济阳坳陷高凸起斜坡带新近系油气成藏与勘探实践

济阳坳陷高凸起斜坡带在构造上表现为向高凸起抬升的单斜,因作为油气向高凸起主体部位运移的通道而常被忽视。受基岩沟、梁相间的古地形及新近系沉积相变等因素的影响,高凸起斜坡带易形成地层超覆油藏、反向屋脊断块油藏、低幅度微型次生油藏、微型低幅度潜山披覆油藏及岩性油藏等5种小而肥的次生油藏。油气运移通道对这类油藏影响较大。以不整合面作为油气运移通道的油藏多为规模较大的层状地层超覆油藏,在平面上呈带状分布,含油条带窄;以继承性活动的边界断层作为油气运移通道所形成的油气藏具有含油井段长、含油层系多、油水关系复杂等特点。在勘探上,针对特殊的成藏特点应采取相应的措施,不同类型的斜坡带油藏应采取相应的方法和策略。

Neogene hydrocarbon reservoiring in slope zone of high salient in Jiyang depression and exploration practice

Slope zone of the high salient in Jiyang depression occurs structurally as a monocline uplifting toward the high salient, and is often neglected because it is usually treated as a pathway for hydrocarbon migration toward the main body of the high salient. Being influenced by the basement palaeotopography with alternation of gullies and ridges and changes of Neogene sedimentary facies, five types of small but prolific secondary reservoirs tend to occur in the slope zone of the high salient, i.e. stratigraphic overlapped oil reservoir, reversed roof fault-block oil reservoir, small and low-amplitude secondary oil reservoir, small and low-amplitude buried hill drape oil reservoir and lithologic oil reservoir. Hydrocarbon migration pathways have relatively large influences on these reservoirs. Most of the reservoirs with unconformities as migration pathways are of relatively large, laintervals, multiple oil-bearing series and complicated oil-water relationship. Suitable exploration methods and strategies should be taken for different types of reservoirs in the slope zone.