塔里木盆地寒武系烃源岩的研究新进展

塔里木盆地的勘探程度较低，下古生界不同烃源岩的特征及其展布仍是困扰地质家的重大问题。通过详细分析已钻揭的寒武系烃源岩，深入探讨了寒武系烃源岩的地球化学特征。结果表明由于不同地区寒武系烃源岩的沉积环境存在差别，因此不同地区有机质的丰度、甾萜烷的分布特征以及“三芴”组成均存在一定的差异，因此进行寒武系的油源对比时应考虑到这种差别，以提高油源对比的精度。总体来讲，寒武系烃源岩的标志性特征主要包括甾烷中的C28含量较高（>25%）、伽马蜡烷的含量较高（峰高与C31H接近，G/C31H22R>0.89）、碳同位素比值偏重（δ13C饱重于-30‰，δ13C芳接近或重于-28‰），三芳甾烷的分布特征也明显区别于中—上奥陶统烃源岩。

New Progress in Studying Cambrian Source Rock of Tarim Basin

The petroleum exploration degree of Tarim Basin is low,and the distinguished character and distribution of Lower Paleozoic source rock is still an important problem puzzling the geologist.By systematic analyses of drilled Cambrian source rock,geochemical character of Cambrian source rock was deeply studied.The result shows that owing to the difference of Cambrian depositional environment,the abundance of organic matter,the distribution of sterane and terpane and relative composition of dibenzothiophene,dibenzofuran,fluorine were varied apparently,and these parameters should be taken into account in oil-source correlation.As a whole,distinguished character of Cambrian source rock mainly include higher content of C28 in sterane,higher content of Gammacerane,and heavier carbon isotope ratios.The distribution of triaromatic hydrocarbon in Cambrian source rock is also different to Upper Ordovician source rock apparently.