苏北盆地高邮凹陷构造转换带控油机制研究

STUDY OF CONTROL MECHANISM OF OIL AND GAS BY THE TRANSFER ZONE IN THE GAOYOU SAG OF THE NORTH JIANGSU BASIN

构造转换带是盆地演化中保持形变守恒而产生的调整构造,它不仅可以发育于伸展构造系统,也可以发育于走滑构造体系,在不同的构造体系中具有不同的控油机制。在伸展构造体系中传递断层一般表现为压扭性质,具有较好的封闭能力;而在走滑构造体系中则往往表现为张性,封闭能力较差。应用构造转换带理论对苏北盆地高邮凹陷真武、吴堡断裂带的研究认为,许庄、陈堡地区分别发育不同性质的构造转换带,具有不同的控油机制,其中许庄地区传递断层封闭油气的能力较好,陈堡地区传递断层封闭油气的能力较差。这一认识较好地解释了这2个地区成藏条件的差异,也为该区的进一步勘探开发提供了理论依据。

Transfer zone is a kind of adjusted structure to keep the conservation of deformation during the evolution of rift-basin. It exists in extensional tectonic system as well as in strike-slip tectonic system. The transfer zone in each system has different control mechanism of oil and gas. The transfer faults in extensional tectonic system have better seal capacity than that in strike-slip tectonic system. So it requires heavy-mud contents in corresponding wall to form a pool for a transfer fault related to strike-slip tectonic system. The paper has applied the theory of transfer zone to study the reasons of success and failure of exploration in the Zhenwu and the Wubao fault zone of the Gaoyou Sag, and concludes that Xuzhuang area has better seal capacity for developing extensional tectonic system than that in Chenbao area for developing strike-slip tectonic system. It helps to reveal the essence of hydrocarbon accumulation mechanism in the given area. All in all, the theory of transfer zone can greatly promote the further exploration and development of the area,and also can promote to choose advantageous traps of exploration.