关键词: 南海, 珠江口盆地, 深水扇系统, 古陆架坡折带, 地震相组合结构, 下第三系, 湖相烃源岩

Abstract: The deep-water fan systems played a dominate role for increment of the international oil production and reserves in the last 20 years.The Pearl River Mouth Basin(PRMB),located at South China Sea,is a Cenozoic passive continental margin rift basin with a great potential for oil and gas exploration.Sequence stratigraphy research and analysis show that there exist huge quantities of stacked low-stand fans in Baiyun Sag having the largest area and the most genetic potential in the PRM basin.Lots of research experiences and abundant exploration results from PRMB as well as the typical high-resolution 2D seismic information analysis proved that the Baiyun deep-water sag has been the depositional center of the ancient Pearl River water system since thirty million years before present.As the results of eustatic changes,the deep-water sedimentary systems with unique seismic face architecture were developed in the low-stand stages corresponding to the third order sequence.The deep-water fan systems were spread over paleo shelf-edge and controlled by growth faulting and its down-slope direction.It is concluded that the deep-water sand rich fan system,which overlies on the lower Tertiary lacustrine source rocks with great thickness,has a prospective future for oil and gas exploration.

Key words: South China Sea, Pearl River Mouth Basin, deep-water fan system, paleo shelf-edge, seismic face architecture, lower Tertiary, lacustrine source rock