黄骅坳陷中区断裂系统分形研究

FRACTAL ANALYSIS OF FAULT SYSTEM OF CENTRAL AREA IN THE HUANGHUA DEPRESSION

利用分形几何方法分析了黄骅坳陷中区断裂分布的分形特征,以探讨该区断裂系统的发育规律及其与油气的关系。利用数盒子方法进行分析表明,黄骅坳陷中区断裂系统在标度区间1.75～7km具有很好的统计自相似性。根据断裂分维值等值线可知,海岸线两侧断裂分维值分布规律有着明显不同,显示了两侧断裂系统在形成机制上的差异性。研究区分维值自西向东逐渐增大,在歧口凹陷南北两侧有着最高的分维值。结合黄骅坳陷中区断裂系统的形成机制及油田的分布,初步探讨了断裂分形特征与黄骅坳陷中区断裂系统的形成机制及断裂分形特征与油田分布之间的关系。研究结果表明,断裂系统分维值的变化特征与断裂的发育规律有着很好的相关性,断裂发育程度高的地区其分维值也更高,也将更有利于油气的运聚。

The fractal geometry is applied to study the fault systems of central area in Huanghua depression. A fractal model of fault distribution is established to investigate correlation between the fractal dimensions of fault system and the distribution of faults. Results indicate that the spatial distribution of faults of central area in Huanghua depression is a distinct fractal set with self-similarity in the non-scale range of 1.75 - 7kin, and the fractal dimension （capacity dimensions）, obtained by a box-counting method, interprets well the characteristics of the spatial distribution of faults. Shown by isoline maps of fractal dimensions,the distribution of the two groups of faults divided by the coastline is obviously different. It indicates that the genesis of the two groups of faults is different too. From the west to the east, the fractal dimensions of faults increase gradually and the max appears in the southern part and northern part of the Qikou sag. Based on the geometry characteristics of faults, this paper describes correlation between fractal distribution of the fault system and distribution of oil field. The results show that the distribution of oil field and the fractal dimension have a high degree of correlation. With the increase of the fractal dimension, the development density of faults is increased, and the oil field is bigger.