珠江口盆地白云凹陷珠江组海底扇深水重力流沉积特征

珠江口盆地白云凹陷珠江组油气藏以其较大的规模、典型的海底扇结构、优越的储集性和巨大的油气勘探开发前景在国内外引起高度关注。 通过对白云凹陷 W 和 H 这 2 个气田珠江组各种原生沉积构造及古生物等相标志分析，确定了珠江组属于以深水重力流沉积为主的海底扇沉积体系；划分出内扇、中扇和外扇 3 个亚相，水道、水道间和前缘朵体等微相，颗粒流、碎屑流、近源浊流和远源浊流等重力流沉积类型；在对各类重力流沉积特征和分布规律进行详细分析的基础上，提出了集源、渠、汇三位一体的海底扇沉积模式。

Sedimentary features of the gravity flows in submarine fan of Zhujiang Formation in Baiyun Sag, Pearl River Mouth Basin

The Zhujiang Formation reservoirs in Baiyun Sag of Pearl River Mouth Basin attained a high degree of attention at home and abroad because of its large scale, typical structures of submarine fan, excellent reservoirs and huge exploration potential. Based on the analysis of various primary sedimentary structures and palaeontology in W and H gas fields, it is believed that the Zhujiang Formation was deposited by submarine fan dominated by debris flows. The submarine fan was divided into three subfacies which were inner fan, middle fan and outer fan, and further divided into channel, inter-channel and lobe microfacies. Many depositionai types were identified, which were grain flow, debris flow, proximal and distal turbidity currents. Based on the detailed analysis of the features of various gravity flows and their distributions, the submarine model comprised of ＂source, drains, and sinks＂ was established.