珠江口盆地珠三坳陷油气成藏模式与分布规律

Research on hydrocarbon pooling and distribution patterns in the Zhu-3 Depression,the Pearl River Mouth Basin

珠江口盆地珠三坳陷是一个典型的南断北超的箕状断陷,属于边缘海盆地,具有丰富的油气资源。受到主干断裂的强烈控制作用,该坳陷可以划分为3个石油系统,分别为文昌A凹、B凹和C凹石油系统。在不同的构造部位发育不同的油气藏类型:在缓坡带和周边隆起带上发育潜山或潜山披覆油气藏,局部发育地层超覆油气藏;在主干断层附近发育岩性-构造油气藏;在陡坡带发育扇三角洲前缘滑塌体隐蔽油气藏;在盆地中心位置,可发育远源浊积扇透镜状油气藏。其中,缓坡带的地层不整合-岩性油气藏和盆地中心远岸浊积砂体形成的透镜体油气藏应该是最为有利的近期勘探目标。

The Zhu-3 depression in Pearl River Mouth Basin is a typical dustpan-shaped basin faulted in its south and overlapping to the north. It belongs to a marginal sea basin abundant in oil and gas resources. Three petroleum systems,namely the Wenchang A, Wenchang B, and Wenchang C, can be recognized in accordance with the strong controlling effect of the major faults. Different types of reservoirs had been developed in different structural zones：buried-hill or buried hill drape anticline hydrocarbon reservoirs and local stratigraphic overlap reservoirs in the gentle slope zone and its peripheral uplift zone, lithological-strnctural reservoir near the major faults, slump subtle reservoirs of fan delta front in the steep slope zone, and lenticular distal turbidite fan reservoirs in central basin. It is suggested that the unconformity-lithological reservoirs in the gentle slope zone and lenticular reservoirs in the central basin be favorable near-term exploration targets.