低角度逆光照射三维可视化描述低幅度构造体系

Using 3D Visualization of Low-Angle Backlight Illumination to Describe Tectonic System of Low Amplitude

摘要: 油气富集带受不同期次、级次的构造体系控制。采用低角度逆光照射三维可视化方式，可清晰描述多方向、多期次的低幅度构造体系；构造体系的期次的确认，可依据区域构造动力、构造形迹关系，结合层拉平技术进行；浅层–深层构造对比，可确认深层古构造；对形态复杂的碳酸盐岩剥蚀面，也可采用低角度逆光三维可视化。应用该方法分析川西坳陷构造体系，发现近EW走向的５条弧形构造、NE向多条线性构造为印支期–燕山期古构造；川南地区，发育一条沿着东吴期古断层发育的大型冲沟。这些部位是值得重点关注的油气富集带。

Abstract: The enrichment zone of oil &gas was controlled by tectonic system which was subjected to multi- stages and multi-directions tectonic movement. To describe tectonic system of low amplitude, 3D visualization of low-angle backlight illumination technique was used. According to the dynamics of regional tectonic evolution and the relationship between the structural features, combining with layer flattening technique, the formation stages of tectonic system can be confirmed. The comparison of structure of deep and shallow layer can confirm the ancient structure; 3D visualization of low-angle backlight can also be used in the description of erosion surface of carbonate with complex morphology. With the application of this method to analyze the tectonic system in western Sichuan depression, it has been found that there are 5 arc structures which are nearly EW direction, and multiple linear structures which are in NE direction. All of these structures were paleostructure formed in indo-china period-Yanshanian; A large gully was developed along the ancient fault of the Dongwu period, southern Sichuan basin. All of these areas are worth focusing on because of the possibility of oil and gas enrichment.