Fault acts as an important vertical migration conduit for hydrocarbons in rift basins and can transport hydrocarbons from deep-buried organic-rich sediments to shallow-buried coarse-grained sequences. Such migration process is expected, but generally needs to pass through thick mudstone intervals and its controlling factors are not well understood. The low-relief regions of the south Bohai Sea in the Bohai Bay rift basin, comprising both Paleogene and Neogene hydrocarbon traps, can act as a good case study for the factors controlling the hydrocarbon transporting capacity of faults. By comparing the hydrocarbon generation potential of source rocks in different formations, we confirm that the hydrocarbons trapped in the Neogene traps mainly originate from the Eocene Shahejie Formation, and need to pass through a thick Oligocene regional caprock. Hydrocarbon fluid inclusions within the Neogene reservoir sandstones indicate two major hydrocarbon charging events in the middle Pliocene to Quaternary, based on which we chose the T₀² seismic marker bed to calculate fault displacement. Seismic profiles show that Neogene hydrocarbon-charged traps are commonly linked to faults with large-amount displacement, where the regional caprock has a limited thickness. Using statistics of the Neogene charged traps in a regional 3D seismic grid, we draw the minimum fault displacement for hydrocarbon migration in the Laizhouwan Sag at 53.6 m and in the Huanghekou Sag at 56 m, and the biggest caprock thickness for hydrocarbon migration in the Laizhouwan Sag at 240.7 m and in the Huanghekou Sag at 320.2 m. These observations emphasize the coupling of fault displacement and regional caprock thickness controlling the hydrocarbon transporting capacity of faults in a rift basin.

断层是裂谷盆地中碳氢化合物的重要垂直运移管道，可以将碳氢化合物从深层富含有机物的沉积物输送到浅层粗粒岩层。这种迁移过程是预料之中的，但通常需要经过厚厚的泥岩层段，而且对其控制因素的了解还很少。渤海湾裂谷盆地南部渤海低洼地区包括古近系和新近系油气圈闭，可以作为控制断层油气运移能力的因素的一个很好的案例研究。通过比较不同地层中烃源岩的生烃潜力，我们可以确定新近系圈闭中的油气主要来自始新世沙河街组，需要穿过较厚的渐新世区域盖层。_用0 ²地震标记床计算断层位移。地震剖面表明，新近系烃类圈闭通常与大位移断层有关，而该区域盖层厚度有限。利用区域3D地震网格中新近纪带电圈闭的统计数据，我们得出莱州湾凹陷的最小断层位移为53.6 m，黄河口凹陷为56 m，而莱州湾的最大盖层厚度为烃类迁移凹陷为240.7 m，黄河口凹陷为320.2 m。这些观察结果强调断层位移与区域盖层厚度的耦合控制裂谷盆地断层的油气输送能力。