【摘要】 岩石空隙中含气造成的地震波低速异常是检测天然气藏的一个重要地震信息.笔者在对鄂博梁Ⅲ号地震解释过程中发现,构造东高点深层地震所反映的构造形态及深、浅层构造叠置样式不仅与相邻构造存在较大差异,与区域构造变形规律也不相吻合.通过对全区地震精细解释及原始地震速度谱的分析判定,构造东高点深层地震反射不是真实构造形态的反映,而是由于地震异常低速造成同相轴"下拉"导致的构造形态畸变.进而,在排除影响地震速度的地表、处理流程、地下特殊岩性体等主要因素的基础上,通过石油地质综合研究认为,构造东高点紧邻生气凹陷、深层储、盖配置良好、晚期成藏,具备形成大型天然气藏的地质条件.圈闭含气是构造东高点深层地震产生低速异常的主要原因.更多还原

【Abstract】 Seismic low velocity anomalies caused by pore rock bearing gas is an important piece of seismic information which can be used to detect natural gas pool.We find that the deep structure attitude and the overriding style of deep structure and shallow structure of the east prominent are distinct from adjacent structures and misfit the regional deformation mechanism while we interpret the two-dimensional seismic data of Eboling-Ⅲ structure.Fine seismic interpretation and the analysis of initial seismic velocity spectrum indicate that the deep zone of seismic reflection isn′t the true image of the east prominent deep structure attitude,but the structure distortion caused by seismic events push-down,and the seismic events push-down is caused by the anomaly of low seismic velocity.Further,on the basis of removing the factors which affect seismic velocity,such as earth′s surface,seismic processing technique and particular lithesome,the comprehensive researches indicate that the east prominent is intimately adjacent to the gas generating sag,and the reservoir bed and capping bed arrangement condition is very good.The east prominent has the feature of late gas accumulation and has the petroleum geology conditions of forming large scale natural gas pool.The closure of structure bearing gas is the primary reason for seismic low velocity anomalies in the east prominent deep zone.更多还原