柴达木盆地北缘油气藏类型、特征及其控制因素探讨

Types, Characteristics and Control Factors of Hydrocarbon Pools In Northern Qaldant Basin

柴达木盆地北缘块断带是柴达木盆地一个一级构造单元 ,至今共发现了 6个油气田 ,分别是冷湖三号油田、冷湖四号油田、冷湖五号油田、鱼卡油田、南八仙油气田和马海气田。根据它们的特征可以划分为背斜油气藏和断块油气藏 2大类 ,其中背斜油气藏又可分为同褶皱作用有关的背斜油气藏和同基底活动有关的背斜油气藏 2个亚类。它们的形成受烃源岩展布、烃源岩的生油生气性、断层活动和圈闭发育的有效性等几个因素的控制。建议今后的勘探活动对冷湖南八仙构造带以南和以北地区应有所侧重 ,南侧以找气为主 ,北侧以找油为主 ,并把重点放在寻找形成时间早。

The fault-block belt in northern Qaidam Basin is a first class structural unit of Qaidam Basin. So far six oil and gas fields, suchas Lenghu No3, No 4, No 5 and Yuqia Oilfields, Nanbaxian Oil and Gas Field and Mahai Gasfield have been discovered. The hydrocarbon pools are divided into two types including anticlinal oil and gas pools and fault-block oil and gas pools based on their characteristics, of which the anticlinal oil and gas pools can be divided into two types, the anticlinal oil and gas pools associated with folding and the ones with basement action. Their formation is controlled by the factors of distribution and oil-prone habit of source rocks, fault action and the effectiveness of trap etc. It is proposed that attention would be paid on the south and north parts of Lenghu-nanbaxian structural belt , oil exploration is in the south, gas exploration is in the north. Emphasis is made to find early formed traps associated with basement action.