二连盆地赛汉塔拉凹陷边界断裂构造特征及其控藏作用

摘要

为了研究赛汉塔拉凹陷的形成、演化及油气成藏规律,利用地震、钻井、测井等资料对边界断层锡林断裂构造特征进行了分析,并探讨了边界断裂构造对油气成藏的控制作用.结果表明,锡林断裂具有明显的分段性,不同段其断面形态存在差异,表现为中段断面相对陡倾,南、北段则相对平缓.由平均断裂活动速率可知,阿尔善组和腾格尔组沉积期是锡林断裂的强烈活动期.锡林断裂的形成与演化对油气成藏具有控制作用,具体表现为:①断裂活动控制生烃洼槽及优质烃源岩的形成,并促进烃源岩的热演化;②断裂活动控制砂体展布,并形成多种类型的圈闭;③断裂、砂体和不整合面共同构成了油气运移的输导格架.因此,生烃洼槽周边受锡林断裂控制而形成的圈闭是油气聚集的有利场所.%Xilin fault is the boundary fault of Saihantala Sag,which controls origin,evolution and hydrocarbon accu-mulation of Saihantala Sag.Based on seismic and well data,the structural characteristics of Xilin fault were ana-lyzed,and its control on hydrocarbon accumulation was discussed.The results show that the Xilin fault is a lis-tric fault in profile and it consists of three segments.The southem and northern segments are low dip,while the central segment is steepened.The mean active rate indicates that Xilin fault had a strong activity during the sedi-mentary period ofA'ershan Formation and Tengge'er Formation.The evolution of Xilin fault controls the reser-voir accumulation,which can be proven by:(1) Xilin fault played an important role on the formation of hydro-carbon generating depression and the accumulation of high-quality source rocks,and it also promoted the maturi-ty of source rocks;(2) the evolution of Xilin fault has a great influence on palaeogeomorphology and the distri-bution of sand bodies,which dominated the formation of varied traps;(3) faults,sand bodies and unconformity surfaces constituted the hydrocarbon drainage system together.Therefore,the traps controlled by Xilin fault around the source depression are favorable for hydrocarbon accumulation.