准噶尔盆地南缘中段第一、二排构造演化与油气成藏

TECTONIC EVOLUTION AND HYDROCARBON ACCUMULATION OF THE FIRST AND SECOND ROWS OF STRUCTURE IN THE CENTRAL PART OF SOUTHERN JUNGGAR BASIN

盆-山转换带一直是构造地质研究的重点及难点,开展其构造样式、形成演化及成藏过程解析,对揭示山前复杂构造的控藏作用、指导盆-山转换带的油气勘探均具有重要意义.综合运用地震资料解释、断层活动定量分析、流体包裹体均一温度测定等手段,结合构造物理模拟实验,对准噶尔盆地南缘中段第一、二排构造特征、演化过程、形成机制及控藏机理进行了综合研究.结果表明:南缘中段第一、二排构造主要发育基底卷入与盖层滑脱断层控制的双重构造样式.侏罗纪末期,齐古-昌吉褶皱带初具雏形;古近纪末期,霍玛吐褶皱带开始形成;第四纪,褶皱带被断裂强烈改造,形成断褶带,滑脱层对应力向盆内传递起重要作用.南缘中段发育多套烃源岩,形成了多期差异性的以“自生自储”和“古生新储”为主要组合模式的成藏过程.

The basin-mountain transition zone has been the focus and difficulty of tectonic geology,thus the analysis of its tectonic style,formation and evolution and accumulation process is of great significance to reveal the reservoir-controlling function of piedmont complex structures and guide oil-gas exploration in basin-mountain transition zone.The tectonic characteristics,evolution process,formation and reservoir-controlling mechanism of the first and second rows of structure in the central part of southern Junggar Basin are studied through the comprehensive application of seismic data interpretation,quantitative analysis of fault activity,and homogenization temperature measurement of fluid inclusion,combined with tectonophysics simulation experiment.The results show that the duplex structure style controlled by basement involvement and caprock detachment fault is mainly developed in the first and second rows of structure.In the Late Jurassic,Qigu-Changji fold belt began to take shape.In the Late Paleogene,Huomatu fold belt was formed.In the Quaternary,the fold belt was intensively transformed by faults to form the fault-fold belt,and the detachment layer played an important role in the transfer of stress into the basin.Multiple sets of source rocks are developed in the central part of southern margin,which formed a multi-stage differential accumulation process with“self-generating and self-storage”and“old-generating and new-storage”as the main combination mode.