石油与天然气地质 ›› 2025, Vol. 46 ›› Issue (5): 1582-1596.doi: 10.11743/ogg20250512

• 油气地质 • 上一篇    

页岩油组分特征及可动性评价——以准噶尔盆地玛湖凹陷二叠系风城组为例

白玉彬1,2(), 任海姣3, 张军1,2, 陈绍蓉3, 吴伟涛1,2, 赵辛楣3, 吴和源1,2, 邹阳3   

  1. 1.西安石油大学 地球科学与工程学院,陕西 西安 710065
    2.陕西省油气成藏地质学重点实验室,陕西 西安 710065
    3.中国石油 新疆油田分公司 勘探开发研究院,新疆 克拉玛依 834000
  • 收稿日期:2025-06-10 修回日期:2025-08-21 出版日期:2025-10-30 发布日期:2025-10-29
  • 第一作者简介:白玉彬(1981—),男,副教授、硕士研究生导师,致密油(页岩油)富集规律与甜点评价。E‑mail: baiyubin@xsyu.edu.cn
  • 基金项目:
    国家自然科学基金项目(42372155)

Component characteristics and mobility assessment of shale oil: A case study of the Permian Fengcheng Formation, Mahu Sag, Junggar Basin

Yubin BAI1,2(), Haijiao REN3, Jun ZHANG1,2, Shaorong CHEN3, Weitao WU1,2, Xinmei ZHAO3, Heyuan WU1,2, Yang ZOU3   

  1. 1.School of Earth Sciences and Engineering,Xi’an Shiyou University,Xi’an,Shaanxi 710065,China
    2.Shaanxi Key Laboratory of Petroleum Accumulation Geology,Xi’an,Shaanxi 710065,China
    3.Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China
  • Received:2025-06-10 Revised:2025-08-21 Online:2025-10-30 Published:2025-10-29

摘要:

中国陆相咸化湖盆混积型页岩油资源潜力大,勘探前景好,明确其产出油组分特征,可为页岩油可动性评价及提高页岩油产量奠定基础。以准噶尔盆地玛湖凹陷二叠系风城组混积型页岩油为例,通过产出油与滞留烃组分特征的对比,明确了页岩油具有组分流动的特点,并进一步探讨了可动油与产出油的关系。研究认为:①玛湖凹陷风城组页岩产出油与滞留溶剂抽提油相比,产出油具有高的烃类含量,并随着开采时间的延长,重烃含量增加,具有组分流动的特征;产出油饱和烃气相色谱以中-低碳数的正构烷烃为主,滞留烃中灰质/白云质页岩和混合质页岩中饱和烃低分子碳数化合物占比大,而长英质页岩中相对发育中-高分子量的饱和烃类化合物。②热解法经轻烃散失量校正和重烃量恢复后,计算出风城组页岩原地滞留烃量平均值为2.87 mg/g(范围1.39 ~ 14.25 mg/g),可动油含量平均值为1.60 mg/g,占比高达55.8%,页岩油可动性好。③从分子地球化学尺度对比了可动油与产出油,认为高含油饱和度指数(OSI)、高可动烃含量和低总有机碳含量(TOC)段,具有更好的页岩油勘探潜力。该研究对深化咸水湖盆页岩油可动性和可采性以及提高页岩油产量具有重要意义。

关键词: 轻烃散失量恢复, 族组分, 可动油, 产出油, 页岩油, 风城组, 玛湖凹陷, 准噶尔盆地

Abstract:

Continental saline lacustrine basins in China hold considerable potential for mixed-type shale oil resources, exhibiting promising exploration prospects. Determining the component characteristics of the produced oil can lay a foundation for the mobility assessment and production increase of shale oil. In this study, we investigate the mixed shale oil in the Permian Fengcheng Formation, Mahu Sag, Junggar Basin. Through comparison of components in produced oil and residual hydrocarbons, we determine that the shale oil is characterized by component-dependent flow. Furthermore, we explore the relationship between movable oil and produced oil. The results indicate that for shales in the Fengcheng Formation in the Mahu Sag, produced oil exhibits higher hydrocarbon content than residual oil obtained through solvent extraction. With an increase in the time of shale oil recovery, the produced oil shows elevated heavy hydrocarbon content, verifying its component-dependent flow. Gas chromatograms indicate that the saturated hydrocarbons in the produced oil are dominated by n-alkanes with medium to low carbon numbers. Regarding residual hydrocarbons, calcareous/dolomitic shales and mixed shales show a high proportion of saturated hydrocarbon compounds with low carbon numbers, while felsic shales contain relatively well-developed saturated hydrocarbon compounds with medium to high molecular weights. After the light hydrocarbon loss correction and the heavy hydrocarbon recovery by pyrolysis method, in-situ residual hydrocarbon content in the Fengcheng Formation shales is calculated at 1.39 ~ 14.25 mg/g (average: 2.87 mg/g). The average movable oil content of this formation is estimated at 1.60 mg/g, which accounts for up to 55.8% of the residual hydrocarbons, indicating high mobility of shale oil. The comparison of the movable oil and produced oil from the perspective of molecular geochemistry reveals that the intervals with a high oil saturation index (OSI), high movable hydrocarbon content, and low total organic carbon (TOC) content hold greater potential for shale oil exploration. This study is significant for the in-depth understanding of the mobility and recoverability of shale oil in saline lacustrine basins and enhancing its production.

Key words: light hydrocarbon loss recovery, group composition, movable oil, produced oil, shale oil, Fengcheng Formation, Mahu Sag, Junggar Basin

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