确地震“弱反射”特征与碳酸盐岩缝洞储层的相关性;然后针对见油井点缝洞储层段地震资料进行“弱反射”特征识别的敏感地震属性分析,证实了利用频率衰减属性能够识别“红波谷”反射特征的缝洞储层;最后采用频率衰减属性与反射强度属性相结合的思路,构建出反射强度调谐累计频率衰减属性,能够同时实现对“串珠状”和“弱反射”特征的碳酸盐岩缝洞型储层进行有效识别。

It is difficult to identify the “weak reflection” characteristics of Ordovician carbonate fracture-vuggy reservoir by common seismic amplitude attributes in Tahe Oilfield.Therefore,we built some types of fracture-vuggy reservoir models to identify the relativity between the “weak reflection” characteristics and the fracture-vuggy reservoirs by forward modeling.Then sensitive seismic attributes analysis with near wellbore seismic traces was performed for the “weak reflections” characteristics recognition,which proved that frequency attenuation attribute was effective for identifying the fracture-vuggy reservoirs with “red trough” reflection.Finally,by combining the frequency attenuation attribute and reflection intensity attribute,reflection intensity tuning cumulative frequency attenuation attribute was constructed,which can effectively identify the “weak reflections” and “string” characteristics of carbonate fracture-vuggy reservoirs at the same time.