泥质烃源岩不同有机显微组分的原始赋存态

Original Preservation of Different Organic Micro-components in Muddy Source Rock

摘要:

利用密度分组将泥质烃源岩划分为不同的密度组分,通过对各密度组分进行孢粉相分析和激光粒度检测,结果表明:密度分组获得的ρ<1.6 g·cm3组分以游离态生物有机质为主,富集了全岩干酪根中大粒级的形态有机质组分;1.6 g·cm-3<ρ<2.2 g·cm-3和ρ>2.2 g·cm-3组分表现为有机质与矿物共生的赋存态特点,富集大量细粒级的颗粒无定形和海绵无定形有机质,说明这些无定形物质通过与矿物(主要是粘土矿物)紧密共生而获得保存.分组结果反映不同有机显微组分在烃源岩中的赋存态存在差异,大量的无定形物质与矿物(主要是粘土矿物)紧密共生,说明有机质与矿物共生组分对于烃源岩油气生成具有十分重要的意义.

Abstract:

The muddy source rock is divided into many density fractions by density fractionation. The palynofacies analysis and the laser particles detection results show that the free organic particle with bio-texture is dominant in the fraction of ρ<1.6 g·cm3, which accumulates the majority of organic particles with well shape and large size in the source rock. The organic matter combines with the mineral tightly in the fractions of 1.6 g·cm-3<ρ<2.2 g·cm-3 and ρ>2.2 g·cm-3, which are rich in the particle amorphous and spongy amorphous organic mater respectively, indicating the amorphous organic matter is preserved by combining with the mineral (especial clay) in the source rock.The preservation ways of different organic micro-components are different in the source rock. A lot of amorphous exists in the fraction of the organic matter combine with the minerals, indicating this fraction is important in generating oil and gas of the source rock.