鄂尔多斯盆地西峰油田长8油组辫状河三角洲沉积特征与层序演化  

Sedimentary Features and Sequence Evolution of Braided River Delta of Chang 8 Oil Formation of Xifeng Oil Field in Ordos Basin

作　　者：杨友运[1] 张蓬勃[1] 张忠义[1] 

机构地区：[1]西安石油大学资源勘察工程系,西安710065

出　　处：《地质科技情报》2005年第1期45-48,共4页Geological Science and Technology Information

摘　　要：对鄂尔多斯盆地西峰油田长8油组辫状河三角洲沉积特征与层序演化的研究表明,在长8组油组沉积时,湖盆分别经历了强烈下降和缓慢下沉两个不同的沉积阶段,湖盆层序的演化明显控制着辫状河三角洲沉积体系及有利相带的发育和分布。在长8油组沉积早期,湖盆缓慢下沉,沉积物供给充分,辫状河三角洲形成强进积层序,其分流作用及侧向迁移能力强,区内平原亚相覆盖面广,有利砂层厚度大,分布稳定,预测其将成为区内进一步油气勘探的重要目的层;在长8油组沉积晚期,湖盆强烈下降,沉积速率减小,以退积层序发育为特征,退积过程中,辫状河三角洲平原亚相向湖岸退缩,导致西峰油田主要赋存于辫状河三角洲前缘水下分流河道之中。The Ordos Basin underwent two stages of strong descending and slow deposition during different depositional stages of Chang 8 oil formation.Therefore, sequence evolution of the basin obviously controlled the development and distribution of the braided river delta system and the favorable facies belt.In the early period of Chang 8 oil formation,the lake basin slowly subsided,with enough sedimentary material supply,and allowed the braided delta to form strong advanced sequence.It is found that the deltaic braided river has strong branch current and side migration a wide cover of plain subfacies in the area,thick favorable sand layer and stable distribution.It is predicted that it will become the important target area for oil exploration.During the late period of Chang 8 oil formation,the lake basin strongly descended and the deposition was slow,so the recessive sequence was developed.The plain subfacies of the braided river delta retreated into the bank of the lake.Xifeng Oil Field is mainly distributed under water branch channel of the front edge of the braided river delta.

关 键 词：辫状河三角洲 沉积层序 延长组 西峰油田 鄂尔多斯盆地 

分 类 号：P512.2[天文地球—地质学]