准噶尔盆地乌夏断裂带三叠系沉积相研究

通过岩心、测井、录井、地震等综合资料,系统研究了准噶尔盆地乌夏断裂带三叠系的沉积相特征及沉积体系。研究表明,研究区三叠系发育冲积扇、扇三角洲、湖底扇和湖泊相等4种沉积相类型,从百口泉组到白碱滩组经历了气候由干旱至潮湿的湖侵过程。百口泉组以冲积环境为特征,发育夏子街冲积扇群和百口泉冲积扇群;克拉玛依组上、下亚组以扇三角洲和滨浅湖相沉积为主;白碱滩组为最大湖侵期,以湖泊相沉积为主,发育小规模扇三角洲及湖底扇沉积。其中,克拉玛依组的扇三角洲前缘储集物性最好,是最有利的沉积相带;百口泉组的冲积扇扇中与断层和不整合面相配合也是较好的储油相带。

Sedimentary Facies of Triassic in Wu-Xia Fault Belt, Junggar Basin

Through core analysis, well logging, borehole log and seismic data, the sedimentary facies feature and depositional system of Triassic in Wu-Xia fault belt of Junggar basin is systematically studied. The result shows that four types of sedimentary facies occur in this area, they are alluvial fan, fan delta, sublacustrine fan and lake facies. The Baikouquan formation to Baijiantan formation here experienced arid-wet changing climate in lake transgressive process. Baikouquan formation is characterized by alluvial fan groups of Xiazijie and Baikouquan areas; Upper and Lower Karamay formation by fan delta and shore-lake sediment; Baijiantan formation as a largest laketransgressional episode dominated by lacustrine fan sediment with small scale fan delta and sublacustrine fan sediments. It is concluded that the fan delta front of Karamay formation is the most favorable sedimentary facies with best reservoir property; the midfan of Baikouquan alluvial fan fitted with the faults and unconformities could also be good prospecting areas for hydrocarbon accumulation.