AVO多参数反演在气层检测和储层定量研究中的应用

利用Aki和Richards的近似方程进行多种AVO岩性参数的反演,可获得零偏移距纵波剖面、横波剖面、纵波和横波相对速度剖面、气层指示剖面和截距与斜率乘积剖面,用于地质解释.为了获取定量的岩石物理参数,将反演得到纵波零偏移距剖面和经重采样后的反射横波剖面进行合成声波测井处理,得到纵、横波速度剖面.利用纵、横波速度与孔隙度和泥质含量的数学模型及已得到的纵、横波速度,定量计算储层的孔隙度和泥质含量,并得到相应的孔隙度和泥质含量剖面.利用不同地区的两个研究实例,按S.R.Rutherford对气藏的定义对其进行分类,并利用AVO反演结果说明其不同的AVO特征.并系统地说明了上述剖面在气藏检测和储层定性→定量解释中的应用.

THE APPLICATION OF AVO MULTIPLE PARAMETER INVERSION IN GAS SAND DETECTION AND RESERVOIR QUANTITATIVE EXAMINATION

AVO lithologic parameters can be inverted with the help of Aki and Richards formulaand the Singular Value Decomposition(SVD) method.Inversion can provide following sec-tions:Zero-offset reflectivity section of p-wave,reflectivity section of S-wave,relative veloci-ty sections of p-wave and S-wave, identification sections of gas sandstone. P-wave and S-wave velocities ,used in reservoir prediction and detection. Synthetic sonic log can be obtainedby sampled S-wave section,a procession of the synthetic accoustic profile obtained through acombination of Zero-offset,P-wave profile and the resample reflective S-wave profile rela-tionships between p-wave and S-wave velocities in clastic rocks,clay contents and porositiesare estimated and their sections are achieved.The paper shows the application of these sections in geological interpretations and detec-tion of gas sandstone which have different AVO characteristics. Case study has confirmedthat the qualitative to quantitative interpretation methods are effective.