渤中34北区浅层油气成藏特征和主控因素分析

Sallow hydrocarbon accumulation characteristics and controlling factors in the northern BZ34 block

渤中34北区浅层主要为河控三角洲沉积,储层横向连续性差,断裂发育,构造复杂。区内油气成藏的主要特征是:油气水的分布整体受构造控制,储层发育程度影响油气富集丰度。油气富集成藏的主控因素是古近系“中转站”和断层,“中转站”的存在为浅层提供了充足的油源,断层的发育为油气运移提供了良好的通道,断层的性质决定了油气运移能力,进而影响了圈闭充满程度。在本区及渤海海域其他凹陷浅层复杂断块区应继续以断块圈闭为主进行油气勘探。

In the northern BZ34 block, the shallow sediments are mainly formed in a fluvial delta, with reservoir poor continuous laterally, faults well developed and structures complicated. The hydrocarbon accumulations are mainly characterized by： （1） the distribution of oil, gas and water is overall controlled by structures; and （2） the abundance of hydrocarbon is affected by reservoir development. The main controlling factors of hydrocarbon accumulation are a Paleogene “transfer station” and faults. The “transfer station” has provided adequate oil sources for the shallow sediments, and the developed faults have served as good paths for hydrocarbon migration. The hydrocarbon migration ability of a fault is dependent on its property, which may further influence the hydrocarbon charge level of traps. For this block and the complex sallow faulted-block areas in other sags of Bohai sea, the faulted-block traps should continuously be taken as the main exploration targets.