Abstract Fault growth and reactivation activities have been interpreted as potential controlling factors in vertical hydrocarbon migration, but the coupling and direct comparison of fault growth/reactivation history and hydrocarbon distribution patterns remain poorly understood. The spatial distribution of oil fields in the Western subsag of the Bozhong subbasin in the Bohai Bay Basin is closely related to fault geometry and presents a unique opportunity to investigate the coupling mechanism of the evolution of normal faults and petroleum migration and accumulation. The evolution history of two major normal faults, Faults F1 and F2, was investigated via three-dimensional seismic reflection data, and Fault F2 was associated with the spatial distribution of oil. Quantitative throw analyses, including throw versus distance plots, throw versus depth (T-z) plots, throw contour projections, and expansion indexes (EI) were employed. Fault F2 exhibited a large displacement between the footwall and hanging wall along most of the fault plane and thickened hanging walls of the upper fault surface. Laterally, the fault comprised three segments that linked along the strike at local throw minima. Vertically, the fault formed through the coalescence of two parts via dip linkage. Both the isolated- and coherent-fault models may have contributed to the evolution of Fault F2 during different periods and can be summarized in several steps, including blind fault propagation as individual segments, free surface breaching, lateral and dip linkage, and subsequent frequent reactivation as a coherent structure. A key result of this study was that petroleum migration and accumulation could be directly controlled by multiple growth and reactivation activities of faults.

中文翻译：

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渤海湾盆地渤中盆地西北部正断裂对油气运聚的直接控制

摘要 断层生长和再活化活动被解释为油气垂直运移的潜在控制因素，但对断层生长/再活化历史和油气分布模式的耦合和直接比较仍知之甚少。渤海湾盆地渤中盆地西洼油田空间分布与断层几何关系密切，为研究正断层演化与石油运聚成藏耦合机制提供了难得的机会。通过三维地震反射资料研究了两条主要正断层F1和F2的演化历史，其中F2断层与石油的空间分布有关。定量投掷分析，包括投掷与距离图，使用了投射与深度 (Tz) 图、投射轮廓投影和扩展指数 (EI)。断层F2沿大部分断层面表现出下盘和上盘之间的大位移，上断面的上盘加厚。横向上，断层由三个部分组成，这些部分沿走向在当地的最低点相连。在垂直方向上，断层是由两部分通过倾角连接合并而成的。孤立断层模型和相干断层模型都可能对断层 F2 在不同时期的演化做出了贡献，可以归纳为几个步骤，包括断层盲传播作为单个段、自由表面破裂、横向和倾角连接以及随后的频繁再激活作为一个连贯的结构。