Abstract: At the time of its deposition, the Qianjiang Formation of Paleogene in the Jianghan Basin was an elevated saline basin, so its geochemical aspects of formation of oil and gas are different from those in other basins of continental deposits in the eastern part of China. Primarily based on organic geochemical data, together with geological and paleontological materials available, the characteristics of oil and gas formation in saline lake deposits are examined, best expressed in low organic content, high ratio of oil trans formation and apparent OEP of n-alkanes. Evolution of organic materials is divided into four stages according to total hydrocarbons/organic carbon; the threshold depth and temperature for oil and gas formation are supposed to be at 2,200 meters and 90℃. Diagrams of depth of burial are used in the study of evolution of source rocks and determination of the main stage of oil generation Oil and gas migration and comparison of oil sources in the basin are also discussed.

摘要： 江汉盆地下第三系潜江组沉积时期为一盐湖,因此,其油气生成的有机地球化学特征有别于我国东部其它陆相沉积盆地。本文以有机地球化学资料为主,结合地质、古生物资料,阐述了盐湖相沉积的油气生成特征。它主要表现为有机质的低丰度、高转化率和正构烷烃中明显的偶奇优势。同时主要依据总烃/有机碳,将有机质演化划分为四个阶段,确定了油、气生成的起始门限:深度2200米,温度90℃。利用埋深图解法,研究了生油岩的埋藏史,确定了主要生油期。