黄骅坳陷沧东凹陷孔二段富有机质泥页岩地球化学特征

黄骅坳陷沧东凹陷孔二段（Ek₂）富有机质泥页岩十分发育，研究其地球化学特征对评价该地区页岩油资源潜力具有重要意义。 在整理大量基础资料和前人研究成果的基础上，补充采集岩心样品，并进行了有机碳含量、岩石热解、氯仿沥青“A”、干酪根显微组分及镜质体反射率等分析测试，同时开展了单井埋藏史与热演化史数值模拟及地球化学演化剖面研究。 Ek₂1，Ek₂2 和 Ek₂3 等 3 个油组富有机质泥页岩总体上均达到最好烃源岩级别，有机质类型均以Ⅰ型和Ⅱ₁ 型为主，含少量Ⅱ₂ 型和Ⅲ型。 有机质热演化程度总体上偏低，中央隆起带泥页岩处于未成熟-低成熟生烃阶段，斜坡带主要处于低成熟-成熟生烃阶段。自始新世初即开始进入未成熟-低成熟生排烃阶段，馆陶组（Ng）沉积末期达到未成熟-低成熟生排烃高峰，之后随着地层持续深埋，进入低成熟-成熟生排烃演化阶段，生烃转化率达 60%。

Geochemical characteristics of organic-rich shales of the second member of Kongdian Formation in Cangdong Sag,Huanghua Depression

The organic-rich shales of the second member of Kongdian Formation （Ek₂） are developed very well in Cangdong Sag, Huanghua Depression. Research on geochemical characteristics of the shales is highly significant for the shale oil resource evaluation. Based on collecting and sorting the research results of predecessors, additional core samples were taken to carry out tests and analysis of organic carbon, rock pyrolysis, chloroform bitumen “A”, kerogen maceral and vitrinite reflectance. Single well numerical simulation of burial and thermal history and geochemical evolution sections were also
studied. Organic-rich shales of Ek₂¹, Ek₂² and Ek₂³ were all evaluated as the best source rocks. The types of organic matterare mainly of ⅠandⅡ₁ , with small amount of Ⅱ₂ and Ⅲ. Immature to low mature shales are mainly distributed in central uplift zone, while the organic-rich shales in slope zones are at low maturity to maturity stage. The organic-rich shales of Ek₂ began to generate and expulse immature to low mature hydrocarbon in early Eocene and reached the peak in the late sedimentary period of Guantao Formation. Then with being continuously buried deeply, the source rocks could entered into
low mature to mature hydrocarbon generation stage and the conversion rates of hydrocarbon generation is as high as 60%.