南宁盆地第三系木质褐煤中甾类化合物热模拟实验研究

STUDY ON STEROIDS IN TERTIARY WOOD COAL FROM NANNING BASIN BY THERMAL-MODELLING EXPERIMENTS

夏燕青 罗斌杰

Xia Yanqing Luo Binjie

中国科学院兰州地质研究所 兰州 730000

Lanzhou Institute of Geology, Acadrmia Sinica

本文根据热模拟实验,探讨了甾烷的产状及其热演规律,不同的甾烷具有不同的产状,规则甾烷、重排甾烷和4-甲基甾烷主要来源于非干酪根前身物质的转变,干酪根降解基本上不生成这些化合物;而孕甾烷却主要来自干酪根降解。8个常用参数aaa(20R)C27、C28、C29%、∑dixt/∑St、C29aaa20S/20(S+R)、C295αββ/(ββ+aa)、C27aaa20S/20(S+R),C275αββ/(ββ+aa)等均存在多解性。aaa(20R)C29%值越大,其余参数越小,对成熟度(低成至成熟)的指示越精确。反之则无指导意义。

In this paper, the occurrence of steranes and their thermal evolutionary patterns are approached based on the results of thermal-modelling experiments. Different steranes have different occurrence. Regular steranes, rearranged steranes and 4-methyl steranes mainly come from the transition of non kerogen precursors, and the degradation of kerogcn do not generate these compounds basically. However, pregnanes are mostly generated by the degradation of kerogen. All eight parameters most in use, such as aaa(20R)C27,C28,C29% +aa),have multiple solutions. The higher the value of aaa(20R)C29% and the lower the value of the other parameters, the more accurately the parameters indicate the maturity (iow-mature to mature). Otherwise, they have not any indicative significance.

https://doi.org/10.11781/sysydz199503301