摘要
万安盆地位于万安断裂西侧 ,是一个大型的走滑拉张盆地 .其中部坳陷为富生烃坳陷 ,发育有渐新统湖沼相、海湾相泥岩和下中新统浅海相泥岩 2套主要烃源岩 ,渐新统烃源岩具有良好的生烃潜力 ,下中新统烃源岩次之 .万安盆地的油气藏主要分布于中部坳陷及其相邻的西北断阶带、北部隆起和中部隆起 ,而在北部坳陷、南部坳陷和东部隆起上仅见油气显示 .研究表明 。
The Wan'an basin, located in the southwestern part of the South China Sea, belongs to a large scale pull-apart basin. The central depression of this basin is an abundant hydrocarbon-generating sag, which includes two sets of source rocks, that are Oligocene lacustrine mudstones, Early-Middle Miocene marine mudstones. The Oligocene lacustrine source rocks in this depression contain dominantly type Ⅰ-Ⅱ kerogen with high organic carbon contents ranging from 0.50% to (2.26%) and increasing usually from margin to depression center. The Early Miocene marine source rocks comprise types (Ⅱ-)Ⅲ kerogen and have a relatively low organic carbon content of 0.69%-0.93%. Potential hydrocarbon source index in the most of the depression has ranges of 4-10 t/m^2 with a maximum value of 14 t/m^2 in the Oligocene source rocks and of 4-7 t/m^2 in Early Miocene source rocks. The oil-gas pools in the Wan'an basin are mainly distributed in the central depression and its adjacent areas including the NW fault-step belt, the northern and central lifts. But in the southern and northern depressions and nearby eastern lift, only a few hydrocarbon shows are observed. The results indicate that the oil-gas distribution in the Wan'an basin is obviously controlled by the abundant hydrocarbon-generating sag.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
2004年第5期525-530,共6页
Earth Science-Journal of China University of Geosciences
基金
国土资源部南沙油气勘查专项 (No .93 -5 17)
关键词
中部坳陷
生烃潜力
油气分布
万安盆地
central depression
hydrocarbon-generating potential
oil-gas distribution
Wan'an basin.
