准噶尔盆地石炭纪末期中央隆起区分布特征及地质意义

Distribution characteristics and geological significance of central uplift area in late Carboniferous in Junggar Basin,China

利用新采集处理的十余条地震格架大剖面,结合相关三维地震和钻井资料,探讨准噶尔盆地中部石炭纪末期构造单元分布及地质意义。通过井震标定与地震不整合面识别,对盆地中部地区石炭系顶部进行连片构造解释,采用层拉平地震剖面方法恢复了石炭纪末期构造单元分布特征。准噶尔盆地中部石炭纪末期存在中央隆起一级构造单元,中央隆起规模大,包含4个凸起和2个凹陷,发育于早石炭世中期,并在晚石炭世-早二叠世处于大幅度隆升与剥蚀状态,是中-晚石炭世盆地西缘、南缘和东北缘三个前陆盆地前缘隆起的叠置区,控制了上覆二叠系沉积与构造格局的展布。中央隆起区发育多火山口、多期喷发火山岩相系统控制的大规模火山岩储集层,是深层油气勘探的重要领域,最有利的勘探区位于中央隆起的西段和南段。

The distribution and geological significance of the late Carboniferous tectonic units in the central Junggar Basin are discussed by using more than ten newly acquired and processed seismic framework profiles and related 3D seismic and drilling data.By means of well seismic calibration and seismic unconformity identification,the top of Carboniferous in the central area of the basin is interpreted in a series of structures,and the distribution characteristics of tectonic units in the late Carboniferous are restored by leveling seismic profile method.There were large scale first-order tectonic units in central uplift of central Junggar Basin at the end of Carboniferous,among which four uplifts and two depressions were formed in the middle of early Carboniferous,and then large uplift and denudation occurred in the late Carboniferous to early Permian.It is the superimposed area of the front uplift of three foreland basins in the western,southern and northeastern margin of the middle-late Carboniferous basin,controlling the sedimentary and tectonic distribution of the overlying Permian strata.In the central uplift area,large-scale volcanic rock reservoirs controlled by volcanic facies system with multiple craters and periods of eruption are important areas for deep oil and gas exploration.It is proposed that the most favorable exploration areas are located in the western and southern sections of the central uplift.