摘要
通过对塔里木盆地煤岩与壳质组的热模拟实验产物饱和烃进行色-质分析指出,在全煤和壳质组中检测出了丰富的甾族系列化合物,且以C29甾烷占优势;煤岩中异常高的αββ构型异构化甾烷的检出反映了该煤在成岩早期经受过微生物改造;利用C29-5αββ/(αα+ββ)与C29ααα20S/(20S+20R)关系可以判识原油是否为未熟或成熟。孕甾烷/甾烷值与温度之间的关系表明孕甾烷可能不是甾烷的热降解产物;热模拟中Σ重排甾烷/Σ甾烷值在400℃开始降低和C29αα20R/C27αα20R值在400℃达到最大反映了甾烷骨架在该温度点以后发生开环裂解效应。
According to the GC-MS analysis of soluble organic matters extracted trom coal and exinite heated in closed system pyrolysis, one characteristic feature of all samples is the abundance of steranes in saturated hydrocarbon fractions with the maximum intensities of C29-regular steranes. The detection of high content αββ steranes from coal suggests the coal would be biodegraded during the early diagenesis, the soluble organic matter can be subdivided into immature and mature by using the relationship between C29 sterane-20S/（20S＋20R） and C29 sterane-ββ/（ββ-αα） ratios. The ∑pregnane/∑regular-sterane ratios in SOM during pyrolysis infer that the regular steranes would not be the precursors of pregnanes. The open ring and cleavage of steroid frameworks occurs according to the onset of the ∑diasteranes/∑regular-sterane decrease and the maximum ratios of C29αα20R/C27αα20R at the temperature of 400℃.
出处
《天然气地球科学》
EI
CAS
CSCD
2007年第2期249-253,265,共6页
Natural Gas Geoscience
