银根—额济纳旗盆地是一个发育在兴蒙海西褶皱带上的白垩纪走滑 -拉分盆地 ,凹隆相间的盆地结构 ,使得各个凹陷具有多物源和近物源的特点 ,三角洲 -滨岸沉积体系十分发育 ,对油气成藏起着重要的作用。查干凹陷是其东北部一个重要的沉积单元。研究表明 :凹陷断陷期 (K1 b—K1 s)火山作用强烈、地温梯度高 (4 .8℃ / 10 0m)、沉积厚度巨大 ,主要勘探目的层 (K1 b—K1 s1 )的成岩作用早而强烈 ,储层物性较差 ,主要为特低孔、渗储层 (Ⅳ、Ⅴ类 )。因受燕山Ⅳ幕运动 (K1 s末 )的强烈改造和差异剥蚀 ,使得早期原型盆地的构造、地层格架发生了明显的变化。因此 ,恢复原型盆地及时空展布 ,寻找受古隆起控制的同生继承性构造 ,是查干凹陷解决较差储层制约因素和寻找油气富集的重要途径之一。而其中受古隆起背景和沉积体系双重控制的有利储集相带是形成查干凹陷油气局部富集的重要制约因素 ,这种构造 -岩性复合型圈闭则是该凹陷油气勘探的主要目标 The Yingen-Ejinaqi Basin, a Cretaceous strike-slip-pull basin developed in the Xingmenghaixi fold belt, has the characteristics of multiple provenances and near-provenances in each depression. The delta-foreshore Shore sedimentary system is very developed, plays an important role in hydrocarbon accumulation. The Chagan depression is an important sedimentary unit in the northeast. The results show that the K1 b-K1 s volcanism is strong, the geothermal gradient is high (4.8 ℃ / 100 m), and the sedimentary thickness is huge. The diagenesis of the main exploration target (K1 b-K1 s1) The strong, poor reservoir properties, mainly for ultra-low porosity, permeability reservoir (Ⅳ, Ⅴ class). Due to the strong remodeling and differential denudation of the Yanshan Ⅳ Curtain Movement (K1 s), the tectonic and stratigraphic frameworks of the early prototype basins changed obviously. Therefore, restoration of the prototype basin and its distribution in time and space and the search for symbiotic inherited structures controlled by the paleo-uplift are one of the important ways to solve the restricted reservoirs in the Chagan Sag and to search for hydrocarbon enrichment. The favorable reservoir facies belonged to paleo-uplift and dual control of sedimentary system are important constraints for the local enrichment of oil and gas in the Chagan Sag. This structural-lithologic composite trap is the main target of hydrocarbon exploration in this depression