地震波衰减技术在鄂尔多斯盆地储层预测中的应用

The application of seismic attenuation technology for reservoir prediction in Erdos basin.

中国石油化工股份有限公司石油勘探开发研究院, 北京100083

Exploration & Production Research Institute, SINOPEC, Beijing 100083, China

鄂尔多斯盆地北部上古生界的陆相致密隐蔽性气藏,具有低孔、低渗、低压、多层叠置的特点,储层与围岩的波阻抗差异小,储层预测存在着多解问题。为此,进行了地震波衰减技术预测储层方法的研究。阐述了地层介质的吸收原理,讨论了基于小波变换的匹配追踪频谱分解算法,并在此基础上对介质品质因子和地震波振幅梯度与储层特性的关系进行了分析;利用该方法计算了鄂尔多斯盆地北部D16井区下石盒子组盒3段地震波振幅的衰减梯度,并结合其它储层信息进行了含气性综合预测。预测结果表明,地震波振幅衰减梯度与实际钻井的含气性相吻合。

The subtle hidden reservoir is characterized by lower porosity, lower permeability, lower pressure and multiple thinner beds in upper Palaeozoic group of north Erdos basin. On the basis of the fundamental theory of seismic attenuation and wavelet transform, a method is studied on the seismic attenuation technology to predict reservoir , we discussed the relationship of seismic quality factor, attenuation gradient and reservoir characterization. The attenuation gradient is calculated by this method, the distribution of reservoir is predicted by integrating attenuation gradient with other reservoir information. By testing real seismic data about H3 segment in upper Palaeozoic group of north Erdos D16 area, the attenuation gradient is well agreement with the drilling result.