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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。
J_1-R (!) On the northwestern margin of the Qaidam basin is a hydrocarbon-bearing system with medium and low oil and gas fullness (SPI <3.9), mixed-trapping, medium-impedance characteristics and apparent resource depletion. The system has the typical bottom-forming features. The Lower Jurassic residual continental facies faulted deposits constitute the major source rock series, and the Tertiary squeezed depression-type sediments are the main transport system. Among them, the regional Eocene muddy caprock controls the vertical migration and accumulation of oil and gas, and the underlying oil and gas in the caprock of the caprock mainly migrates laterally. On top of it, Migration window "appears concentrated vertical migration of oil and gas, with double-layer transport model. The system was initially established from the early Oligocene. The Oligocene is the formation period of primary oil and gas reservoirs, the early Pliocene is the formation of secondary reservoirs and dry gas reservoirs, and the system is in the critical stage of preservation in the early Quaternary. The extent to which the top seal of the system is preserved and the effectiveness of the system boundaries are the major determinants of the amount of lost system resources.