辽河坳陷冷东地区沙三段浊积岩体的反射特征和发育部位预测

辽河坳陷冷东地区沙三段发育浊积岩体,对该区某些关键井的岩性、声波时差曲线、钻测井资料的统计、分析及解释,利用地震相移法波动方程正演方法,确定出浊积岩体的地震反射特征,为其分布提供了判别标志.采用G-log技术进行层速度反演处理,将层速度从波阻抗中分离出来,利用层速度与岩性、孔、渗关系曲线,将其转换为岩性平面图,结合浊积岩体的岩性、物性特征,预测了沙三段浊积岩体的发育部位.预测结果与钻井实测情况相符,表明地震反演层速度变化大体反映岩性的变化;正演模拟结果表明在时间剖面上解释的地震特征具有扇三角洲-浊积岩的速度结构.图3表1参2(谭荣摘)

Reflectance signature and occurring position of turbidite in the third Member of Shahejie Formation, Lengdong region, Liaohe depression.

By statistically analyzing and explaining lithology, AC curve, drilling and logging data of some key wells and combined with seismic phase displacement wave equation forward modelling, s eismic reflectance signature of turbidite is established, which provides a diagn ostic criterion for turbidite. Interval velocity was inverted by G-log technolo gy, so that interval velocity was separated from wave impedance by using the cor relation curves of interval velocity vs. lithology, porosity and permeability, a nd then transformed into lithological plane views. Combining with lithology, pet rophysical property of turbidite, the occurring position of turbidite was succes sfully predicted. From the above study, it can be concluded that:(1) Interval ve locity change in seismic inversion, generally reflects the change of lithology. (2) Forward modelling result indicates that seismic characteristic explained in time-section has velocity structure of fan delta-turbidite.