AVO技术在徐家围子断陷油气检测中的应用

APPLICATION OF AVO TECHNOLOGY IN HYDROCARBON DETECTION OF XUJIAWEIZI FAULT DEPRESSION

利用松辽盆地徐家围子断陷的火山岩资料开展了火山岩含气测井响应特征分析和火山岩含气地震响应特征分析,探索了AVO技术用于火山岩气藏直接检测的方法 通过地震资料高精度处理获得了符合AVO分析要求的高保真地震资料 在岩石物理分析的基础上找到了火山岩弹性模量对地球物理参数的影响因素 采用Aki-Richards和Shuey近似公式建立了8种AVO模型.模型分析和对AVO属性的综合分析表明,泊松比和纵、横波速度比是识别徐家围子断陷气藏的敏感属性,垂直入射反射系数与泊松比变化率之积是识别气藏的有效AVO属性,由此确定了徐家围子断陷气藏AVO特征类型.

The analysis of logging and seismic response characteristics of gas-bearing volcanic rock is conducted by using the data from volcanic rock of Xujiaweizi Fault-Depression in Songliao Basin, and the method of applying AVO technology to direct detection of volcanic-rock gas reservoir is searched. The seismic data with high fidelity that meets the requirement of AVO analysis is acquired through the high-accuracy processing of seismic data. The influence factor of volcanic-rock elastic modulus on geophysical parameters is found on the base of petrophysical analysis. Eight types of AVO model are built using Aki-Richards and Shuey approximate formulas. The comprehensive analysis of model and AVO attributes shows that the poisson and P/S wave velocity ratios are the sensitive attributes of identifying Xujiaweizi Fault-Depression gas reservoir. The product of vertical incidence reflection coefficient and variation rate of poisson ratio is the effective AVO attribute to identify the gas reservoir. Thus, AVO characteristic type of Xujiaweizi Fault-Depression gas reservoir is determined.