渤海渤中A区断层差异输导及控藏作用分析

Analysis of Differential Oil and Gas Migration by Fault and Hydrocarbon Accumulation Controlling Factors in Bozhong A Area of Bohai Sea

张宏国 王昕 官大勇 宿雯

ZHANG Hongguo WANG Xin GUAN Dayong SU Wen

中海石油(中国)有限公司天津分公司勘探开发研究院, 天津 300452

Institute of Exploration and Development of Tianjin Branch of CNOOC Ltd., Tianjin 300452, China

渤中A区位于渤海海域的渤南低凸起北部斜坡带,前期勘探重点为潜山与古近系,而新近系的含油气性日益引起重视。从油气输导体系研究入手,明确了断层垂向输导油气是新近系成藏的关键,通过断层样式、断层活动性的分析,认为背形负花状构造及断层活动差异共同控制新近系差异成藏,并指示构造脊部位是油气优势的运移方向。另外,利用分形几何学原理,对研究区断层分形特征进行研究,构造脊部位断层分形分维数值较高,表明构造脊部位油气运移效率较高,佐证了常规方法的论断且对断层输导体系进行半定量-定量的评价。近期钻井在构造脊部位的新近系有良好发现,证实了断层输导分析的正确性。

Bozhong A area is located in the northern slope of Bonan low uplift in Bohai Sea, and the main exploration targets were buried hill and Paleocene in the early exploration period. In recent years, the hydrocarbon bearing conditions of Neocene has attracted great attentions. Through study on the hydrocarbon transformation systems, it has been made clear that hydrocarbon vertical migration through faults is the key factor for hydrocarbon accumulation in the Neocene. Based on analyzing results of fault patterns and activity, it has been concluded that back shaped negative flower structure and fault activity controlled the differential oil and gas accumulation, indicating structural ridges might be the beneficial direction of oil and gas migration. Furthermore, with fractal geometry principle, the fractal feature in the study area has been studied. The fractal dimension value of faults is high in the structural ridges, indicating that hydrocarbon migration efficiency is high in the structural ridges, which confirmed the results from conventional method by semi-quantitative or quantitative evaluation. Recent drilling results in structural ridge had excellent finding of oil and gas bearing layers in Neocene, demonstrating the analyzing results of fault migration mentioned above.

"十二五"国家科技重大专项"渤海海域大中型油气田地质特征"(2011ZX05023-006-002)资助

https://doi.org/10.3969/j.issn.1008-2336.2014.03.016