密点速度分析方法在新疆亚肯北部地区速度分析中的应用

The application of dense velocity analysis in the fine velocity analysis in northern Yaken area,Xinjiang.

新疆亚肯北部地区表层和地下地质条件复杂,浅层第三系巨厚高速砾岩以及深层上第三系低速膏盐存在速度和厚度的变化,使得区内构造和圈闭难以落实。为此,提出了密点速度分析方法,该方法逐道求取强波组地震波速度,并应用速度滤波、频率滤波、倾角滤波等手段提高速度参数的精度。将该方法应用于亚肯北库1井区600km2的叠前三维地震资料的精细速度分析,搞清了浅层高速砾岩区和深部低速膏盐层的速度变化规律,预测了浅层高速砾岩的平面分布范围。

The extraordinarily thick high-velocity in shallow Tertiary conglomerate and the variable velocity and thickness of the low-velocity in upper Tertiary gypsum-salt beds hamper the delineation of structures and traps. This paper adopted dense velocity analysis technique (with an areal grid of 40m×20m) to determine trace-by-trace the velocities of strong seismic wave groups. With the fine velocity data calculated from the 3-D prestack seismic data of 600km2 around well Kul in northern Yaken, the paper investigated the variability of velocity in the high-velocity shallow conglomerate region and the low-velocity deep gypsum-salt beds, and predicted the area distribution of the high-velocity shallow conglomerate formation. The results . demonstrated the feasibility of dense velocity analysis technique in detailed velocity investigation in northern Yaken.