裂谷盆地断层连锁对沉积及油气分布的控制——以二连盆地赛汉塔拉凹陷为例

利用二连盆地赛汉塔拉凹陷70余口完钻探井的分层数据，结合二维和三维地震资料，确定控制早白垩世不同时期沉积的主要断层的精确位置和断距，根据各阶段地层和断裂的空间展布分析断层连锁过程及对沉积的控制作用。研究结果发现，巴彦花群沉积期区域构造应力场发生了自北西向朝北西西向的旋转，凹陷裂陷强度由北向南转移，北部经历凹陷东界断层的传递与连锁交替发展过程，南部以持续下降为主要特征，中央隆起带两侧主断层的阶段式连锁使沉积中心发生迁移。赛汉塔拉凹陷巴彦花群的沉积演化受控于凹陷内主要断层的传递和连锁，传递带是油气运移的长期指向。裂谷盆地的断层连锁过程对沉积和油气分布具有明显的控制作用，对于勘探具有重要的意义。图7参5

Sedimentation response in rift basin to tectonics and its control to hydrocarbon distribution--An example of Saihantala Sag in Erlian Basin

It was thought that a single rift was controlled by single boundary fault and there was only one depocenter. However, after studying Saihantala Sag in Erlian Basin, the author found that the depocenter was shifting. According to the evolution of deposition in three dimension, the East boundary fault in the sag was linked after K1 bt1 Formation was deposited, at the same time, the regional stress fields changed from northwest oriented to northwest-west oriented. In the forming history of hydrocarbon pools, the main faults propagated and linked alternatively, and the transfer zones were the favorable places of hydrocarbon accumulation, which controlled the distribution of hydrocarbon clearly. The deposition controlled by propagation and linkage of boundary faults has instructive significance to exploration work in rift basin.