渤中凹陷西次洼断层空间分布的多重分形特征

Multifractal characteristics of spatial distribution of the faults in west subsag of Bozhong Sag

赵家琳 李瑾 张震 杨传超 张笑桀

ZHAO Jialin LI Jin ZHANG Zhen YANG Chuanchao ZHANG Xiaojie

中海石油(中国)有限公司天津分公司

Tianjin Branch of China National Offshore Oil Co., Ltd., Tianjin 300459, China

分形几何作为定量描述自然界里极不规则形状的强有力工具被应用于渤中凹陷西次洼断裂体系的研究中，通过多重分形方法计算了新近系明化镇组断层及不同展布方向断裂的分维值，研究结果表明断裂分布的分维值能有效地描述断裂的空间分布特征，当研究区断裂体系在0.5~8 km尺度下具有很好的统计自相似性和明显的分形特征，以此为基础，初步探讨了断裂分形特征与油气盆地分布之间的关系，当断层空间分布的分维值在1.382~1.428的区域时，是油气的主要富集区，但是分维值大于1.45以上，则不利于油气的保存。根据分维值等值线平面分布图，油气聚集区与断裂发育叠合性较好，为本区下一步勘探及井位部署提供参考依据。

Fractal geometry, as a powerful tool to quantitatively describe the irregular shapes in nature, is applied to study the fault system in west subsag of Bozhong Sag.In this paper, the fractal dimension of the Neogene Minghuazhen Formation fault and that of the faults in different distribution directions were calculated by means of multifractal method.It is shown that the multifractal method is feasible.The fractal dimension of fault distribution can effectively describe the spatial distribution characteristics of faults.The fault system in the study area presents good statistical self-similarity and obvious fractal features when it is in the scale of 0.5-8 km.Then, the relationship between the fractal characteristics of faults and the distribution of oil and gas basins was discussed preliminarily.It is indicated that the area whose fractal dimension of spatial distribution of fault is in the range of 1.382-1.428 is the main hydrocarbon enrichment area.When the fractal dimension is higher than 1.45, it is not conducive to hydrocarbon preservation.The superposition of hydrocarbon accumulation area and fault development which is shown in the plane distribution map of fractal dimension contour can provide the reference and basis for the following exploration and well location deployment in this area.

10.13639/j.odpt.2018.S0.004