The shale oil of the Lucaogou Formation in the Jimusaer Sag of the Junggar Basin was divided into two sweet spots for exploration and development. Crude oil in the upper and lower sweet spots comes from the upper and lower source rocks. After years of exploration, it has been found that the crude oil in the lower sweet spot has worse physical properties than that of the upper sweet spot. In this study, through the physical and geochemical analysis of crude oil in the upper and lower sweet spots, combined with the organic petrological observation of the upper and lower source rocks, the cause of the poor physical properties of the crude oil in the lower sweet spot has been identified. n-Alkanes in the saturated hydrocarbons of crude oil in the upper and lower sweet were complete while odd-to-even predominance was evident, indicating that the poor physical properties of the crude oil are unrelated to biodegradation. In addition, the correlation between the biogenic parameters and the physical properties of crude oil was analyzed, finding that the difference in crude oil is mainly related to the composition of biogenic precursors of upper and lower source rocks. Combined with organic petrological observation, the lower source rock was found to be rich in telalginite (green algae), which is therefore the primary reason for the difference in physical properties. In comparing results from the characteristics of crude oil biomarkers from both the upper and lower sweet spots, crude oils in the upper sweet spot are similar to each other, indicating that the enrichment of crude oil has experienced a certain migration. In contrast, the differences in biomarkers between the crude oils of the lower sweet spot were relatively large and changed regularly with depth, suggesting the self-generated and self-stored characteristics of crude oil enrichment. At the same time, it was found that the crude oil in the lower sweet spot is also affected by the maturity of adjacent source rocks under the condition of a consistent parent material source. Overall, it was determined that the lower the maturity of source rocks, the poorer the physical property of the crude oil produced.

中文翻译：

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吉木萨尔凹陷芦草沟组原油的特殊分布及其物理差异的成因分析

准gar尔盆地吉木萨尔凹陷芦草沟组的页岩油分为两个勘探开发的甜点区。上下甜点区中的原油来自上下烃源岩。经过多年的探索，发现下部甜点的原油的物理性能比上部甜点的物理性能差。本研究通过对上，下甜点区原油的物理地球化学分析，结合上，下烃源岩的有机岩石学观察，探讨了下甜点区原油物理性能较差的原因。地点已确定。ñ-上部和下部甜油中的饱和烃中的烷烃完全，而奇数至偶数占主导地位是明显的，这表明原油的不良物理性质与生物降解无关。此外，通过分析生物成因参数与原油物理性质之间的相关性，发现原油差异主要与上，下烃源岩的生物成因前体组成有关。结合有机岩石学观察，发现下部烃源岩富含辉石藻（绿藻），因此这是物理性质差异的主要原因。比较上，下甜区原油生物标志物的特征结果时，上甜区中的原油彼此相似，表明原油浓缩经历了一定的迁移。相反，低甜点原油之间的生物标记差异较大，并且随深度而变化，这表明原油富集的自生和自储特征。同时发现，在母质来源一致的情况下，下甜点区的原油也受到相邻烃源岩成熟度的影响。总的来说，已确定烃源岩的成熟度越低，所生产原油的物理性能就越差。低甜点原油之间的生物标志物差异较大，且随深度变化规律，提示原油富集的自生和自储特征。同时发现，在母质来源一致的情况下，下甜点区的原油也受到相邻烃源岩成熟度的影响。总的来说，已确定烃源岩的成熟度越低，所生产原油的物理性能就越差。低甜点原油之间的生物标志物差异较大，且随深度变化规律，提示原油富集的自生和自储特征。同时发现，在母质来源一致的情况下，下甜点区的原油也受到相邻烃源岩成熟度的影响。总的来说，已确定烃源岩的成熟度越低，所生产原油的物理性能就越差。