石油学报 ›› 2014, Vol. 35 ›› Issue (1): 68-75.DOI: 10.7623/syxb201401007

• 地质勘探 • 上一篇    下一篇

天然气中CO2氧同位素在线检测技术与应用

李谨, 李志生, 王东良, 李剑, 谢增业, 孙庆伍   

  1. 中国石油勘探开发研究院廊坊分院 中国石油天然气集团公司天然气成藏与开发重点实验室 河北廊坊 065007
  • 收稿日期:2013-06-07 修回日期:2013-09-06 出版日期:2014-01-25 发布日期:2013-12-09
  • 通讯作者: 李 谨,男,1982年9月生,2004年获长江大学学士学位,2007年获长江大学地球化学专业硕士学位,现为中国石油勘探开发研究院廊坊分院工程师,主要从事天然气地球化学研究工作。Email:Lijin69@petrochina.com.cn
  • 作者简介:李 谨,男,1982年9月生,2004年获长江大学学士学位,2007年获长江大学地球化学专业硕士学位,现为中国石油勘探开发研究院廊坊分院工程师,主要从事天然气地球化学研究工作。Email:Lijin69@petrochina.com.cn
  • 基金资助:

    国家重大科技专项"中国大型气田形成条件、富集规律及目标评价"(2011ZX05007)资助。

On-line detection of oxygen isotope of CO2 in natural gases and its application

Li Jin, Li Zhisheng, Wang Dongliang, Li Jian, Xie Zengye, Sun Qinwu   

  1. Langfang Branch, PetroChina Research Institute of Petroleum Exploration and Development;
    PetroChina Key Laboratory of Gas Formation & Development, Langfang 065007, China
  • Received:2013-06-07 Revised:2013-09-06 Online:2014-01-25 Published:2013-12-09

摘要:

氧同位素作为有效的地球化学参数,在同位素地质年代学、环境科学研究等许多领域得到广泛应用,CO2氧同位素也是一个非常有效的示踪剂,可用于判识气源,然而这一指标尚未应用于油气勘探领域。应用气相色谱-气体稳定同位素质谱联用技术,建立了天然气中CO2的氧同位素在线检测方法。在对松辽盆地、四川盆地、塔里木盆地天然气组分、组分碳同位素、稀有气体组成与稀有气体同位素等地球化学资料研究的基础上,对盆地天然气中CO2氧同位素进行分析,发现不同盆地、不同来源天然气中CO2的碳、氧同位素分布特征存在明显差异,表明CO2的氧同位素具有较好的成因指示意义。通过CO2的碳-氧同位素分布,可将气藏中CO2细分为上地幔来源、碳酸盐岩来源以及有机成因,为天然气成因及气源对比研究提供了新手段。

关键词: 天然气, CO2, 氧同位素, 在线检测技术, 成因判识

Abstract:

Oxygen isotope, as a valid tracer, has been widely used in isotopic geochronology, environmental science and many other fields. The oxygen isotope composition of CO2 is also a very effective tracer and can be used to characterize the origin of natural gases. However, this approach has not yet been applied to oil-gas exploration and development. A deteation method of on-line chromatography separation-mass spectrometric (GC-IRMS) was created to determine the oxygen isotope of CO2, which can effectively avoid artificial errors in the sample preparation process and greatly improve the detection precision and efficiency. CO2 carbon and oxygen isotopes of natural gases from the Songliao, Sichuan and Tarim Basins were analyzed. The result showed that the CO2 samples from different basin have obviously different carbon and oxygen isotopic distributions, indicating that the CO2 oxygen isotope has a special merit in providing source information. By measuring CO2 carbon-oxygen isotopic values, we may better divide CO2 genetic types into the mantle, carbonate and organic origins, which can provide a new method to study the origin and source correlation of natural gases.

Key words: natural gas, CO2, oxygen isotope, online detection, origin identification

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