渤海海域渤南低凸起中段新近系油气成藏的主控因素

DOMINANT FACTORS TO THE NEOGENE HYDROCARBON ACCUMULATION ON MIDDLE OF BONAN LOWER-UPLIFT

近年,渤南低凸起中段新近系油气勘探获得突破,为掌握该区新近系油气富集规律,根据最新勘探成果,利用区内大量勘探资料和实验分析资料,在总结新近系已发现油气藏特征的基础上,提出了3个油气成藏主控因素:距离油源远近控制了新近系油气成藏规模大小;切至潜山的长期活动断层对新近系油气成藏至关重要;"包心菜式"断层组合的不同部位决定了新近系油气富集程度。通过主控因素分析,总结其油气成藏模式为远源阶梯式油气成藏模式,这对该区下步新近系油气勘探具有重要的现实指导意义。

Breakthroughs of hydrocarbon exploration have been made in the Neogene in the middle part of the Bonan lower-uplift over the last two years.The study of hydrocarbon accumulation patterns upon latest exploration achievements,geological and geophysical data and testing results suggest that there are three controlling factors over oil and gas accumulation in the region.The distance of reservoir to source controls the reservoir size;the existence of long-lived faults,which cut down to the buried hill,provide pathways for hydrocarbon migration in the Neogene;and the position of reservoirs within the‘cabbage＇-type fault system plays a critical role in hydrocarbon enrichment.These understandings lead to the proposal of the model of stepped lateral migration from distant oil sources for hydrocarbon accumulation on the Bonan lower-uplift,which are of great significance to the exploration of Neogene hydrocarbon in the study area.