【摘要】 川东地区地表条件极为复杂,地形起伏大,构造顶部多出露二叠系、三叠系碳酸盐岩。地腹地层强烈褶皱,地层倾角大,直立甚至倒转,逆冲断层发育。地震原始资料的声波、面波、侧面波及其它干扰波能量较强。由于受回转波、侧面波、绕射波等互相干涉和速度横向变化的影响,叠加剖面成像质量较差,造成构造形态失真。本文针对川东地区高陡复杂构造的特殊情况,首先采取了提高叠前资料的信噪比,然后在建立合理的构造模式的基础上,建立正确的偏移速度模型(速度模型包括界面形态和速度值)和选用合适的偏移方法(本文采用了叠前深度偏移)。利用本文的方法,对川东高陡构造复杂区的多条测线进行了重新处理,使叠加剖面上的反射波归位和偏移成像质量有明显的提高。更多还原

【Abstract】 In east Sichuan, surface condition is very complicated, landform undulates terribly, and the cropped anticline mostly consists of Permian and Triassic carbonate rocks. Its limb beds were folded severely to become very steep, vertical and even reverse, so that there occur many overthrust faults. There are quite heavy acoustic wave, surface wave, side wave and other noise waves in raw seismic data in this area. Influenced by both lateral velocity variation and some noise waves (bow tie, side wave, diffraction wave, etc.), the stacked seismic sections have quite poor image quality to cause some distorted geological structures. To cope with the terrible complicated steep anticlines in east Sichuan, the authors have taken some effective measures: improving the signal/noise ratio of seismic data before stack, constructing reasonable structure style to have good migration velocity model including interface shape and velocity values, and using optimum migration method (prestack depth migration). The technique was taken to reprocess many seismic lines in structural complicated east Sichuan, ameliorating greatly the image of stacked seismic sections.更多还原