石油学报 ›› 2018, Vol. 39 ›› Issue (5): 541-553.DOI: 10.7623/syxb201805005

• 地质勘探 • 上一篇    下一篇

鄂尔多斯盆地延长组7段页岩全组分定量生烃模拟及原油可动性评价

王强1,2, 彭平安1, 张文正3, 刘金钟1, 于赤灵1   

  1. 1. 中国科学院广州地球化学研究所 广东广州 510640;
    2. 中国科学院大学 北京 100049;
    3. 中国石油长庆油田公司勘探开发研究院 陕西西安 710018
  • 收稿日期:2017-06-16 修回日期:2017-10-26 出版日期:2018-05-25 发布日期:2018-06-06
  • 通讯作者: 彭平安,男,1960年11月生,1982年获浙江大学地球化学专业学士学位,1991年获中国科学院广州地球化学研究所博士学位,现为中国科学院广州地球化学研究所研究员、中国科学院院士,主要从事油气地球化学与环境地球化学相关研究工作。Email:pinganp@gig.ac.cn
  • 作者简介:王强,男,1987年10月生,2010年获中山大学地球科学系学士学位,现为中国科学院广州地球化学研究所博士研究生,主要从事原油生物标志物、油源对比和生烃模拟研究工作。Email:qiangwang_gig@163.com
  • 基金资助:

    中国科学院战略先导项目(XDB10010201)和国家自然科学基金项目(No.41621062)资助。

Q uantitative full-component hydrocarbon-generating simulation and crude oil mobility evaluation of shale in 7th Member of Yanchang Formation, Ordos Basin

Wang Qiang1,2, Peng Ping'an1, Zhang Wenzheng3, Liu Jinzhong1, Yu Chiling1   

  1. 1. Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangdong Guangzhou 510640, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. Research Institute of Exploration and Development, PetroChina Changqing Oilfield Company, Shaanxi Xi'an 710018, China
  • Received:2017-06-16 Revised:2017-10-26 Online:2018-05-25 Published:2018-06-06

摘要:

页岩油和致密油是中国目前油气勘探的热点,页岩生烃模拟实验可为此类油气资源勘探提供重要数据。以鄂尔多斯盆地延长组7段(长7段)页岩为例,利用金管-高压釜模拟生烃装置,系统研究了Ⅱ型有机质在与"生油窗"对应的成熟度范围(Easy Ro 0.7%~1.6%)内生烃产物中的气体烃(C1-5)、轻烃(C6-14)、重烃(C14+)、各族组分,以及生烃残渣的地球化学特征。发现长7段页岩在生油期可同时生成2.35~103.91 mL/g的气体烃和10.83~88.24 mg/g的轻烃。重烃的生成高峰对应的Easy Ro约为1.0%,与其中的饱和烃、芳烃和非烃的高峰产率对应的成熟度非常接近。重烃中沥青质的产率在Easy Ro约1.35%后开始下降,说明沥青质在此后才开始大量裂解与固化。而对原油物性影响很大的轻重比[(气体烃+轻烃)/重烃]及气油比[气体烃/(轻烃+重烃)]随成熟度增加而不断增大,其增速分别在Easy Ro为1.05%~1.15%之后明显变快。在生油过程中,长7段页岩残渣HI值和H元素的大量减少、干酪根固体碳同位素的变重均发生在Easy Ro约1.00%之前。干酪根碳同位素的变化相对较小,在鄂尔多斯盆地可以作为母源指标。通过对生烃产物中6种常见生物标志物成熟度参数的对比,证实多环芳烃成熟度参数中的甲基菲指数(MPI)和甲基菲比值(F1)在整个生油窗内都与成熟度有很好的线性相关性,可用于鄂尔多斯盆地母源为长7段页岩的原油成熟度判识。生烃产物的各地球化学特征变化节点、以及成熟度指标可用于鄂尔多斯盆地长7段页岩油或相关致密油资源的可采性评价。

关键词: 延长组7段, 金管-高压釜系统, 生烃模拟, 全组分分析, 页岩油生成, 生油窗后期, 成熟度指标

Abstract:

Shale oil and tight oil are current hot spots of oil and gas exploration, and the shale hydrocarbon-generating simulation experiment can provide important information for the exploration of these oil and gas resources. Taking the shale in 7th Member of Yanchang Formation (Chang-7 Member), Ordos Basin, the gold tube-autoclave hydrocarbon-generating simulator is used to systematically study the Type-Ⅱ organic matter, the gaseous hydrocarbon (C1-5), light hydrocarbon (C6-14), heavy hydrocarbon (C14+), other components of hydrocarbon-generating products in the maturity range (Easy Ro 0.7% -1.6%) corresponding to "oil-generation window", and the geochemical characteristics of hydrocarbon generation residues. It is found that in the shale of Chang-7 Member during oil-generation period, gaseous hydrocarbons of 2.35-103.91 mL/g and light hydrocarbons of 10.83-88.24 mg/g are produced simultaneously. The peak yield of heavy hydrocarbons corresponds to Easy Ro of 1.00%, closely approaching to the maturities corresponding to the peak yield of saturated hydrocarbons, aromatics and non-hydrocarbons. Moreover, the asphaltene yield of heavy hydrocarbons starts to decline after reaching the Easy Ro of 1.35%, reflecting subsequent large scale of asphaltene cracking and solidification. However, the light/heavy ratio (gaseous hydrocarbon/light hydrocarbon) and gas/oil ratio (light hydrocarbon/heavy hydrocarbon) vital for physical property of crude oil are continuously increasing as the maturity getting higher, and the increasing rates are evidently accelerated after Easy Ro of 1.05% -1.15%. During oil-generating process, the massive loss of HI and H element of shale residue and the kerogen solid carbon isotope becoming heavier occur prior to Easy Ro of 1.00%; the kerogen solid carbon isotope changes less, and can be taken as an original source index in Ordos Basin. Through comparing six kinds of common biomarker maturity parameters in the hydrocarbon-generating products, it is validated that MPI and F1 among the PAH maturity are linearly correlated to maturity in the whole oil-generating window, and can be used to identify the crude oil maturity in the shale of Chang-7 Member in Ordos Basin. The change nodes of various geochemical characteristics of hydrocarbon-generating products and the maturity indexes can be applied to the exploitability assessment for shale oil or correlative tight oil in 7th Member of Yanchang Formation, Ordos Basin.

Key words: 7th Member of Yanchang Formation, golden capsule-autoclave system, hydrocarbon-generating simulation, full-components analysis, shale oil generation, later oil-generating window, maturity index

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