银根—额济纳盆地构造演化与油气勘探方向

银根—额济纳盆地基底由多板块组成.中、新生代盆地构造演化经历了早三叠世热拱隆张、早—中侏罗世初始裂谷、早白垩世裂谷发育、晚白垩世引张坳陷及第三纪挤压坳陷等阶段,形成了不同类型的构造圈闭,与中—下侏罗统煤系烃源岩、下白垩统半深湖相烃源岩形成生储组合.油气勘探方向为单断凹陷多级断阶带的断鼻、断块构造油气藏和缓坡带的地层岩性油气藏以及双断凹陷的滚动背斜构造油气藏.提出了小湖盆围绕"洼槽"烃源岩开展"近源"油气勘探的思路. 

TECTONIC EVOLUTION AND PETROLEUM PROSPECTION IN THE YIN''''GEN-EJINA BASIN

The basement formed by plates and sutural zones apparently controls the evolution of Yin'gen-Ejina Basins.The tectonic evolution has undergone 5 stages: heat-upheaval and tension-crack stage of the Early Triassic,rudiment rift basin stage of the Early-Middle Jurassic,stretch faulting stage of the Early Cretaceous,relaxation depression stage of the Late Cretaceous and inland convergence stage of Tertiary.Different tectonic stages result in different trap styles.Hydrocarbon source rocks of the Lower-Middle Jurassic and the Lower Cretaceous form source and reservoir.The exploration realms of half graben-like basin are fault noses and fault block traps in the central fracture and ridgy zones,and litho-(logic) traps and stratigraphic unconformity traps in the gentle slope zones.The exploration realm of downfaulted basin is roll anticline in the fracture zones controlling basin.A new notion of source nearby exploration around sub-depression in little lacustrine basins are proposed.