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柴西南地区具备E13构造岩性油气藏形成的地质条件。生油岩地球化学特征和油源对比研究表明,柴西南地区下第三系发育扎哈泉和英雄岭2个大的生油凹陷,凹陷内发育E13和E232套有效生油岩,为构造岩性油气藏形成提供了油源条件。柴西南地区存在与英雄岭和扎哈泉生油凹陷相接的红柳泉—跃进、铁木里克和昆北断阶带3个古斜坡,为构造岩性油气藏形成创造了大型的古构造斜坡背景。柴西南地区昆北断阶带和尕斯断陷内存在下倾方向与生油凹陷相邻的成排成带发育的断背斜和断鼻等构造,为构造岩性油气藏的形成提供了局部构造斜坡背景。在区域和局部构造斜坡背景上柴西南地区下干柴沟组下段(E13)沉积时期存在辫状河三角洲和湖泊相构成的沉积体系,发育了6个辫状河三角洲。柴西南辫状河三角洲外前缘发育河口坝、远端坝和席状砂,主要分布在尕斯断陷内的构造圈闭的斜坡区,油源和圈闭条件优越,是构造岩性油气藏勘探最有利的地区。柴西南辫状河三角洲前缘发育水下分流河道砂体,分布在昆北断阶带和尕斯断陷部分断鼻或断背斜的斜坡带,油源较充裕,但封堵条件较差,是构造岩性油气藏勘探较有利的区带。
The geological conditions for the formation of lithologic reservoirs with E13 tectonics in the southwest of Qaidam Basin are as follows. The geochemical characteristics of oil source rocks and the comparison of oil sources show that there are two large oil-producing sags in Zhahequan and Yingxiongling in the lower Tertiary in the southwestern Qaidam basin. E13 and E232 sets of effective source rocks are developed in the sags, Formation of oil and gas reservoirs provided oil conditions. There are three ancient slopes of Hongliuquan - Yuejin, Tiemurike and Kunbei fault strata connecting with Yingxiongling and Zhahaquan oil sags in the southwest of Qaidam, which have created large paleostructures for the formation of lithologic reservoirs Slopes background. In the Qaidam fault zone of the northwestern Qaidam Basin, faults such as faulted anticline and fault nose developed in the down-dip direction and adjacent to the oil-bearing depression are located in the Kunbai fault-step belt and gas faulted depression in the southwestern part of Qaidam basin, providing local structure for the formation of lithologic reservoirs Slopes background. On the regional and local tectonic slope backgrounds, there are sedimentary systems of braided delta and lacustrine sedimentary facies during the deposition of the Lower Ganchaigou Formation (E13) in the southwestern Qaidam basin, and six braided delta are developed. In the southwestern margin of the braided delta of the southwestern Qaidam, the estuarine dam, distal dam and sand are developed. They are mainly distributed in the structural traps in the Gasse fault depression. The oil source and trap conditions are favorable. Tibet exploration the most favorable areas. The submarine distributary channel sand bodies are developed in the braided delta front of southwestern Qaidam and distributed in the slope zone of the Kun-Bei fault zone and the part of the Gas faulting in the fault nose or ancillary anticline. The source of oil is abundant but the sealing conditions are poor, Is the construction of lithologic reservoir exploration more favorable zone.