M盆地的构造特征及与油气的关系

STRUCTURAL FEATURE OF M BASIN AND ITS RELATION TO OIL AND GAS

王秀林 汪望泉 李素珍 张亚敏 方建明

Wang Xiulin Wang Wangquan Li Suzhen Zhang Yamin Fang Jianming

位于非洲的M盆地为前寒武系基底上发育起来的中、新生代内陆断陷盆地。该盆地主要由EW向和NW向两大构造体系组成,前者控制盆地构造的总体发育方向。依据断裂规模,控盆作用及形成、活动时间,此盆地的断裂可分为 5个级别。与盆地三大演化阶段相匹配,盆地内发育 5个期次的断裂构造,长期继承性发育的构造带是油气聚集的有利场所;后期(第三、第四纪)发育的断层对早期油藏有破坏作用,后期形成的圈闭不具成藏条件。由于断层发育,油气以垂向运移为主,发育较早(AM组沉积前)的断层具有封闭作用。

M Basin located in African Plate is a intracontinental fault-depressed basin developed on Pre-Cambrian basement during Meso-Cenozoic.The basin mainly consists of EW and NW directional tectonic systems.According to fault scales,their control over the basin and their formation and faulting times,the faults of the basin can be divided into five grades,which correspond to the three major evolution stages of the basin.The long-term inherited developed structural belts are favourable for oil and gas accumulation;the faults developed in late period did destruction to the pools formed in early period,and the traps formed in late period didn't possess pool-forming condition.Since faults developed well in the basin,oil and gas migrated vertically.The faults developed earlier(before AM Formation deposition)have sealing function.

10.11743/ogg20000118