由于柴达木盆地西部北区第三系的烃源岩属不纯泥岩，具有强烈的非均质性，因此目前对该区烃源岩的认识和评价结果尚存争议，同时，柴西北区的油源也是人们争论的焦点。针对这一情况，首先划分出有效的烃源岩，再对其进行综合评价，这比直接采用参数的平均值更为科学。据此发现研究区的主力烃源岩层位是N12和E23，最重要的生油区域位于小梁山—南翼山—油泉子一带。根据油源对比结果，认为柴西北区的原油并非来自茫崖凹陷，而是来自本区的N12和E23烃源岩，原油以自生自储和短距离的垂向、侧向运移为主，这是因为研究区缺乏油气长距离运移的地质条件；小梁山凹陷及其周缘不管是深层还是浅层，均是本区的一个重要的生油中心；这一研究结果可为今后的勘探指明方向。

The Tertiary source rocks in the Northwest Qaidam basin are greatly heterogeneous because they are impure mudstone, so there are many disputes in the understanding and evaluation on the source rocks. In addition, the oil source is the controversial focus in this area. In view of these problems, this research firstly distinguishes the effective source rocks, and then synthetically evaluates on them, which is more reasonable than directly averaging the parameters. According to this research, the main strata of the source rocks are N1 2 and E2 3 in this area, and the most important oil forming zone is located in the area of Xiaoliangshan Nanyisha ouquanzi. On the basis of the oil source correlation result, the oil in the northwest Qaidam originate from indigenous source rocks of N1 2 or E2 3 instead of originating from Mangya depression. The oil is self generating and self preserving and vertically and horizontally migrates in short distance. Xiaoliangshan depression and its peripheral areas are the most important oil forming center and are the exploration orientation in the future.
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