南黄海盆地北部坳陷—中部隆起区沉积物中渗漏烃的三维荧光特征

在南黄海中部隆起区沉积物样品三维荧光研究的基础上,继续分析北部坳陷三维荧光、饱和烃及芳烃地球化学特征,探讨三维荧光指标在研究区油气渗漏系统中的指示意义。分析认为,三维荧光主峰及次峰的激发波长和发射波长、最大荧光强度等指标与中部隆起区相当。利用最大荧光强度、T/D指标、芳烃百分含量组成三指标异常下限的提取方法,相互印证确定了9个地球化学异常区,异常点表现为凝析油特征。并结合南黄海盆地油气地质条件,对异常区的可靠性进行了分类,划分了1个可靠性良好区、4个较好区、2个一般区、2个较差区。

TOTAL SCANNING FLUORESCENCE INDEX PATTERN AND ITS IMPLICATION FOR HYDROCARBON SEEPAGE AT THE CENTRAL UPLIFT AND NORTH DEPRESSION OF THE SOUTH YELLOW SEA BASIN

After the usage of the Total Scanning Fluorescence（TSF）index on the Central Uplift of the South Yellow Sea Basin,more parameters,such as TSF,alkane and aromatic hydrocarbon were measured for the North Depression.The maximum TSF Fluorescence Intensity（MFI）excitation wavelengths is 227nm-233 nm and the emission wavelengths 324-337 nm,while the sub-MFI excitation is 257-260 nm and emission 357-361 nm,both of which show similar patterns with those of the Central Uplift.The starting threshold for screening indicator of MFI,T/Dand aromatic hydrocarbon percentage content determined by frequency histogram is 800 units,2.5and thirteen percent respectively.With the distribution pattern of the index,nine comprehensive anomalous areas can be determined.Based on the synthetic judgement of anomalous index conformity,structure matching and source rock development,the areas can be classified into four ranks according to the reliability of the anomalies.