柴达木盆地第四系生物气藏的地震反射特征

THE CHARACTERISTICS OF SEISMIC REFLEC-TIONS OF QUATERNARY BIOGENIC GAS POOLS

通过对柴达木盆地第四系含气区地震反射资料的描述，阐述了该区第四系含气地层的“地震异常反射特征”，并通过异常反射与探明气藏空间分布的相关性和异常幅度与含气丰度一致性的对比分析，对地震剖面上各种不同级别的异常反射赋予了明确的地质意义。同时，根据波动反射理论，结合该区第四系沉积疏松、埋藏浅的特殊地质条件，对该区第四系含气地震异常的形成机理进行了探讨，并明确指出：沉积疏松、整体低速的地质背景，正是形成该区第四系特殊“含气地震异常”的特殊地质条件。

According to the description of seismic reflections of Quarternary petroliferous area, this article presents characteristics of seismic anomalous reflection of Quarternary petroliferous strata. The anomalous reflections of different grades on the seismic sections are endowed with clear geologic meaning by analysing the correlation between relevance of anomalous reflection and proven reservoirs distributions and conformity of anamolous extent and petroliferous abundance. Meanwhile, considering the special geologic condition, loose sediments and low buried depth, in Quarternary, we effectively discussed the formation mechanism of petroliferous seismic anomaly with the theory of wave reflection. It is clearly concluded that the geologic environment of loose sediments and the whole low velocity is the unique geologic condition of formation of special petroliferous seismic anomaly in Sanhu Quarternary.