南海万安盆地中部油气成藏特征

Characteristics of The Oil And Gas Reservoir in the Center of Wan'an Basin, South China Sea

本文系统分析了万安盆地中部油气藏的基本特征,并探讨了油气藏形成的地质模式。研究表明,在万安盆地中部存在构造、岩性及构造岩性三种类型的油气藏,其中以构造油气藏占主导地位。油气藏的形成主要通过三种运聚模式,即侧向运聚(S型)、垂向运聚(V)型和阶梯式运聚(S-V、V S和S-V-S等类型)。油气成藏模式与圈闭所处的构造位置直接相关,位于隆起上的圈闭,油气藏的形成一般以侧向运聚和阶梯式运聚为主,以垂向运聚为辅;而位于坳陷中的圈闭,油气以垂向运聚为主,以阶梯式运聚和侧向运聚为辅;在隆坳结合部则以阶梯式运聚为主,以侧向运聚和垂向运聚为辅。

This paper analyzed the basic features of the oil-gas reservoirs in the center of Wan'an basin, discussed the geological formation model of the oil-gas reservoirs. There are three types of the oil-gas reservoir, such as tectonic, lithogenetic, and tectonic-lithogenetic, and the tectonic reservoir is the preponderant type. The oil-gas reservoirs are formed by three migration models, such as horizontal (S), vertical (v), and ladder (S-V, V-S, S-V-S). The migration models are related to the tectonic position of the trap. To the traps in the upheaval, the oil and gas reservoirs are formed mainly by horizontal and ladder models, and the vertical model is supplementary. To the traps in the depression, the oil-gas reservoirs are formed main- ly by vertical model, and the ladder and horizontal model are supplementary. On the conjunc- tional area between upheaval and depression, the oil-gas reservoirs are formed mainly by ladder model, the horizontal and vertical model are supplementary.