断层体系的分形维数及其对深源气运移条件的指示作用

Fractal Dimensions of Fault Systems and Their Hints to Migration Conditions of Gas from Deep Source Rocks

本文根据分形理论计算了松辽盆地北部大庆长垣以东地区T2、T3、T4反射层不同区域内断层体系的计盒维数和信息维数，通过对各区断层体系分维特征的分析，发现断层体系分维高值区域与深源气藏的分布存在较好的对应关系，这不仅表明断层是该区深源气的主要运移通道，同时也表明断层体系分维特征是定量描述深源气运移、聚集条件的一个重要参数。

Based upon the theory of fractal geometry, fractal dimensions of fault systems in the area east to the Daqing placanticline, Songliao Basin, were calculated using the box-counting approach to the reflecting T2,T3 and T4 horizon and the studied area was divided into eight zones with different oil and gas distribution features. From the analysis of fractal behaviours on different sub-systems of faults in the studied area, it was found that the zone with high fault fractal dimensions is in good correspondence with the distribution of gas accumulation from deep source rocks. This suggested that faults are main paths for gas migration from deep source rocks. It was also concluded that the fratcal dimension of an fault system is an important parameter to quantitatively characterize the nature of migration and distribution of gas from deep source rocks.