石油与天然气地质 ›› 2005, Vol. 26 ›› Issue (5): 618-622.doi: 10.11743/ogg20050510

• 论文 • 上一篇    下一篇

塔河油田天然气的碳同位素特征及其成因类型

高波1, 范明2, 刘文汇1, 南青云3, 张殿伟1   

  1. 1. 中国石化石油勘探开发研究院,北京,100083;
    2. 中国石化石油勘探开发研究院无锡石油地质研究所,江苏无锡,214151;
    3. 中国科学院兰州地质研究所,甘肃兰州,730000
  • 收稿日期:2005-06-10 出版日期:2005-10-25 发布日期:2012-01-16
  • 基金项目:

    中国石油化工股份有限公司科技项目(P04090)

Carbon isotope features and genetic type of natural gas in Tahe oilfield

Gao Bo1, Fan Ming2, Liu Wenhui1, Nan Qingyun3, Zhang Dianwei1   

  1. 1. Exploration & Production Research Institute, SINOPEC, Beijing;
    2. Institute of Petroleum Geology, Exploration & Production Research Institute, SINOPEC, Wuxi, Jiangsu;
    3. Lanzhou Institute of Geology, Chinese Academy of Sciences, Lanzhou, Gansu
  • Received:2005-06-10 Online:2005-10-25 Published:2012-01-16

摘要:

塔河油田天然气组分以烃类气体为主,平均含量占气体总体积的94.09%;非烃气体以N2和CO2为主,平均含量分别占4.2%和1.19%。烃类气体中以甲烷占绝对优势,平均含量为76.23%;重烃含量较高,平均含量为17.86%;干燥系数(C1/C1-5)平均为0.81,整体上属典型的湿气。塔和油田所有样品的δ13C2都轻于-30‰,属于典型的油型气范畴;天然气的δ13C113C213C3,呈明显的正序排列,显示天然气为典型的有机成因。塔河油田伴生天然气主体属于典型油型气,未发现其他母质类型天然气的混入。甲烷碳同位素组成反映其母质演化程度已处于成熟-过成熟阶段,且以高过成熟阶段为主。结合地质背景进行分析,源岩应属寒武—奥陶系。部分系列碳同位素的非线性分布模式显示,塔河油田的天然气具有两期充注特征:早期充注的为原油伴生气;晚期充注的为高温裂解气。

关键词: 组分, 碳同位素, 油型气, 天然气, 塔河油田

Abstract:

Natural gas in Tahe oilfield is mainly composed of hydrocarbon gas with an average content of(94.09)%.The non-hydrocarbon gas is mainly composed of N2 and CO2,with average contents of 4.2% and 1.19%,respectively.Hydrocarbon gas is mainly composed of methane with an average content of 76.23%;while the heavy hydrocarbon has an average content of 17.86%.The drying coefficient(C1/C1-5) averages(0.81),indicating typical wet gas as a whole.The δ13C2 values of all samples in this area are less than-30‰,indicating that it is of petroleum gas;and the δ13C values are in obvious positive sequence,i.e.δ13C113C213C3,indicating that it is typically of organic origin.The associated gas in Tahe oilfield mostly belongs to typical petroleum gas,without any mixture of gas from other sources.The carbon isotope composition of me-thane reveals that the evolution of its source rocks is in the range of mature to over mature stages,and is mainly in highly over-mature stage.Analysis in combination with geologic setting indicates that the source rocks are of Cambrian-Ordovician.The non-linear distribution of some series of carbon isotopes shows that the gas in Tahe oilfield has been charged in two stages.Associated gas has been charged in the early stage,while pyrolysis gas has been charged in the late stage.

Key words: component, carbon isotope, petroleum gas, natural gas, Tahe oilfield

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