松辽盆地北部西部斜坡稠油的来源分析

Analysis of the source of thickened-oil of western ramp north of Songliao Basin

为了确定松辽盆地北部西部斜坡稠油的成因 ,评价该区域稠油资源量 ,对比分析了源岩和原油特征 .结果表明 :松辽盆地北部西部斜坡主要烃源岩为青一段和嫩一段地层 ,镜质体反射率一般小于 0 .5 0 % ,处于未成熟或低成熟阶段 ,而西部斜坡的原油主要为成熟油 ;齐家古龙凹陷主要烃源岩青一段和嫩一段地层的镜质体反射率一般在 1.10 %以上 ,处于成熟阶段的生油高峰期 ;西部斜坡的稠油是从齐家古龙凹陷长距离运移而来 ,并受到不同程度的生物降解 .

The source of thickened oil is the important groundwork for analysis of cause of formation of thickened oil as well as the groundwork for evaluating the potential of thickened oil exploration. Contrasting and analyzing of the characteristics of source rock and oil indicates that thickened oil mostly comes from Qijia-Gulong sag. The main source rock is K1qn1 and K1n1, Ro commonly is under 0.5% during the immature or low mature phase. Yet the source oil of western ramp is main mature oil. The Ro of sourcerock of K1qn1 and K1n1 in Qijia-Gulong sag is commonly above 1.1%, during oil generation peak. The thickened-oil of western ramp comes from Qijia-Gulong sag, and undergo different biodegradation.