渤中凹陷西洼区新近系油气分布特征及“脊-断”联控成藏模式

Neogene hydrocarbons distribution characteristics and “ridge-fault” joint control accumulation mode in western Bozhong sag,Bohai sea

渤中凹陷是渤海海域主要的富油气凹陷之一。总结了渤中西洼区(渤中凹陷西部)近年勘探成果,重点剖析了油气分布特征、成藏机制及成藏控制因素。渤中西洼区油气分布不均衡,纵向上主要分布在新近系明化镇组和馆陶组,平面上集中分布在活动性断裂带;古构造脊的规模和断层的形态共同控制了新近系油气运聚和空间分布,二者的有效配置决定了该区形成大规模油气藏的条件。建立了渤中西洼区“脊-断”联控成藏模式,划分出2类“脊-断”配置关系、3种垂向组合模式。本文研究成果对深化环渤中凹陷油气成藏认识和寻找有利勘探目标具有重要指导意义。

The Bozhong sag is one of the main hydrocarbon-rich sags in the Bohai sea. This paper summarizes the exploration results of western Bozhong sag, and focuses on the distribution characteristics, accumulation mechanisms and control factors of hydrocarbons accumulation. The distribution of oil and gas in western Bozhong sag is uneven;they are mainly distributed in the Neogene Minghuazhen and Guantao Formations vertically, and are concentrated in the active fault zone on the plane;the scale of the ancient tectonic ridge and the fault morphology jointly control the Neogene hydrocarbons migration/accumulation and spatial distribution, and the effective configuration of these two elements determine the formation of large-scale reservoirs in this area. The “ridge-fault” joint control accumulation mode of western Bozhong sag was established, and two types of “ridge-fault” configuration relationships and three vertical combination modes were divided. The research results of this paper are of important guiding significance for deepening the understanding on hydrocarbons accumulation in Bozhong sag and seeking the favorable exploration targets.