渤海海域石臼坨凸起油气输导体系与运聚模式

Hydrocarbon transportation system and migration-accumulation pattern in Shijiutuo uplift,Bohai sea

运用油气优势运移路径模拟、断面精细刻画及成藏综合分析等技术手段和方法,阐明了渤海海域石臼坨凸起油气输导体系与成藏模式。石臼坨凸起深层古近系油气输导体系由边界断层和古近系砂体组成,浅层新近系油气输导体系由馆陶组砂砾岩横向输导层和明化镇组断砂耦合组成;石臼坨凸起内部形成2种"Z"字形油气运移模式,即断层两侧砂-砂对接条件下的跨断层型及远离断层的砂-砂侧接型"Z"字形油气运移模式。结合典型油气田成藏特征解剖,建立了石臼坨凸起"运-分-聚"立体油气运聚模式,直接指导了石臼坨凸起秦皇岛33-1南亿吨级油田的发现,对渤海其他及类似地区的勘探工作具有重要的参考意义。

The transportation system and accumulation model of Shijiutou uplift in the Bohai sea are clarified with simulation of dominant hydrocarbon migration pathway,meticulous depiction of fracture surface and comprehensive analysis of accumulation.The transportation systems of Shijiutou uplift in the Palaeogene are composed of boundary fault and Palaeogene sandbody,while the Neogene transportation systems consist sandy conglomerate in Guantao Formation and the coupling of fracture and sand in Minghuazhen Formation.There are 2 kinds of'Z'shaped hydrocarbon migration patterns in Shijiutou uplift,i.e.,across the fault type,in which the sand bodies on both sides of the fault are connected and butt-jointed;away from the faults type,in which the sand bodies are far away from the faults and side-jointed.Combined with the typical feature analysis of accumulation in oil and gas fields,Shijiutuo uplift's hydrocarbon'Horizontal migration-vertical migration-accumulation'3D pattern is established,which directly leads to the big discovery of QHD33-1S oilfield in Shijiutuo uplift.The pattern can provide reference for exploration in the Bohai sea and other similar areas.