大港油田埕北断阶带存在的多个不整合对于油气的长距离、大规模运移及油气的富集，具有十分重要的作用。地震剖面综合解释显示，埕北断阶带不整合可划分为削截不整合、断褶不整合、褶皱不整合、超覆不整合和平行不整合5 种类型，油气沿不整合运移的规律受不整合类型控制。在测井曲线组合对比、分析的基础上，结合岩心观察，将不整合面上、下分为三段式结构：底砾岩、风化泥岩和半风化岩石。这种结构构成油气运移的双重通道，它将不同时代的储集层、断裂等连接起来，组成区域性的运移通道网络。埕北断阶带不整合不仅是油气运移的重要通道，而且是油气聚集的有利场所，受不整合纵向结构和类型控制形成了多种类型的油气藏。

There are many unconformity surfaces in Chengbei fault step belt ofDagangOilfield, which are very important for hydrocarbon to migrate with long-distance and in great-scale and to accumulate. Seismic section comprehensively interpreted to discover that patterns of unconformity sections in Chengbei fault step belt include truncation conformity, fault-fold unconformity, fold unconformity, onlap unconformity and parallel unconformity. Each of them has the different distributing regularities, and the type of unconformity surface controls hydrocarbon migration. On the basis of analyzing log responses and cores, the unconformity surfaces in vertices are divided into three parts: basal conglomerate, weatheringmudstone and semi-weathering rock, this structure forms the double paths of the hydrocarbon migration. It connects reservoirs and faults which formed in different times to construct the regional migrating network. The unconformity surfaces in Chengbei fault step belt not only are the important paths for the hydrocarbon migration, but also are the good places for the hydrocarbon accumulation. The Chengbei fault step belt forms various reservoirs under the control of the vertical structure and types of unconformity surface.