柴达木盆地北缘侏罗系烃源岩干酪根13C核磁共振研究

柴达木盆地北缘是柴达木盆地三大油气区之一,其源岩为早、中侏罗世煤系地层.烃源岩有机质类型以Ⅲ₁型和Ⅱ型干酪根为主,Ⅰ₂型干酪根仅在局部地区有分布.通过对柴达木盆地北缘侏罗系烃源岩中不同类型干酪根的¹³C核磁共振研究,指出了研究区Ⅰ₂、Ⅱ、Ⅲ₁型干酪根的化学结构特征以及化学结构中“芳构碳”、“油潜力碳”与“气潜力碳”的相对含量,据此从定量分析的角度对不同类型干酪根的生油气贡献作了评价.Ⅰ₂、Ⅱ、Ⅲ₁型干酪根的生烃能力依次减弱,对生油的贡献也依次减弱,且生成油气的比例不同,Ⅰ₂、Ⅱ型干酪根以生油为主,Ⅲ₁型干酪根则以生气为主.

13C NMR RESEARCH ON THE KEROGENS OF JURASSIC HYDROCABON SOURCE ROCK IN THE NORTHEN EDGE,QAIDAM BASIN

The northern edge in Qaidam Basin is one of the three hydrocarbon bearing areas in the basin.Its source rock is the early and middle Jurassic coal measures.Organic matter types of source rock are mainly type Ⅲ₁ and type Ⅱ Kerogen,type Ⅰ₂ Kerogen distributes only at some limited areas.By ¹³C nuclear magnetic resonance research on different types of Kerogen of Jurassic hydrocarbon source rock in the northern edge,the paper gives the chemical structure of the type Ⅰ₂、Ⅱ、Ⅲ₁ Kerogen in the studied area and the relative content of“oil potential C”, “gas potential C”,“aromatic C”in the chemical structure,based on which the paper evaluates the contribution of different types of Kerogen to the generation of oil and gas through quantitative analysis.The paper draws the conclusion that hydrocarbon-generating potential of the type Ⅰ₂、Ⅱ、Ⅲ₁ Kerogen decrease and their contribution to the oil generating also decrease and the ratio of oil or gas generated depends on the type of Kerogen.Type Ⅰ₂ and type Ⅱ Kerogen generate mainly oil and typeⅢ1Kerogen mainly generates gas.