地层品质因子Q值地震反演问题剖析

发布时间：2018-05-26 17:06

本文选题：品质因子 + Q值反演　；参考：《石油地球物理勘探》2017年01期

【摘要】：针对目前地层品质因子地震反演及估算研究中存在的5个方面的问题,指出了模型结构、厚度以及模型参数选择的合理性是吸收衰减正演模拟分析的关键。探讨了Q值反演与阻抗反演的异同,明确了连续Q值反演的理论局限性。分析了叠前Q反演与AVO反演的差异,揭示了地层吸收衰减导致地震反射波振幅随炮检距增加而减小的内在本质为射线品质因子随炮检距增大而增大,可称之为"QVO效应"。阐明了单一薄层衰减地震响应的可检测性问题,指出了利用薄层衰减地震响应变化来准确反演或估算地层品质因子Q值的困难性和反演估算结果的不确定性。揭示了尽管品质因子比速度对储层含气饱和度更敏感,但并不反映含油气检测更有效,只有二者引起的地震响应强弱变化才是真正意义上含油气检测的敏感性度量指标。与速度相比,单一含气薄层因品质因子Q值降低引起的衰减地震响应变化并不占优势。基于品质因子Q值地震反演结果检测薄储层含油气性具有极大的风险。
[Abstract]:In view of the five problems existing in seismic inversion and estimation of formation quality factors at present, it is pointed out that the rationality of model structure, thickness and model parameters is the key to the forward modeling analysis of absorption attenuation. The similarities and differences between Q-value inversion and impedance inversion are discussed, and the theoretical limitations of continuous Q-value inversion are clarified. The difference between prestack Q inversion and AVO inversion is analyzed. It is revealed that the inherent essence of seismic reflection wave amplitude decreasing with offset increasing is that the ray quality factor increases with offset, which can be called "QVO effect". The detectability of the attenuation seismic response of a single thin layer is clarified. The difficulty of accurately retrieving or estimating the Q value of the formation quality factor by using the variation of the seismic response of thin layer attenuation and the uncertainty of the inversion estimation result are pointed out. It is revealed that although the quality factor is more sensitive to the gas saturation than the velocity, it does not reflect that the oil and gas detection is more effective. Only the change of the seismic response caused by the two factors is the real sensitivity metric of the oil and gas detection. Compared with the velocity, the attenuation seismic response of a single gas-bearing thin layer due to the decrease of Q value of the quality factor is not dominant. Seismic inversion based on Q value of quality factor is of great risk in detecting oil and gas properties of thin reservoir.
【作者单位】：河南理工大学资源环境学院;中原经济区煤层(页岩)气河南省协同创新中心;
【基金】：河南理工大学博士基金项目(B2009-85)资助
【分类号】：P631.4

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