白云凹陷断裂活动与油气成藏耦合关系的盆地模拟研究

热带海洋学报 JOURNAL OF TROPICAL OCEANOGRAPHY2015年第34卷第1期: 30−41

白云凹陷断裂活动与油气成藏耦合关系的盆地模拟研究*

谢志远1, 李元平2 , 孙珍1, 孙龙涛1, 邱宁1,4, 杨建民3

1. 中国科学院边缘海地质重点实验室中国科学院南海海洋研究所, 广州 510301;

2. 中海石油(中国)有限公司深圳分公司, 广州 510240;

3. 中海石油(中国)有限公司天津分公司, 天津 300452;

4. 同济大学海洋地质国家重点实验室, 上海 200092

摘要:白云凹陷位于南海北部被动大陆边缘, 断裂发育, 对油气的运聚成藏具有重要意义。研究表明, 始新世至早渐新世的断陷活动控制了烃源岩的发育, 晚渐新世至中中新世的断层活动控制了储层的分布, 晚中新世后的断层活化则影响了盖层和圈闭的展布。综合考虑泥岩涂抹作用和断裂活动性, 并结合最新勘探研究成果, 运用盆地模拟系统模拟研究了两条过井剖面, 结果表明: 白云凹陷断裂活动期次与排烃期次形成了较好的耦合关系, 主要的耦合期为23.8~16.5Ma 和13.8~10.5Ma; 其中, 生烃增压作用可能强化了18.5Ma时期的断裂活动; 当活动断裂处于开启状态时, 形成了良好的垂向运移通道; 平静期的断裂则倾向于封闭, 限制了油气的垂向运移; 与单独考虑断裂活动性相比, 泥岩涂抹作用能更好地反映静止期断层的封堵特性; 另外, 模拟预测显示白云深水区的南部断裂发育区具有更好的成藏条件, 易形成大型油气藏。

关键词:断裂活动性分析; 盆地模拟; 泥岩涂抹; 油气运聚; 白云凹陷

中图分类号: P736.1; P744.4 文献标识码: A文章编号: 1009-5470(2015)01-0030-12

A basin modeling study on the coupling of fault activity and hydrocarbon accumulation in the Baiyun Sag

XIE Zhi-yuan1, LI Yuan-ping2, SUN Zhen1, SUN Long-tao1, QIU Ning1,4, YANG Jian-min3

1. Key Laboratory of Marginal Sea Geology, Chinese Academy of Sciences/South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China;

2. Shenzhen Branch of China National Offshore Oil Corporation, Guangzhou 510240, China;

3. Tianjin Branch of China National Offshore Oil Corporation, Tianjin 300452, China;

4. State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China

Abstract: The Baiyun Sag is located in the northern passive continental margin of the South China Sea. The widespread faults around the sag affect the migration and accumulation of hydrocarbon profoundly. Faults control the sedimentation of source rocks from the Eocene to the Early Oligocene, regulate the range of reservoirs from the Late Oligocene to the Middle Miocene and dominate the seals and traps during the reactivation period in the Late Miocene. We attempt to study the controls of fault activity on hydrocarbon migration and accumulation through faults sealing analysis and basin modeling. Results are as follows. (1) The episodes of fault activity couple well with the generation of hydrocarbon. (2) Overpressure due to hydrocarbon generation may accelerate faulting activity at ~18.5 Ma. (3) Active faults act as perfect conduits for vertical migration of hydrocarbon. (4) Shale smear is much more credible in reflecting the sealing ability of motionless faults than the simple fault activity analysis. (5) The southern faulted area in the deep water tends to be more favorable for hydrocarbon accumulation than the northern area.

Key words: fault activity analysis; basin modelling; shale smear; hydrocarbon accumulation; the Baiyun Sag

收稿日期：2013-12-29; 修订日期: 2014-05-21。林强编辑

基金项目：十二五油气重大专项子课题(2011ZX05025-003-005); 国家自然科学基金青年科学基金项目(41106055); 国家自然科学基金(41206038); 海洋地质国家重点实验室(MGK1213)

作者简介：谢志远(1990~), 男, 河南省南阳市人, 硕士生, 从事海洋地质和石油地质研究。Email: xiezhiyuan1990@

*感谢中海油深圳分公司深水项目部的大力支持和帮助, 感谢审稿专家对本文的修改和建议！