摘要
湖底扇是深湖区所有重力流沉积的总称。在面积为2500km2的二连盆地乌里雅斯太凹陷,湖底扇发育面积达800km2,厚1000～2000m,在我国中、新生代陆相盆地同类沉积中是典型一例,揭示其特征对勘探和丰富深湖沉积学具有意义。以系统的岩心观察为基础,根据钻井剖面、测井曲线及地震剖面等,从旋回性、韵律性的视角,探索湖底扇沉积时空演化的规律。湖底扇有缓坡、陡坡和深水平原3种类型,共有6个亚相7种微相和多种岩相,各有特定的规模和分布空间。依据湖底扇发育的时空特征,概括出了湖底扇退积地层模式,即“向上变薄、变细的序列”。发育湖底扇的条件是:不对称汇水盆地的古地理景观;典型的单断箕状凹陷结构;持续强烈差异沉降的古构造背景;温暖潮湿的古气候条件。从储集层角度看,厚层内扇主沟道和中扇辫状沟道应是隐蔽油气藏的勘探目标。
Sublacustrine fans developed widely, with an area of 800km^2 and thickness of 1000-2000m, in Wuliyasitai Sag, Erlian Basin. The systemic core observation reveals 3 types of sublacustrine fans. including gentle slope, abrupt slope and deep water plain, which can be subdivided into 6 subfaeies, 7 microfacies. as well as many lithofacies with specific sizes and distributing spaces. The generation of sublaustrine fan is related to dissymmetry catchment basin, typical halfgraben-like depression, standing and strong differential subsidence, warm and moist paleoclimate. The thick main groove sediment in inner fan and braided groove in middle fan are play targets for subtle reservoir.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2005年第3期27-32,共6页
Petroleum Exploration and Development
基金
"十五"国家科技攻关计划"中国油气资源发展关键技术"项目(2001BA605A)
关键词
二连盆地
乌里雅斯太凹陷
腾格尔组
重力流
湖底扇
浊流
地层模式
Erlian Basin
Wuliyasitai Sag
Tenggeer Formation
density current
sublacustrine fan
turbidity current
sedimentary sequence
