北部湾盆地涠西南和海中凹陷新生代局部构造演化史

Structural evolvement history of Weixinan and Haizhong depression in Beibuwan basin during Cenozoic Era

卢林 汪企浩 黄建军

Lu Lin Wang Qihao Huang Jianjun

中国石油化工股份有限公司上海海洋油气分公司研究院, 上海 200120; 同济大学海洋与地球科学学院, 上海 200092

Institute of SINOPEC Shanghai Offshore Oil & Gas Company, Shanghai 200120; School of Ocean and Earth Science, Tongji University, Shanghai 200092

通过Multibackstrip软件, 选择研究区内几个能反映断裂活动强弱的井点, 进行单点构造沉降速率的研究, 同时, 根据对解释剖面进行地层回剥拉平, 从线上分析了构造演化史。然后结合断层平面展布, 通过点线面结合, 对研究区的涠西南凹陷和海中凹陷的构造演化进行了研究。研究表明, 新生代以来盆地区内存在两幕断陷期和一幕坳陷期。T5为两次断陷期的分界, 海中凹陷和涠西南凹陷构造演化既有联系又有区别。

Through the Multibackstrip Software, the well spots which can reveal the movement strength of fault are selected as the places to study how structural subsidence velocity changed. Meanwhile, structural evolvement history on the seismic section are also analyzed in the study, according to backstripping the stratigraphy of interpreted seismic section. Combining both the above study results and fault distribution, it is studied how structure in Weixinan and Haizhong depression evolved. The research shows that there are two period of rifting and one period of depression during the Cenozoic, T5 is the interface between the two riftings. And there are both contact and difference between the two depression.