扎哈泉凹陷烃源岩特征及演化史研究

扎哈泉凹陷周缘已发现昆北、乌南等大量油气藏,但其油源层位和凹陷源岩生烃能力尚不十分清楚。通过开展烃源岩展布、有机质丰度、类型和成熟度的研究,指出扎哈泉凹陷烃源岩分布范围从E1+2到N12具有东移或北移的特征。E13和E23烃源岩有机碳和氯仿沥青"A"含量均较高,按照青海油田分类标准,达到好-较好烃源岩标准;N1和N12烃源岩有机碳含量较低,生烃能力较差。烃源岩干酪根显微组分以腐泥组为主,达90%以上,有机质类型以Ⅰ型为主。通过一维数值模拟,认为目前E13和E23烃源岩达到成熟阶段,N1和N12烃源岩处于未-低成熟阶段;E13和E23烃源岩生烃能力较强,可为周缘构造提供丰富的油气。

Study on the characteristics of hydrocarbon source rocks and evolution history in Zhahaquan depression

Kunbei, Wunan and other large quantity of hydrocarbon reservoir along Zhahaquan depression have been discovered, but its oil source layer and depression source rocks generation capacity is unclear. According to the study on source rocks distribution, organic matter abundance, type and maturity, it is pointed out that Zhahaquan depression source rocks distributed from E1+2 to N12 with the eastward movement and northward movement features. A content level in organic carbon and chloroform bitumen is higher in E13 and E23 source rocks, which reached good source rocks standards in accordance with the classification criteria of Qinhai oilfield. Organic carbon content in N1 and N12 source rocks is lower with lower generation capacity.Source rocks kerogen maceral are mainly sapropelinite, which is more than 90%, organic matter is type I. Based on the one-dimensional numerical simulation, E13 and E23 source rocks reached maturity, N1 and N12 source rock are in the non or low mature period. The study indicated that E13 and E23 source rock have better hydrocarbon generation capacity and can provide rich oil and gas.