An exploration breakthrough was made in the Paleogene strata in the Binhai fault nose of the Huanghua Depression, but the distribution of hydrocarbons remained insufficient to understand. A series of fault-controlled traps were formed around the Gangdong fault, especially a large number of fault-block traps, which gave us a unique opportunity to use seismic data to study the distribution of the hydrocarbons under the control of normal fault and caprocks. By analysing the vertical and lateral changes of the fault throws (T-x and T-z plots), combined with the expansion index (EI), the characteristics of the Gangdong fault were studied and the evolution process of the fault was reconstructed. The fault has undergone the evolution process of lateral and dip linkage, and finally, the Gangdong fault was formed. The reconstruction of the evolution process and determination of charging stages found that the Gangdong fault was formed dip linkage just before late Neogene, providing an excellent vertical pathway for hydrocarbon migration. Besides, when the fault throw exceeds than 39 m, hydrocarbons were found near the fault, indicating a lower limit of fault throw. However, there were differences in the spatial distribution of hydrocarbons in the study area, which may be related to the integrity of the caprock. A lower thickness limit was found by analysing the relationship between the difference in hydrocarbon distribution above and below the regional caprock and the effective caprock thickness. When the effective caprock thickness is greater than this lower thickness limit, hydrocarbons can only accumulate below the caprock. When the effective caprock thickness is less than this lower limit, there is hydrocarbon accumulation above the caprock. This work highlights the evolution of normal fault and the control effect of fault-caprocks on hydrocarbon accumulation and further understands the spatial distribution of petroleum near the fault.

黄骅坳陷滨海断鼻古近系地层勘探取得突破，但油气分布尚不清晰。港东断裂周围形成了一系列断控圈闭，特别是大量的断块圈闭，这为我们利用地震资料研究正断层和盖层控制下的油气分布提供了独特的机会。通过分析断层断距（Tx和Tz图）的垂向和横向变化，结合膨胀指数（EI），研究了港东断层的特征，重构了断层的演化过程。断裂经历了侧向联动演化过程，最终形成了港东断裂。演化过程重构和充注期次确定发现，刚东断裂在晚新近纪之前形成倾角连锁，为油气运移提供了良好的垂向通道。此外，当断距超过39 m时，在断层附近发现烃类，表明断距下限。但研究区油气的空间分布存在差异，这可能与盖层的完整性有关。通过分析区域盖层上下油气分布差异与有效盖层厚度的关系，发现了厚度下限。当有效盖层厚度大于该厚度下限时，碳氢化合物只能在盖层下方聚集。当有效盖层厚度小于该下限时，盖层上方有油气聚集。该工作突出了正断层的演化和断盖层对油气聚集的控制作用，进一步了解了断层附近石油的空间分布。