塔里木盆地巴楚—麦盖提地区志留纪同生断裂及其对砂质分散体系的控制

Syngenetic fault and its control of sandy dispersion system of Silurian in Bachu--Maigaiti area,Tarim basin

在塔里木盆地巴楚—麦盖提地区志留系地震资料解析基础上,利用生长指数反映该区断层发育情况,并通过井约束反演得出该区的砂体展布,研究该区断层对砂体的控制作用。铲式同生逆断层是该区主要的断层类型,包含有蛇头背斜、冲起构造等典型的逆冲构造样式;断层在平面上多呈弧形,走向以近北西向为主;研究区受北东向挤压形成两套倾向相反的平行逆冲断层,断层组合型式为"向斜式逆冲断层系"。该区同生断层对砂质分散体系的控制作用表现出两种不同的类型:当同生逆断层走向与物源方向近正交时,其对砂体分散的控制表现为"遏止作用";当同生逆断层走向与物源方向斜交时,其对砂体分散的控制表现为"疏导作用"。

On the basis of seismic data interpretation of Silurian in Bachu--Maigaiti area of Tarim Basin,we did the research on the faults by using growth index method,got the sand body distribution by using well constrained inversion,and finally studied the controlling effect of the faults on sand body. In this area,the faults are mainly shovel-like contemporaneous reverse in type. They contain some typical thrust tectonic styles such as the snakehead anticline and the rushed up structure. Many faults appear arc in the plane,with nearly NW as the main trend. By the NE extruding,the studied area has formed two sets of opposite dip parallel thrust faults. The combined fault type is ＂syncline type thrust system＂in type. In this area,the controlling effect of contemporaneous faults on sand body displays two different type that when the contemporaneous reverse fault and the provenance direction are nearly orthogonal,the controlling effect of contemporaneous faults for sand body is characterized by＂curb effect＂; while they are crossing obliquely,it is characterized by＂leading effect＂.