利用地震小层对比技术分析层序及岩性圈闭

为了精确划分柴达木盆地三湖地区七个泉组地震层序和明确层序内部结构特征,采用地震小层追踪、对比技术对该区的地震剖面进行处理和精细解释,并结合地震小层的Wheeler域转换图以及岩心、钻测井、分析化验等资料的综合分析,将七个泉组从下向上划分为5个沉积层序,明确了各层序界面和最大湖泛面的识别标志,指出缺乏明显地形坡折的七个泉组沉积层序由湖侵体系域和湖退体系域组成,其中湖侵体系域以退积型序列为主要特征,而湖退体系域以进积型序列为主要特征,建立了研究区的层序地层充填模式。综合地震小层上倾尖灭点识别、连井砂体对比以及构造等分析成果,指出研究区岩性圈闭在平面上主要分布在台东、涩东、驼西鼻隆区和驼南、涩南、盐西斜坡带。

Analysis of sequence and lithologic traps by seismic sub-layer correlation

In order to divide exactly seismic sequences of Qigequan formation and understand structural features inside these sequences in Sanhu area of Qaidam Basin,seismic sub-layer correlation is used to process and interpret seismic data.Combining with the Wheeler domain transformation map of seismic sub-layers,core data,well logging data and analysis test data,Qigequan formation is subdivided into five sequences from the bottom to the top,and the identification marks of sequence boundaries and flooding surfaces are determined.Each Qigequan formation sequence which has no obvious breaks is comprised of lacustrine transgressive system tract and lacustrine regressive system tract.And the lacustrine transgressive system tracts are mainly characterized by retroprogradation sequence while the lacustrine regressive system tracts mainly characterized by oprogradation sequence.Then the sequence mode of the research area is proposed.Combining with the updip pinchout of seismic sub-layers,sandbody correlation and structural analysis,our study points that the lithologic traps of work area mainly distribute in eastern Taijinar,eastern Seniehu,western Tuofengshan uplift area and northern Tuofengshan,southern Seniehu,western Salt Lake slope area.