石油与天然气地质 ›› 1991, Vol. 12 ›› Issue (2): 95-106.doi: 10.11743/ogg19910201

• 论文 •    下一篇

珠江口盆地东部油气生成与勘探

陈斯忠, 张明辉, 张俊达   

  1. 南海东部石油公司, 广州
  • 收稿日期:1990-12-20 出版日期:1991-06-25 发布日期:2012-01-16

STUDY ON OIL AND GAS GENERATION AND EXPLORATION IN EASTERN PEARL RIVER MOUTH BASIN

Chen Sizhong, Zhang Minghui, Zhang Junda   

  1. Nanhai East Oil Corp. , Guangzhou
  • Received:1990-12-20 Online:1991-06-25 Published:2012-01-16

摘要:

有机地化特征的分析资料说明,区内原油母质为陆源生物,主要烃源岩是文昌组泥岩和恩平组煤系。中中新世-晚中新世大量排烃期,有利于油气聚集在同期或较早期形成的圈闭构造。根据甾烷运移指标C29ββ20R/C29ααα20R的变化规律,表明区内油气可作较长距离的运移,运移方向恰与构造脊的延展方向相吻合。邻接生油凹陷的隆起区是寻找大油气田的有利场所。

关键词: 珠江口盆地, 地球化学, 陆相沉积, 生油岩, 油源对比, 油气勘探

Abstract:

A lot of physical and geochemical data of crude oils from Eastern Pearl River Mouth Basin show tnat all the oils are terrestrial-derived ones. The distribution of biomarkers,such as n-alkanes, isoprenoids, steranes, triterpanes and tricyciic terpanes in these oils was studied and lots of special biomarkers which were derived from terrestrial higher plants and fresh algae were discovered. This indicats that they were all sourced by both lacustrine Wenchang Formation mudstone and coaly Enping Formation deposited in Eocene and Eocene-Oiigocene terrestrial environment. Wenchang Formation was a good oil source with high hydrocarbon potential and Enping coaly source rock has been proved to be able to generate oil and gas. Both have therefore provided much abundant reserve of the oil and gas. Since many trap structures were formed earlier than main oil and gas expulsion periods, and the source-reservoir-cap rocks in the basin were well combined, the migration and accumulation of the oil and gas were very ideal. The geochemical migration parameters show that the oils found in Dongsha uplift underwent long distance migration. The migra-tory directions determined by the sterane parameter were coincident with those of important structural ridge, indicating that the oils migrated from oil generating depressions up to the traps in Dongsha uplift along the migratory pathways of the structural ridges, and thus the wide area of the uplift should be the important exploration target for searching big oil fields.