柴达木盆地西北缘含油气系统  

Petroleum System of Northwestern Margin of Qaidam Basin.

作　　者：张映红[1] 李伟[1] 门相勇[1] 白淑燕 岑小春[1] 

机构地区：[1]中国石油勘探开发研究院,北京100083

出　　处：《勘探家（石油与天然气）》2000年第3期83-88,共6页

摘　　要：柴达木盆地西北缘J_1—R(！)为一具有中低油气充满度(SPI<3.9)、混合型排运聚、中等阻抗特征和明显资源散失的含油气系统。该系统具有典型的底生式特征,下侏罗统残余陆相断陷沉积构成主要的烃源岩系,第三系挤压坳陷型沉积为主要运聚体系。其中,中始新统的区域性泥质盖层控制油气的垂向运聚,该盖层的下伏层系中油气以侧向运聚为主,其上仅在局部受断层贯通形成的“运移窗”出现油气集中垂向运移,具有双层运聚模型。系统从渐新世早期开始初步建立,渐新世早期为原生油气藏形成期,上新世早期为次生油气藏及干气气藏形成期,在第四纪的早期进入保存关键时期。系统顶封层的保存程度以及系统边界的有效性是决定这个系统资源散失量的主要因素。A petroleum system of J_1-R(!) at northwestern mar-gin of Qaidam Basin has been found and studied inthis research, which is a system with characters of low-middle degree of oil charging (SPI<3.9), mixedtype of charging-migrating-accumulating, middle im-pedance and obviously resource loss. The system ischaracterized by a bottom hydrocarbon-generating, inwhich main source rocks are composed of relict la-custrine fault-depression sediments of Lower Jurassic;Tertiary compressive depression deposits form themajor migrating and accumulating system. The verti-cal migrating and accumulating are controlled by a re-gional. pelitic caprock of the Middle Eocene, belowwhich, the migration and accumulation of oil-gas aremainly happened in lateral direction and vertical mi-grating of oil-gas only appears in layer above the cap-ping because a 'migrating window' is formed by localfault, where a double layer type can be detected withinthe system. The system had been primarily formedfrom early Oligocene which is a period of formingprimary oil-gas pools. A secondary oil-gas pools anddry-gas pools should be formed at the early Pliocene,and the key preservation stage came during the earlyQuaternary The major factors for controlling qualityand amount of resource lost should be both of the pre-serving degree of top capping beds in the system andthe effective boundary of the system.

关 键 词：含油气系统 系统演化 系统类型 柴达木 油气藏 

分 类 号：TE121.11[石油与天然气工程—油气勘探] TE121.12