摘要
塔里木盆地东北地区下白垩统巴什基奇克组湖相沉积受盆缘冲积扇控制明显,发育有冲积扇-辫状河三角洲和扇三角洲两大沉积体系。冲积扇-辫状河三角洲沉积体系从南北山前带向沉积中心依次发育冲积扇相、辫状河三角洲平原亚相和辫状河三角洲前缘亚相;扇三角洲沉积体系主要由扇三角洲前缘亚相构成,分布在研究区西北库车坳陷附近。巴什基奇克组沉积期气候炎热干旱、湖盆水体浅,地层含砂率高。湖侵期,湖盆边缘沉积的地层厚度远大于湖盆中心区域沉积的厚度;湖退期,正好相反。钻井和地震资料分析表明,研究区从湖侵到湖退,东北部仅受北侧古天山隆起单一陆源沉积物影响,南部仅受南侧东昆仑—阿尔金隆起影响,而中部地区由单一物源控制逐渐变为多物源影响。因此,湖退期在湖盆中部沉积的地层也具有良好的储集性能。
The Cretaceous Bashijiqike formation in northeastern Tarim basin was the product of lacustrine basin margin alluvial fan deposition involving two major sedimentary systems：an alluvial fan-braided fluvial delta depositional system and a fan delta depositional system.The alluvial fan-braided fluvial delta depositional system is composed of an alluvial fan facies,a braided fluvial delta plain facies and a delta front facies from the foothill belt in S-N direction to the basin center.The fan delta depositional system is mainly composed of fan delta front subfacies,which developed near Kuqa depression in the northwest of the study area.When Bashijiqike formation was deposited,the lake was shallow and the climate was arid,which led to deposits with a high sand ratio.During transgression strata deposited in the lake basin margin is thicker than that in the basin center.During regression,in contrast,the basin center experienced more deposition than the margins.Drilling and seismic data show that the northeast of the study area was controlled by single terrigenous depositional source from the paleo-Tianshan mountains in north.Deposition in the southern part of the basin was controlled by the East Kunlun-Altun mountains during transgression and regression.Deposition in central area was controlled by a single sediment source which was gradually supplanted by multiple sources.Therefore,the strata deposited during regressive phase in lake basin center are of good reservoir quality.
出处
《新疆石油地质》
CAS
CSCD
北大核心
2014年第1期45-48,共4页
Xinjiang Petroleum Geology
基金
国家自然科学基金(41102087)
国家973项目(2012CB214802)
国家重大科技专项(2011ZX05005-002-010HZ
2011ZX05009-002)
关键词
塔里木盆地
东北地区
下白垩统
巴什基奇克组
沉积体系
发育模式
Tarim basin
north eastern area
Lower Cretaceous
Bashijiqike formation
sedimentary system
development model
