Discussion on hydrocarbon generation potential and secondary hydrocarbon generation of organic matter from Permo-Carboniferous coal measures in the southern North China

On the basis of analysis about the abundance and the types of Permo-Carboniferous coal measures organic matters in the southern North China area,and research on the source rocks' maturity and the thermal evolution history,this article evaluates synthetically the hydrocarbon generation potential by means of organic petrology,Rock-Evel and geochemistry.It is concluded that hydrocarbon source rocks of Carboniferous(Taiyuan Formation and Benxi Formation) are better than that of Permian(Shanxi Formation and Shihezi Formation);the type Ⅲ of organic matter is dominant and the type Ⅱ is less.Thermal evolution of the most organic matter is in mature stage and high-mature stage,or even over-mature in part area,they are all generating gas.Through systematic research the condition about secondary hydrocarbon generateon with the tectonic-thermal evolution history,point out that the Tanzhuang-Shenqiu Depression and the Niqiuji Depression have lower beginningmaturity and superior burial history conditions for secondary hydrocarbon generation and can lead to form gas field.