【摘要】 中国南方下古生界页岩成熟度很高、缺乏镜质组、固体沥青反射率变化大,成熟度的精确评价一直没有得到完善解决。通过对取自扬子地区古生界页岩样品中固体沥青(BRO=0.43%~5.51%)激光拉曼光谱特征的研究,发现固体沥青的激光拉曼光谱参数:峰位参数(WD与WG)、峰位差(RBS)、半高宽(FWHM-D与FWHM-G)及峰强度比(ID/IG)与沥青反射率均体现出一定的相关性,但相关程度差别明显,而且还明显受到成熟度水平的制约。对这些参数与沥青反射率进行了直线回归,筛选出了相关性比较好的指标是RBS(BRO值范围为1.5%~3.5%)与ID/IG(BRO>3.5%),两者相关系数高达0.95以上。研究认为,在建立标准方法的基础上,固体沥青激光拉曼光谱的这2个参数对早古生代及前寒武纪地层成熟度评价具有实际应用价值。更多还原

【Abstract】 The Lower Paleozoic shale from the South China region has very high maturity and is lack of vitrinite.Although solid bitumen usually occurs in shale,its measuring reflectance value varies widely,thus there is a big challenge to determine the exact maturity of the shale,which puzzles the conventional and unconventional petroleum exploration conducted in this area for many years.In this study,the Raman spectroscopic characteristics of solid bitumen in shale samples taken from the Yangtze region with different maturities(BRO=0.43%-5.51%)were investigated.The results indicate that the Raman spectral parameters of the solid bitumen,including band position(WDand WG),band separation(RBS),full width at half maximum(FWHM-D and FWHM-G),and band intensity ratio(ID/IG)are all related to the bitumen reflectance,but with considerably different correlations,constrained apparently by maturity.Linear regressions were performed between these parameters and bitumen reflectance,and some parameters with higher correlation were selected.They are RBS(within 1.5%-3.5%of BRO)and ID/IG(with BRO>3.5%),showing a correlation coefficient as high as 0.95.It is believed that the two Raman spectral parameters of solid bitumen will be of significant practical use for the maturity assessment of the Lower Paleozoic shale when standard measurement and curve fitting procedures are utilized.更多还原