渤海湾盆地黄骅坳陷上古生界煤系烃源岩地球化学特征及生烃特性——以大港探区为例

Geochemical characteristics and hydrocarbon generation characteristics of Upper Paleozoic coal measures source rocks in Huanghua Depression,Bohai Bay Basin:Case study of Dagang exploration area

为揭示渤海湾盆地黄骅坳陷上古生界煤岩的油气资源潜力,基于岩石热解、显微组分鉴定、热模拟等实验及前人研究资料,对黄骅坳陷内大港探区石炭系—二叠系煤层的地球化学特征、显微组分、生烃情况进行了详细研究。结果表明:黄骅坳陷内石炭系—二叠系煤系烃源岩显微组分以镜质组为主,惰质组次之。其中镜质组含量为60.35%,惰质组为28.6%,壳质组+腐泥组则为11.05%。该套烃源岩有机质类型以Ⅱ_(2)型和Ⅲ型为主,有机质丰度较高,有机质以成熟阶段为主,部分地区受到岩浆作用影响处于高成熟阶段,且该套烃源岩具有生气为主、生油为辅的特征,具有很好的生烃潜力。

In order to reveal the oil and gas resource potential of Upper Paleozoic coal measure source rocks in Huanghua Depression,Bohai Bay Basin,based on experiments such as rock pyrolysis,maceral identification,thermal simulation and previous research data,the geochemical characteristics,macerals and hydrocarbon generation of C-P coal seam in Dagang exploration area in Huanghua Depression are studied in detail.The results show that the macerals of C-P coal measure source rocks in Huanghua Depression are mainly vitrinite,followed by inertinite.The content of vitrinite is 60.35%,inertinite is 28.6%,and crustite+sapropel group is 11.05%.The organic matter types of the source rock are mainly type Ⅱ_(2) and type Ⅲ,with high abundance of organic matter.The organic matter is mainly in the mature stage.Some areas are in the high mature stage due to magmatism.Moreover,the source rock has the characteristics of gas generation and oil generation,and has good hydrocarbon generation potential.