Joint inversion method for interval quality factor based on amplitude and phase information

基于振幅和相位信息的地层品质因子联合反演方法研究（英文）

Estimating the quality factor Q accurately signifi cantly improves the seismic data resolution and reservoir characterization.The commonly used log-spectral ratio method uses least-squares fi tting to obtain Q values and involves only the amplitude information of seismic data while neglecting phase information.This paper proposes a joint interval Q inversion method based on the spectral ratio method and employs both amplitude and phase information to improve the accuracy.Based on the assumption that Q is independent of frequency,the nonlinear relation between the Q value and the two types of information is jointly used to construct an objective function,which clarifies the quantitative relation between amplitude spectrum,phase information,and Q value.The interval Q value can be inverted by calculating the minimum value of the objective function.The model test exhibits that the proposed method has higher precision and stability than the spectral ratio method;furthermore,the application to field data demonstrates that accurate Q inversion results are consistent with reservoir characteristics.

精确求取Q值对于提高地震资料分辨率和储层特征描述具有重要意义。常用的谱比法利用最小二乘拟合求取Q值,仅利用了地震资料的振幅信息,没有充分利用其相位信息。本文在谱比法的基础上,提出了一种地层Q值的联合反演方法,综合利用振幅和相位信息来提高Q值反演精度。在假设Q值不随频率变化的基础上,利用振幅和相位信息与Q值间的非线性关系,构建了联合反演地层Q值的目标函数,明确了振幅谱和相位信息与Q值之间的量化关系,通过求解该目标函数的极值即可反演出地层Q值。模型数据测试表明,该方法比谱比法具有更高的精度和稳定性,实际资料应用表明精确的Q值反演结果与储层特征间具有较好的对应关系。