大杨树盆地中部甘河地区嫩江组烃源岩生烃潜力分析

Hydrocarbon-generating potential of source rocks from Nenjiang Formation in Ganhe region of central Dayangshu Basin

通过岩石热解、总有机碳、镜质体反射率、饱和烃气相色谱-质谱等测试方法,系统分析大杨树盆地中部甘河地区嫩江组烃源岩有机地球化学、生物标志化合物特征,评价其生烃潜力。结果表明,大杨树盆地中部甘河地区嫩江组暗色泥岩有机质丰度较高,属于中等-好烃源岩,有机质类型主要为Ⅱ型干酪根,处于成熟阶段,是一套好的烃源岩。烃源岩形成于还原性的淡-微咸水的水体沉积环境中,有机质来源为混合来源,且以陆生高等植物来源贡献较大。总体显示大杨树盆地中部甘河地区嫩江组烃源岩具有一定的生烃潜力。

The organic geochemistry and biomarker compound features of hydrocarbon source rocks from Nenjiang Formation in Ganhe region of central Dayangshu Basin are systematically analyzed and the hydrocarbon-generating potential is evaluated by means of rock pyrolysis,total organic carbon,vitrinite reflectance,gas chromatography-mass spectrometry of saturated hydrocarbon,etc. The results show that the dark mudstones from Nenjiang Formation in Ganhe region are with high organic abundance,belonging to medium-good hydrocarbon source rocks,and the kerogen type of organic matter is dominated by Ⅱ-type and is in the mature stage,which is a set of excellent hydrocarbon source rocks. The source rocks formed in the fresh-brackish water sedimentary environment with reduction condition,the organic matter is from mixed sources and mainly from terrestrial higher plants. Overall,it is suggested that the hydrocarbon source rocks from Nenjiang Formation in Ganhe region of central Dayangshu Basin have certain hydrocarbon-generating potential.