准噶尔盆地车排子地区新近系沙湾组层序地层格架分析

 根据陆相地层层序在地震剖面和电测曲线上的识别标志、合成记录标志以及岩石类型组合特点等方面的特征，将车排子地区新近系沙湾组划分出1个二级层序和2个三级层序。其中，层序I为辫状河三角洲层序，层序II为湖泊层序。又可以根据各层序的特点，将其分为3个体系域：低水位体系域、湖侵体系域和高水位体系域。针对研究区目的层段层序发育的特点，在层序地层单元划分和对比的基础上，结合构造背景和地层厚度的变化，展示了该区层序东南部厚度较大，发育完整，厚度稳定；西北部由于遭受剥蚀，厚度较小，层序发育不完整的格架特征。初步分析了层序与含油气性的关系，预测了不同层序的勘探重点和目标，认为层序I的低水位体系域和层序II的湖侵体系域为寻找岩性油气藏的有利部位。

Sequence Stratigraphy Framework Analyses of the Neogene Shawan Formation in Chepaizi Area,Junggar Basin

Based on the identification features of continental stratigraphic sequences on seismic profiles and wire-line logs, synthetic seismograms and the characteristics of lithologic combination, the Neogene Shawan formation is divided into one second-order sequence and two third-order sequences. The third-order sequence I is braided as a delta front sequence, while the sequence II is a lacustrine sequence. Each third-order sequence according to its characteristics can be divided into three system tracts: low stand, transgressive and high stand system tracts. Based on the identification and correlation of sequence stratigraphic unit, and according to the characteristics of the stratigraphic sequences, the tectonic evolution history and the variation of strata thickness, the sequence stratigraphy framework is shown to have a great, complete and stable thickness in the study area of south-east, and a thinner, incomplete one in the north-west. A preliminary analysis is made on the relationship between sequences and oil-gas exploration potentials, and exploration priorities and goals in each sequences are predicted. The favorable lithological reservoirs are found to be located mainly in the low stand system tracts of sequence I and in the transgressive system tracts of sequence II.