一个典型的地震"模糊带"的AVO检测

AVO detection to a typical seismic illegibility zone

1. 中国地质大学能源学院,北京 100083;2. 中国地质大学水环系,北京 100083;3. 中国石化西北分公司,新疆乌鲁木齐 830011;4. 中原石油勘探局,河南濮阳 457001

School of Energy Resources, China University of Geosciences, Beijing 100083, China

在M气田存在着地震"模糊带",采用常规处理手段难以获得好的效果,为此利用AVO属性分析技术进行 了异常检测。阐述了AVO属性分析技术的基本原理。AVO属性分析对叠前振幅有较高的要求,因此对实际地 震资料进行了球面扩散、吸收补偿和地表一致性振幅补偿等处理,以保留入射角变化对叠前振幅的影响。属性 分析采用了Shuey的简化Zoeppritz方程。在M气田的某2条交叉测线上存在着"烟囱效应",对这2条测线进 行了AVO属性分析,得到了P波、G波、拟泊松比和碳氢检测等AVO属性剖面。AVO异常对应时间剖面深度 为1200ms的"亮点"振幅,表现为气藏特征,由此预测地震"模糊带"为储层含气后所致。

A history case in gas exploration with AVO technology is presented. The study indicates that prestack amplitude preserving should be the foundation of AVO processing. As the example of two 2-D seismic line reflected data processing in M gas field, it’s suggested removing the influence of spherical divergence, absorption, array and condition on reflected amplitude except incidence angle. In AVO attribute processing, it has obtained attribute-processing sections of pseudo-P wave,G wave, pseudo-Poisson ratio and hydrocar- bon profiles using Shuey approximation formula. The pres-tack amplitude analysis and AVO anomalies coincide perfectly with drilling data.